The Fifth Generation (5G) networks, including the 5G Vehicular Cloud Computing (5G-VCC) systems, have evolved rapidly offering multiple services to users. The operating principles of vehicular networks, Cloud Computing (CC), Fog Computing (FC), Mobile Edge Computing (MEC) and Software Defined Networks (SDN) are applied to 5G infrastructures. In a 5G-VCC system, the vehicles are equipped with On-Board Units (OBUs) which communicate with each other as well as with Road Side Units (RSUs). Each RSU interacts with a Cloud infrastructure which offers vehicular services with strict Quality of Service (QoS) requirements, including Driver Assistance (DA), Passengers Entertainment and Information (PEnI) and Medical (MED) services. Dense deployments of 5G access networks are also implemented, called Ultra Dense Networks (UDNs), aiming to support high data rates produced by an increased number of vehicular users. In this environment, heterogeneous technologies are used to transfer the network services to vehicles. Optimal manipulation of the communication resources is required, while at the same time vehicular users should always obtain connectivity to the most appropriate network access technology, in order the constraints of the vehicular services to be satisfied. In this thesis, existing schemes for resource allocation as well as for mobility management are studied, while novel solutions are proposed for each topic.
Review of the paper: Traffic-aware Frequency Scaling for Balanced On-Chip Net...Luca Sinico
This work has been done as assignment and as part of the exam of the Distributed Systems course, while attending the Master's Degree in Computer Engineering at University of Padua.
If you find something wrong or not clear, or if you don't agree with me with the work done or the grades of the assessment, please tell me.
Checkpoint and recovery protocols are commonly used in distributed applications for providing fault
tolerance. A distributed system may require taking checkpoints from time to time to keep it free of arbitrary
failures. In case of failure, the system will rollback to checkpoints where global consistency is preserved.
Checkpointing is one of the fault-tolerant techniques to restore faults and to restart job fast. The algorithms
for checkpointing on distributed systems have been under study for years.
It is known that checkpointing and rollback recovery are widely used techniques that allow a distributed
computing to progress inspite of a failure.There are two fundamental approaches for checkpointing and
recovery.One is asynchronus approach, process take their checkpoints independenty.So,taking checkpoints
is very simple but due to absence of a recent consistent global checkpoint which may cause a rollback of
computation.Synchronus checkpointing approach assumes that a single process other than the application
process invokes the checkpointing algorithm periodically to determine a consistent global checkpoint.
A Summative Comparison of Blind Channel Estimation Techniques for Orthogonal ...IJECEIAES
The OFDM technique i.e. Orthogonal frequency division multiplexing has become prominent in wireless communication since its instruction in 1950’s due to its feature of combating the multipath fading and other losses. In an OFDM system, a large number of orthogonal, overlapping, narrow band subchannels or subcarriers, transmitted in parallel, divide the available transmission bandwidth. The separation of the subcarriers is theoretically optimal such that there is a very compact spectral utilization. This paper reviewed the possible approaches for blind channel estimation in the light of the improved performance in terms of speed of convergence and complexity. There were various researches which adopted the ways for channel estimation for Blind, Semi Blind and trained channel estimators and detectors. Various ways of channel estimation such as Subspace, iteration based, LMSE or MSE based (using statistical methods), SDR, Maximum likelihood approach, cyclostationarity, Redundancy and Cyclic prefix based. The paper reviewed all the above approaches in order to summarize the outcomes of approaches aimed at optimum performance for channel estimation in OFDM systems.
3GPP has introduced LTE Femtocells to manipulate the traffic for indoor users and to minimize
the charge on the Macro cells. A key mechanism in the LTE traffic handling is the packet
scheduler which is in charge of allocating resources to active flows in both the frequency and
time dimension. So several scheduling algorithms need to be analyzed for femtocells networks.
In this paper we introduce a performance analysis of three distinct scheduling algorithms of
mixed type of traffic flows in LTE femtocells networks. The particularly study is evaluated in
terms of throughput, packet loss ratio, fairness index and spectral efficiency.
A Bandwidth Efficient Scheduling Framework for Non Real Time Applications in ...ijdpsjournal
The key concern on the bandwidth allocation and scheduling for non real time traffic are the fulfillment of its minimum throughput requirement and improvement of bandwidth utilization with acceptable delay. This paper proposes a simple and efficient scheduling framework for allocating bandwidth to non real time
polling service (nrtPS) users in IEEE 802.16 networks. In this framework, jointly selective repeat ARQ at the MAC layer and adaptive modulation and coding techniques at the physical are considered. Numerical simulations demonstrate that the proposed scheduling approach provides a graceful compromise between bandwidth utilization and packet delivery delay while maintaining the minimum throughput requirements of nrtPS applications. Thus proves the efficiency of the proposed framework. The simulation is done for unicast scenario.
Review of the paper: Traffic-aware Frequency Scaling for Balanced On-Chip Net...Luca Sinico
This work has been done as assignment and as part of the exam of the Distributed Systems course, while attending the Master's Degree in Computer Engineering at University of Padua.
If you find something wrong or not clear, or if you don't agree with me with the work done or the grades of the assessment, please tell me.
Checkpoint and recovery protocols are commonly used in distributed applications for providing fault
tolerance. A distributed system may require taking checkpoints from time to time to keep it free of arbitrary
failures. In case of failure, the system will rollback to checkpoints where global consistency is preserved.
Checkpointing is one of the fault-tolerant techniques to restore faults and to restart job fast. The algorithms
for checkpointing on distributed systems have been under study for years.
It is known that checkpointing and rollback recovery are widely used techniques that allow a distributed
computing to progress inspite of a failure.There are two fundamental approaches for checkpointing and
recovery.One is asynchronus approach, process take their checkpoints independenty.So,taking checkpoints
is very simple but due to absence of a recent consistent global checkpoint which may cause a rollback of
computation.Synchronus checkpointing approach assumes that a single process other than the application
process invokes the checkpointing algorithm periodically to determine a consistent global checkpoint.
A Summative Comparison of Blind Channel Estimation Techniques for Orthogonal ...IJECEIAES
The OFDM technique i.e. Orthogonal frequency division multiplexing has become prominent in wireless communication since its instruction in 1950’s due to its feature of combating the multipath fading and other losses. In an OFDM system, a large number of orthogonal, overlapping, narrow band subchannels or subcarriers, transmitted in parallel, divide the available transmission bandwidth. The separation of the subcarriers is theoretically optimal such that there is a very compact spectral utilization. This paper reviewed the possible approaches for blind channel estimation in the light of the improved performance in terms of speed of convergence and complexity. There were various researches which adopted the ways for channel estimation for Blind, Semi Blind and trained channel estimators and detectors. Various ways of channel estimation such as Subspace, iteration based, LMSE or MSE based (using statistical methods), SDR, Maximum likelihood approach, cyclostationarity, Redundancy and Cyclic prefix based. The paper reviewed all the above approaches in order to summarize the outcomes of approaches aimed at optimum performance for channel estimation in OFDM systems.
3GPP has introduced LTE Femtocells to manipulate the traffic for indoor users and to minimize
the charge on the Macro cells. A key mechanism in the LTE traffic handling is the packet
scheduler which is in charge of allocating resources to active flows in both the frequency and
time dimension. So several scheduling algorithms need to be analyzed for femtocells networks.
In this paper we introduce a performance analysis of three distinct scheduling algorithms of
mixed type of traffic flows in LTE femtocells networks. The particularly study is evaluated in
terms of throughput, packet loss ratio, fairness index and spectral efficiency.
A Bandwidth Efficient Scheduling Framework for Non Real Time Applications in ...ijdpsjournal
The key concern on the bandwidth allocation and scheduling for non real time traffic are the fulfillment of its minimum throughput requirement and improvement of bandwidth utilization with acceptable delay. This paper proposes a simple and efficient scheduling framework for allocating bandwidth to non real time
polling service (nrtPS) users in IEEE 802.16 networks. In this framework, jointly selective repeat ARQ at the MAC layer and adaptive modulation and coding techniques at the physical are considered. Numerical simulations demonstrate that the proposed scheduling approach provides a graceful compromise between bandwidth utilization and packet delivery delay while maintaining the minimum throughput requirements of nrtPS applications. Thus proves the efficiency of the proposed framework. The simulation is done for unicast scenario.
A REAL TIME PRIORITY BASED SCHEDULER FOR LOW RATE WIRELESS SENSOR NETWORKSIJCNCJournal
This paper presents a priority approach for censorious real-time traffic which flows particularly for low
data rate wireless sensor and actor network (LR-WSAN). In the recent years, the demand for low rate
wireless data transmission has been increased drastically in small scale industrial and non-industrial
applications. The different traffic flows are increased by incorporating a variety of distinct sensing devices.
In particular, injection of different traffic into network makes the communication system unstable and
unreliable because of unnecessarily resource utilization, wasting energy for surplus delivery management
and violation of time constraints. This paper aims to presents the new priority-based algorithm at actuator
node for appropriate classification and categorization of data packets for delay sensitive and delaytolerant
applications. A novel real-time priority-based scheduler (RTPS) is proposed to handle
heterogeneous data flows simultaneously according to their transmission type. The priority-based data
delivery is an essential research topic for low rate multi-event IEEE 802.15.4 sensor networks. A priority
metric is designed to dynamically control various types of traffic based flows with considerations of packet
type, delay, and buffer processing rate. TestBed results describe significant improvements in data reporting
mechanism for delay sensitive and delay-tolerant applications over various topologies. The high priority
transient traffic suffers less delay and presents effective packet delivery ratio compared with traditional
approaches
this paper they introduced UWMAC, a transmitter-based CDMA MAC protocol for UWASNs that integrates a new closed-loop distributed algorithm to establish the optimum transmit power and code length to decrease the near-far impact. UW-MAC objective is to obtain three goals i.e. low channel access delay, high network throughput and low energy consumption. It is shown that UW-MAC maintains to simultaneously obtain limited channel access delay, high network throughput and low energy consumption in deep water communications, which are not critically influenced by multipath. Fatma Bouabdallah and Raouf Boutaba suggested UW-OFDMAC, a distributed Medium Access Control (MAC) protocol which
LBRP: A RESILIENT ENERGY HARVESTING NOISE AWARE ROUTING PROTOCOL FOR UNDER WA...ijfcstjournal
Underwater detector network is one amongst the foremost difficult and fascinating analysis arenas that open the door of pleasing plenty of researchers during this field of study. In several under water based sensor applications, nodes are square measured and through this the energy is affected. Thus, the mobility of each sensor nodes are measured through the water atmosphere from the water flow for sensor based protocol formations. Researchers have developed many routing protocols. However, those lost their charm with the time. This can be the demand of the age to supply associate degree upon energy-efficient and ascendable strong routing protocol for under water actuator networks. During this work, the authors tend to propose a customary routing protocol named level primarily based routing protocol (LBRP), reaching to offer strong, ascendable and energy economical routing. LBRP conjointly guarantees the most effective use of total energy consumption and ensures packet transmission which redirects as an additional reliability in compare to different routing protocols. In this work, the authors have used the level of forwarding node, residual energy and distance from the forwarding node to the causing node as a proof in multicasting technique comparisons. Throughout this work, the authors have got a recognition result concerning about 86.35% on the average in node multicasting performances. Simulation has been experienced each in a wheezy and quiet atmosphere which represents the endorsement of higher performance for the planned protocol.
S URVEY OF L TE D OWNLINK S CHEDULERS A LGORITHMS IN O PEN A CCESS S IM...ijwmn
he LTE/LTE-A has become a catchphrase for research
and lot of research are being conducted and
carried out in LTE in various issues by various peo
ple. New tools are developed and introduced in the
market to interpret the results of the new algorith
ms proposed by various people. Some tools are open
access which are free to use but some tools are pro
duced by the companies which are not open access. I
n
this paper some of the open access simulation tools
like LTE-Sim and NS-3 are analyzed and LTE downlin
k
scheduler algorithms are simulated using those tool
s. In LTE systems, the downlink scheduler is an
important component for radio resource management;
hence in the context of LTE simulation, a study
between the downlink scheduler models between the s
imulators are performed.
The 3GPP Long Term Evolution Advanced (LTE-A) standard specifies a set of pioneer features such as relay nodes and carrier aggregation. At the same time, the Software Defined Networks (SDN) have become an emerging technology which provides centralized control and programmability to modern networks. In the current communication environment, cloud computing could combine the advantages of both technologies in order to create a novel cloud assisted Software Defined LTEA architecture with relay nodes. Moreover, due to the increased requirements of modern services, the optimal resource allocation is a necessity. In such a context, this paper describes a QoS aware cross carrier scheduler for downlink flows, aiming at the optimization of system resources allocation. The proposed scheduler is evaluated against the PF, MLWDF, EXP/PF, EXP RULE, LOG RULE, FLS and FLSA schedulers in a cloud assisted Software Defined LTE-A topology with relay nodes. Simulation results show that the proposed scheduler improves the real time services performance while at the same time maintains an acceptable performance for best effort flows.
