The document discusses securing query processing in cloud computing environments. It identifies three key requirements for secure query processing: 1) authenticating users and machines, 2) securing data transfer across machines, and 3) ensuring integrity of query results. The document also analyzes existing and proposed systems for wireless multi-hop networks, including analyzing performance under different conditions.
Checkpointing and Rollback Recovery Algorithms for Fault Tolerance in MANETs:...Eswar Publications
Mobile Ad Hoc Networks (MANETs) are emerging as a major technology in mobile computing. A MANET is a collection of mobile devices or nodes that communicate with each other using wireless links without availability of any static infrastructure or centralized control. A node in such a network should be fault tolerable and failure free execution of processes on the network nodes is vital. In order to make devices fault tolerant checkpoint based recovery technique can be used. Checkpointing is a technique that can be used to make device or node fault tolerant and reduce the recovery time in case of failure. It takes the snapshot of current application state of process and stores it in some memory area and then using it to resume the computation from current checkpoint instead of resuming it from the beginning. Some limitations of MANETs such as mobility, dynamic topology,
limited bandwidth of channel, limited storage space and power restrictions makes checkpointing as a major challenge in mobile ad hoc networks. This paper presents the survey of some existing algorithms, which have been proposed for making MANETs fault tolerant and implementing or deploying checkpointing in mobile ad hoc network.
Marvell Network Telemetry Solutions for Data Center and Enterprise NetworksMarvell
Marvell network telemetry - which enables accurate measurement of the network’s performance in real-time. In this white paper we will discuss how network telemetry is evolving in modern data center networks. Details will then be given of how the generic approach to network telemetry that has been taken by Marvell is providing greater visibility into network performance, plus flexible support of existing telemetry protocols, as well as the future ones emerging.
To know more visit @ https://www.marvell.com/switching/
Network Monitoring and Traffic Reduction using Multi-Agent TechnologyEswar Publications
In this paper the algorithms which could improve Transmission band and Network Traffic reduction for computer network has been shown. Problem solving is an area with which many Multiagent-based applications are concerned. Multiagent systems are computational systems in which several agents interact or work together to achieve some purposes. It includes distributed solutions to problems, solving distributed problems and distributed techniques for problem solving. Multiagent using for maximizing group performance with planning, execution, monitoring, communication and coordination. This paper also addresses some critical issues in developing
Multi agent-based traffic control and monitoring systems, such as interoperability, flexibility, and extendibility. Finally, several future research directions toward the successful deployment of Multiagent technology in traffic control and monitoring systems are discussed.
Checkpointing and Rollback Recovery Algorithms for Fault Tolerance in MANETs:...Eswar Publications
Mobile Ad Hoc Networks (MANETs) are emerging as a major technology in mobile computing. A MANET is a collection of mobile devices or nodes that communicate with each other using wireless links without availability of any static infrastructure or centralized control. A node in such a network should be fault tolerable and failure free execution of processes on the network nodes is vital. In order to make devices fault tolerant checkpoint based recovery technique can be used. Checkpointing is a technique that can be used to make device or node fault tolerant and reduce the recovery time in case of failure. It takes the snapshot of current application state of process and stores it in some memory area and then using it to resume the computation from current checkpoint instead of resuming it from the beginning. Some limitations of MANETs such as mobility, dynamic topology,
limited bandwidth of channel, limited storage space and power restrictions makes checkpointing as a major challenge in mobile ad hoc networks. This paper presents the survey of some existing algorithms, which have been proposed for making MANETs fault tolerant and implementing or deploying checkpointing in mobile ad hoc network.
Marvell Network Telemetry Solutions for Data Center and Enterprise NetworksMarvell
Marvell network telemetry - which enables accurate measurement of the network’s performance in real-time. In this white paper we will discuss how network telemetry is evolving in modern data center networks. Details will then be given of how the generic approach to network telemetry that has been taken by Marvell is providing greater visibility into network performance, plus flexible support of existing telemetry protocols, as well as the future ones emerging.
To know more visit @ https://www.marvell.com/switching/
Network Monitoring and Traffic Reduction using Multi-Agent TechnologyEswar Publications
In this paper the algorithms which could improve Transmission band and Network Traffic reduction for computer network has been shown. Problem solving is an area with which many Multiagent-based applications are concerned. Multiagent systems are computational systems in which several agents interact or work together to achieve some purposes. It includes distributed solutions to problems, solving distributed problems and distributed techniques for problem solving. Multiagent using for maximizing group performance with planning, execution, monitoring, communication and coordination. This paper also addresses some critical issues in developing
Multi agent-based traffic control and monitoring systems, such as interoperability, flexibility, and extendibility. Finally, several future research directions toward the successful deployment of Multiagent technology in traffic control and monitoring systems are discussed.
From Simulation to Online Gaming: the need for adaptive solutions Gabriele D'Angelo
In many fields such as distributed simulation and online gaming the missing piece is adaptivity. There is a strong need for dynamic and adaptive solutions that can improve performances and react to problems.
