Fuzzy Cells is a new technology that improves cell-edge performance in multi-carrier cellular systems. It does this by allowing user equipment to connect to component carriers from multiple base stations, blurring the boundaries between cells. This improves the average signal quality for cell-edge users compared to traditional single-connection systems. Fuzzy Cells requires less coordination between base stations than similar technologies like Coordinated Multi-Point, placing fewer demands on network interfaces. System simulations show that Fuzzy Cells can significantly increase both total cell throughput and crucial cell-edge throughput.
OPTIMIZATION OF 5G VIRTUAL-CELL BASED COORDINATED MULTIPOINT NETWORKS USING D...ijwmn
Providing seamless mobility and a uniform user experience, independent of location, is an important challenge for 5G wireless networks. The combination of Coordinated Multipoint (CoMP) networks and Virtual- Cells (VCs) are expected to play an important role in achieving high throughput independent of the mobile’s location by mitigating inter-cell interference and enhancing the cell-edge user throughput. Userspecific VCs will distinguish the physical cell from a broader area where the user can roam without the need for handoff, and may communicate with any Base Station (BS) in the VC area. However, this requires rapid decision making for the formation of VCs. In this paper, a novel algorithm based on a form of Recurrent Neural Networks (RNNs) called Gated Recurrent Units (GRUs) is used for predicting the triggering condition for forming VCs via enabling Coordinated Multipoint (CoMP) transmission. Simulation results, show that based on the sequences of Received Signal Strength (RSS) values of different mobile nodes used for training the RNN, the future RSS values from the closest three BSs can be accurately predicted using GRU, which is then used for making proactive decisions on enabling CoMP transmission and forming VCs.
Scheduling for interference mitigation using enhanced intercell interference ...eSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
Advanced antenna techniques and high order sectorization with novel network t...ijwmn
Mobile operators commonly use macro cells with trad
itional wide beam antennas for wider coverage in th
e
cell, but future capacity demands cannot be achieve
d by using them only. It is required to achieve max
imum
practical capacity from macro cells by employing hi
gher order sectorization and by utilizing all possi
ble
antenna solutions including smart antennas. This pa
per presents enhanced tessellation for 6-sector sit
es
and proposes novel layout for 12-sector sites. The
main target of this paper is to compare the perform
ance
of conventional wide beam antenna, switched beam sm
art antenna, adaptive beam antenna and different
network layouts in terms of offering better receive
d signal quality and user throughput. Splitting mac
ro cell
into smaller micro or pico cells can improve the ca
pacity of network, but this paper highlights the
importance of higher order sectorization and advanc
e antenna techniques to attain high Signal to
Interference plus Noise Ratio (SINR), along with im
proved network capacity. Monte Carlo simulations a
t
system level were done for Dual Cell High Speed Dow
nlink Packet Access (DC-HSDPA) technology with
multiple (five) users per Transmission Time Interva
l (TTI) at different Intersite Distance (ISD). The
obtained results validate and estimate the gain of
using smart antennas and higher order sectorization
with
proposed network layout.
Random access improvement for M2M communication in LTE-A using femtocellIJECEIAES
When an area is highly populated with Machine-to-Machine devices and all these devices attempt to access the Random Access Network Simultaneously, congestion is created on the network which degrades the performance of the network to other users. In this paper, the researchers are seeking to improve network accessibility by deploying more Femtocell into the network. They engaged the use of Extended Access Barring to restrict the M2M devices from accessing the network via macrocell eNB when a minimum load threshold is attained, thereby preventing the macrocell eNB from being congested. Deploying these Femtocells underneath the macrocell eNB comes with the issue of Inter-Cell Interference which nullifies any gains made by this deployment. The researchers employed Fractional Frequency Reuse and Complete Frequency Reuse schemes to mitigate the negative effects of ICI to augment the throughput of the network, improve the system capacity and enhanced the user experience within the network.
International Journal of Computational Engineering Research(IJCER) ijceronline
International Journal of Computational Engineering Research (IJCER) is dedicated to protecting personal information and will make every reasonable effort to handle collected information appropriately. All information collected, as well as related requests, will be handled as carefully and efficiently as possible in accordance with IJCER standards for integrity and objectivity.
A Novel Approach for Cell Selection and Synchronization in LTE-AdvancedT. L. Singal
Long Term Evolution (LTE) is the result of the standardization work done by the 3rd Generation Partnership Project (3GPP) to achieve a new high speed radio access in the mobile communications frame. Cell selection by a mobile UE is another issue in LTE. In particularly, an interesting challenge in the physical layer of LTE is how the mobile unit immediately after powering on, select a radio cell and locks on to it. More specifically, to understand how the mobile unit establishes the connection with the strongest cell station in surrounding region. To do this, the mobile unit has to overcome the challenges of estimating the channel to communicate with the cell site and frequency synchronization. To appropriately synchronize the mobile unit with the base station when multiple mobile unit are communicating with same receiver from various distances.
OPTIMIZATION OF 5G VIRTUAL-CELL BASED COORDINATED MULTIPOINT NETWORKS USING D...ijwmn
Providing seamless mobility and a uniform user experience, independent of location, is an important challenge for 5G wireless networks. The combination of Coordinated Multipoint (CoMP) networks and Virtual- Cells (VCs) are expected to play an important role in achieving high throughput independent of the mobile’s location by mitigating inter-cell interference and enhancing the cell-edge user throughput. Userspecific VCs will distinguish the physical cell from a broader area where the user can roam without the need for handoff, and may communicate with any Base Station (BS) in the VC area. However, this requires rapid decision making for the formation of VCs. In this paper, a novel algorithm based on a form of Recurrent Neural Networks (RNNs) called Gated Recurrent Units (GRUs) is used for predicting the triggering condition for forming VCs via enabling Coordinated Multipoint (CoMP) transmission. Simulation results, show that based on the sequences of Received Signal Strength (RSS) values of different mobile nodes used for training the RNN, the future RSS values from the closest three BSs can be accurately predicted using GRU, which is then used for making proactive decisions on enabling CoMP transmission and forming VCs.
Scheduling for interference mitigation using enhanced intercell interference ...eSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
Advanced antenna techniques and high order sectorization with novel network t...ijwmn
Mobile operators commonly use macro cells with trad
itional wide beam antennas for wider coverage in th
e
cell, but future capacity demands cannot be achieve
d by using them only. It is required to achieve max
imum
practical capacity from macro cells by employing hi
gher order sectorization and by utilizing all possi
ble
antenna solutions including smart antennas. This pa
per presents enhanced tessellation for 6-sector sit
es
and proposes novel layout for 12-sector sites. The
main target of this paper is to compare the perform
ance
of conventional wide beam antenna, switched beam sm
art antenna, adaptive beam antenna and different
network layouts in terms of offering better receive
d signal quality and user throughput. Splitting mac
ro cell
into smaller micro or pico cells can improve the ca
pacity of network, but this paper highlights the
importance of higher order sectorization and advanc
e antenna techniques to attain high Signal to
Interference plus Noise Ratio (SINR), along with im
proved network capacity. Monte Carlo simulations a
t
system level were done for Dual Cell High Speed Dow
nlink Packet Access (DC-HSDPA) technology with
multiple (five) users per Transmission Time Interva
l (TTI) at different Intersite Distance (ISD). The
obtained results validate and estimate the gain of
using smart antennas and higher order sectorization
with
proposed network layout.
Random access improvement for M2M communication in LTE-A using femtocellIJECEIAES
When an area is highly populated with Machine-to-Machine devices and all these devices attempt to access the Random Access Network Simultaneously, congestion is created on the network which degrades the performance of the network to other users. In this paper, the researchers are seeking to improve network accessibility by deploying more Femtocell into the network. They engaged the use of Extended Access Barring to restrict the M2M devices from accessing the network via macrocell eNB when a minimum load threshold is attained, thereby preventing the macrocell eNB from being congested. Deploying these Femtocells underneath the macrocell eNB comes with the issue of Inter-Cell Interference which nullifies any gains made by this deployment. The researchers employed Fractional Frequency Reuse and Complete Frequency Reuse schemes to mitigate the negative effects of ICI to augment the throughput of the network, improve the system capacity and enhanced the user experience within the network.