DESIGN OF A COMPACT CIRCULAR MICROSTRIP PATCH ANTENNA FOR WLAN APPLICATIONS pijans
This paper presents the design of a compact circular microstrip patch antenna for WLAN applications which covers the band 5.15 to 5.825 GHz. The antenna is designed using 1.4mm thick FR-4 (lossy)substrate with relative permittivity 4.4 and a microstrip line feed is used. The radius of the circular patch is chosen as 7.62mm. To reduce the size and enhance the performance of the proposed antenna, a circular slot is loaded on circular patch and a square slot is etched on the ground plane of dimension 30mm×30mm. Design of the antenna is carried out using CST Microsoft Studio Sonimulation Software. The proposed antenna resonates at 5.5 GHz with a wider bandwidth of 702 MHz and it provides low return loss of -31.58 dB, good gain of 3.23 dB and directivity of 4.28 dBi and high efficiency of around 79% against the resonance frequency. The geometry of the proposed circular antenna with reduced size and its various performance parameters such as return loss, bandwidth, VSWR, gain, directivity, efficiency and radiation pattern plots are presented and discussed.
Dynamic bandwidth allocation scheme in lr pon with performance modelling and ...IJCNCJournal
We consider models of telecommunication systems that incorporate probability, dense real-time and data.
We present a new formal abstraction method for computing minimum and maximum reachability
probabilities for such models. Our approach uses strictly local formal abstract steps to reduce both the size
of abstract specifications generated and the complexity of operations needed, in comparison to previous
approaches of this kind. A selection of large case studies are implemented the techniques and evaluate,
which include some infinite-state probabilistic real time models, demonstrating improvements over existing
tools in several cases. The capacity of metro and access networks are extended the reach and split ratio of
the conventional Long - Reach Passive Optical Networks (LR-PONs). The efficient solutions of LR-PONs
are appeared in feeder distances around 100km and high split ratios up to 1000-way . Among many
existing approaches, one of the most effective options to improve network performance in LR-PONs are the
multi-thread based dynamic bandwidth allocation (DBA) scheme where several bandwidth allocation
processes are performed in parallel is considered. Without proper intercommunication between the
overlapped threads, multi-thread DBA may lose efficiency and even perform worse than the conventional
single thread algorithm. Real Time Probabilistic Systems are used to evaluate a typical PON systems
performance. This approach is more convenient, flexible, and lower cost than the former simulation method,
which do not need develop special hardware and software tools. Moreover, how changes in performance
depend on changes in the particular modes can be easily analysis by supplying ranges for parameter values.
The proposed algorithm with traditional DBA is compared, and shows its advantage on average packet
delay. The key parameters of the algorithm are analysed and optimized, such as initiating and tuning
multiple threads, inter -thread scheduling, and fairness among users. The algorithms advantage in
numerical results are decreased the average packet delay and improve network throughput under varying
offered loads.
Macro with pico cells (hetnets) system behaviour using well known scheduling ...ijwmn
This paper demonstrates the concept of using Heterogeneous networks (HetNets) to improve Long Term Evolution (LTE) system by introducing the LTE Advance (LTE-A). The type of HetNets that has been chosen for this study is Macro with Pico cells. Comparing the system performance with and without Pico cells has clearly illustrated using three well-known scheduling algorithms (Proportional Fair PF, Maximum Largest Weighted Delay First MLWDF and Exponential/Proportional Fair EXP/PF). The system is judged based on throughput, Packet Loss Ratio PLR, delay and fairness.. A simulation platform called LTE-Sim has been used to collect the data and produce the paper’s outcomes and graphs. The results prove that adding Pico cells enhances the overall system performance. From the simulation outcomes, the overall system performance is as follows: throughput is duplicated or tripled based on the number of users, the PLR is almost quartered, the delay is nearly reduced ten times (PF case) and changed to be a half (MLWDF/EXP cases), and the fairness stays closer to value of 1. It is considered an efficient and cost effective way to increase the throughput, coverage and reduce the latency.
GLOBAL FRONTRUNNER ROUTING ALGORITHM (GFRA) FOR V2V COMMUNICATION IN VANETS cscpconf
VANET (Vehicular Ad hoc NETwork) is the emerging research area that making the phrase
“Network on Wheel” true. In this new age network the basic WLAN (IEEE 802.11) standard is
used. As the necessity of such network increases the implementation challenges are being taken
into account. They are broadcasting, routing, priority scheduling and security and privacy. In
this paper the routing is considered as the research factor. A proposal for routing with
frequently changing topology to avoid disconnection of network on road and for the routing
among overlapping networks in flyovers with multiple ramps and stack to avoid wrong
messaging is given.
Using Request Queues for Enhancing the Performance of Operations in Smart HomesAndreas Kamilaris
This is the presentation for the research paper "Using Request Queues for Enhancing the Performance of Operations in Smart Buildings". It has been presented during the 7th ACM International Workshop on Performance Monitoring, Measurement and Evaluation of Heterogeneous Wireless and Wired Networks (PM2HW2N), in Proc. of MSWiM 2012, in Paphos, Cyprus, October 2012.
Its abstract is as follows: Modern houses and buildings are being equipped with embedded wireless sensors and actuators, offering advanced automation possibilities. Embedded technology is becoming mature, forming an enticing option for real-life deployments. Still, embedded wireless computing does not constitute a guaranteed reliable solution since transmission failures occur in the wireless medium while resource-constrained devices have battery limitations and frequent failures. In this
paper, we examine the use of request queues as a mechanism to manage the communication with embedded devices. Located in a middleware application framework for smart homes, request queues offer enhanced reliability and fault tolerance, supporting multiple tenants simultaneously.
QoS-aware scheduling in LTE-A networks with SDN control (presentation)University of Piraeus
The 3GPP Long Term Evolution Advanced (LTE-A) standard specifies a set of pioneer features such as relay nodes and carrier aggregation. At the same time, the Software Defined Networks (SDN) have become an emerging technology which provides centralized control and programmability to modern networks. In the current communication environment, cloud computing could combine the advantages of both technologies in order to create a novel cloud assisted Software Defined LTEA architecture with relay nodes. Moreover, due to the increased requirements of modern services, the optimal resource allocation is a necessity. In such a context, this paper describes a QoS aware cross carrier scheduler for downlink flows, aiming at the optimization of system resources allocation. The proposed scheduler is evaluated against the PF, MLWDF, EXP/PF, EXP RULE, LOG RULE, FLS and FLSA schedulers in a cloud assisted Software Defined LTE-A topology with relay nodes. Simulation results show that the proposed scheduler improves the real time services performance while at the same time maintains an acceptable performance for best effort flows.
Mobile and roaming access to connectivity remain core requirements of the modern campus, whether via our flagship eduroam service, or through innovative local applications of new technologies.
This session addressed developments in the wireless world and its related technologies in and around campus.
eduroam and city-centre wifi, by Dean Phillips, University of Aberdeen.
5G, by Andy Sutton, University of Salford.
A REAL TIME PRIORITY BASED SCHEDULER FOR LOW RATE WIRELESS SENSOR NETWORKSIJCNCJournal
This paper presents a priority approach for censorious real-time traffic which flows particularly for low
data rate wireless sensor and actor network (LR-WSAN). In the recent years, the demand for low rate
wireless data transmission has been increased drastically in small scale industrial and non-industrial
applications. The different traffic flows are increased by incorporating a variety of distinct sensing devices.
In particular, injection of different traffic into network makes the communication system unstable and
unreliable because of unnecessarily resource utilization, wasting energy for surplus delivery management
and violation of time constraints. This paper aims to presents the new priority-based algorithm at actuator
node for appropriate classification and categorization of data packets for delay sensitive and delaytolerant
applications. A novel real-time priority-based scheduler (RTPS) is proposed to handle
heterogeneous data flows simultaneously according to their transmission type. The priority-based data
delivery is an essential research topic for low rate multi-event IEEE 802.15.4 sensor networks. A priority
metric is designed to dynamically control various types of traffic based flows with considerations of packet
type, delay, and buffer processing rate. TestBed results describe significant improvements in data reporting
mechanism for delay sensitive and delay-tolerant applications over various topologies. The high priority
transient traffic suffers less delay and presents effective packet delivery ratio compared with traditional
approaches
this paper they introduced UWMAC, a transmitter-based CDMA MAC protocol for UWASNs that integrates a new closed-loop distributed algorithm to establish the optimum transmit power and code length to decrease the near-far impact. UW-MAC objective is to obtain three goals i.e. low channel access delay, high network throughput and low energy consumption. It is shown that UW-MAC maintains to simultaneously obtain limited channel access delay, high network throughput and low energy consumption in deep water communications, which are not critically influenced by multipath. Fatma Bouabdallah and Raouf Boutaba suggested UW-OFDMAC, a distributed Medium Access Control (MAC) protocol which
LBRP: A RESILIENT ENERGY HARVESTING NOISE AWARE ROUTING PROTOCOL FOR UNDER WA...ijfcstjournal
Underwater detector network is one amongst the foremost difficult and fascinating analysis arenas that open the door of pleasing plenty of researchers during this field of study. In several under water based sensor applications, nodes are square measured and through this the energy is affected. Thus, the mobility of each sensor nodes are measured through the water atmosphere from the water flow for sensor based protocol formations. Researchers have developed many routing protocols. However, those lost their charm with the time. This can be the demand of the age to supply associate degree upon energy-efficient and ascendable strong routing protocol for under water actuator networks. During this work, the authors tend to propose a customary routing protocol named level primarily based routing protocol (LBRP), reaching to offer strong, ascendable and energy economical routing. LBRP conjointly guarantees the most effective use of total energy consumption and ensures packet transmission which redirects as an additional reliability in compare to different routing protocols. In this work, the authors have used the level of forwarding node, residual energy and distance from the forwarding node to the causing node as a proof in multicasting technique comparisons. Throughout this work, the authors have got a recognition result concerning about 86.35% on the average in node multicasting performances. Simulation has been experienced each in a wheezy and quiet atmosphere which represents the endorsement of higher performance for the planned protocol.
S URVEY OF L TE D OWNLINK S CHEDULERS A LGORITHMS IN O PEN A CCESS S IM...ijwmn
he LTE/LTE-A has become a catchphrase for research
and lot of research are being conducted and
carried out in LTE in various issues by various peo
ple. New tools are developed and introduced in the
market to interpret the results of the new algorith
ms proposed by various people. Some tools are open
access which are free to use but some tools are pro
duced by the companies which are not open access. I
n
this paper some of the open access simulation tools
like LTE-Sim and NS-3 are analyzed and LTE downlin
k
scheduler algorithms are simulated using those tool
s. In LTE systems, the downlink scheduler is an
important component for radio resource management;
hence in the context of LTE simulation, a study
between the downlink scheduler models between the s
imulators are performed.
The 3GPP Long Term Evolution Advanced (LTE-A) standard specifies a set of pioneer features such as relay nodes and carrier aggregation. At the same time, the Software Defined Networks (SDN) have become an emerging technology which provides centralized control and programmability to modern networks. In the current communication environment, cloud computing could combine the advantages of both technologies in order to create a novel cloud assisted Software Defined LTEA architecture with relay nodes. Moreover, due to the increased requirements of modern services, the optimal resource allocation is a necessity. In such a context, this paper describes a QoS aware cross carrier scheduler for downlink flows, aiming at the optimization of system resources allocation. The proposed scheduler is evaluated against the PF, MLWDF, EXP/PF, EXP RULE, LOG RULE, FLS and FLSA schedulers in a cloud assisted Software Defined LTE-A topology with relay nodes. Simulation results show that the proposed scheduler improves the real time services performance while at the same time maintains an acceptable performance for best effort flows.
DESIGN OF A COMPACT CIRCULAR MICROSTRIP PATCH ANTENNA FOR WLAN APPLICATIONS pijans
This paper presents the design of a compact circular microstrip patch antenna for WLAN applications which covers the band 5.15 to 5.825 GHz. The antenna is designed using 1.4mm thick FR-4 (lossy)substrate with relative permittivity 4.4 and a microstrip line feed is used. The radius of the circular patch is chosen as 7.62mm. To reduce the size and enhance the performance of the proposed antenna, a circular slot is loaded on circular patch and a square slot is etched on the ground plane of dimension 30mm×30mm. Design of the antenna is carried out using CST Microsoft Studio Sonimulation Software. The proposed antenna resonates at 5.5 GHz with a wider bandwidth of 702 MHz and it provides low return loss of -31.58 dB, good gain of 3.23 dB and directivity of 4.28 dBi and high efficiency of around 79% against the resonance frequency. The geometry of the proposed circular antenna with reduced size and its various performance parameters such as return loss, bandwidth, VSWR, gain, directivity, efficiency and radiation pattern plots are presented and discussed.
Dynamic bandwidth allocation scheme in lr pon with performance modelling and ...IJCNCJournal
We consider models of telecommunication systems that incorporate probability, dense real-time and data.