An Adaptive Load Balancing Middleware for Distributed SimulationGabriele D'Angelo
The simulation is useful to support the design and performance evaluation of complex systems, possibly composed by a massive number of interacting entities. For this reason, the simulation of such systems may need aggregate computation and memory resources obtained by clusters of parallel and distributed execution units. Shared computer clusters composed of available Commercial-Off-the-Shelf hardware are preferable to dedicated systems, mainly for cost reasons. The performance of distributed simulations is influenced by the heterogeneity of execution units and by their respective CPU load in background. Adaptive load balancing mechanisms could improve the resources utilization and the simulation process execution, by dynamically tuning the simulation load with an eye to the synchronization and communication overheads reduction. In this work it will be presented the GAIA+ framework: a new load balancing mechanism for distributed simulation. The framework has been evaluated by performing testbed simulations of a wireless ad hoc network model. Results confirm the effectiveness of the proposed solutions.
Allocation of processors to processes in Distributed Systems. Strategies or algorithms for processor allocation. Design and Implementation Issues of Strategies.
Review of Some Checkpointing Schemes for Distributed and Mobile Computing Env...Eswar Publications
Fault Tolerance Techniques facilitate systems to carry out tasks in the incidence of faults. A checkpoint is a local state of a process saved on stable storage. In a distributed system, since the processes in the system do not share memory; a global state of the system is defined as a combination of local states, one from each process. In case of a fault in distributed systems, checkpointing enables the execution of a program to be resumed from a previous consistent global state rather than resuming the execution from the commencement. In this way, the sum of constructive processing vanished because of the fault is appreciably reduced. In this paper, we talk about various issues related to the checkpointing for distributed systems and mobile computing environments. We also confer
various types of checkpointing: coordinated checkpointing, asynchronous checkpointing, communication induced
checkpointing and message logging based checkpointing. We also present a survey of some checkpointing algorithms for distributed systems.
4.1Introduction
- Potential Threats and Attacks on Computer System
- Confinement Problems
- Design Issues in Building Secure Distributed Systems
4.2 Cryptography
- Symmetric Cryptosystem Algorithm: DES
- Asymmetric Cryptosystem
4.3 Secure Channels
- Authentication
- Message Integrity and Confidentiality
- Secure Group Communication
4.4 Access Control
- General Issues
- Firewalls
- Secure Mobile Code
4.5 Security Management
- Key Management
- Issues in Key Distribution
- Secure Group Management
- Authorization Management
AN OPTIMIZED MECHANISM FOR ADAPTIVE AND DYNAMIC POLICY BASED HANDOVER IN CLUS...pijans
On-going revolution in ever-improving wireless communication enforces the necessity of a self configuring,
rapidly deployable and infrastructure less network. MANET is such an autonomous wireless network that
meets the requirements. At the same time MANET’s random behavior and absence of any central
intelligence to gather unambiguous knowledge about user contexts complexes QoS maintenance and
hampers proper utilization of network resources resulting into unnecessary handovers. In past, few policy
driven handover approaches have been proposed for MANET but none of them explores a comprehensive
policy design. Therefore in this paper we propose an adaptive and optimized policy based handover
mechanism which is based on explicitly designed policies like load balancing, service discovery and next
hop selection .Efficient procedures for these policies are also explored .This work predicts the high time of
handover need on the basis of application specific needs of individual freely roaming mobile nodes,
avoiding unnecessary handovers and provides efficient handover procedure with optimized resource
consumption, reduced latency and interruption time.
TEST-COST-SENSITIVE CONVOLUTIONAL NEURAL NETWORKS WITH EXPERT BRANCHESsipij
It has been proven that deeper convolutional neural networks (CNN) can result in better accuracy in many
problems, but this accuracy comes with a high computational cost. Also, input instances have not the same
difficulty. As a solution for accuracy vs. computational cost dilemma, we introduce a new test-cost-sensitive
method for convolutional neural networks. This method trains a CNN with a set of auxiliary outputs and
expert branches in some middle layers of the network. The expert branches decide to use a shallower part
of the network or going deeper to the end, based on the difficulty of input instance. The expert branches
learn to determine: is the current network prediction is wrong and if the given instance passed to deeper
layers of the network it will generate right output; If not, then the expert branches stop the computation
process. The experimental results on standard dataset CIFAR-10 show that the proposed method can train
models with lower test-cost and competitive accuracy in comparison with basic models.
A COMBINATION OF THE INTRUSION DETECTION SYSTEM AND THE OPEN-SOURCE FIREWALL ...IJCNCJournal
There are many security models for computer networks using a combination of Intrusion Detection System and Firewall proposed and deployed in practice. In this paper, we propose and implement a new model of the association between Intrusion Detection System and Firewall operations, which allows Intrusion Detection System to automatically update the firewall filtering rule table whenever it detects a weirdo intrusion. This helps protect the network from attacks from the Internet.