International Journal of Computational Engineering Research(IJCER) ijceronline
International Journal of Computational Engineering Research (IJCER) is dedicated to protecting personal information and will make every reasonable effort to handle collected information appropriately. All information collected, as well as related requests, will be handled as carefully and efficiently as possible in accordance with IJCER standards for integrity and objectivity.
A Novel Approach for Cell Selection and Synchronization in LTE-AdvancedT. L. Singal
Long Term Evolution (LTE) is the result of the standardization work done by the 3rd Generation Partnership Project (3GPP) to achieve a new high speed radio access in the mobile communications frame. Cell selection by a mobile UE is another issue in LTE. In particularly, an interesting challenge in the physical layer of LTE is how the mobile unit immediately after powering on, select a radio cell and locks on to it. More specifically, to understand how the mobile unit establishes the connection with the strongest cell station in surrounding region. To do this, the mobile unit has to overcome the challenges of estimating the channel to communicate with the cell site and frequency synchronization. To appropriately synchronize the mobile unit with the base station when multiple mobile unit are communicating with same receiver from various distances.
Planning Non Line-of-Sight Wireless Backhaul NetworksFrank Rayal
This white paper provides an overview of the planning and design of Non-line-of-sight (NLOS) wireless backhaul systems. NLOS systems can be deployed anywhere very quickly and as a result provide a very cost effective solution both in terms of capital and operational expenditures than current wireless and wireline solutions that are significantly more expensive. The design of NLOS backhaul network is different from that of LOS microwave since detailed path analysis is no longer required. Rather, planning tools are used to provide an estimate of the performance at a location where small cell is desired. The paper sets the fundamentals of NLOS wireless backhaul network design and provides an example of how a planning tool can be used in this regard.
Wimax technology has reshaped the framework of broadband wireless internet
service. It provides the internet service to unconnected or detached areas such as east South
Africa, rural areas of America and Asia region. Full duplex helpers employed with one of
the relay stations selection and indexing method that is Randomized Distributed Space Time
are used to expand the coverage area of primary Wimax station. The basic problem was
identified at cell edge due to weather conditions (rain, fog), insertion of destruction because
of multiple paths in the same communication channel and due to interference created by
other users in that communication. It is impractical task for the receiver station to decode
the transmitted signal successfully at the cell edges, which increases the high packet loss and
retransmissions. But Wimax is a outstanding technology which is used for improving the
quality of internet service and also it offers various services like Voice over Internet
Protocol, Video conferencing and Multimedia broadcast etc where a little delay in packet
transmission can cause a big loss in the communication. Even setup and initialization of
another Wimax station nearer to each other is not a good alternate, where any mobile
station can easily handover to another base station if it gets a strong signal from other one.
But in rural areas, for few numbers of customers, installation of base station nearer to each
other is costlier task. In this review article, we present a scheme using R-DSTC technique to
choose and select helpers (relay nodes) randomly to expand the coverage area and help to
mobile station as a helper to provide secure communication with base station. In this work,
we use full duplex helpers for better utilization of bandwidth.
Enhanced fractional frequency reuse approach for interference mitigation in f...journalBEEI
Small cell networks are expected to heavily be deployed in wireless communication networks due to it ability to enhance signals quality and spectrum utilisation. However, interference is posing a major threat to wireless communication especially cellular femtocell networks whereby its performance is degraded in dense deployment areas. For this reason, an enhanced fractional frequency reuse approach is proposed in this paper to mitigate the interference in femtocell networks. This is achieved by dividing the service area and frequency into three regions and three sets whereby each set is allocated different frequency set. The femtocell location is later obtained and assigned frequency in accordance to the region. The proposed approach helps in reducing the interference, boost the signal to interference plus noise (SINR), and enhance the throughput.
The continuously increasing demand for higher data rates results in increasing network density, so that inter-cell interference is becoming the most serious obstacle towards spectral efficiency Considering that radio resources are limited and expensive, new techniques are required for the next generation of cellular networks, to enable a more efficient way to allocate and use radio resources In this framework, we target the design of a frequency reuse 1 scheme, which exploits the coordination between base stations as a tool to mitigate inter-cell interference Aamir Nazir Beigh | Er. Prabhjot Kaur "Inter-Cell Interference" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-2 | Issue-6 , October 2018, URL: http://www.ijtsrd.com/papers/ijtsrd18406.pdf
Capacity planning(CP) determines operational expenditure, capital expenditure and long-term performance of the system hence it is the most important phase in the life cycle of a cellular system. For the past three decades, capacity planning problems have studied for all generations of the cellular system. So, to increase the capacity of the network in future we focus on small cells of cell structure. Cellular network includes the variety of different cell sizes and types, heterogeneous networks, control, and data plane split architectures, coordinated multipoint, massive multiple inputs multiple outputs.
The objective of this presentation is to focus on traditional deployment reviews and identify future opportunities, challenges, and trends in detail. More specifically we investigate the future capacity planning by reviewing the CP process including its objective input and output parameter to an optimization process and the CP phases.
Comprehensive investigation of coherent optical OFDM-RoF employing 16QAM exte...IJECEIAES
Given the growing need for long haul transmission that requires a high rate of data, the orthogonal frequency division multiplexing scheme (OFDM), is regarded as a technique with high potentials for high-capacity optical networks. OFDM transmits over both optical and wireless channels, with the data distributed over a huge amount of the subcarrier, and the data is distributed over a huge number of subcarriers. OFDM achieves RF signal for a long-haul transmitting by utilizing Radio over Fiber (RoF) system, which is known to produce higher orthogonality of the OFDM modulated signal designed for the wireless network. RoF systems comprise of heterogeneous networks designed through the use of wireless and optical links. The aim of this paper is to carry out an investigation of the performance of the external modulation in RoF links, while analyzing the shortcomings caused by the various elements of the optical system. The Mach–Zehnder modulator (MZM) can be applied in external modulation, and exhibits a more robust performance when implemented with the OFDM modulation technique.
Energy consumption in cellular networks has rapidly
moved from an area of low priority to a focus area of the
whole telecommunication community. When analysing the
energy consumption of wireless access networks it becomes clear that in order reduce the total energy usage it is important to concentrate the efforts on the most abundant network nodes namely the base stations (BS).
This paper discusses how energy consumption can be
significantly reduced in mobile networks by introducing
discontinuous transmission (DTX) on the base station side.
RF Planning and Optimization in GSM and UMTS NetworksApurv Agrawal
The report covers various aspects involved in improving the network coverage as well as the parameters used in planning of new network sites for GSM and UMTS networks.
Las campanas México ppc nos permite implementar y optimizar las campañas publicitarias de nuestros clientes para conseguir las mejores posiciones en los diferentes resultados de búsquedas.
Planning Non Line-of-Sight Wireless Backhaul NetworksFrank Rayal
This white paper provides an overview of the planning and design of Non-line-of-sight (NLOS) wireless backhaul systems. NLOS systems can be deployed anywhere very quickly and as a result provide a very cost effective solution both in terms of capital and operational expenditures than current wireless and wireline solutions that are significantly more expensive. The design of NLOS backhaul network is different from that of LOS microwave since detailed path analysis is no longer required. Rather, planning tools are used to provide an estimate of the performance at a location where small cell is desired. The paper sets the fundamentals of NLOS wireless backhaul network design and provides an example of how a planning tool can be used in this regard.