We present a new formal abstraction method for computing minimum and maximum reachability
probabilities for such models. Our approach uses strictly local formal abstract steps to reduce both the size
of abstract specifications generated and the complexity of operations needed, in comparison to previous
approaches of this kind. A selection of large case studies are implemented the techniques and evaluate,
which include some infinite-state probabilistic real time models, demonstrating improvements over existing
tools in several cases. The capacity of metro and access networks are extended the reach and split ratio of
the conventional Long - Reach Passive Optical Networks (LR-PONs). The efficient solutions of LR-PONs
are appeared in feeder distances around 100km and high split ratios up to 1000-way . Among many
existing approaches, one of the most effective options to improve network performance in LR-PONs are the
multi-thread based dynamic bandwidth allocation (DBA) scheme where several bandwidth allocation
processes are performed in parallel is considered. Without proper intercommunication between the
overlapped threads, multi-thread DBA may lose efficiency and even perform worse than the conventional
single thread algorithm. Real Time Probabilistic Systems are used to evaluate a typical PON systems
performance. This approach is more convenient, flexible, and lower cost than the former simulation method,
which do not need develop special hardware and software tools. Moreover, how changes in performance
depend on changes in the particular modes can be easily analysis by supplying ranges for parameter values.
The proposed algorithm with traditional DBA is compared, and shows its advantage on average packet
delay. The key parameters of the algorithm are analysed and optimized, such as initiating and tuning
multiple threads, inter -thread scheduling, and fairness among users. The algorithms advantage in
numerical results are decreased the average packet delay and improve network throughput under varying
offered loads.
Macro with pico cells (hetnets) system behaviour using well known scheduling ...ijwmn
This paper demonstrates the concept of using Heterogeneous networks (HetNets) to improve Long Term Evolution (LTE) system by introducing the LTE Advance (LTE-A). The type of HetNets that has been chosen for this study is Macro with Pico cells. Comparing the system performance with and without Pico cells has clearly illustrated using three well-known scheduling algorithms (Proportional Fair PF, Maximum Largest Weighted Delay First MLWDF and Exponential/Proportional Fair EXP/PF). The system is judged based on throughput, Packet Loss Ratio PLR, delay and fairness.. A simulation platform called LTE-Sim has been used to collect the data and produce the paper’s outcomes and graphs. The results prove that adding Pico cells enhances the overall system performance. From the simulation outcomes, the overall system performance is as follows: throughput is duplicated or tripled based on the number of users, the PLR is almost quartered, the delay is nearly reduced ten times (PF case) and changed to be a half (MLWDF/EXP cases), and the fairness stays closer to value of 1. It is considered an efficient and cost effective way to increase the throughput, coverage and reduce the latency.
GLOBAL FRONTRUNNER ROUTING ALGORITHM (GFRA) FOR V2V COMMUNICATION IN VANETS cscpconf
VANET (Vehicular Ad hoc NETwork) is the emerging research area that making the phrase
“Network on Wheel” true. In this new age network the basic WLAN (IEEE 802.11) standard is
used. As the necessity of such network increases the implementation challenges are being taken
into account. They are broadcasting, routing, priority scheduling and security and privacy. In
this paper the routing is considered as the research factor. A proposal for routing with
frequently changing topology to avoid disconnection of network on road and for the routing
among overlapping networks in flyovers with multiple ramps and stack to avoid wrong
messaging is given.
Using Request Queues for Enhancing the Performance of Operations in Smart HomesAndreas Kamilaris
This is the presentation for the research paper "Using Request Queues for Enhancing the Performance of Operations in Smart Buildings". It has been presented during the 7th ACM International Workshop on Performance Monitoring, Measurement and Evaluation of Heterogeneous Wireless and Wired Networks (PM2HW2N), in Proc. of MSWiM 2012, in Paphos, Cyprus, October 2012.
Its abstract is as follows: Modern houses and buildings are being equipped with embedded wireless sensors and actuators, offering advanced automation possibilities. Embedded technology is becoming mature, forming an enticing option for real-life deployments. Still, embedded wireless computing does not constitute a guaranteed reliable solution since transmission failures occur in the wireless medium while resource-constrained devices have battery limitations and frequent failures. In this
paper, we examine the use of request queues as a mechanism to manage the communication with embedded devices. Located in a middleware application framework for smart homes, request queues offer enhanced reliability and fault tolerance, supporting multiple tenants simultaneously.
QoS-aware scheduling in LTE-A networks with SDN control (presentation)University of Piraeus
The 3GPP Long Term Evolution Advanced (LTE-A) standard specifies a set of pioneer features such as relay nodes and carrier aggregation. At the same time, the Software Defined Networks (SDN) have become an emerging technology which provides centralized control and programmability to modern networks. In the current communication environment, cloud computing could combine the advantages of both technologies in order to create a novel cloud assisted Software Defined LTEA architecture with relay nodes. Moreover, due to the increased requirements of modern services, the optimal resource allocation is a necessity. In such a context, this paper describes a QoS aware cross carrier scheduler for downlink flows, aiming at the optimization of system resources allocation. The proposed scheduler is evaluated against the PF, MLWDF, EXP/PF, EXP RULE, LOG RULE, FLS and FLSA schedulers in a cloud assisted Software Defined LTE-A topology with relay nodes. Simulation results show that the proposed scheduler improves the real time services performance while at the same time maintains an acceptable performance for best effort flows.
Mobile and roaming access to connectivity remain core requirements of the modern campus, whether via our flagship eduroam service, or through innovative local applications of new technologies.
This session addressed developments in the wireless world and its related technologies in and around campus.
eduroam and city-centre wifi, by Dean Phillips, University of Aberdeen.
5G, by Andy Sutton, University of Salford.
A downlink scheduler supporting real time services in LTE cellular networks (...University of Piraeus
The wide spread of real-time services in wireless networks demands scheduling mechanisms supporting strict Quality of Service (QoS) requirements. Nevertheless, the specifications of the LTE standard for mobile connectivity defined by the 3rd Generation Partnership Project (3GPP) does not impose any specific scheduler for the proper allocation of resources to services. Therefore, several LTE schedulers have been proposed in the literature meeting the QoS requirements of modern services. In this paper a QoS aware scheduler for the LTE downlink is proposed namely the FLS-Advanced (FLSA) aiming at prioritizing real-time traffic. The proposed scheduler has been built on three distinct levels assigning the available radio resources to services according to their requirements. Based on simulation results, the FLSA outperforms in terms of packet loss ratio, attainable throughput and fairness the performance of existing schedulers including PF, MLWDF, EXP/PF, FLS, EXP RULE and LOG RULE.
A Platform for Data Intensive Services Enabled by Next Generation Dynamic Opt...Tal Lavian Ph.D.
The new architecture is proposed for data intensive enabled by next generation dynamic optical networks
Offers a Lambda scheduling service over Lambda Grids
Supports both on-demand and scheduled data retrieval
Supports bulk data-transfer facilities using lambda-switched networks
Provides a generalized framework for high performance applications over next generation networks, not necessary optical end-to-end
Supports out-of-band tools for adaptive placement of data replicas
A generic Network Cost provision framework is described, accompanied with a preliminary proofof-concept implementation. Deployment considerations and open research issues are also discussed.
A Network Selection Algorithm for supporting Drone Services in 5G Network Arc...University of Piraeus
Flying Ad-hoc Networks (FANETs) use 5G network access technologies to fulfill the requirements of their services. In this environment, Drone to Infrastructure (D2I) communication is supported, while each drone could use both Disaster Management (DM) and non-Disaster Management (nDM) services. Efficient network selection algorithms are required to satisfy the constraints of the used services, since the presence of DM services affects the importance of nDM services in situations where a natural disaster occurs. This paper proposes a network selection algorithm which is called Dynamic Trapezoidal Fuzzy Topsis with Adaptive Criteria Weights (DTFT-ACW). DTFT-ACW accomplishes the ranking of the candidate networks considering the importance of each service, as well as the weights of the corresponding selection criteria, as they are obtained with respect to the severity level of a natural disaster occurred. Interval-Valued Trapezoidal Fuzzy Numbers (IVTFN) are used for the criteria evaluation. Experimental results show that the suggested method outperforms existing algorithms by satisfying the constraints of DM services when a disaster becomes severe. Furthermore, DTFT-ACW eliminates the computational complexity of the network selection by considering past decisions.
A Platform for Data Intensive Services Enabled by Next Generation Dynamic Opt...Tal Lavian Ph.D.
The new architecture is proposed for data intensive enabled by next generation dynamic optical networks
Encapsulates “optical network resources” into a service framework to support dynamically provisioned and advanced data-intensive transport services
Provides a generalized framework for high performance applications over next generation networks, not necessary optical end-to-end
Supports both on-demand and scheduled data retrieval
Supports a meshed wavelength switched network capable of establishing an end-to-end lightpath in seconds
Supports bulk data-transfer facilities using lambda-switched networks
Supports out-of-band tools for adaptive placement of data replicas
Offers network resources as Grid services for Grid computing
A Route Selection Scheme for supporting Virtual Tours in Sites with Cultural ...University of Piraeus
Virtual tourism is a novel trend that enhances the experience the users perceive from touristic places, such as archaeological sites. Drones are equipped with 360o video cameras and used for video capturing of the heritage sites. The video material is streamed to the users in real time, enriched with additional 3D, Augmented Reality (AR) or Mixed Reality (MR) material. Furthermore, the selection of the appropriate flying route for each drone should be performed, in order to provide a satisfactory tour experience to the user, considering his preferences about specific monuments. To address this issue, this paper describes a heritage route selection scheme for supporting real-time virtual tours in sites with cultural interest using drones. The proposed scheme applies a Fuzzy Multiple Attribute Decision Making (FMADM) algorithm, the Trapezoidal Fuzzy Topsis for Heritage Route Selection (TFT-HRS), to accomplish the ranking of the candidate heritage routes. The algorithm uses Interval-Valued Trapezoidal Fuzzy Numbers (IVTFN) for the representation of heritage routes evaluation values. Performance evaluation shows that the suggested method produces better results compared to the Fuzzy Topsis (FTOPSIS) by selecting the most appropriate flying route for the drone.
A Route Selection Scheme for supporting Virtual Tours in Sites with Cultural ...University of Piraeus
Virtual tourism is a novel trend that enhances the experience the users perceive from touristic places, such as archaeological sites. Drones are equipped with 360o video cameras and used for video capturing of the heritage sites. The video material is streamed to the users in real time, enriched with additional 3D, Augmented Reality (AR) or Mixed Reality (MR) material. Furthermore, the selection of the appropriate flying route for each drone should be performed, in order to provide a satisfactory tour experience to the user, considering his preferences about specific monuments. To address this issue, this paper describes a heritage route selection scheme for supporting real-time virtual tours in sites with cultural interest using drones. The proposed scheme applies a Fuzzy Multiple Attribute Decision Making (FMADM) algorithm, the Trapezoidal Fuzzy Topsis for Heritage Route Selection (TFT-HRS), to accomplish the ranking of the candidate heritage routes. The algorithm uses Interval-Valued Trapezoidal Fuzzy Numbers (IVTFN) for the representation of heritage routes evaluation values. Performance evaluation shows that the suggested method produces better results compared to the Fuzzy Topsis (FTOPSIS) by selecting the most appropriate flying route for the drone.
A VHO Scheme for supporting Healthcare Services in 5G Vehicular Cloud Computi...University of Piraeus
Fifth Generation Vehicular Cloud Computing (5G-VCC) systems use heterogeneous network access technologies in order to fulfill the requirements of modern services, including medical services with strict constraints. Therefore, the need for efficient Vertical Handover (VHO) management schemes must be addressed. In this paper, a VHO management scheme for supporting medical services in 5G-VCC systems, is described. It consists of the VHO initiation and the network selection processes, while at the same time, the vehicle’s velocity, its current connection type, as well as the status of the onboard patient’s health, are considered. Specifically, during the VHO initiation process the necessity to perform handover is evaluated. Subsequently, the network selection process selects the appropriate network alternative considering both medical service requirements and patients’ health status. The proposed scheme is applied to a 5G-VCC system which includes Long Term Evolution (LTE) and Worldwide Interoperability Microwave Access (WiMAX) Macrocells and Femtocells, as well as Wireless Access for Vehicular Environment Road Side Units (WAVE RSUs). Performance evaluation shows that the proposed algorithm outperforms existing VHO management schemes.
A Network Selection Scheme with Adaptive Criteria Weights for 5G Vehicular Sy...University of Piraeus
Fifth Generation Vehicular Cloud Computing (5G-VCC) systems use heterogeneous network access technologies to fulfill the requirements of modern vehicular services. Efficient network selection algorithms are required to satisfy the constraints of Driver Assistance (DA) services, Passengers Entertainment and Information (PEnI) services and Medical (MED) services that provided to vehicular users. The presence of MED services affects the importance of other services in situations where patients with immediate health status exist within the vehicle. This paper proposes a network selection scheme which considers the patient health status to adapt the importance of each service. The scheme consists of two Fuzzy Multi Attribute Decision Making (FMADM) algorithms: the Trapezoidal Fuzzy Adaptive Analytic Network Process (TF-AANP) to calculate the relative importance of each vehicular service and the selection criteria, as well as the Trapezoidal Fuzzy Topsis with Adaptive Criteria Weights (TFT-ACW) to accomplish the ranking of the candidate networks. Both algorithms use Interval-Valued Trapezoidal Fuzzy Numbers (IVTFN). Performance evaluation shows that the suggested method outperforms existing algorithms by satisfying the constraints of MED services when the patient health status becomes immediate.