PERFORMANCE ANALYSIS OF OLSR PROTOCOL IN MANET CONSIDERING DIFFERENT MOBILITY...ijwmn
A Mobile Ad Hoc Network (MANET) is created when an independent mobile node network is connected
dynamically via wireless links. MANET is a self-organizing network that does not rely on pre-existing
infrastructure such as wired or wireless network routers. Mobile nodes in this network move randomly,
thus, the topology is always changing. Routing protocols in MANET are critical in ensuring dependable
and consistent connectivity between the mobile nodes. They conclude logically based on the interaction
between mobile nodes in MANET routing and encourage them to choose the optimum path between source
and destination. Routing protocols are classified as proactive, reactive, or hybrid. The focus of this project
will be on Optimized Link State Routing (OLSR) protocol, a proactive routing technique. OLSR is known as
the optimized variant of link state routing in which packets are sent throughout the network using the
multipoint relay (MPR) mechanism. This article evaluates the performance of the OLSR routing protocol
under condition of changing mobility speed and network density. The study's performance indicators are
average packet throughput, packet delivery ratio (PDR), and average packet latency. Network Simulator 2
(NS-2) and an external patch UM-OLSR are used to simulate and evaluate the performance of such
protocol. As a result of research, the approach of implementing the MPR mechanism are able to minimise
redundant data transmission during the normal message broadcast. The MPRs enhance the link state
protocols’ traditional diffusion mechanism by selecting the right MPRs. Hence, the number of undesired
broadcasts can be reduced and limited. Further research will focus on different scenario and environment
using different mobility model
Presentation on Static Network Architecture for multi-programming and multi-processing. Architecture, Ring Architecture, Ring Chordal Architecture, Barrel Shifter Architecture, Fully Connected Architecture.
From Simulation to Online Gaming: the need for adaptive solutions Gabriele D'Angelo
In many fields such as distributed simulation and online gaming the missing piece is adaptivity. There is a strong need for dynamic and adaptive solutions that can improve performances and react to problems.
An Adaptive Load Balancing Middleware for Distributed SimulationGabriele D'Angelo
The simulation is useful to support the design and performance evaluation of complex systems, possibly composed by a massive number of interacting entities. For this reason, the simulation of such systems may need aggregate computation and memory resources obtained by clusters of parallel and distributed execution units. Shared computer clusters composed of available Commercial-Off-the-Shelf hardware are preferable to dedicated systems, mainly for cost reasons. The performance of distributed simulations is influenced by the heterogeneity of execution units and by their respective CPU load in background. Adaptive load balancing mechanisms could improve the resources utilization and the simulation process execution, by dynamically tuning the simulation load with an eye to the synchronization and communication overheads reduction. In this work it will be presented the GAIA+ framework: a new load balancing mechanism for distributed simulation. The framework has been evaluated by performing testbed simulations of a wireless ad hoc network model. Results confirm the effectiveness of the proposed solutions.
Allocation of processors to processes in Distributed Systems. Strategies or algorithms for processor allocation. Design and Implementation Issues of Strategies.
Review of Some Checkpointing Schemes for Distributed and Mobile Computing Env...Eswar Publications
Fault Tolerance Techniques facilitate systems to carry out tasks in the incidence of faults. A checkpoint is a local state of a process saved on stable storage. In a distributed system, since the processes in the system do not share memory; a global state of the system is defined as a combination of local states, one from each process. In case of a fault in distributed systems, checkpointing enables the execution of a program to be resumed from a previous consistent global state rather than resuming the execution from the commencement. In this way, the sum of constructive processing vanished because of the fault is appreciably reduced. In this paper, we talk about various issues related to the checkpointing for distributed systems and mobile computing environments. We also confer
various types of checkpointing: coordinated checkpointing, asynchronous checkpointing, communication induced
checkpointing and message logging based checkpointing. We also present a survey of some checkpointing algorithms for distributed systems.
4.1Introduction
- Potential Threats and Attacks on Computer System
- Confinement Problems
- Design Issues in Building Secure Distributed Systems
4.2 Cryptography
- Symmetric Cryptosystem Algorithm: DES
- Asymmetric Cryptosystem
4.3 Secure Channels
- Authentication
- Message Integrity and Confidentiality
- Secure Group Communication
4.4 Access Control
- General Issues
- Firewalls
- Secure Mobile Code
4.5 Security Management
- Key Management
- Issues in Key Distribution
- Secure Group Management
- Authorization Management
AN OPTIMIZED MECHANISM FOR ADAPTIVE AND DYNAMIC POLICY BASED HANDOVER IN CLUS...pijans
On-going revolution in ever-improving wireless communication enforces the necessity of a self configuring,
rapidly deployable and infrastructure less network. MANET is such an autonomous wireless network that
meets the requirements. At the same time MANET’s random behavior and absence of any central
intelligence to gather unambiguous knowledge about user contexts complexes QoS maintenance and
hampers proper utilization of network resources resulting into unnecessary handovers. In past, few policy
driven handover approaches have been proposed for MANET but none of them explores a comprehensive
policy design. Therefore in this paper we propose an adaptive and optimized policy based handover
mechanism which is based on explicitly designed policies like load balancing, service discovery and next
hop selection .Efficient procedures for these policies are also explored .This work predicts the high time of
handover need on the basis of application specific needs of individual freely roaming mobile nodes,
avoiding unnecessary handovers and provides efficient handover procedure with optimized resource
consumption, reduced latency and interruption time.