Wimax technology has reshaped the framework of broadband wireless internet
service. It provides the internet service to unconnected or detached areas such as east South
Africa, rural areas of America and Asia region. Full duplex helpers employed with one of
the relay stations selection and indexing method that is Randomized Distributed Space Time
are used to expand the coverage area of primary Wimax station. The basic problem was
identified at cell edge due to weather conditions (rain, fog), insertion of destruction because
of multiple paths in the same communication channel and due to interference created by
other users in that communication. It is impractical task for the receiver station to decode
the transmitted signal successfully at the cell edges, which increases the high packet loss and
retransmissions. But Wimax is a outstanding technology which is used for improving the
quality of internet service and also it offers various services like Voice over Internet
Protocol, Video conferencing and Multimedia broadcast etc where a little delay in packet
transmission can cause a big loss in the communication. Even setup and initialization of
another Wimax station nearer to each other is not a good alternate, where any mobile
station can easily handover to another base station if it gets a strong signal from other one.
But in rural areas, for few numbers of customers, installation of base station nearer to each
other is costlier task. In this review article, we present a scheme using R-DSTC technique to
choose and select helpers (relay nodes) randomly to expand the coverage area and help to
mobile station as a helper to provide secure communication with base station. In this work,
we use full duplex helpers for better utilization of bandwidth.
Enhanced fractional frequency reuse approach for interference mitigation in f...journalBEEI
Small cell networks are expected to heavily be deployed in wireless communication networks due to it ability to enhance signals quality and spectrum utilisation. However, interference is posing a major threat to wireless communication especially cellular femtocell networks whereby its performance is degraded in dense deployment areas. For this reason, an enhanced fractional frequency reuse approach is proposed in this paper to mitigate the interference in femtocell networks. This is achieved by dividing the service area and frequency into three regions and three sets whereby each set is allocated different frequency set. The femtocell location is later obtained and assigned frequency in accordance to the region. The proposed approach helps in reducing the interference, boost the signal to interference plus noise (SINR), and enhance the throughput.
The continuously increasing demand for higher data rates results in increasing network density, so that inter-cell interference is becoming the most serious obstacle towards spectral efficiency Considering that radio resources are limited and expensive, new techniques are required for the next generation of cellular networks, to enable a more efficient way to allocate and use radio resources In this framework, we target the design of a frequency reuse 1 scheme, which exploits the coordination between base stations as a tool to mitigate inter-cell interference Aamir Nazir Beigh | Er. Prabhjot Kaur "Inter-Cell Interference" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-2 | Issue-6 , October 2018, URL: http://www.ijtsrd.com/papers/ijtsrd18406.pdf
Capacity planning(CP) determines operational expenditure, capital expenditure and long-term performance of the system hence it is the most important phase in the life cycle of a cellular system. For the past three decades, capacity planning problems have studied for all generations of the cellular system. So, to increase the capacity of the network in future we focus on small cells of cell structure. Cellular network includes the variety of different cell sizes and types, heterogeneous networks, control, and data plane split architectures, coordinated multipoint, massive multiple inputs multiple outputs.
The objective of this presentation is to focus on traditional deployment reviews and identify future opportunities, challenges, and trends in detail. More specifically we investigate the future capacity planning by reviewing the CP process including its objective input and output parameter to an optimization process and the CP phases.
Comprehensive investigation of coherent optical OFDM-RoF employing 16QAM exte...IJECEIAES
Given the growing need for long haul transmission that requires a high rate of data, the orthogonal frequency division multiplexing scheme (OFDM), is regarded as a technique with high potentials for high-capacity optical networks. OFDM transmits over both optical and wireless channels, with the data distributed over a huge amount of the subcarrier, and the data is distributed over a huge number of subcarriers. OFDM achieves RF signal for a long-haul transmitting by utilizing Radio over Fiber (RoF) system, which is known to produce higher orthogonality of the OFDM modulated signal designed for the wireless network. RoF systems comprise of heterogeneous networks designed through the use of wireless and optical links. The aim of this paper is to carry out an investigation of the performance of the external modulation in RoF links, while analyzing the shortcomings caused by the various elements of the optical system. The Mach–Zehnder modulator (MZM) can be applied in external modulation, and exhibits a more robust performance when implemented with the OFDM modulation technique.
Energy consumption in cellular networks has rapidly
moved from an area of low priority to a focus area of the
whole telecommunication community. When analysing the
energy consumption of wireless access networks it becomes clear that in order reduce the total energy usage it is important to concentrate the efforts on the most abundant network nodes namely the base stations (BS).
This paper discusses how energy consumption can be
significantly reduced in mobile networks by introducing
discontinuous transmission (DTX) on the base station side.
RF Planning and Optimization in GSM and UMTS NetworksApurv Agrawal
The report covers various aspects involved in improving the network coverage as well as the parameters used in planning of new network sites for GSM and UMTS networks.
Las campanas México ppc nos permite implementar y optimizar las campañas publicitarias de nuestros clientes para conseguir las mejores posiciones en los diferentes resultados de búsquedas.
Cablexa, a preferred manufacturer of high quanlity cables and connectivity products, offers a wide range of solutions and unrivaled customer service for the electronics and data communications industries. The company's product portfolio includes cable assemblies, connectors, adapters, computer networking components, and custom products, as well as optical fiber communication equipments which include ethernet switches, optical transceivers, fiber optic patch cord, WDM system, optical protection system, optical Bypass system etc.
Digital communication lab lectures
Engineering + education purpose
This series of LAB lectures was prepared for the third class of computer networks department IN AL-Bani University College / Baghdad / Iraq.
This series of lectures is not finished yet; I will complete it and update the PDF as soon as possible.
You will find the theory and tutorial lectures in the same website
Forgive me for any wrong by mistake.
My regards
Marwa Moutaz/ M.Sc. studies of Communication Engineering / University of Technology/ Bagdad / Iraq
OPTIMIZATION OF 5G VIRTUAL-CELL BASED COORDINATED MULTIPOINT NETWORKS USING D...ijwmn
Providing seamless mobility and a uniform user experience, independent of location, is an important challenge for 5G wireless networks. The combination of Coordinated Multipoint (CoMP) networks and Virtual- Cells (VCs) are expected to play an important role in achieving high throughput independent of the mobile’s location by mitigating inter-cell interference and enhancing the cell-edge user throughput. Userspecific VCs will distinguish the physical cell from a broader area where the user can roam without the need for handoff, and may communicate with any Base Station (BS) in the VC area. However, this requires rapid decision making for the formation of VCs. In this paper, a novel algorithm based on a form of Recurrent Neural Networks (RNNs) called Gated Recurrent Units (GRUs) is used for predicting the triggering condition for forming VCs via enabling Coordinated Multipoint (CoMP) transmission.
Simulation results, show that based on the sequences of Received Signal Strength (RSS) values of different mobile nodes used for training the RNN, the future RSS values from the closest three BSs can be accurately predicted using GRU, which is then used for making proactive decisions on enabling CoMP transmission and forming VCs.
Inter-cell Interference Management Technique for Multi-Cell LTE-A Network IJECEIAES
In modern cellular system such as LTE Advanced (LTE-A), frequency reuse scheme is targeted to be applied to fulfill the requirement of high capacity broadband access and high spectrum efficiency. But this kind of frequency planning may lead to the worse inter-cell interference (ICI) level experienced especially by a user located at the cell edge. Soft Frequency Reuse (SFR) is considered as an effective way to mitigate inter-cell interference and maintain capacity. We propose a power division SFR, known as multi level SFR technique to minimize ICI in a designed LTE-A network for sub-urban environment. Service area of LTE-A network was first developed to deploy particular number of eNB by using LTE network planning tools in the frequency of 1800 MHz with the use of SISO (Single Input Single Output) antennas. Coverage dimensioning and propagation consideration determine LTE-A parameters which were used in the simulation. Monte carlo simulation is executed to examine the performance of SFR for LTE-A downlink transmission to address different power ratio and traffic loads problem. Both performance of cell edge users and overall cell performance are evaluated in terms of CINR, BLER, and throughput. Performance with SFR is also compared with the classical frequency reuse one and three.