A Network Selection Algorithm for supporting Drone Services in 5G Network Arc...University of Piraeus
Flying Ad-hoc Networks (FANETs) use 5G network access technologies to fulfill the requirements of their services. In this environment, Drone to Infrastructure (D2I) communication is supported, while each drone could use both Disaster Management (DM) and non-Disaster Management (nDM) services. Efficient network selection algorithms are required to satisfy the constraints of the used services, since the presence of DM services affects the importance of nDM services in situations where a natural disaster occurs. This paper proposes a network selection algorithm which is called Dynamic Trapezoidal Fuzzy Topsis with Adaptive Criteria Weights (DTFT-ACW). DTFT-ACW accomplishes the ranking of the candidate networks considering the importance of each service, as well as the weights of the corresponding selection criteria, as they are obtained with respect to the severity level of a natural disaster occurred. Interval-Valued Trapezoidal Fuzzy Numbers (IVTFN) are used for the criteria evaluation. Experimental results show that the suggested method outperforms existing algorithms by satisfying the constraints of DM services when a disaster becomes severe. Furthermore, DTFT-ACW eliminates the computational complexity of the network selection by considering past decisions.
A Survey on Medium Access Control Schemes for 5G Vehicular Cloud Computing Sy...University of Piraeus
Fifth generation (5G) vehicular systems support multiple services with strict Quality of Service (QoS) constraints. To fulfill the increased communication needs, 5G Vehicular Cloud Computing (5G-VCC) architectures with dense deployments of the access network infrastructures have been proposed. In such systems, the network resources manipulation is a critical task that could be addressed by the Medium Access Control (MAC) layer. MAC schemes that have been proposed for vehicular networks, can be applied to 5G-VCC systems in order optimal manipulation of communication resources to be accomplished. This paper makes an overview of available MAC schemes, while a comprehensive discussion about their implementation in 5G-VCC systems is performed leading to useful conclusions.
A Survey on Medium Access Control Schemes for 5G Vehicular Cloud Computing Sy...University of Piraeus
Fifth generation (5G) vehicular systems support multiple services with strict Quality of Service (QoS) constraints. To fulfill the increased communication needs, 5G Vehicular Cloud Computing (5G-VCC) architectures with dense deployments of the access network infrastructures have been proposed. In such systems, the network resources manipulation is a critical task that could be addressed by the Medium Access Control (MAC) layer. MAC schemes that have been proposed for vehicular networks, can be applied to 5G-VCC systems in order optimal manipulation of communication resources to be accomplished. This paper makes an overview of available MAC schemes, while a comprehensive discussion about their implementation in 5G-VCC systems is performed leading to useful conclusions.
The enhancement of Underwater Cultural Heritage Assets using Augmented Realit...University of Piraeus
Τhe development in the fields of Underwater Cultural Heritage (UCH) management and Maritime Archaeology, yields an interdisciplinary and creative academic framework, such as the Information and Communication Technologies (ICT) sector that has been proved to build intelligent systems and applications. However, the ways to fully make use of these technologies are still being explored, as their potential have not been exploited yet. Underwater archaeological sites, semi (/or fully) submerged settlements, ancient ports and shipwrecks, unlike land sites, are not accessible to public due to their special (sub) marine environment and depth. In this paper, an innovative research idea of using Augmented Reality (AR) for maintaining the memory and the information of underwater archaeological sites, is presented. Although the “artificial” visual documentation cannot replace the authentic values of the underwater tangible heritage, the AR technology can contribute to the protection of the intangible properties and the conquered knowledge of the past of a place. This research work will focus, among other case studies, on the (semi) submerged fortifications and their contiguous contents of the acropolis of Halai in east Lokris, Greece. Hence, along with the climate change that may lead more antiquities covered by water during the following years, the advances in the communication field and the up-coming 5G and cloud technologies will make the idea fully applicable, contributing to the enhancement of the coastal and the underwater archaeological remains.
Fifth generation (5G) Vehicular Cloud Computing (VCC) systems use heterogeneous network access technologies to
fulfill the requirements of modern services. Multiple services with dierent Quality of Service (QoS) constraints could be available in each vehicle, while at the same time, user requirements and provider policies must be addressed. Therefore, the design of ecient Vertical Handover (VHO) management schemes for 5G-VCC infrastructures is needed. In this paper, a novel VHO management scheme for 5G-VCC systems is proposed. Whenever the user satisfaction grade becomes less than a predefined threshold, VHO is initiated and network selection is performed, considering the velocity of the vehicle, network characteristic criteria such as throughput, delay, jitter and packet loss, as well as provider policy criteria such as service reliability, security and price. The proposed scheme uses linguistic values for VHO criteria attributes represented by Interval Valued Pentagonal Fuzzy Numbers (IVPFNs) to express the information using membership intervals. The VHO scheme is applied to a 5G-VCC system which includes 3GPP Long Term Evolution (LTE) and IEEE 802.16 Worldwide Interoperability for Microwave Access (WiMAX) Macrocells and Femtocells, as well as IEEE 802.11p Wireless Access for Vehicular Environment (WAVE) Road Side Units (RSUs). Performance evaluation shows that the suggested method ensures the Always Best Connection (ABC) principle, while at the same time outperforms existing VHO management schemes.
Performance Analysis and Optimization of Next Generation Wireless NetworksUniversity of Piraeus
The Fifth Generation (5G) networks, including the 5G Vehicular Cloud Computing (5G-VCC) systems, have evolved rapidly offering multiple services to users. The operating principles of vehicular networks, Cloud Computing (CC), Fog Computing (FC), Mobile Edge Computing (MEC) and Software Defined Networks (SDN) are applied to 5G infrastructures. In a 5G-VCC system, the vehicles are equipped with On-Board Units (OBUs) which communicate with each other as well as with Road Side Units (RSUs). Each RSU interacts with a Cloud infrastructure which offers vehicular services with strict Quality of Service (QoS) requirements, including Driver Assistance (DA), Passengers Entertainment and Information (PEnI) and Medical (MED) services. Dense deployments of 5G access networks are also implemented, called Ultra Dense Networks (UDNs), aiming to support high data rates produced by an increased number of vehicular users. In this environment, heterogeneous technologies are used to transfer the network services to vehicles. Optimal manipulation of the communication resources is required, while at the same time vehicular users should always obtain connectivity to the most appropriate network access technology, in order the constraints of the vehicular services to be satisfied. In this thesis, existing schemes for resource allocation as well as for mobility management are studied, while novel solutions are proposed for each topic.
Personalized Real-Time Virtual Tours in Places with Cultural InterestUniversity of Piraeus
Virtual tours using drones enhance the experience the users perceive from a place with cultural interest. Drones equipped with 360o cameras perform real-time video streaming of the cultural sites. The user preferences about each monument type should be considered in order the appropriate flying route for the drone to be selected. This paper describes a scheme for supporting personalized real-time virtual tours in sites with cultural interest using drones. The user preferences are modeled using the MPEG-21 and the MPEG-7 standards, while Web Ontology Language (OWL) ontologies are used for the description of the metadata structure and semantics. The Metadata-aware Analytic Network Process (MANP) algorithm is proposed in order the weights about the user preferences for each monument type to be estimated. Subsequently, the Trapezoidal Fuzzy Topsis for Heritage Route Selection (TFT-HRS) algorithm accomplishes ranks the candidate heritage routes. Finally, after each virtual tour, the user preferences metadata are updated in order the scheme to continuously learn about the user preferences.
The Convergence of Blockchain, Internet of Things (IoT) and Building Informat...University of Piraeus
The Architecture, Engineering and Construction (AEC) industry has not embraced digital transformation with the same enthusiasm as other industries (e.g. such as manufacture industry). Building Information Modeling (BIM) is a revolutionary technology that is characterized as the opportunity of the AEC industry to move to the digital era and improve the collaboration amongst the partners of this industry by exploiting Information and Communications Technologies (ICT). BIM provides all the necessary tools and automations to achieve end-to-end communication, data exchange and information sharing between project actors. Thus, the virtual 3D models generated in the context of engaging in the BIM process and as-delivered physical assets through Building Management Systems (BMS) could adopt Internet of Things (IoT) architectures and services. However, the orchestration of IoT in a highly modular environment with many moving parts and inter-dependencies between the stakeholders of this environment, lead to many security issues. Therefore, this paper proposes a system architecture that employs the Blockchain technology as a measure to secure and control the BIM technology coupled with IoT. The system architecture under scrutiny is considering the case of a museum building, where efficient security, management and monitoring are of great importance.
The convergence of blockchain, internet of things (io t) and building informa...University of Piraeus
The Architecture, Engineering and Construction (AEC) industry has not embraced digital transformation with the same enthusiasm as other industries (e.g. such as manufacture industry). Building Information Modeling (BIM) is a revolutionary technology that is characterized as the opportunity of the AEC industry to move to the digital era and improve the collaboration amongst the partners of this industry by exploiting Information and Communications Technologies (ICT). BIM provides all the necessary tools and automations to achieve end-to-end communication, data exchange and information sharing between project actors. Thus, the virtual 3D models generated in the context of engaging in the BIM process and as-delivered physical assets through Building Management Systems (BMS) could adopt Internet of Things (IoT) architectures and services. However, the orchestration of IoT in a highly modular environment with many moving parts and inter-dependencies between the stakeholders of this environment, lead to many security issues. Therefore, this paper proposes a system architecture that employs the Blockchain technology as a measure to secure and control the BIM technology coupled with IoT. The system architecture under scrutiny is considering the case of a museum building, where efficient security, management and monitoring are of great importance.
The revival of back-filled monuments through Augmented Reality (AR) (presenta...University of Piraeus
The development of three-dimensional (3D) models and the use of Augmented Reality (AR) in the field of cultural heritage consists an innovative process the recent years that provides the visitors of archaeological sites with additional information. This has been made possible due to achievements in digital technologies, communications, devices and developments in software engineering. Nevertheless, the research to fully make use of these new methods continues, as the potentials of new technologies have not been exploited. In archaeological sites, the production of 3D models for AR is focused on the virtual reconstruction of ruined monuments at their original form, aiming to give visitors the third dimension (height, volume etc.), especially to those who do not have special knowledge of archaeology. This paper describes an innovative approach of using AR for maintaining the memory and the information of monuments, as they have been originally excavated, but that are going to be back -filled due to the particularity of their material or their location. Also, the system architecture of the proposed scheme is described considering two study cases, a Neolithic settlement in the archaeological site of Halai, Lokris and the remains of a Classical Temple on open field of a hill in Thebes, Boeotia. Both mentioned monuments are under the direction of the American School of Classical Studies in Athens (ASCSA).
An analytic network process and trapezoidal interval-valued fuzzy technique f...University of Piraeus
Next generation wireless networks consist of many heterogeneous access technologies that should support various service types with different quality of service (QoS) constraints, as well as user, requirements and provider policies. Therefore, the need for network selection mechanisms that consider multiple factors must be addressed. In this paper, a network selection method is proposed by applying the analytic network process to estimate the weights of the selection criteria, as well as a fuzzy version of technique for order preference by similarity to ideal solution to perform the ranking of network alternatives. The method is applied to a heterogeneous network environment providing different QoS classes and policy characteristics. Each user applies the method to select the most appropriate network, which satisfies his or her requirements in respect of his or her service-level agreement (SLA). Performance evaluation shows that when the user requests only one service, the proposed method performs better compared to the original technique for order preference by similarity to ideal solution, as well as the Fuzzy AHP-ELECTRE method. Moreover, the proposed method can be applied in cases where a user requires multiple services simultaneously on a device. The sensitivity analysis of the proposed method shows that it can be properly adjusted to conform to network environment changes.
A Personalized Audio Web Service using MPEG-7 and MPEG-21 standards (presenta...University of Piraeus
This paper presents a web service which delivers personalized audio information. The personalization process is automated and decentralized. The metadata which support personalization are separated in two categories: the metadata describing user preferences stored at each user and the resource adaptation metadata stored at the web service host. The multimedia models MPEG-21 and MPEG-7 are used to describe metadata information and the Web Ontology Language (OWL) to produce and manipulate ontological descriptions. SPARQL is used for querying the OWL ontologies. The MPEG Query Format (MPQF) is also used, providing a wellknown framework for applying queries to the metadata and to the ontologies.
A Personalized Audio Server using MPEG-7 and MPEG-21 standards (presentation)University of Piraeus
This paper presents a semantic model which delivers personalized audio information. The personalization process is automated and decentralized. The metadata which support personalization are separated in two categories: the metadata describing user preferences stored at each user and the resource adaptation metadata stored at the server. The multimedia models MPEG-21 and MPEG-7 are used to describe metadata information. The Web Ontology Language (OWL) language is used to produce and manipulate the relative ontological descriptions.