TEST-COST-SENSITIVE CONVOLUTIONAL NEURAL NETWORKS WITH EXPERT BRANCHESsipij
It has been proven that deeper convolutional neural networks (CNN) can result in better accuracy in many
problems, but this accuracy comes with a high computational cost. Also, input instances have not the same
difficulty. As a solution for accuracy vs. computational cost dilemma, we introduce a new test-cost-sensitive
method for convolutional neural networks. This method trains a CNN with a set of auxiliary outputs and
expert branches in some middle layers of the network. The expert branches decide to use a shallower part
of the network or going deeper to the end, based on the difficulty of input instance. The expert branches
learn to determine: is the current network prediction is wrong and if the given instance passed to deeper
layers of the network it will generate right output; If not, then the expert branches stop the computation
process. The experimental results on standard dataset CIFAR-10 show that the proposed method can train
models with lower test-cost and competitive accuracy in comparison with basic models.
A COMBINATION OF THE INTRUSION DETECTION SYSTEM AND THE OPEN-SOURCE FIREWALL ...IJCNCJournal
There are many security models for computer networks using a combination of Intrusion Detection System and Firewall proposed and deployed in practice. In this paper, we propose and implement a new model of the association between Intrusion Detection System and Firewall operations, which allows Intrusion Detection System to automatically update the firewall filtering rule table whenever it detects a weirdo intrusion. This helps protect the network from attacks from the Internet.
PERFORMANCE ANALYSIS OF OLSR PROTOCOL IN MANET CONSIDERING DIFFERENT MOBILITY...ijwmn
A Mobile Ad Hoc Network (MANET) is created when an independent mobile node network is connected
dynamically via wireless links. MANET is a self-organizing network that does not rely on pre-existing
infrastructure such as wired or wireless network routers. Mobile nodes in this network move randomly,
thus, the topology is always changing. Routing protocols in MANET are critical in ensuring dependable
and consistent connectivity between the mobile nodes. They conclude logically based on the interaction
between mobile nodes in MANET routing and encourage them to choose the optimum path between source
and destination. Routing protocols are classified as proactive, reactive, or hybrid. The focus of this project
will be on Optimized Link State Routing (OLSR) protocol, a proactive routing technique. OLSR is known as
the optimized variant of link state routing in which packets are sent throughout the network using the
multipoint relay (MPR) mechanism. This article evaluates the performance of the OLSR routing protocol
under condition of changing mobility speed and network density. The study's performance indicators are
average packet throughput, packet delivery ratio (PDR), and average packet latency. Network Simulator 2
(NS-2) and an external patch UM-OLSR are used to simulate and evaluate the performance of such
protocol. As a result of research, the approach of implementing the MPR mechanism are able to minimise
redundant data transmission during the normal message broadcast. The MPRs enhance the link state
protocols’ traditional diffusion mechanism by selecting the right MPRs. Hence, the number of undesired
broadcasts can be reduced and limited. Further research will focus on different scenario and environment
using different mobility model
Presentation on Static Network Architecture for multi-programming and multi-processing. Architecture, Ring Architecture, Ring Chordal Architecture, Barrel Shifter Architecture, Fully Connected Architecture.
This slide show will help you troubleshoot a lot of different problems with your computer. Feel free to flip through the slides and see if your problem is in here. If so I hope that it helps you resolve your problem.
Además de la información genética contenida en el núcleo celular (en los cromosomas), las células cuentan también con una pequeña proporción de ADN extranuclear que se encuentra localizado en las mitocondrias.
Las enfermedades mitocondriales son desórdenes resultantes de la deficiencia de una o más proteínas localizadas en las mitocondrias e involucradas en el metabolismo.1 Hay descritas unas 150 mutaciones que acaban en enfermedades de distinto tipo. Las enfermedades mitocondriales pueden estar causadas por mutaciones en el ADN mitocondrial, o bien por mutaciones en genes nucleares que codifican para proteínas implicadas en el correcto funcionamiento de la mitocondria. Las enfermedades mitocondriales causan el mayor daño a las células del cerebro, corazón, hígado, músculos esqueléticos, riñones y del sistema endocrino y respiratorio, ya que los tejidos con mayor dependencia del metabolismo mitocondrial (es decir, aquellos que requieren un mayor aporte energético) son los más sensibles a las mutaciones mitocondriales.
La gravedad y el espectro de estas enfermedades parecen desproporcionados respecto a la contribución del ADN mitoncondrial al genoma humano.