Advanced antenna techniques and high order sectorization with novel network t...ijwmn
Mobile operators commonly use macro cells with traditional wide beam antennas for wider coverage in the
cell, but future capacity demands cannot be achieved by using them only. It is required to achieve maximum
practical capacity from macro cells by employing higher order sectorization and by utilizing all possible
antenna solutions including smart antennas. This paper presents enhanced tessellation for 6-sector sites
and proposes novel layout for 12-sector sites. The main target of this paper is to compare the performance
of conventional wide beam antenna, switched beam smart antenna, adaptive beam antenna and different
network layouts in terms of offering better received signal quality and user throughput. Splitting macro cell
into smaller micro or pico cells can improve the capacity of network, but this paper highlights the
importance of higher order sectorization and advance antenna techniques to attain high Signal to
Interference plus Noise Ratio (SINR), along with improved network capacity. Monte Carlo simulations at
system level were done for Dual Cell High Speed Downlink Packet Access (DC-HSDPA) technology with
multiple (five) users per Transmission Time Interval (TTI) at different Intersite Distance (ISD). The
obtained results validate and estimate the gain of using smart antennas and higher order sectorization with
proposed network layout.
Capacity Improvement of Cellular System Using Fractional Frequency Reuse (FFR)IJEEE
Today wireless communication is mostly used rather than wired communication, due to remote location reach ability, less fault occurrence, less time to commissioning and low cost etc. But wireless network has less frequency spectrum to cover the whole world. To improve the capacity of cellular system in a limited spectrum without major technological changes, frequency is reused in cells. But it offers interferences mostly for cell edge users. To solve the problem of spectral congestion and user capacity, fractional frequency reuse is used. This paper gives idea about different frequency reuse factors, fractional frequency reuse and super cell with sectoring to improve the capacity of cellular system.
Heterogeneous LTE Networks and Inter-Cell Interference Coordination - Dec 201...Eiko Seidel
Initial deployments of LTE networks are based on so-called homogeneous networks consisting of base stations providing basic coverage, called macro base stations. The concept of heterogeneous networks has recently attracted considerable attention to optimize performance particularly for unequal user or traffic distribution. Here, the layer of planned high-power macro eNBs is overlaid with layers of lower-power pico or femto eNBs that are deployed in a less well planed or even entirely uncoordinated manner. Such deployments can achieve significantly improved overall capacity and cell-edge performance and are often seen as the second phase in LTE network deployment.
This paper discusses the concept of heterogeneous networks as compared to homogeneous networks. It demonstrates the need for inter-cell interference coordination (ICIC) and outlines some ICIC methods that are feasible with release 8 /9 of the LTE standard. System-level simulation results illustrate the benefits of the various features discussed in the following.
Radio Resource Management for Eicic, Comp, Relaying and Back-hauls Techniques...ijwmn
Frequency reuse in cells is one of the strategies that LTE (Long Term Evolution) uses to maximize the spectrum efficiency. However, it leads to an interference among the cells, especially at the cell edges where the probability for a cell-edge user to be scheduled on a resource block that is being transmitted by the neighbouring cell is high; consequently, the interference is high. In-order to mitigate Inter-Cell Interference (ICI), Inter-Cell Interference Coordination (ICIC) was proposed by the Third Generation Partnership Project (3GPP) standards for the LTE network, and later on, the enhanced Inter-Cell Interference Coordination (eICIC) was proposed for the LTE-Advanced network. ICIC reduces cell-edge interference on traffic channels from neighbouring cells by the use of three interference reduction schemes that works in the power and frequency domain, and they are based on lowering the power of some channels to limit their reception to the users that are close to the base station, and by reducing the chance of frequency overlap. eICIC was proposed to handle ICI in Heterogeneous Network (HetNet) deployments. It reduces the interference on both the traffic and control channels. It uses power, frequency and also time domain to mitigate intra-frequency interference in HetNets. Another technique that was proposed by the 3GPP for the LTE-Advanced network that can reduce the ICI and improve the cell average and cell-edge user throughput is the Coordinated Multi-Point (CoMP) transmission/reception technique. CoMP can increase the cell average and cell edge user throughput in both the uplink and downlink transmission by joint scheduling and data processing in multiple cells/eNBs. Another technique that was proposed by the 3GPP for the LTE-Advanced network that can improve the LTE network coverage in difficult conditions is to deploy Relay Nodes (RNs). In this paper, we survey Radio Resource Management (RRM) for some of the techniques that are used with LTE-A. The included techniques in this paper are; the ICIC, eICIC, CoMP, Relaying and Back-hauls. We start by explaining the concepts of these techniques. Then, by summarizing the radio resource management approaches that were proposed in the literature for these techniques. And finally, we provide some concluding remarks in the last section.
RADIO RESOURCE MANAGEMENT FOR EICIC, COMP, RELAYING AND BACK-HAULS TECHNIQUES...ijwmn
Frequency reuse in cells is one of the strategies that LTE (Long Term Evolution) uses to maximize the
spectrum efficiency. However, it leads to an interference among the cells, especially at the cell edges where
the probability for a cell-edge user to be scheduled on a resource block that is being transmitted by the
neighbouring cell is high; consequently, the interference is high. In-order to mitigate Inter-Cell
Interference (ICI), Inter-Cell Interference Coordination (ICIC) was proposed by the Third Generation
Partnership Project (3GPP) standards for the LTE network, and later on, the enhanced Inter-Cell
Interference Coordination (eICIC) was proposed for the LTE-Advanced network. ICIC reduces cell-edge
interference on traffic channels from neighbouring cells by the use of three interference reduction schemes
that works in the power and frequency domain, and they are based on lowering the power of some channels
to limit their reception to the users that are close to the base station, and by reducing the chance of
frequency overlap. eICIC was proposed to handle ICI in Heterogeneous Network (HetNet) deployments. It
reduces the interference on both the traffic and control channels. It uses power, frequency and also time
domain to mitigate intra-frequency interference in HetNets. Another technique that was proposed by the
3GPP for the LTE-Advanced network that can reduce the ICI and improve the cell average and cell-edge
user throughput is the Coordinated Multi-Point (CoMP) transmission/reception technique. CoMP can
increase the cell average and cell edge user throughput in both the uplink and downlink transmission by
joint scheduling and data processing in multiple cells/eNBs. Another technique that was proposed by the
3GPP for the LTE-Advanced network that can improve the LTE network coverage in difficult conditions is
to deploy Relay Nodes (RNs). In this paper, we survey Radio Resource Management (RRM) for some of the
techniques that are used with LTE-A. The included techniques in this paper are; the ICIC, eICIC, CoMP,
Relaying and Back-hauls. We start by explaining the concepts of these techniques. Then, by summarizing
the radio resource management approaches that were proposed in the literature for these techniques. And
finally, we provide some concluding remarks in the last section.
Powerful business model for fixed wireless data using outdoor antennas - PaperAndre Fourie
Paper presented at the 2nd Africa Radio Comms Conference in Johannesburg - Nov 2015
By Andre Fourie
The revenue that can be generated by an LTE base station is influenced by the quality of the signal received by the customer premise equipment (CPE). Most CPE come with omni-directional indoor antennas, but have provision for the connection to external antennas.
Substituting the indoor antennas for directional outdoor antennas has a marked effect on the data transfer speeds of the network. There are two reasons for this. Firstly, outdoor antennas are physically larger than their indoor counterparts and thus have a higher gain. The increase in antenna gain translates directly to an increase in received signal strength. The second advantage is that the outdoor antenna sits in an environment that has much better propagating properties than the indoor antenna. Tests have shown that data speeds 3-5 times faster are possible using external antennas compared to indoor antennas.
It is shown, using a primitive financial model that fairly large financial gains can be made by equipping CPE devices with external antennas.