A Vertical Handover Management Scheme for VANET Cloud Computing SystemsUniversity of Piraeus
Vehicular Cloud Computing (VCC) systems use heterogeneous network access technologies in order to fulfill the requirements of modern services. Therefore, the need for efficient Vertical Handover (VHO) management schemes must be addressed. In this paper a VHO management scheme for VCC systems is described. The proposed method takes into account the vehicles velocity as well as its current connection type and applies a two step VHO algorithm to reduce operations’ costs and optimize mobility management. Accordingly, as a first step a VHO initiation process evaluates the necessity to perform handover and subsequently a network selection process selects the appropriate network alternative considering both vehicular service requirements and operators’ policies. The proposed scheme is applied to a VCC system which includes Long Term Evolution (LTE) Macrocells and Femtocells as well as 802.11p Road Side Units (RSUs). Performance evaluation shows that the suggested algorithm ensures the Always Best Connection (ABC) principle, while at the same time outperforms existing VHO management schemes.
A downlink scheduler supporting real time services in LTE cellular networksUniversity of Piraeus
The wide spread of real-time services in wireless networks demands scheduling mechanisms supporting strict Quality of Service (QoS) requirements. Nevertheless, the specifications of the LTE standard for mobile connectivity defined by the 3rd Generation Partnership Project (3GPP) does not impose any specific scheduler for the proper allocation of resources to services. Therefore, several LTE schedulers have been proposed in the literature meeting the QoS requirements of modern services. In this paper a QoS aware scheduler for the LTE downlink is proposed namely the FLS-Advanced (FLSA) aiming at prioritizing real-time traffic. The proposed scheduler has been built on three distinct levels assigning the available radio resources to services according to their requirements. Based on simulation results, the FLSA outperforms in terms of packet loss ratio, attainable throughput and fairness the performance of existing schedulers including PF, MLWDF, EXP/PF, FLS, EXP RULE and LOG RULE.
A QoS aware scheduler, the FLS-Advanced (FLSA), a modified version of FLS, for the LTE downlink transmission is proposed.
The main idea is to prioritize the real-time type traffic against the other types.
FLSA has been built on three distinct levels which cooperate each other to allocate the network resources to users.
Generating a custom Ruby SDK for your web service or Rails API using Smithyg2nightmarescribd
Have you ever wanted a Ruby client API to communicate with your web service? Smithy is a protocol-agnostic language for defining services and SDKs. Smithy Ruby is an implementation of Smithy that generates a Ruby SDK using a Smithy model. In this talk, we will explore Smithy and Smithy Ruby to learn how to generate custom feature-rich SDKs that can communicate with any web service, such as a Rails JSON API.
Kubernetes & AI - Beauty and the Beast !?! @KCD Istanbul 2024Tobias Schneck
As AI technology is pushing into IT I was wondering myself, as an “infrastructure container kubernetes guy”, how get this fancy AI technology get managed from an infrastructure operational view? Is it possible to apply our lovely cloud native principals as well? What benefit’s both technologies could bring to each other?
Let me take this questions and provide you a short journey through existing deployment models and use cases for AI software. On practical examples, we discuss what cloud/on-premise strategy we may need for applying it to our own infrastructure to get it to work from an enterprise perspective. I want to give an overview about infrastructure requirements and technologies, what could be beneficial or limiting your AI use cases in an enterprise environment. An interactive Demo will give you some insides, what approaches I got already working for real.
JMeter webinar - integration with InfluxDB and GrafanaRTTS
Watch this recorded webinar about real-time monitoring of application performance. See how to integrate Apache JMeter, the open-source leader in performance testing, with InfluxDB, the open-source time-series database, and Grafana, the open-source analytics and visualization application.
In this webinar, we will review the benefits of leveraging InfluxDB and Grafana when executing load tests and demonstrate how these tools are used to visualize performance metrics.
Length: 30 minutes
Session Overview
-------------------------------------------
During this webinar, we will cover the following topics while demonstrating the integrations of JMeter, InfluxDB and Grafana:
- What out-of-the-box solutions are available for real-time monitoring JMeter tests?
- What are the benefits of integrating InfluxDB and Grafana into the load testing stack?
- Which features are provided by Grafana?
- Demonstration of InfluxDB and Grafana using a practice web application
To view the webinar recording, go to:
https://www.rttsweb.com/jmeter-integration-webinar
Elevating Tactical DDD Patterns Through Object CalisthenicsDorra BARTAGUIZ
After immersing yourself in the blue book and its red counterpart, attending DDD-focused conferences, and applying tactical patterns, you're left with a crucial question: How do I ensure my design is effective? Tactical patterns within Domain-Driven Design (DDD) serve as guiding principles for creating clear and manageable domain models. However, achieving success with these patterns requires additional guidance. Interestingly, we've observed that a set of constraints initially designed for training purposes remarkably aligns with effective pattern implementation, offering a more ‘mechanical’ approach. Let's explore together how Object Calisthenics can elevate the design of your tactical DDD patterns, offering concrete help for those venturing into DDD for the first time!
Slack (or Teams) Automation for Bonterra Impact Management (fka Social Soluti...Jeffrey Haguewood
Sidekick Solutions uses Bonterra Impact Management (fka Social Solutions Apricot) and automation solutions to integrate data for business workflows.
We believe integration and automation are essential to user experience and the promise of efficient work through technology. Automation is the critical ingredient to realizing that full vision. We develop integration products and services for Bonterra Case Management software to support the deployment of automations for a variety of use cases.
This video focuses on the notifications, alerts, and approval requests using Slack for Bonterra Impact Management. The solutions covered in this webinar can also be deployed for Microsoft Teams.
Interested in deploying notification automations for Bonterra Impact Management? Contact us at sales@sidekicksolutionsllc.com to discuss next steps.
State of ICS and IoT Cyber Threat Landscape Report 2024 previewPrayukth K V
The IoT and OT threat landscape report has been prepared by the Threat Research Team at Sectrio using data from Sectrio, cyber threat intelligence farming facilities spread across over 85 cities around the world. In addition, Sectrio also runs AI-based advanced threat and payload engagement facilities that serve as sinks to attract and engage sophisticated threat actors, and newer malware including new variants and latent threats that are at an earlier stage of development.
The latest edition of the OT/ICS and IoT security Threat Landscape Report 2024 also covers:
State of global ICS asset and network exposure
Sectoral targets and attacks as well as the cost of ransom
Global APT activity, AI usage, actor and tactic profiles, and implications
Rise in volumes of AI-powered cyberattacks
Major cyber events in 2024
Malware and malicious payload trends
Cyberattack types and targets
Vulnerability exploit attempts on CVEs
Attacks on counties – USA
Expansion of bot farms – how, where, and why
In-depth analysis of the cyber threat landscape across North America, South America, Europe, APAC, and the Middle East
Why are attacks on smart factories rising?
Cyber risk predictions
Axis of attacks – Europe
Systemic attacks in the Middle East
Download the full report from here:
https://sectrio.com/resources/ot-threat-landscape-reports/sectrio-releases-ot-ics-and-iot-security-threat-landscape-report-2024/
UiPath Test Automation using UiPath Test Suite series, part 4DianaGray10
Welcome to UiPath Test Automation using UiPath Test Suite series part 4. In this session, we will cover Test Manager overview along with SAP heatmap.
The UiPath Test Manager overview with SAP heatmap webinar offers a concise yet comprehensive exploration of the role of a Test Manager within SAP environments, coupled with the utilization of heatmaps for effective testing strategies.
Participants will gain insights into the responsibilities, challenges, and best practices associated with test management in SAP projects. Additionally, the webinar delves into the significance of heatmaps as a visual aid for identifying testing priorities, areas of risk, and resource allocation within SAP landscapes. Through this session, attendees can expect to enhance their understanding of test management principles while learning practical approaches to optimize testing processes in SAP environments using heatmap visualization techniques
What will you get from this session?
1. Insights into SAP testing best practices
2. Heatmap utilization for testing
3. Optimization of testing processes
4. Demo
Topics covered:
Execution from the test manager
Orchestrator execution result
Defect reporting
SAP heatmap example with demo
Speaker:
Deepak Rai, Automation Practice Lead, Boundaryless Group and UiPath MVP
Key Trends Shaping the Future of Infrastructure.pdfCheryl Hung
Keynote at DIGIT West Expo, Glasgow on 29 May 2024.
Cheryl Hung, ochery.com
Sr Director, Infrastructure Ecosystem, Arm.
The key trends across hardware, cloud and open-source; exploring how these areas are likely to mature and develop over the short and long-term, and then considering how organisations can position themselves to adapt and thrive.
Transcript: Selling digital books in 2024: Insights from industry leaders - T...BookNet Canada
The publishing industry has been selling digital audiobooks and ebooks for over a decade and has found its groove. What’s changed? What has stayed the same? Where do we go from here? Join a group of leading sales peers from across the industry for a conversation about the lessons learned since the popularization of digital books, best practices, digital book supply chain management, and more.
Link to video recording: https://bnctechforum.ca/sessions/selling-digital-books-in-2024-insights-from-industry-leaders/
Presented by BookNet Canada on May 28, 2024, with support from the Department of Canadian Heritage.
UiPath Test Automation using UiPath Test Suite series, part 3DianaGray10
Welcome to UiPath Test Automation using UiPath Test Suite series part 3. In this session, we will cover desktop automation along with UI automation.
Topics covered:
UI automation Introduction,
UI automation Sample
Desktop automation flow
Pradeep Chinnala, Senior Consultant Automation Developer @WonderBotz and UiPath MVP
Deepak Rai, Automation Practice Lead, Boundaryless Group and UiPath MVP
UiPath Test Automation using UiPath Test Suite series, part 3
Performance Analysis and Optimization of Next Generation Wireless Networks (PhD Thesis presentation)
1. Performance Analysis and Optimization
of Next Generation Wireless Networks
PhD Thesis of:
Emmanouil Skondras
Department of Informatics
University of Piraeus
2. PhD Thesis of Emmanouil Skondras, Department of Informatics, University of Piraeus
Outline
• Introduction.
• Background.
• Resource Allocation - Scheduling.
• Mobility Management.
• A Proposed Mobility Management Approach for
5G-VCC Systems.
• Conclusion.
2
3. PhD Thesis of Emmanouil Skondras, Department of Informatics, University of Piraeus
Introduction - Thesis Scope
• Key enabling technologies for 5G networks.
• Cloud Computing (CC).
• Fog Computing (FC).
• Mobile Edge Computing (MEC).
• Software Defined Networking (SDN).
• Ultra Dense Networking (UDN).
• Multiple Femtocells.
• Macrocells with Massive MIMO (MMIMO).
Multiple mobile users with increased communication needs.
• Requirement for optimal manipulation of:
Communication resources (scheduling).
Users mobility.
3
Thesis Scope
4. PhD Thesis of Emmanouil Skondras, Department of Informatics, University of Piraeus
Resources Manipulation -
Scheduling
4
5. PhD Thesis of Emmanouil Skondras, Department of Informatics, University of Piraeus
Scheduling Strategies for LTE-A Pro
• Several downlink packet schedulers have been proposed in
the current literature.
• Resource Blocks (RBs) are allocated to users.
• The minimum allocation unit.
• They can be classified into two groups:
• Non-QoS aware.
• Does not take into account parameters that affect the service quality.
• QoS aware.
• Considers the specific constraints of each service.
5
6. PhD Thesis of Emmanouil Skondras, Department of Informatics, University of Piraeus
Non-QoS aware schedulers
• Maximum Throughput (MT)
• Proportional Fair (PF)
• Throughput to Average (TTA)
• Blind Equal Throughput (BET)
di
k(t): Available throughput in the kth RB of the ith user.
𝑅i(t-1): Past average throughput.
di(t): Available throughput in the ith user.
6
7. PhD Thesis of Emmanouil Skondras, Department of Informatics, University of Piraeus
QoS aware schedulers
• Modified Largest Weighted
Delay First (M-LWDF)
• LOG RULE
• EXP RULE
• Exponential/PF (EXP/PF)
DHOL,i: Head of line delay.
bi and c: Configurable parameters.
Γi
k: Spectral efficiency for the ith flow on the kth RB.
δi: Target packet loss ratio.
τi: Delay constraint.
Nrt: The number of active real time flows. 7
8. PhD Thesis of Emmanouil Skondras, Department of Informatics, University of Piraeus
QoS aware schedulers
• Frame Level Scheduler (FLS)
• Two level QoS aware strategy.
• Upper Level
• Estimates the ui(x) quota of data
that the ith real time flow must
transmit at the xth frame to
succeed its QoS constraints.
• Lower Lever
• Uses the PF metric to allocate
RBs to flows
qi(x): Queue length in the xth frame.
Mi: the number of coefficients used.
ci(n): The nth coefficient value.
τi: The target delay.
8
9. PhD Thesis of Emmanouil Skondras, Department of Informatics, University of Piraeus
The Proposed FLS Advanced (FLSA) Scheduler
• It has been built on three distinct levels.
• Real time flows receive higher priority
than the best effort ones.