Dependiendo de cuáles sean las células afectadas, los síntomas pueden incluir: pérdida del control motor (pérdida de equilibrio, epilepsia, temblores, etc.), debilidad muscular y dolor, desórdenes gastrointestinales y dificultades para tragar, retardo en el crecimiento, enfermedad cardíaca, enfermedad hepática, diabetes, complicaciones respiratorias, crisis, problemas visuales (ceguera, catarátas, entre otros) y auditivos (sordera-a menudo afectando a ambos oídos-), acidosis láctica, retrasos en el desarrollo, susceptibilidad a las infecciones, problemas de fertilidad (sobre todo en el sexo femenino), problemas hormonales y dificultad al tragar y al absorber nutrientes (conllevando a una pérdida de peso, entre otras muchas patologías observadas
Online stream mining approach for clustering network trafficeSAT Journals
Abstract A large number of research have been proposed on intrusion detection system, which leads to the implementation of agent based intelligent IDS (IIDS), Non – intelligent IDS (NIDS), signature based IDS etc. While building such IDS models, learning algorithms from flow of network traffic plays crucial role in accuracy of IDS systems. The proposed work focuses on implementing the novel method to cluster network traffic which eliminates the limitations in existing online clustering algorithms and prove the robustness and accuracy over large stream of network traffic arriving at extremely high rate. We compare the existing algorithm with novel methods to analyse the accuracy and complexity. Keywords— NIDS, Data Stream Mining, Online Clustering, RAH algorithm, Online Efficient Incremental Clustering algorithm
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
HOST AND NETWORK SECURITY by ThesisScientist.comProf Ansari
Network management means different things to different people. In some cases, it involves a solitary network consultant monitoring network activity with an outdated protocol analyzer. In other cases, network management involves a distributed database, auto polling of network devices, and high-end workstations generating real-time graphical views of network topology changes and traffic. In general, network management is a service that employs a variety of tools, applications, and devices to assist human network managers in monitoring and maintaining networks.
A brief report on Client Server Model and Distributed Computing. Problems and Applications are also discussed and Client Server Model in Distributed Systems is also discussed.
As the complexity of the scan algorithm is dependent on the number of design registers, large SoC scan
designs can no longer be verified in RTL simulation unless partitioned into smaller sub-blocks. This paper
proposes a methodology to decrease scan-chain verification time utilizing SCE-MI, a widely used
communication protocol for emulation, and an FPGA-based emulation platform. A high-level (SystemC)
testbench and FPGA synthesizable hardware transactor models are developed for the scan-chain ISCAS89
S400 benchmark circuit for high-speed communication between the host CPU workstation and the FPGA
emulator. The emulation results are compared to other verification methodologies (RTL Simulation,
Simulation Acceleration, and Transaction-based emulation), and found to be 82% faster than regular RTL
simulation. In addition, the emulation runs in the MHz speed range, allowing the incorporation of software
applications, drivers, and operating systems, as opposed to the Hz range in RTL simulation or submegahertz
range as accomplished in transaction-based emulation. In addition, the integration of scan
testing and acceleration/emulation platforms allows more complex DFT methods to be developed and
tested on a large scale system, decreasing the time to market for products.
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We all have good and bad thoughts from time to time and situation to situation. We are bombarded daily with spiraling thoughts(both negative and positive) creating all-consuming feel , making us difficult to manage with associated suffering. Good thoughts are like our Mob Signal (Positive thought) amidst noise(negative thought) in the atmosphere. Negative thoughts like noise outweigh positive thoughts. These thoughts often create unwanted confusion, trouble, stress and frustration in our mind as well as chaos in our physical world. Negative thoughts are also known as “distorted thinking”.
Model Attribute Check Company Auto PropertyCeline George
In Odoo, the multi-company feature allows you to manage multiple companies within a single Odoo database instance. Each company can have its own configurations while still sharing common resources such as products, customers, and suppliers.
Synthetic Fiber Construction in lab .pptxPavel ( NSTU)
Synthetic fiber production is a fascinating and complex field that blends chemistry, engineering, and environmental science. By understanding these aspects, students can gain a comprehensive view of synthetic fiber production, its impact on society and the environment, and the potential for future innovations. Synthetic fibers play a crucial role in modern society, impacting various aspects of daily life, industry, and the environment. ynthetic fibers are integral to modern life, offering a range of benefits from cost-effectiveness and versatility to innovative applications and performance characteristics. While they pose environmental challenges, ongoing research and development aim to create more sustainable and eco-friendly alternatives. Understanding the importance of synthetic fibers helps in appreciating their role in the economy, industry, and daily life, while also emphasizing the need for sustainable practices and innovation.
This is a presentation by Dada Robert in a Your Skill Boost masterclass organised by the Excellence Foundation for South Sudan (EFSS) on Saturday, the 25th and Sunday, the 26th of May 2024.
He discussed the concept of quality improvement, emphasizing its applicability to various aspects of life, including personal, project, and program improvements. He defined quality as doing the right thing at the right time in the right way to achieve the best possible results and discussed the concept of the "gap" between what we know and what we do, and how this gap represents the areas we need to improve. He explained the scientific approach to quality improvement, which involves systematic performance analysis, testing and learning, and implementing change ideas. He also highlighted the importance of client focus and a team approach to quality improvement.
The Indian economy is classified into different sectors to simplify the analysis and understanding of economic activities. For Class 10, it's essential to grasp the sectors of the Indian economy, understand their characteristics, and recognize their importance. This guide will provide detailed notes on the Sectors of the Indian Economy Class 10, using specific long-tail keywords to enhance comprehension.