Scheduling for interference mitigation using enhanced intercell interference ...eSAT Journals
Abstract Deployment of low power base station (pico) in macro cell is a key for providing high data rates. Cell range expansion is one of the features of LTE-advanced where low power base station in a heterogeneous network can increase their coverage area and neighboring cells can offload users to low power base station to reduce overload in macro cell. This presents a very challenging multi-user communication problem. Co-channel deployed Het-Net will experience interference between pico and macro. The main challenge of pico cells embedded into a macro cell is to let more users profit from the additional bandwidth introduced into the network. Enhanced Inter-cell Interference Coordination (eICIC) has been introduced to solve interference problem. Scheduling for eICIC is used to provide best solution for interference mitigation, overload in macro cell, fairness in resource usage by users. In this paper we have analyzed Round Robin scheduling for eICIC, results prove that fairness is maintained between users and throughput has been improved. Key Words: LTE - Long term Evolution, UE - User Equipment, eNB – eNodeB.
Promoting fractional frequency reuse performance for combating pilot contami...IJECEIAES
Massive multiple-input multiple-output (MIMO) improves spectrum efficiency by increasing the capacity of the wireless structure. Therefore, massive MIMO is promising for fifth generation (5G) wireless communications. In massive MIMO, channel estimation is a crucial part that should achieve reliable performance. Pilots are sent from the end-users to be used for estimating the channel. However, the problem of interference in pilot contamination affects the performance for cell-edge users. Specifically, pilot contamination appears when the same pilot sequence is utilized at the same time by more than one terminal. This lead to an inaccurate estimation of the channel. Consequently, the decoded data will not be reliable. For mitigating these pilot contamination effects, an enhanced fractional frequency reuse (eFFR) scheme is proposed that uses an algorithm in the allocation of pilot sequences to end users’ devices based on the locations of the users from the target base station (BS). The simulation results exhibit that the proposed scenario outweighs the traditional FFR within both signal to interference, and noise ratio (SINR), and capacity. Consequently, the suggested scenario enhances the performance of more than 80% of the cell terminals and the other 20% of the terminals have a slightly lower performance compared to the FFR.
Spectrum Sharing between Cellular and Wi-Fi Networks based on Deep Reinforcem...IJCNCJournal
Recently, mobile traffic is growing rapidly and spectrum resources are becoming scarce in wireless networks. Due to this, the wireless network capacity will not meet the traffic demand. To address this problem, using cellular systems in an unlicensed spectrum emerged as an effective solution. In this case, cellular systems need to coexist with Wi-Fi and other systems. For that, we propose an efficient channel assignment method for Wi-Fi AP and cellular NB, based on the DRL method. To train the DDQN model, we implement an emulator as an environment for spectrum sharing in densely deployed NB and APs in wireless heterogeneous networks. Our proposed DDQN algorithm improves the average throughput from 25.5% to 48.7% in different user arrival rates compared to the conventional method. We evaluated the generalization performance of the trained agent, to confirm channel allocation efficiency in terms of average throughput under the different user arrival rates.
Spectrum Sharing between Cellular and Wi-Fi Networks based on Deep Reinforcem...IJCNCJournal
Recently, mobile traf ic is growing rapidly and spectrum resources are becoming scarce in wireless
networks. Due to this, the wireless network capacity will not meet the traf ic demand. To address this
problem, using cellular systems in an unlicensed spectrum emerged as an ef ective solution. In this case,
cellular systems need to coexist with Wi-Fi and other systems. For that, we propose an ef icient channel
assignment method for Wi-Fi AP and cellular NB, based on the DRL method. To train the DDQN model,
we implement an emulator as an environment for spectrum sharing in densely deployed NB and APs in
wireless heterogeneous networks. Our proposed DDQN algorithm improves the average throughput from
25.5% to 48.7% in dif erent user arrival rates compared to the conventional method. We evaluated the
generalization performance of the trained agent, to confirm channel allocation ef iciency in terms of
average throughput under the dif erent user arrival rates
Modeling, Analysis, and Design of Multi-tier and Cognitive Cellular Wireless ...indonesiabelajar
Abstract: Multi-tier architecture with small cells such as femtocells, picocells, macrocells, and metrocells, overlaid with traditional macrocells is considered as a promising option to improve the network coverage and capacity of the next generation cellular wireless networks. Also, in such multi-tier networks, cognitive radio concepts will likely to be used by these small cells to improve the radio spectrum utilization. In this context, modeling, analysis, and design of multi-tier and cognitive cellular networks is increasingly attracting the attention of the research community. Recently, stochastic geometry models have been shown to provide tractable yet accurate performance bounds for multi-tier and cognitive cellular wireless networks. Given the need for interference characterization in multi-tier cellular networks, stochastic geometry models provide high potential to simplify their modeling and provide insights into their design. In this seminar, I will present a review of the stochastic geometry models for single-tier as well as multi-tier and cognitive cellular wireless networks. I will also present a taxonomy based on the target network model, the point process used, and the performance evaluation technique. To this end, I will discuss the open research challenges and future research directions.
Prof Ekram Hossain
B ENCHMARKING OF C ELL T HROUGHPUT U SING P ROPORTIONAL F AIR S CHEDULE...ijwmn
The proportional fair (PF) scheduling algorithm com
promises between cell throughput and fairness. Many
research findings have been published by various re
searchers about PF algorithm based on mathematical
model and simulations. In this paper we have taken
the practical route to analyse the algorithm based
on
three types of subscription. In this benchmarking s
tudy, the user subscriptions are differentiated as
Gold,
Silver and Bronze schemes and they are provisioned
with certain throughputs. Apart from subscriptions
plans, the channel condition also plays a major rol
e in determining the throughput. So in order to ens
ure
fairness among different subscriptions even in the
bad channel conditions and to deliver the provision
ed
throughputs certain priorities are attached with th
e subscriptions. As per the subscription plans Gold
subscribers are assigned with 50% of the speed offe
red by the network as maximum based on CAT3 speed
(100 Mbps in DL and 50 Mbps in UL), Silver is assig
ned with 25% of the max speed and Bronze is
assigned with 12% of the max speed. The priorities
assigned to subscribers determines the fairness in
the
unfavourable channel conditions - Bronze (high), Si
lver and Gold (medium). In this paper, an
benchmarking tests have been performed with all of
three types of subscribers for nearly two hours in
the
live single cell network without any heterogeneous
cells influencing it. Furthermore, the results are
compared with the simulation results.
Co channel deployment cross layer approach for lte heterogeneous networkseSAT Journals
Abstract This paper presents a method of developing a stairs climbing robot with self balancing chair mounted on the top of the robot. It is one of the major task in the field of Mechatronics require a mechanical arrangement and electronics based control of the actuators using wireless technology. In most of the mechanism it is hard to maintain the slope position of the seat while carrying some goods on it, so taking in action all these condition the robot is to design and develop [1] which will climb on the stairs and adjust themselves as per environmental condition. Keywords:- Accelerometer, CC2500, Touch Screen, Microcontroller, Relays
Co channel deployment cross layer approach for lte heterogeneous networkseSAT Journals
Abstract
Nowadays Heterogeneous Networks (HetNets) are envisioned as the major capacity and performance enhancement enablers by
means of increasing the spectral efficiency per unit area. In LTE, since pico cells typically share the frequency band as macro
cells, the performance of a low-power pico access node could be severely impaired by interference from a high power macro
access node. In co-channel deployment it is necessary to balance the load and Share the resources between the different layers,
where macro and pico cells share the same carrier frequency. In this case, one of the main problem that need to be addressed in
order to improve the network performance is: Cell selection. For this reason we propose a throughput-based cell selection
algorithm. This algorithm targets to optimize the throughput of each user.
Keywords: LTE, Heterogeneous Networks, Macro cell, Pico cell and Co-Channel Deployment.