• Because of their strict service
constraints that must be fulfilled.
9
10. PhD Thesis of Emmanouil Skondras, Department of Informatics, University of Piraeus
The Upper Level of the Scheduler
• Uses the formula of FLS.
• To estimate the quota ui(t) of data that
the ith real time flow should transmit in
each tth TTI, to satisfy its QoS constraints.
• ui(t) quota is estimated in each tth TTI of a
frame.
• Whereas in FLS it is estimated once at the
beginning of each kth frame.
• In FLS, when a real time flow transmits its
ui(k) quota of data:
• It loses the opportunity to continue the
transmission until the beginning of the next
frame.
The FLSA provides more resources to real
time flows that have remaining data for
transmission.
10
11. PhD Thesis of Emmanouil Skondras, Department of Informatics, University of Piraeus
The Middle Level of the Scheduler
• The use of the QoS aware M-LWDF
scheduler:
• Realizes improved resource distribution
among the real time flows.
• In comparison with the FLS scheduler
which at the second level uses the non-
QoS aware PF algorithm.
11
12. PhD Thesis of Emmanouil Skondras, Department of Informatics, University of Piraeus
The Lower Level of the Scheduler
• Allocates the remaining RBs of each TTI to
both real time and best effort flows using
the M-LWDF algorithm.
• RBs are allocated to:
• Real time flows.
• For transmitting their qi-ui(t) data.
• qi denotes the queue length for the flow i.
• Best effort flows.
• Considering the fact they have no specific
service constraints.
12
13. PhD Thesis of Emmanouil Skondras, Department of Informatics, University of Piraeus
The Proposed FLSA-CC Scheduler
• Improved version of the Frame Level Scheduler Advanced (FLSA).
• Cross Carrier (CC) scheduling.
13
B) Cross Carrier Scheduling:
Scheduling grant and resource NOT
on the same carrier
- Carrier Indicator Field (CIF)
LTE-A Carrier Aggregation: A) non-Cross Carrier Scheduling
Scheduling grant and resource on
the same carrier
14. PhD Thesis of Emmanouil Skondras, Department of Informatics, University of Piraeus
FLSA FLSA-CC
Real time flows receive higher priority than the best effort
ones to fulfill their constraints.
Maintains an acceptable level of performance for BE
flows.
The Proposed FLSA-CC Scheduler
14
15. PhD Thesis of Emmanouil Skondras, Department of Informatics, University of Piraeus
Performance Evaluation
• The performance of the FLSA and FLSA-CC was evaluated against the schedulers:
• PF , M-LWDF , EXP/PF , FLS , EXP-RULE and LOG-RULE.
• An extended version of the open source simulator LTE-Sim used.
• The iCanCloud and the OpenFlow modules of the Omnet++ simulator have been
configured and embedded to the Lte-Sim.
• Enabling the ability to include cloud infrastructure and SDN controllers to the simulated LTE
topology.
• The simulation parameters:
15
16. PhD Thesis of Emmanouil Skondras, Department of Informatics, University of Piraeus
Performance Evaluation
• Flow forwarding as well as resource
scheduling in each DeNB and RN.
• Are performed using a centralized
global controller.
• Placed into the SGW on the
cloud.
• The parameters considered in each
scheduler:
16
17. PhD Thesis of Emmanouil Skondras, Department of Informatics, University of Piraeus
VoIP and Video packet loss ratio
17
• FLSA-CC accomplishes
lower PLR.
18. PhD Thesis of Emmanouil Skondras, Department of Informatics, University of Piraeus
VoIP and Video throughput
and fairness index
18
• FLSA-CC achieves higher throughputs
than the rest of the algorithms
providing rates of up to 800kbps for
VoIP and up to 28Mbps for video
services.
• FLSA-CC scheduler improves the fairness
for both VoIP and video flows.
19. PhD Thesis of Emmanouil Skondras, Department of Informatics, University of Piraeus
Best Effort throughput
and fairness index
19
• FLSA-CC outperforms the
other two schedulers.
20. PhD Thesis of Emmanouil Skondras, Department of Informatics, University of Piraeus
Mobility Management
20
21. PhD Thesis of Emmanouil Skondras, Department of Informatics, University of Piraeus
Mobility Management -Introduction
• 5G Vehicular Cloud Computing (5G-VCC) architectures combine the operating principles of both
Vehicular Networks and Cloud Computing.
• Vehicular environment.
• Vehicles equipped with On-Board Units (OBUs) with computational, storage and communication resources.
• Vehicles communicate with each other or with Road Side Units (RSUs).
• Road Side Units (RSUs):
• Could provide access to a Cloud infrastructure. (a)
• Could be equipped with additional computational and storage resources. (b)
• Fog infrastructure.
• Both Cloud and Fog infrastructures could coexist. (c)
Vehicular users should always obtain connectivity to the most appropriate network access technology.
21
(a) (b) (c)
22. PhD Thesis of Emmanouil Skondras, Department of Informatics, University of Piraeus
The Interval-Valued Pentagonal
Fuzzy Numbers (IVPFN)
• Make a decision from indeterminate and approximate information.
• Triangular, trapezoidal or pentagonal fuzzy numbers are frequently used.
• A pentagonal fuzzy number can be defined as a vector:
• with membership function:
22
23. PhD Thesis of Emmanouil Skondras, Department of Informatics, University of Piraeus
The Interval-Valued Pentagonal
Fuzzy Numbers (IVPFN)
• An Interval-Valued Fuzzy Number (IVFN) is defined as A=[AL,AU ] consisting of the lower AL
and the upper AU fuzzy numbers.
• IVFNs replace the crisp membership values by intervals in [0,1].
• The Interval-Valued Pentagonal Fuzzy Number (IVPFN) is the most general IVFN case
defined as:
where:
,
23
24. PhD Thesis of Emmanouil Skondras, Department of Informatics, University of Piraeus
Pentagonal Fuzzy Analytic
Network Process (PF-ANP)
• The steps of the method are as follows:
1. Model Construction and Problem Structuring.
2. Pairwise comparison matrices and priority
vectors.
3. Construction of the Supermatrix.
4. Construction of the Weighted Supermatrix.
5. Deffuzification of the Weighted Supermatrix.
6. Calculation of the Limited Supermatrix.
24
Organization of criteria into clusters.
• The steps of the method are as follows:
1. Model Construction and Problem Structuring.
2. Pairwise comparison matrices and priority
vectors.
3. Construction of the Supermatrix.
4. Construction of the Weighted Supermatrix.
5. Deffuzification of the Weighted Supermatrix.
6. Calculation of the Limited Supermatrix.
One for each cluster of criteria.
• n is the number of the cluster elements.
Each matrix segment represents the
relationship between two clusters of criteria.
Assume q clusters, Ck with k=[1,2,…,q]:
• Each cluster has nq elements, denoted as
ek1, ek2, …, eknk.
• The steps of the method are as follows:
1. Model Construction and Problem Structuring.
2. Pairwise comparison matrices and priority
vectors.
3. Construction of the Supermatrix.
4. Construction of the Weighted Supermatrix.
5. Deffuzification of the Weighted Supermatrix.
6. Calculation of the Limited Supermatrix.
• The steps of the method are as follows:
1. Model Construction and Problem Structuring.
2. Pairwise comparison matrices and priority
vectors.
3. Construction of the Supermatrix.
4. Construction of the Weighted Supermatrix.
5. Deffuzification of the Weighted Supermatrix.
6. Calculation of the Limited Supermatrix.
• The steps of the method are as follows:
1. Model Construction and Problem Structuring.
2. Pairwise comparison matrices and priority
vectors.
3. Construction of the Supermatrix.
4. Construction of the Weighted Supermatrix.
5. Deffuzification of the Weighted Supermatrix.
6. Calculation of the Limited Supermatrix.
• The steps of the method are as follows:
1. Model Construction and Problem Structuring.
2. Pairwise comparison matrices and priority
vectors.
3. Construction of the Supermatrix.
4. Construction of the Weighted Supermatrix.
5. Deffuzification of the Weighted Supermatrix.
6. Calculation of the Limited Supermatrix.
• W is raised to limiting powers until all the entries converge.
• The overall priorities are calculated.
• All the columns of the Limit Supermatrix, are the same.
• Their values show the estimated weight for each criterion.
25. PhD Thesis of Emmanouil Skondras, Department of Informatics, University of Piraeus
The Proposed Mobility
Management Scheme
25
26. PhD Thesis of Emmanouil Skondras, Department of Informatics, University of Piraeus
The Proposed Mobility
Management Scheme
• The methods described in the previous
slides are used.
• The scheme is optimized for 5G
network architectures.
• Where both Fog and Cloud infrastructures
are available.
• The Mobility Management process
includes:
1. The VHO Initiation.
2. The Velocity Monitoring.
3. The Network Selection.
4. The VHO Execution.
26
27. PhD Thesis of Emmanouil Skondras, Department of Informatics, University of Piraeus
• The MPFIS considers two inputs (Input1
and Input2) to estimate the value of the
Output.
• The MFInput1, MFInput2, MFOutput
membership functions (MF) are defined.
• For the fuzzy representation of the SINRu,i, Qu,i
and Su,i respectively.
• Created using the Equalized Universe
Method (EUM) method.
• They are equally distributed inside the
domain [Umin, Umax] = [0, 1].
27
System Setup: Modeling the User Satisfaction Grade
- The Mamdani Pentagonal Fuzzy Inference System (MPFIS)
28. PhD Thesis of Emmanouil Skondras, Department of Informatics, University of Piraeus
System Setup: Modeling the User Satisfaction Grade
- The Mamdani Pentagonal Fuzzy Inference System (MPFIS)
• The steps of the method are as follows:
1. Fuzzy rule (or knowledge) base.
2. Fuzzification.
3. Combining the fuzzified inputs
(Fuzzy Operations).
4. Implication method.
5. Aggregation method.
6. Defuzzification.
28
if SINR is Enough AND/OR Q is Good
then S is More than Acceptable
• The steps of the method are as follows:
1. Fuzzy rule (or knowledge) base.
2. Fuzzification.
3. Combining the fuzzified inputs
(Fuzzy Operations).
4. Implication method.
5. Aggregation method.
6. Defuzzification.
• SINR and Q are:
• Normalized in order to have values within the range [0, 1].
• Converted to degrees of membership indicated as SINR' and Q'.
• By a lookup in MFSINR and MFQ membership functions,
respectively.
• The steps of the method are as follows:
1. Fuzzy rule (or knowledge) base.
2. Fuzzification.
3. Combining the fuzzified inputs
(Fuzzy Operations).
4. Implication method.
5. Aggregation method.
6. Defuzzification.
• A Z'r degree is calculated considering the rule's condition,
indicating the strength of the r rule.
• The `Algebraic product' is applied for the `AND' operator:
• The `Algebraic sum ' is applied for the ` OR ' operator :
• The steps of the method are as follows:
1. Fuzzy rule (or knowledge) base.
2. Fuzzification.
3. Combining the fuzzified inputs
(Fuzzy Operations).
4. Implication method.
5. Aggregation method.
6. Defuzzification.
• Estimates the consequence of the rule
conclusion.
• Considering the rule strength Z'u,i,r.
• The MFOutputr height is trimmed with respect to
the Z'r degree, using the Min method:
• The steps of the method are as follows:
1. Fuzzy rule (or knowledge) base.
2. Fuzzification.
3. Combining the fuzzified inputs
(Fuzzy Operations).
4. Implication method.
5. Aggregation method.
6. Defuzzification.
• It combines the R rules' consequences to calculate
the OutputA fuzzy set, using the Max method:
• The steps of the method are as follows:
1. Fuzzy rule (or knowledge) base.
2. Fuzzification.
3. Combining the fuzzified inputs
(Fuzzy Operations).
4. Implication method.
5. Aggregation method.
6. Defuzzification.
• The OutputA fuzzy set is transformed to
the crisp value Output, using the
Weighted Average method:
• μr is the height
• hr is the centroid of each rule obtained
from the OutputA.
29. PhD Thesis of Emmanouil Skondras, Department of Informatics, University of Piraeus
• The satisfaction indicators chart presents the S values obtained for each possible
SINR and Q combination.
29
System Setup: Modeling the User Satisfaction Grade
- The Mamdani Pentagonal Fuzzy Inference System (MPFIS)
30. PhD Thesis of Emmanouil Skondras, Department of Informatics, University of Piraeus
VHO Initiation
• The user's equipment continuously monitors its perceived the SINRu,i and the Qu,i values.
• When either the SINRu,i or the Qu,i becomes less than a predefined threshold:
• The user equipment sends the obtained values to the Fog infrastructure.
• The Fog determines the Su,i satisfaction grade of user u by performing a lookup at the
satisfaction chart:
If Su,i is less than a predefined Sth threshold value, the network selection process is executed
Considering the Velocity Monitoring results.
30
• thu,i,k, du,i,k, ju,i,k and plu,i,k : Throughput, delay, jitter and the packet loss ratio, obtained by
user u from current network i for the service k.
• wth,k, wd,k, wj,k and wpl,k : The weights of the parameters.