For more information, visit-www.vavaclasses.com
Welcome to TechSoup New Member Orientation and Q&A (May 2024).pdfTechSoup
In this webinar you will learn how your organization can access TechSoup's wide variety of product discount and donation programs. From hardware to software, we'll give you a tour of the tools available to help your nonprofit with productivity, collaboration, financial management, donor tracking, security, and more.
How to Split Bills in the Odoo 17 POS ModuleCeline George
Bills have a main role in point of sale procedure. It will help to track sales, handling payments and giving receipts to customers. Bill splitting also has an important role in POS. For example, If some friends come together for dinner and if they want to divide the bill then it is possible by POS bill splitting. This slide will show how to split bills in odoo 17 POS.
Cambridge International AS A Level Biology Coursebook - EBook (MaryFosbery J...
Cloud data management
1. Abstract:
A significant challenge in cloud data management is ensuring that all query processing is
carried out securely within a cloud infrastructure. To be secure, query processing must
(1) authenticate users and machines involved in query processing, (2) secure the transfer
of data across machines in the cloud, and (3) ensure the integrity of all query results. All
three requirements can be directly applied to mitigate potential threats at the
infrastructure, network, and user levels
2. System Analysis:
2.1 Existing System :
Efforts at each layer of network systems
Mesh network between STAs
Ad hoc mode in IEEE 802.11 standard
2.2 Proposed System:
• IEEE 802.11 protocol under unsaturated traffic conditions for multi-hop
networks
2. • Bandwidth reservation
• QoS Routing
• Congestion Control
• MAC protocol : DCF(CP) / PCF(CFP)
• Decision making
• two-dimensional Markov chain model to analyze the performance of the
IEEE 802.11 protocol in single hop wireless networks
2.3 Feasibility Study:
A feasibility study is an evaluation of a proposal designed to
determine the difficulty in carrying out a designated task. Generally, It
precedes technical development and project implementation. Its an
evaluation or analysis of the potential impact of a proposed project.
2.3.1 Economical Feasibility
3. Economic analysis is the most frequently used method for evaluating
the effectiveness of a new system, benefits outweigh costs, then the decision
is made to design and implement the system.
2.3.2 Operational Feasibility
Operational feasibility is a measure of how well a proposed system
solves the problems, and takes advantage of the opportunities identified
during scope definition and how it satisfies the requirements identified in the
requirements analysis phase of system development
2.3.3 Technical Feasibility
An outline design of system requirements in terms of Input, Processes,
Output, Fields, Programs, and Procedures. This can be quantified in terms of
volumes of data, trends, frequency of updating, etc. in order to estimate
whether the new system will perform adequately or not. Technological
feasibility is carried out to determine whether the company has the
capability, in terms of software, hardware, personnel and expertise, to handle
the completion of the project
4. 3. SYSTEM REQUIREMENTS:
3.1 Hardware Requirements:
Processor Type : Pentium -IV
Speed : 2.4GHZ
Ram : 256 MB RAM
Hard disk : 20 GB HD
3.2 Software Requirements:
Operating System : Linux
Programming Package : Tcl Scripting , C++
Tools : VMware
4 Software Descriptions
5. Network simulation is a technique where a program models the
behavior of a network either by calculating the interaction between the
different network entities (hosts/routers, data links, packets, etc) using
mathematical formulas, or actually capturing and playing back observations
from a production network. The behavior of the network and the various
applications and services it supports can then be observed in a test lab;
various attributes of the environment can also be modified in a controlled
manner to assess how the network would behave under different conditions.
When a simulation program is used in conjunction with live applications and
services in order to observe end-to-end performance to the user desktop, this
technique is also referred to as network emulation.
Motivation for Simulations
• Cheap -- does not require costly equipment
• Complex scenarios can be easily tested
• Results can be quickly obtained – more ideas can
• be tested in a smaller timeframe
• The real thing isn't yet available
6. • Controlled experimental conditions
• Repeatability helps aid debugging
• Disadvantages: Real systems too complex to model
Most of the commercial simulators are GUI driven, while some network
simulators require input scripts or commands (network parameters). The
network parameters describe the state of the network (node placement,
existing links) and the events (data transmissions, link failures, etc).
Important outputs of simulations are the trace files. Trace files can document
every event that occurred in the simulation and are used for analysis. Certain
simulators have added functionality of capturing this type of data directly
from a functioning production environment, at various times of the day,
week, or month, in order to reflect average, worst-case, and best-case
conditions
Most network simulators use discrete event simulation, in which a list
of pending "events" is stored, and those events are processed in order, with
some events triggering future events -- such as the event of the arrival of a
packet at one node triggering the event of the arrival of that packet at a
downstream node.
7. Some network simulation problems, notably those relying on queuing
theory, are well suited to Markov chain simulations, in which no list of
future events is maintained and the simulation consists of transiting between
different system "states" in a memory less fashion. Markov chain simulation
is typically faster but less accurate and flexible than detailed discrete event
simulation. Some simulations are cyclic based simulations and these are
faster as compared to event based simulations.