Hybrid optimization of pumped hydro system and solar- Engr. Abdul-Azeez.pdffxintegritypublishin
Advancements in technology unveil a myriad of electrical and electronic breakthroughs geared towards efficiently harnessing limited resources to meet human energy demands. The optimization of hybrid solar PV panels and pumped hydro energy supply systems plays a pivotal role in utilizing natural resources effectively. This initiative not only benefits humanity but also fosters environmental sustainability. The study investigated the design optimization of these hybrid systems, focusing on understanding solar radiation patterns, identifying geographical influences on solar radiation, formulating a mathematical model for system optimization, and determining the optimal configuration of PV panels and pumped hydro storage. Through a comparative analysis approach and eight weeks of data collection, the study addressed key research questions related to solar radiation patterns and optimal system design. The findings highlighted regions with heightened solar radiation levels, showcasing substantial potential for power generation and emphasizing the system's efficiency. Optimizing system design significantly boosted power generation, promoted renewable energy utilization, and enhanced energy storage capacity. The study underscored the benefits of optimizing hybrid solar PV panels and pumped hydro energy supply systems for sustainable energy usage. Optimizing the design of solar PV panels and pumped hydro energy supply systems as examined across diverse climatic conditions in a developing country, not only enhances power generation but also improves the integration of renewable energy sources and boosts energy storage capacities, particularly beneficial for less economically prosperous regions. Additionally, the study provides valuable insights for advancing energy research in economically viable areas. Recommendations included conducting site-specific assessments, utilizing advanced modeling tools, implementing regular maintenance protocols, and enhancing communication among system components.
Water scarcity is the lack of fresh water resources to meet the standard water demand. There are two type of water scarcity. One is physical. The other is economic water scarcity.
Welcome to WIPAC Monthly the magazine brought to you by the LinkedIn Group Water Industry Process Automation & Control.
In this month's edition, along with this month's industry news to celebrate the 13 years since the group was created we have articles including
A case study of the used of Advanced Process Control at the Wastewater Treatment works at Lleida in Spain
A look back on an article on smart wastewater networks in order to see how the industry has measured up in the interim around the adoption of Digital Transformation in the Water Industry.
1. Fuzzy Cells
• Cellular systems evolution is making great
strides in offering higher data rates, but there is
a growing gap between peak and average rates
• Interference limits uniform performance and
capacity across the cell and at cell-edge
• Fuzzy Cells technology improves cell-edge
performance with higher throughput and
better coverage
• With Fuzzy Cells, service providers can
drastically improve user experience across
the entire network
Fuzzy Cells
Improving cell-edge performance
in multi-carrier cellular systems
White Paper
2. Fuzzy Cells
Introduction
Over the past ten years, improvements in cellular technologies have been characterized by dramatic increases in peak data rates.
Figure 1 illustrates substantial increases in theoretical peak data rates for 3GPP cellular systems - evolving from sub 1 Mbps to in
excess of 100 Mbps. However, technology and standards have not placed enough emphasis on ensuring more uniform data rates
and consistent user experience across the entire cell.
one
Figure 1 3GPP Peak Data Rates Roadmap
100 Mbps
DL R’99-384k
HSDPA 1.8M
HSDPA 3.6M
HSDPA 7.2M
HSDPA 14.4M
MIMO 2x2 28M
MIMO/64QAM 42M
DL LTE(20MHz) 300M
DL LTE(20MHz) 140M
UL LTE(10MHz) 50M
Source: 3G Americas’ Member Company Contributions
UL LTE(10MHz) 25M
Uplink Speeds
2004 2005 2006 2007 2008 2009 2010 2011 2012 2013
HSUPA/16QAM 11M
• HSPA DL and UL peak throughputs expected
to double every year on average
• Limitations not induced by the technology itself
but time frames required to upgrade
infrastructure and transport networks, obtain
devices with corresponding capabilities and
interoperability tests
HSUPA 5.6M
HSUPA 1.5M
UL R’99 384k
20 Mbps
10 Mbps
Downlink Speeds
10 Mbps
1 Mbps
100 kbps
3. Fuzzy Cells
Figure 2 Peak vs. Average Cell Efficiency for Major Cellular Systems
Peak Efficiency Average Efficiency
Source: Agilent presentation + IMT submissions
100
bits/sec/Hz
10
1
0.1
0.01
AMPS GSM GPRS EDGE W-CDMA HSDPA 802.16e LTE 802.16m LTEA
11x
4x
It is imperative that service providers find solutions today for this growing spectral efficiency gap, which will become noticeably
more severe over the next several years due to the expected explosive growth in demand for wireless data. In the 2010 National
Broadband Plan wireless data demand will grow anywhere from 20x to 45x by 2014. This growth will be driven by the rapid shift
from voice to data traffic, resulting from the increasing popularity of smartphones, netbooks and mobile consumer electronics
(CE) devices. Wireless users will expect the same high degree of Quality of Experience (QoE) for data services as they currently
demand for voice service, which will be a key differentiator among service providers. As with dropped voice calls and garbled
voice reception, slow internet access, poor video streaming experiences and interruptions in real time data services due to poor
cell throughput will also be motivators for churn. In order to overcome QoE challenges, caused by poor cell-edge performance,
the traditional solution has been to reduce the size of existing cells through CAPEX/OPEX intensive cell-splitting. In addition to the
costs of adding physical cell sites, scarce and valuable spectrum resources are consumed as well, and networks may require some
re-planning to accommodate the new cells.
Regardless of the technology used, service providers will be faced with the challenge of providing exceptional user experience for
data services, just as they have had to do for voice services, in order to maintain and grow their data user subscriber base and
service revenues. Those who adequately address these challenges early-on, can use their higher levels of network quality as a
competitive differentiator. Today, wireless technology leaders use a more holistic approach to wireless network optimization by
developing new technologies that consider the Radio Access Network (RAN), Packet Core and Circuit Switched Core Networks
(CNs) together in contrast to the traditional focus on only optimizing each subsystem individually. Wireless network operators will
need to take advantage of these new developments in network technologies to find cost effective ways to meet the ever increasing
demand for capacity and higher levels of QoE across the entire cell area while ensuring a high level of customer satisfaction.
two
When it comes to average data rates across an entire cell, there is a growing gap between the peak rates and average rates. This
gap is more severe for users operating in poorer signal conditions or at the cell-edge. Figure 2 illustrates this gap by showing peak
vs. average cell efficiency over time for the evolution of cellular systems. Based on the present understanding of the requirements for
LTE-Advanced (LTE-A), this gap is projected to widen to an 11x difference when LTE-A is deployed.
4. Fuzzy Cells
Roadmap of Solutions for Cell-Edge Performance Gains
InterDigital has consistently been one of the key contributors to the 3GPP and IEEE wireless standards bodies in pushing
higher peak data rates. In addition, the company has an advanced roadmap of next generation cellular technologies, as shown
in Figure 3, that are expected to greatly improve cell edge throughput in order to address user experience across the entire cell.
Many aspects of this roadmap will form the foundation for InterDigital’s contributions to the 3GPP standard releases 11 and 12,
and relevant future releases. Some of these advanced technologies may not end up in a standard, and therefore present an
excellent opportunity for infrastructure OEMs and operators to create a competitive advantage with proprietary solutions that
deliver superior and differentiated network performance.