• N : The number of the parameters considered.
• K : The number of the available services.
31. PhD Thesis of Emmanouil Skondras, Department of Informatics, University of Piraeus
• During the entire vehicle movement:
• Its velocity is monitored by the Fog-Cloud infrastructure.
• An enhanced version of the Mobility State Estimation (MSE) model
defined in 3GPP LTE Release 11 is used to estimate vehicles' velocity.
• It considers the number of handovers (NCRu) performed by a vehicle
during a sliding time window (TCRmax).
31
Velocity Monitoring
32. PhD Thesis of Emmanouil Skondras, Department of Informatics, University of Piraeus
• The estimated residence time of vehicle u in each available cell
i is estimated using formula:
• rf is the radius of femtocell i.
• vu is the velocity of the vehicle u.
• Following, the vehicle velocity is obtained:
• The vehicle is categorized into one of three velocity states, namely the Normal, the
Medium and the High.
• The more handovers the vehicle performs during the TCRmax period, the faster the vehicle is moving.
32
Velocity Monitoring
The λu parameter, obtained by the SDN
controller, denotes the cell's density in
the location of vehicle u.
33. PhD Thesis of Emmanouil Skondras, Department of Informatics, University of Piraeus
Network selection -
Pentagonal Fuzzy Topsis (PFT)
• If the vehicle mobility state is Normal.
• The vehicle considers all the available networks as alternatives.
• If vehicle mobility state is Medium.
• The vehicle skips some Femtocells along its trajectory.
• A femtocell i is considered as alternative if
• is the average residence time of vehicle u considering all the available
femtocells in its current location.
• If vehicle mobility state is High.
• Only Macrocells are considered as alternatives.
33
34. PhD Thesis of Emmanouil Skondras, Department of Informatics, University of Piraeus
Network selection -
Pentagonal Fuzzy Topsis (PFT)
• PFT concept:
The best alternative should have the shortest distance from the positive ideal solution
and the longer distance from the negative ideal solution.
• Linguistic values of criteria attributes are represented by IVPFNs.
The set of possible alternatives:
• A = {AL1, AL2,…, ALn}
The set of criteria:
• C = {CR1, CR2,…, CRn}
The weights of each criterion:
• w1, w2, …, wm
The decision matrix:
34
35. PhD Thesis of Emmanouil Skondras, Department of Informatics, University of Piraeus
Network selection -
Pentagonal Fuzzy Topsis (PFT)
• The steps of the method are as
follows:
1. Construction of the decision matrix.
2. Normalization of the decision matrix.
3. Construction of the weighted
normalized decision matrix.
4. Determination of the positive and
negative ideal solution.
5. Measurement of the distance of each
alternative from the ideal solutions.
6. Calculation of the relative closeness
of each alternative.
7. Alternatives ranking.
35
if Q decision makers exist:
• The steps of the method are as
follows:
1. Construction of the decision matrix.
2. Normalization of the decision
matrix.
3. Construction of the weighted
normalized decision matrix.
4. Determination of the positive and
negative ideal solution.
5. Measurement of the distance of each
alternative from the ideal solutions.
6. Calculation of the relative closeness
of each alternative.
7. Alternatives ranking.
• The steps of the method are as
follows:
1. Construction of the decision matrix.
2. Normalization of the decision matrix.
3. Construction of the weighted
normalized decision matrix.
4. Determination of the positive and
negative ideal solution.
5. Measurement of the distance of each
alternative from the ideal solutions.
6. Calculation of the relative closeness
of each alternative.
7. Alternatives ranking.
• The steps of the method are as
follows:
1. Construction of the decision matrix.
2. Normalization of the decision matrix.
3. Construction of the weighted
normalized decision matrix.
4. Determination of the positive and
negative ideal solution.
5. Measurement of the distance of each
alternative from the ideal solutions.
6. Calculation of the relative closeness
of each alternative.
7. Alternatives ranking.
• The steps of the method are as
follows:
1. Construction of the decision matrix.
2. Normalization of the decision matrix.
3. Construction of the weighted
normalized decision matrix.
4. Determination of the positive and
negative ideal solution.
5. Measurement of the distance of
each alternative from the ideal
solutions.
6. Calculation of the relative closeness
of each alternative.
7. Alternatives ranking.
• The steps of the method are as
follows:
1. Construction of the decision matrix.
2. Normalization of the decision matrix.
3. Construction of the weighted
normalized decision matrix.
4. Determination of the positive and
negative ideal solution.
5. Measurement of the distance of each
alternative from the ideal solutions.
6. Calculation of the relative closeness
of each alternative.
7. Alternatives ranking.
• The steps of the method are as
follows:
1. Construction of the decision matrix.
2. Normalization of the decision matrix.
3. Construction of the weighted
normalized decision matrix.
4. Determination of the positive and
negative ideal solution.
5. Measurement of the distance of each
alternative from the ideal solutions.
6. Calculation of the relative closeness
of each alternative.
7. Alternatives ranking. …
36. PhD Thesis of Emmanouil Skondras, Department of Informatics, University of Piraeus
Simulation Setup
• A Software Defined Vehicular Cloud topology is simulated.
• Mobility trace indicating the map of the city of Piraeus along with road traffic data.
• Created using the Open Street Map (OSM) software.
• Then, the mobility trace has been used as input in the Simulator of Urban Mobility (SUMO)
simulator.
• Production of a realistic mobility pattern for the simulated vehicles including 39807 vehicles in
total, moving inside the Piraeus city in a 24 hours period.
36
37. PhD Thesis of Emmanouil Skondras, Department of Informatics, University of Piraeus
Simulation Setup
37
• The network topology is being built upon the map, using the Network Simulator 3 (NS3).
• It includes a Fog infrastructure and a Cloud infrastructure.
• The Fog infrastructure consists of 18 LTE Macrocell e-Node Bs (eNBs), 39 LTE Femtocell eNBs, 16
WiMAX Macrocell Base Stations (BSs), 26 WiMAX Femtocell BSs and 22 802.11p WAVE RSUs.
• Equipped with additional computational and storage resources.
• The access networks have been located on the map.
• According to the Hellenic Telecommunications and Post Commission (EETT) data about BSs’ positions in the city of Piraeus.
38. PhD Thesis of Emmanouil Skondras, Department of Informatics, University of Piraeus
Simulation Setup
• The positions and the spectrum of the LTE eNBs
(Macrocells and Femtocells):
38
• The positions and the spectrum of the WiMAX BSs
(Macrocells and Femtocells):
• The positions and the spectrum of the WAVE RSUs:
39. PhD Thesis of Emmanouil Skondras, Department of Informatics, University of Piraeus
Simulation Setup
• The SDN controller has global view of the entire network environment.
• It provides centralized control of the entire system.
39
40. PhD Thesis of Emmanouil Skondras, Department of Informatics, University of Piraeus
Simulation Setup - Services and SLAs
• Each access network supports at least one of the offered Cloud services:
• Navigation Assistance (NAV).
• Voice over IP (VoIP).
• Conversational Video (CV).
• Buffered Streaming (BS)
• Web Browsing (WB).
• Four Service Level Agreements (SLAs).
• SLA1 has the higher service priority and SLA 4 has the lower service priority.
• SLA1 supports all service types and provides the best values for QoS as well as policy
decision criteria.
• SLA2 supports less service types, by not providing support for the VoIP and NAV services.
• It provides slightly worse decision criteria values than those offered by the SLA1.
• SLA4 supports only the WB service while it provides acceptable decision criteria values.
• SLA3 supports only the BS and the WB services and satisfactory QoS characteristics and
policies.
40
41. PhD Thesis of Emmanouil Skondras, Department of Informatics, University of Piraeus
Simulation Setup
- Network Specifications
• Network specifications are expressed using linguistic terms.
41
42. PhD Thesis of Emmanouil Skondras, Department of Informatics, University of Piraeus
Simulation Setup
- Network Specifications per SLA
42
43. PhD Thesis of Emmanouil Skondras, Department of Informatics, University of Piraeus
Study of a Simulation Snapshot
• A snapshot of the simulation at time equal to 3600 seconds is evaluated.
• The case where 10 of the vehicles are monitored is studied.
• The available networks in the location of each vehicle:
43
44. PhD Thesis of Emmanouil Skondras, Department of Informatics, University of Piraeus
Study of a Simulation Snapshot
-VHO initiation
• The services weights used for the Qu,i estimation are calculated using the PF-
ANP method:
• The Sth,SLA thresholds are estimated considering:
The minimum acceptable QSLA and SINRSLA values per SLA.
44
45. PhD Thesis of Emmanouil Skondras, Department of Informatics, University of Piraeus
Study of a Simulation Snapshot
-VHO initiation
• The VHO initiation results for each vehicle:
• As it can be observed, vehicle 8 will remain to its current network i,
while the rest vehicles will proceed to handover.
45
46. PhD Thesis of Emmanouil Skondras, Department of Informatics, University of Piraeus
Study of a Simulation Snapshot
- Velocity monitoring
• For each one of the monitored vehicles, the following table presents its SLA, the
services used, its geographical position and its estimated velocity.
46
47. PhD Thesis of Emmanouil Skondras, Department of Informatics, University of Piraeus
Study of a Simulation Snapshot
- Network selection
• The PF-ANP method is applied in order to estimate
the weights of network selection criteria per
service type and SLA.
• Criteria are classified into two clusters:
• Network selection is performed using PFT.
• Considering the PF-ANP criteria weights.
47
48. PhD Thesis of Emmanouil Skondras, Department of Informatics, University of Piraeus
Study of a Simulation Snapshot
- Results
• The proposed scheme is compared with:
• The Velocity Aware Handover (VAH) [arshad2017].
• The Fuzzy AHP TOPSIS (FAT) [goyal2017].
• The Fuzzy AHP SAW (FAS) [goyal2017].
• The Fuzzy AHP MEW (FAM) [goyal2017].
• The Fuzzy AHP ELECTRE (FAE) [charilas2009].
48
[arshad2017] R. Arshad, H. ElSawy, S. Sorour, T. Y. Al-Na ouri, M.-S. Alouini, “Velocity-aware handover management in two-tier cellular
Networks”, IEEE Transactions on Wireless Communications, vol. 16, pp. 1851-1867, 2017.
[goyal2017] R. K. Goyal, S. Kaushal, A. K. Sangaiah, “The utility based non-linear fuzzy ahp optimization model for network selection in
heterogeneous wireless networks”, Applied Soft Computing, Elsevier, vol.67, pp. 800-811, 2017.
[charilas2009] D. E. Charilas, O. I. Markaki, J. Psarras, P. Constantinou, “Application
of fuzzy ahp and electre to network selection”, Mobile Lightweight Wireless Systems, Springer, pp. 63-73, 2009.
49. PhD Thesis of Emmanouil Skondras, Department of Informatics, University of Piraeus
Study of a Simulation Snapshot
- Results
• The suggested algorithm outperforms the existing schemes since it
selects as target networks for vehicles the ones with the best ranks.
• Also, in special cases where the velocity of vehicles is high (e.g. for
vehicle 7):
The proposed scheme avoids the handovers to femtocell networks.
49
50. PhD Thesis of Emmanouil Skondras, Department of Informatics, University of Piraeus
Study of a Simulation Snapshot
- Results
• The user's satisfaction grade after the execution of each
VHO scheme.
The proposed approach achieves higher satisfaction grades than
the existing schemes.
50
51. PhD Thesis of Emmanouil Skondras, Department of Informatics, University of Piraeus
24 Hours Simulation Results
• The average PFT rankings of each VHO scheme, where the entire 39807 vehicles
are considered:
The proposed scheme accomplishes higher ranking than the other schemes.
• The VAH scheme accomplishes the lower ranking.
• It does not consider either QoS related parameters, or operator policy related
parameters.
• The rest schemes accomplish intermediate results.
51
52. PhD Thesis of Emmanouil Skondras, Department of Informatics, University of Piraeus
24 Hours Simulation Results
The proposed approach accomplishes the highest average values, compared to the rest VHO schemes.
Less VHOs imply less network signaling overhead in both user and operator sides.
52
53. PhD Thesis of Emmanouil Skondras, Department of Informatics, University of Piraeus
Conclusions - Resource Manipulation
• Resource Manipulation.
• FLSA-CC cross carrier downlink scheduler.
• Performance evaluation against other scheduling algorithms.
• In a cloud assisted SDN architecture.
• LTE-A network with relay nodes.
FLSA-CC achieves better performance in terms of PLR, attainable
throughput and fairness.
• Mobility Management.
• The proposed scheme outperforms existing VHO management algorithms
in terms of:
The ranks of the selected networks.
The user satisfaction grade.
The HOs count.
• Future Work?
VHO Execution.