Advantages of simulation
* Normal analytical techniques make use of extensive mathematical
models which require assumptions and restrictions to be placed on the
model. This can result in an avoidable inaccuracy in the output data.
Simulations avoid placing restrictions on the system and also take random
processes into account; in fact in some cases simulation is the only practical
modeling technique applicable
* Analysts can study the relationships between components in detail and
can simulate the projected consequences of multiple design options before
having to implement the outcome in the real-world.
* It is possible to easily compare alternative designs so as to select the
optimal system.
8. * The actual process of developing the simulation can itself provide
valuable insights into the inner workings of the network which can in turn be
used at a later stage.
Disadvantages of simulation
* Accurate simulation model development requires extensive resources.
* The simulation results are only as good as the model and as such are
still only estimates / projected outcomes.
* Optimization can only be performed involving a few alternatives as the
model is usually developed using a limited number of variables.
* Simulations cost a lot of money to build and are very expensive to make
Input data
Simulation models are generated from a set of data taken from a
stochastic system. It is necessary to check that the data is statistically valid
by fitting a statistical distribution and then testing the significance of such a
fit. Further, as with any modelling process, the input data’s accuracy must be
checked and any outliers must be removed.
9. Output data
When a simulation has been completed, the data needs to be analysed.
The simulation's output data will only produce a likely estimate of real-
world events. Methods to increase the accuracy of output data include:
repeatedly performing simulations and comparing results, dividing events
into batches and processing them individually, and checking that the results
of simulations conducted in adjacent time periods “connect” to produce a
coherent holistic view of the system
The main idea is to partly implement HTTP, FTP and TCP protocols.
Routing is the process of selecting paths in a network along which to send
network traffic. Routing is performed for many kinds of networks, including
the telephone network (Circuit switching) , electronic data networks (such as
the Internet), and transportation networks. This article is concerned primarily
with routing in electronic data networks using packet switching technology.
In packet switching networks, routing directs packet forwarding, the transit
of logically addressed packets from their source toward their ultimate
destination through intermediate nodes, typically hardware devices called
10. routers, bridges, gateways, firewalls, or switches. General-purpose
computers can also forward packets and perform routing, though they are
not specialized hardware and may suffer from limited performance. The
routing process usually directs forwarding on the basis of routing tables
which maintain a record of the routes to various network destinations. Thus,
constructing routing tables, which are held in the router's memory, is very
important for efficient routing. Most routing algorithms use only one
network path at a time, but multipath routing techniques enable the use of
multiple alternative paths.
Routing, in a more narrow sense of the term, is often contrasted with
bridging in its assumption that network addresses are structured and that
similar addresses imply proximity within the network. Because structured
addresses allow a single routing table entry to represent the route to a group
of devices, structured addressing (routing, in the narrow sense) outperforms
unstructured addressing (bridging) in large networks, and has become the
dominant form of addressing on the Internet, though bridging is still widely
used within localized environments.
Routing schemes differ in their delivery semantics:
• unicast delivers a message to a single specified node;
11. • broadcast delivers a message to all nodes in the network;
• multicast delivers a message to a group of nodes that have
expressed interest in receiving the message;
• anycast delivers a message to any one out of a group of nodes,
typically the one nearest to the source.
Path selection
Path selection involves applying a routing metric to multiple routes, in order
to select (or predict) the best route.
In the case of computer networking, the metric is computed by a
routing algorithm, and can cover such information as bandwidth, network
delay, hop count, path cost, load, MTU, reliability, and communication cost
(see e.g. this survey for a list of proposed routing metrics). The routing table
stores only the best possible routes, while link-state or topological databases
may store all other information as well.
12. Because a routing metric is specific to a given routing protocol, multi-
protocol routers must use some external heuristic in order to select between
routes learned from different routing protocols. Cisco's routers. A local
network administrator, in special cases, can set up host-specific routes to a
particular machine which provides more control over network usage, permits
testing and better overall security. This can come in handy when required to
debug network connections or routing tables.
As the Internet and IP networks become mission critical business
tools, there has been increased interest in techniques and methods to monitor
the routing posture of networks. Incorrect routing or routing issues cause
undesirable performance degradation, flapping and/or downtime. Monitoring
routing in a network is achieved using Route analytics tools and techniques.
Protocols: TCP, UDP, HTTP, Routing algorithms etc
• Traffic Models: CBR, VBR, Web etc
• Error Models: Uniform, bursty etc
• Radio propagation, Mobility models
• Energy Models
• Topology Generation tools
13. • Visualization tools
• Extensibility
Simulators help in easy verification of protocols in less time, money
• NS offers support for simulating a variety of
• protocol suites and scenarios
• Front end is oTCL, back end is C++
• NS is an on-going effort of research and development
5 Project Descriptions
5.1 Problem Definition
• Error-free retransmission
• No delay bound under bad link
• Resource fluctuation due to wireless medium
• Delay for adaptation
14. 5.2 Overview of the Project
Single hop IEEE 802.11 networks under saturated traffic conditions.