Figure 3 InterDigital’s Roadmap of Next Generation Cellular Technologies
Short Term
(0-5 Years)
Mid Term
(5-10 Years)
Long Term
(10 Years)
Spectral Efficiency Solutions
Fuzzy Cells
Coordinated MultiPoint (E-CoMP)
Spectrum Opportunities
Unlicensed/Lightly Licensed Spectrum
High Frequency Solutions
Advanced Topologies
Enhanced Relays
Cellular-Controlled Direct Mobile-to-Mobile Communications
three
5. Fuzzy Cells
Fuzzy Cells - Enhancing User Experience at Cell-Edge
In current and evolving cellular systems, such as Long Term Evolution (LTE) and Multi-Carrier High Speed Packet Access
(MC-HSPA), the user experience at cell-edge is limited by interference from other cells. In the standard frequency reuse-1 case,
the cell-edge downlink (DL) Signal-to-Interference-plus-Noise-Ratio (SINR) can be several dB below zero, limiting such users’
throughput. In LTE systems that comply with the 3GPP Release 8 standards version, the 3GPP specifications are effectively single
carrier systems and can selectively use parts of the carrier spectrum for data transmissions, but not for control. The introduction
of Carrier Aggregation in Release 10 of the 3GPP LTE Standards (also referred to as LTE-A) provides a means for a User
Equipment (UE) or terminal to connect to multiple Component Carriers (CCs) at the same time. Each CC is similar to a Release 8
carrier that has its own control channel, pilots, scheduler, etc. It is important to clarify the terminology with respect to Component
Carriers and Component Carrier Frequencies. For example, in the simplest cellular deployment case of a single sector per site
deployment with a single frequency (i.e. a reuse-1, single sector deployment), each cell site represents transmission of one CC
over one CC frequency. In a site with a single frequency and 3 sectors (with 1 antenna per sector), the site is serviced with
3 separate CC’s, since each sector is separated from the other with its own pilots, control channel, scheduler, etc. When an
additional CC frequency is added to the same site, each antenna supports the two frequencies for the sector it is communicating
in, resulting in the formation of 6 CCs on 2 CC frequencies for the entire site. Extending this example to a 6-sector, 2 frequency
site results in the formation of 12 Component Carriers within the site. Fuzzy Cells technology enables CCs to be transmitted at
different power levels and in various directions. Using Fuzzy Cells technology, UEs can connect to CCs that originate from a
variety of base stations; resulting in the overall improvement in cell-edge performance. This is illustrated in Figure 4 wherein the
red frequency is transmitted at higher power from the site on the left and the green frequency is transmitted at a higher power at
the site on the right. The UE in the center of the figure is enabled to receive data from both sites (green from right site and red
from left site).
With Fuzzy Cells, the coverage area of each CC is altered in a controlled way such that for each CC frequency, the cell
boundaries are in different locations. The aggregate effect over all CC frequencies is to blur the cell boundary - hence the name
“Fuzzy Cells.” On the left side of Figure 5 is a traditional deployment with the downlink SINR for points between two sites in a
standard frequency reuse of 1 and with equal Transmit (Tx) power. Note the deep drop in SINR at the cell boundary. On the right
side of Figure 5, the system bandwidth is split into two CC frequencies (red and blue). The UE is free to connect to either site for
each CC frequency. The black curve in this figure illustrates the effective SINR for the UE when it is connected to both the blue
and red frequencies and is free to choose the best site in any position. The effective SINR is nearly the same as the SINR in the
left side of the figure when the UE is near the base station and is significantly better than the figure on the left when the UE is
near the cell edge.
four
Figure 4 Illustration of different coverage areas in different frequencies and UE connections
High Power
Low Power
BS 1 BS 2
1 12 2
6. Fuzzy Cells
One of the key aspects of Fuzzy Cells technology is the ability to split the UE data between two different base stations. From an
architectural point-of-view, this can be done in either the Core Network (CN) or remain entirely within the Radio Access Network
(RAN) domain. The benefit of keeping this function within the RAN is that it can be deployed in an earlier timeframe due to having
less impact on the system specifications as compared with data-splitting in the CN. The disadvantage is that this method is less
efficient than if the data-splitting was performed in the CN prior to distribution to the RAN nodes involved in communication with
the subject UE.
five
Figure 5 Illustration of Fuzzy Cells Technology Benefits
User LocationUser Location
SINR
Fuzzy Cells DeploymentTraditional Deployment
Effective SINR over both carriers
Cell-edge region
removed
Freq1 Freq2
7. Fuzzy Cells
Relation to Coordinated Multi-Point (CoMP) Technology
Several types of CoMP technology to manage intercell interference have been discussed in wireless standards forums such
as 3GPP. These include Joint Transmission (JT), Fast Cell Selection (FSC), Coordinated Scheduling (CS) and Coordinated
Beamforming (CB). Of these, CoMP JT has superficial similarity to Fuzzy Cells in that both schemes include simultaneous data-
transmission from multiple sites. However, there are fundamental differences. The data transmission in CoMP JT is generally
envisioned as a kind of Soft Hand Over (SHO), where the same data and DeModulation Reference Signals (DMRS) are sent from
two or more sites in such a way that the receiver only perceives a single data transmission (PDSCH), albeit through a different
propagation channel than if the transmission came from a single source, as is the case for the control channel (PDCCH). Such
transmission would preferentially be precoded (i.e., have antenna weights applied) so that the received signal would be received
with the highest possible quality, cause the least interference or, otherwise, optimize some system performance metric. This
places very tight requirements on the synchronization between transmissions of multiple sites that current X2 interfaces would
have difficulty supporting. The same data must first be available at both sites, the selection of radio resources need to be
coordinated, the selection Modulation and Coding Set (MCS) needs to be coordinated, and the effective Channel Quality Indicator
(CQI) and proper precoding for the joint transmission need to be determined.
The requirements to support Fuzzy Cells are much more relaxed. Each site needs to have data that will be transmitted to the
UE, but it is not the same data. Since data is not sent in a SHO-like manner, but rather as two separate data flows, there is also
no need to coordinate the selection of MCS or compute the effective CQI and joint precoders. The resulting demands on the X2
interface are therefore comparatively small.
It has been noted in recent contributions to 3GPP RAN1 that much of the gains associated with CoMP require high accuracy CSI
feedback. While the exact overhead to support such CSI has not been determined, there is no expected requirement for improved
CSI for Fuzzy Cells.
Fuzzy Cells technology can also be viewed as supplemental to CoMP. CoMP is envisioned as a mechanism to improve cell-
edge performance, in part because it is those UEs that can benefit from a multi-site transmission. Such UEs are able to receive
transmission from multi-sites at approximately the same power, which is needed to show gains. Since Fuzzy Cells actually
increase the geographical region in which an UE can find transmissions from multi-sites at about the same received power, the
region over which CoMP is useful may be extended.
While Relay technology is quite different and distinct from Fuzzy Cells technology, Relays are mentioned for completeness as
they are another solution being actively discussed and specified within the standards forums. The initial deployment models for
Relay technology will primarily be for coverage extension beyond the cell-edge. Later deployments of more sophisticated Relay
technology will consider coordinated operation of the Relay within a cell in order to improve cell-edge throughput. The main
disadvantage of Relays with respect to Fuzzy Cells is the additional CAPEX and OPEX impact of deploying the Relay since it is
essentially a light version of a base station and must have an approved site for installation, power, etc.
six
8. Fuzzy Cells
Demonstrating Fuzzy Cells Benefits
A one-dimensional analysis of SINR between two sites does not give a complete picture of the potential of Fuzzy Cells. In
order to provide a more accurate view of Fuzzy Cells benefits, results from a system level simulation of a two dimensional
deployment are presented. The simulation is conducted by randomly placing many UEs throughout the system that then
must compete for radio resources, referred to in LTE as Resource Blocks (RBs). Each such placement of UEs is referred to
as a “drop” and many such drops are required to provide meaningful statistics about the system performance. Many UEs are
dropped at once and compete for resources. Scheduling and UE-CC association rules are developed for use in a Fuzzy Cells
system deployment. This analysis is conducted using a hexagonal arrangement of sites and multiple CC frequencies. Two
cases are simulated and shown in Figure 6: A typical case using 3 antennas per site, each with coverage of 120 degrees is
shown on the left side of the figure. The full system BW (i.e., all CC frequencies) is supported by each antenna. The center of
Figure 6 illustrates the second case which uses a total of six antennas per site; however, each antenna still has 120 degree
coverage. Three of the antennas are deployed as in the left side of the figure, but the other three are deployed with a 60 degree
rotation relative to that set. Additionally, each antenna only supports a fraction of the full system BW (e.g., if there are two CC
frequencies in the system, One CC frequency is used for each set of antennas. Note that this Fuzzy Cells deployment scenario
requires a total of six CCs within the site for a two CC frequency deployment (i.e. three CCs using one CC frequency and three
CCs on the second CC frequency, with each antenna supporting a single CC). This latter case causes an intentional antenna
pattern overlap, which has the effect of blurring the intra-site cell edges. For reference, the right side of Figure 6 illustrates
a typical 6-sector site with non-overlapping antenna patterns. In this case, given the same two CC frequency deployment
scheme within the site, the full system BW is supported by each antenna with 60 degree coverage. Note that in this case,
12 CCs are required, or twice as many CCs compared to the 6-antenna/3-sector Fuzzy Cells case.
The two main metrics of interest are the total cell throughput and the cell-edge throughput. The cell-edge throughput is
typically measured in terms of the performance of a set of the lowest performing UEs; for example, if we arrange all UEs
by their performance and take X% of those with the worst performance, these would be considered the cell-edge UEs.