53
54. PhD Thesis of Emmanouil Skondras, Department of Informatics, University of Piraeus
Publications
• Journals
1. Emmanouil Skondras, Angelos Michalas, Dimitrios D. Vergados, “Mobility Management on 5G Vehicular Cloud Computing Systems”,
Vehicular Communications Journal, Elsevier, vol. 16, pp. 15-44, April 2019
2. Emmanouil Skondras, Aggeliki Sgora, Angelos Michalas, Dimitrios D. Vergados, “An analytic network process and trapezoidal
interval-valued fuzzy technique for order preference by similarity to ideal solution network access selection method”, International
Journal of Communication Systems (IJCS), Wiley, September 2014
3. Emmanouil Skondras, Konstantina Siountri, Angelos Michalas, Dimitrios D. Vergados, “Personalized Real-Time Virtual Tours in Places
with Cultural Interest”, International Journal of Computational Methods in Heritage Science (IJCMHS), IGI Global, vol. 3, issue 1,
January 2019
• Book Chapters
1. Emmanouil Skondras, Angelos Michalas, Malamati Louta, George Kouzas, “Personalized Multimedia Web Services in Peer to Peer
Networks Using MPEG-7 and MPEG-21 Standards”, Studies in Computational Intelligence – Semantic Hyper/Multimedia Adaptation,
Volume 418/2013 (book chapter), pp. 361-383, Springer-Verlag Berlin Heidelberg, 2013
• Conferences
1. Emmanouil Skondras, Eirini Zoumi, Angelos Michalas, Dimitrios D. Vergados, “A Network Selection Algorithm for supporting Drone
Services in 5G Network Architectures”, Wireless Telecommunications Symposium (WTS), New York, USA, April 9-12, 2019
2. Emmanouil Skondras, Angelos Michalas, Dimitrios D. Vergados, “A Survey on Medium Access Control Schemes for 5G Vehicular
Cloud Computing Systems”, Global Information Infrastructure and Networking Symposium (GIIS), Thessaloniki, Greece, October 23-
25, 2018
3. Emmanouil Skondras, Angelos Michalas, Nikolaos Tsolis, Dimitrios D. Vergados, “A Network Selection Scheme with Adaptive Criteria
Weights for 5G Vehicular Systems”, International Conference on Information, Intelligence, Systems and Applications (IISA),
Zakynthos, Greece, July 23-25, 2018
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55. PhD Thesis of Emmanouil Skondras, Department of Informatics, University of Piraeus
Publications
• Conferences (cont.)
4. Emmanouil Skondras, Angelos Michalas, Nikolaos Tsolis, Dimitrios D. Vergados, “A VHO Scheme for supporting Healthcare Services
in 5G Vehicular Cloud Computing Systems”, Wireless Telecommunications Symposium (WTS), Phoenix, Arizona, USA, April 18-20,
2018
5. Emmanouil Skondras, Angelos Michalas, Nikolaos Tsolis, Aggeliki Sgora, Dimitrios D. Vergados, “A Network Selection Scheme for
Healthcare Vehicular Cloud Computing Systems”, International Conference on Information, Intelligence, Systems and Applications
(IISA), Larnaka, Cyprus, August 28-30, 2017
6. Emmanouil Skondras, Angelos Michalas, Aggeliki Sgora, Dimitrios D. Vergados, “A Vertical Handover management scheme for
VANET Cloud Computing systems”, IEEE Symposium on Computers and Communications (ISCC), Heraklion, Crete, Greece, July 3-6,
2017
7. Emmanouil Skondras, Angelos Michalas, Aggeliki Sgora, Dimitrios D. Vergados, “QoS aware scheduling in LTE-A networks with SDN
control”, International Conference on Information, Intelligence, Systems and Applications (IISA), Chalkidiki, Greece, July 13-15, 2016
8. Emmanouil Skondras, Angelos Michalas, Aggeliki Sgora, Dimitrios D. Vergados, “A downlink scheduler supporting real time services
in LTE cellular networks”, International Conference on Information, Intelligence, Systems and Applications (IISA), Ionian University,
Corfu, Greece, July 6-8, 2015
9. Emmanouil Skondras, Angelos Michalas, Aggeliki Sgora, Dimitrios D. Vergados, “A QoS Aware Three Level Scheduler for the LTE
Downlink”, Wireless Telecommunications Symposium (WTS), Poster Paper, New York, USA, April 15-17, 2015
10. Konstantina Siountri, Emmanouil Skondras, Theodoros Mavroeidakos, Dimitrios D. Vergados, “The Convergence of Blockchain,
Internet of Things (IoT) and Building Information Modeling (BIM): The smart museum case”, Wireless Telecommunications
Symposium (WTS), New York, USA, April 9-12, 2019
11. Konstantina Siountri, Emmanouil Skondras, Dimitrios D. Vergados, Christos-Nikolaos Anagnostopoulos, “The Revival of Back-Filled
Monuments through Augmented Reality (AR)”, Visual Heritage Congress, Vienna, Austria, November 12-15, 2018
12. Konstantina Siountri, Emmanouil Skondras, Dimitrios D. Vergados, “A Delivery Model for Cultural Heritage Services in Smart Cities
Environments”, Euro-Mediterranean Conference (EUROMED), Springer, pp.279-288, Nicosia, Cyprus, October 29-November 3, 2018
13. Emmanouil Skondras, Konstantina Siountri, Angelos Michalas, Dimitrios D. Vergados, “A Route Selection Scheme for supporting
Virtual Tours in Sites with Cultural Interest using Drones”, International Conference on Information, Intelligence, Systems and
Applications (IISA), Zakynthos, Greece, July 23-25, 2018 55
56. PhD Thesis of Emmanouil Skondras, Department of Informatics, University of Piraeus
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57. PhD Thesis of Emmanouil Skondras, Department of Informatics, University of Piraeus
Scheduling Strategies for LTE-A Pro
• In LTE info is transmitted in 10ms
frames.
• Each frame is spit into 10 sub-frames
of 1ms TTI.
• Each TTI consists of resource blocks
(RBs) - the minimum allocation unit.
• A scheduler assigns an RB to the user
with the biggest metric.
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58. PhD Thesis of Emmanouil Skondras, Department of Informatics, University of Piraeus
The Middle & Lower Levels
• The middle level uses a CC version of
MLWDF in each TTI.
• Realizes improved resource distribution
among the real time flows.
• In comparison with the FLS
scheduler which at the second
level uses the non-QoS aware PF.
• The lower level uses a CC version of the PF.
• Allocates the remaining RBs of each TTI to
real time and best effort flows.
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59. PhD Thesis of Emmanouil Skondras, Department of Informatics, University of Piraeus
The Upper Level
• Uses the formula of FLS.
• To estimate the quota ui(x) of data that the
ith real time flow should transmit in each
xth TTI, to succeed its QoS constraints.
• The FLSA-CC estimates the coefficient
value ci(n) using formula:
where N is the number of aggregated
component carriers.
• ui(x) quota is estimated in each xth TTI of a
frame.
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60. PhD Thesis of Emmanouil Skondras, Department of Informatics, University of Piraeus
VoIP and Video packet loss ratio
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• Considered target delays:
100ms for VoIP and 150ms for
video flows, as determined by
the LTE QoS class specifications.
• FLSA-CC results in a lower PLR
than the rest of the algorithms.
• The impact of the target delay
parameter for the case of having
100 users per RN.
• FLSA-CC accomplishes lower PLR
independent of the target delay
parameter.
61. PhD Thesis of Emmanouil Skondras, Department of Informatics, University of Piraeus
Jain Fairness Index
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62. PhD Thesis of Emmanouil Skondras, Department of Informatics, University of Piraeus
• Vehicular users should always obtain connectivity to the most
appropriate network access technology.
• According to the requirements of their services, as well as the operators' policies.
• Mobility Management as a Service (MMaaS).
• It could be applied to accomplish mobility management operations by the
Cloud infrastructure.
• It allows the creation of a Mobility Instance (MI) for each vehicular user.
• Which could be considered as a service that manipulates user mobility.
In this way, the user equipment resources will have decreased workload
and consume reduced energy.
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Mobility Management -Introduction
63. PhD Thesis of Emmanouil Skondras, Department of Informatics, University of Piraeus
• The Equalized Universe Method (EUM) creates IVFNs with their centroids
equally spaced along a predefined domain of values.
• Specifically, the values of the ith IVPFN are calculated as follows:
• Umin and Umax are the minimum and maximum value of the domain.
• c represents the number of the IVPFNs created.
• and are defined by the user.
The Equalized Universe Method
(EUM)
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64. PhD Thesis of Emmanouil Skondras, Department of Informatics, University of Piraeus
System Setup: Definition of the linguistic terms and
the corresponding IVPFNs
• For the fuzzy representation of the SINRu,i, Qu,i and Su,i
respectively.
• Created using the Equalized Universe Method (EUM)
method.
• They are equally distributed inside the domain [Umin,
Umax] = [0, 1].
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65. PhD Thesis of Emmanouil Skondras, Department of Informatics, University of Piraeus
• VHO Initiation is executed in the Fog.
• Both the Fog and the Cloud cooperate to
accomplish the Velocity Monitoring process.
• Network Selection is executed in the Cloud.
• The vehicle is informed through the Fog, to make a
handover to the selected network.
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The Proposed Mobility
Management Scheme
66. PhD Thesis of Emmanouil Skondras, Department of Informatics, University of Piraeus
• During the entire vehicle movement:
• Its velocity is monitored by the Fog-Cloud infrastructure.
• An enhanced version of the Mobility State Estimation (MSE) model defined in 3GPP LTE
Release 11 is used to estimate vehicles' velocity.
• It considers the number of handovers or reselections (NCRu) performed by a vehicle during a
sliding time window (TCRmax).
• The vehicle is categorized into one of three velocity states, namely the Normal, the
Medium and the High.
• Considering the NCRMedium and NCRHigh thresholds with NCRMedium < NCRHigh.
• The more handovers the vehicle performs during the TCRmax period, the faster the vehicle
is moving.
• According to LTE specifications:
• In heterogeneous network environments including both Macrocells and Femtocells:
• The default TCRmax value is 120 seconds.
• The default NCRMedium and NCRHigh values are equal to 10 and 16 handovers, respectively.
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Velocity Monitoring
67. PhD Thesis of Emmanouil Skondras, Department of Informatics, University of Piraeus
Simulation Setup
- Network Specifications
• Network specifications are expressed using linguistic terms.
• Crisp values of network QoS characteristics are converted into linguistic terms.
• Which correspond to specific ranges of values per service type.
• Indicatively, the following table illustrates the mapping between ranges of network QoS
characteristics values and the respective linguistic terms for the VoIP service.
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68. PhD Thesis of Emmanouil Skondras, Department of Informatics, University of Piraeus
Computational Complexity of the
Proposed Approach
• The VHO initiation subprocess requires constant time to complete its
tasks resulting in O(1).
• By performing simple checks against predefined thresholds.
• The network selection phase introduces a O(n2) complexity.
• Due to the weighting and normalization of n x m decision matrices.
• Similar complexities are introduced by other handover algorithms
proposed in the research literature.
The novelty in our approach is that most of the computational
complexity is performed at the Cloud/Fog infrastructure.
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69. PhD Thesis of Emmanouil Skondras, Department of Informatics, University of Piraeus
PF-ANP Example
- Network selection
• Then, these pairwise comparison decision matrices are used to evaluate the priority vectors of
criteria and form the supermatrix per service type and SLA
• Subsequently, the weighted supermatrices and finally the limited supermatrices are obtained.
• Indicatively, for the SLA1 NAV service, the initial supermatrix:
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70. PhD Thesis of Emmanouil Skondras, Department of Informatics, University of Piraeus
PF-ANP Example
- Network selection
• Then, these pairwise comparison decision matrices are used to evaluate the priority vectors of
criteria and form the supermatrix per service type and SLA
• Subsequently, the weighted supermatrices and finally the limited supermatrices are obtained.
• Indicatively, for the SLA1 NAV service, the weighted supermatrix:
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71. PhD Thesis of Emmanouil Skondras, Department of Informatics, University of Piraeus
PF-ANP Example
- Network selection
• Then, these pairwise comparison decision matrices are used to evaluate the priority vectors of
criteria and form the supermatrix per service type and SLA
• Subsequently, the weighted supermatrices and finally the limited supermatrices are obtained.
• Indicatively, for the SLA1 NAV service, the limited supermatrix:
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72. PhD Thesis of Emmanouil Skondras, Department of Informatics, University of Piraeus
Simulation Setup
• Summary of the simulation parameters:
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73. PhD Thesis of Emmanouil Skondras, Department of Informatics, University of Piraeus
Simulation Setup
- Vehicles Distribution
• The number of vehicles that start
their movement from each LTE
network and their corresponding
velocities.
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74. PhD Thesis of Emmanouil Skondras, Department of Informatics, University of Piraeus
• The number of vehicles that start
their movement from each WiMAX
network and their corresponding
velocities.
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Simulation Setup
- Vehicles Distribution
75. PhD Thesis of Emmanouil Skondras, Department of Informatics, University of Piraeus
• The number of vehicles that start
their movement from each WAVE
network and their corresponding
velocities.
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Simulation Setup
- Vehicles Distribution
76. PhD Thesis of Emmanouil Skondras, Department of Informatics, University of Piraeus
Simulation Setup
- Vehicles Distribution
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