The threshold for a cell-edge UE is taken to be the 10%-tile user throughput UE in this case. Since there are two measures
of interest, it is better to present data as the possible trade-off available between these metrics, i.e., a curve of cell-edge
throughput vs. cell total throughput.
seven
Figure 6 Antenna Patterns for 3-Sector and 6-Sector Cell Sites
3-Antenna/3-Sector 6-Antenna/3-Sector 6-Antenna/6-Sector
9. Fuzzy Cells
A comparison of the throughput trade-off curves for different techniques is shown in Figure 7 below using a common Proportional
Fair scheduling algorithm and full-buffer traffic models for Fuzzy Cells. The other deployment scenarios are Fractional Frequency
Reuse (FFR) and the reuse-1 baseline case. FFR offers a means to trade-off cell-edge and total cell throughput, but note that the
trade-off for Fuzzy Cells is much more favorable. In fact, as one can see from the chart, for the 6-antenna case, Fuzzy Cells offers
up to 60% better cell-edge throughput performance at comparable total cell throughput in this scenario. For the 3-antenna case,
Fuzzy Cells still outperforms FFR by up to 25% better cell-edge performance.
When considering the available cell-edge throughput at the same total cell throughput for the different scenarios, Fuzzy Cells
technology in the 6-antenna deployment offers up to 80% better cell-edge performance versus a reuse-1 deployment; and even
with a basic 3-antenna configuration, Fuzzy Cells outperforms the reuse-1 case by up to 40%.
eight
Figure 7 Fuzzy Cells Simulation Results - Proportional Fair Scheduling
Total Cell Throughput (Mbps)
3
2.5
2
1.5
1
0.5
0
70 80 90 100 11075 85 95 105 115 120
FFR Baseline3-antenna Fuzzy Cells6-antenna Fuzzy Cells
10PercentileCell-EdgeThroughput(Mbps)
25% 60%
80%
40%
Better Total Cell TP at
same Cell-Edge TP
Better Cell-Edge TP
at same Total Cell TP
Typical operating point
(Beta=0.75 in PF Scheduler)
10. Fuzzy Cells
Improving Handover Performance
Robust handover between sectors or sites is vital to a cellular system. While data applications today are a bit more tolerant than
voice service supported on a circuit switched (CS) connection, in due time high Quality-of-Service (QoS) services such as Voice
Over IP (VoIP) will be supported on cellular wireless data networks with expectations of seamless handovers and no dropped
calls under high mobility conditions. In addition to improving cell-edge throughput performance, Fuzzy Cells technology can also
improve the performance of Handover (HO). Several aspects of HO improvement are addressed with Fuzzy Cells technology:
• Fundamental HO Improvement: The variation in coverage areas of different CCs means that HO is indicated at different times
for each CC frequency. By enabling the UE to change the set of CCs that it is connected to one at a time and across sites, the
probability of occurrence of dropped voice calls and/or data sessions during HO is reduced.
• Radio Link Failure (RLF) Reduction: Reduction in RLF (a defined state in which the UE is at least temporarily not connected
to the network) can be achieved by allowing the UE to remain connected to the network through any CC of high enough quality
(signal strength). Since Fuzzy Cells deployment is specifically designed to make sure each UE sees at least one good quality CC
at all times, RLF probability is reduced, thus improving QoS/QoE in otherwise degraded cell-edge conditions. This is true even if
the UE requires only a single CC to support its service, e.g., in a voice call.
• Maintaining Control Plane Signaling: Control plane signaling is more easily maintained because control channels may be
supported on any CC and the UE only needs to start monitoring a designated CC in another CC frequency as it starts to get
close to the cell boundary in the current CC frequency. In this way, even CS voice calls may see reduced drop rates during HO
in multi-carrier systems that support CS calls.
• Reducing Data Plane Interruption: During reconfiguration, data plane interruption is also mitigated by re-routing higher
priority traffic to a CC with better quality and overlapping coverage. Also, by taking the Radio Resource Control (RRC)
Connection establishment out of the critical path, RRC signaling associated delays are also reduced.
Fuzzy Cells and Standards
While certain aspects of Fuzzy Cells may be supported within the framework of specifications defined in Release 10 of the
3GPP LTE standards, not all features are expected to be. For example, transmission of different CCs at different power levels
and through different antennas will likely not be specifically excluded and could still be advantageous when implemented
as a proprietary solution. Other aspects of Fuzzy Cells are very unlikely to be supported in Release 10 without upgrading
the specifications such as data flow splitting between sites controlled by distinct base stations, such as enhanced-NodeB’s
(eNodeBs) and, by extension, reduced radio link failure in HO. These aspects are required in order to realize the full benefits of the
Fuzzy Cells technology and are good candidates to bring into later releases (Release 11 or 12) of the 3GPP LTE standards.
The data-flow splitting is used to route UE data to multiple sites in Fuzzy Cells, but may use independent scheduling for the
sub-flows from each CC to the UE. Compared to techniques like CoMP, data-flow splitting eliminates inter-site synchronization
of packet data transmissions. It may, however, impose additional transmission latency as the inter-arrival time varies due to
differences between sub-flow routing path delays. The re-ordering entity at the receiving end handles the sub-flow merging and
transmission latency for each packet delivered within the requested QoS latency requirement. This approach makes transport
layer routing change transparent to network layer protocol such as TCP. Therefore, the introduction of Fuzzy Cells data flow split
does not impose any substantial synchronization issues. In fact, Fuzzy Cells improves TCP performance during handover by
decreasing handover latency. This minimizes TCP round trip time (RTT) variance introduced by HO delay, and therefore, reduces
potential TCP packet drops due to congestion window changes.
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11. Fuzzy Cells
While Fuzzy Cells technology has been explained in terms of an LTE system as a framework, it can be applied to any multi-carrier
Radio Access Technology (RAT) that allows certain flexibilities in the configuration of the multiple carriers. MC-HSPA is one
such RAT to which Fuzzy Cells can be applied with similarly low complexity. The carriers in MC-HSPA are treated very much as
separate cells and in that sense are similar to CCs in LTE.
Conclusion
Today’s wireless service providers are facing a growing gap between cell peak data rates and the performance at cell-edge. This
results in a growing performance disparity between users who are close to the base station and those further away. With growing
demand for wireless data, subscribers will demand better service from their service providers as they did with the evolution of
mobile voice service. The use of cell-splitting provides the traditional, but costly, solution to improving coverage and capacity in
poorly served areas of a cell. Fuzzy Cells technology offers an intelligent way to improve cell-edge performance and to increase
overall cell spectral efficiency in a cost effective manner.
InterDigital extends an invitation to fellow global market participants in the wireless eco-system to collaborate on integrating its
advanced technologies into products and services for field testing and deployment.
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