A model that describe the behavior of IEEE 802.11 under different offered
traffic loads. This model shows the effect of the offered load on the
transmission probability. We also propose a three dimensional model to
attempt to describe the behavior of multi-hop 802.11 networks. The 3D
model allows the modeling of not only data sources but also relay stations
that forward traffic. The IEEE 802.11 DCF scheme, stressing key elements
related to this paper. The protocol under unsaturated traffic loads is
discussed.
5.3 Module Description
1. Multi-hop Wireless Network
A wireless network adopting multihop wireless technology without
deployment of wired backhaul links Similar to Mobile Ad hoc Networks
(MANET), but nodes in MWN is relative ‘fixed’ , it may introduce
‘hierarchy’ network architecture. every station is assumed to be a data
source that sends out saturated traffic. In a multi-hop wireless network, each
15. station in the whole network is not necessarily a data source. A station may
act as a data source for a period of time when it has original data to send,
while at other times it may act as a relay station that simply forwards other
stations’ data
2. IEEE 802.11 MAC protocol
Recently, the IEEE has standardized the 802.11 protocol for Wireless
Local Area Networks. The primary medium access control (MAC) technique
of 802.11 is called distributed coordination function (DCF). DCF is a carrier
sense multiple access with collision avoidance (CSMA/CA) scheme with
binary slotted exponential back off. We provides a simple, but nevertheless
extremely accurate, analytical model to compute the 802.11 DCF
throughput, in the assumption of finite number of terminals and ideal
channel conditions. The proposed analysis applies to both the packet
transmission schemes employed by DCF, namely, the basic access and the
RTS/CTS access mechanisms. In addition, it also applies to a combination
of the two schemes, in which packets longer than a given threshold are
transmitted according to the RTS/CTS mechanism.
16. Media Access Scheme: CSMA/CA
Avoidance by RTS/CTS
ACK mechanism
Exponential Back off
3. Implementation of saturated traffic in relay
station
Stations are statistically identical, each station has idle periods that are
exponentially distributed, and packet length is constant. At any given time,
statistically, a certain number of stations within a given station’s
transmission range act as data sources that inject data traffic. These are
called source stations. Other stations act as data relays that forward traffic
within the network. These are called relay stations. A relay station listens to
the medium, gets packets from it and forwards the packets it receives. The
number of packets a relay station receives and accepts to forward depends
on the upper layer routing protocol. the analysis of the MAC protocol, we
need to find a way to isolate or take into account the upper layer protocol.
The different routing protocols distribute the traffic load among the stations
in different ways
17. 4. Performance Analysis
• Energy Conception
• Packet delay
• Flow of traffic
5.3.1 Modules
1. Multi-hop Wireless Network
2. IEEE 802.11 MAC protocol
3. Implementation of saturated traffic in relay station
4. Performance analysis
18. 5.4 Data Flow Diagram
Level 0:
Multi-hop
Node Ad-Hoc Single hop
Networks neighbor
creation
Level 1:
Source Node Destination
Node
Response
IEEE802.11
protocol
19. Level 2:
Source Relay Node Destination
One hop neighbor
Traffic Monitoring IEEE802.11
protocol
5.5 Use case Diagram
20. Intermediate
Source Relay Destination
Station
Request
One hop neighbor
Response
IEEE802.11
Routing
Traffic Monitoring
6. System Testing
21. The program ``validate'' in the root directory of the ns distribution runs all
current standard tests. Protocols covered in validate represent the most stable
core of ns. We insure that validate passes on several different systems for
each ns release, and we run it over the daily snapshot (see below).
We encourage you to report problems with validated protocols to us. We try
to resolve these problems rapidly (as resources allow).
Even though we consider these protocols ``validated'', our test suite coverage
is not complete. You are advised to look at what aspects of the protocols are
tested in the test suite before drawing research conclusions from these
protocols.
Protocols and modules covered at least in part by validate include the
following:
Application-level:
• HTTP, web caching and invalidation, TcpApp (test-suite-
webcache.tcl)
• telnet and ftp sources (test-suite-simple.tcl)
• Constant-Bit-Rate (CBR) sources (e.g., in test-suite-cbq.tcl)
• On/Off sources (in test-suite-intserv.tcl)
22. Transport protocols (UDP, TCP, RTP, SRM):
• basic TCP behavior (test-suite-simple.tcl, test-suite-v1{,a}.tcl)
• Tahoe, Reno, New-Reno, and SACK TCP under different losses (test-
suite-tcpVariants.tcl)
• FACK TCP (limited validation in test-suite-tcpVariants.tcl)
• TCP vegas (test-suite-vegas-v1.tcl)
• New-Reno TCP (test-suite-newreno.tcl)
• SACK TCP (test-suite-sack{,-v1,v1a})
• full TCP (test-suite-full.tcl), partial validation only.
• TCP initial window behavior (test-suite-tcp.tcl)
• rate-based pacing TCP (test-suite-rbp.tcl)
• RFC-2001 (Reno) TCP behavior (test-suite-rfc2001.tcl)
• RTP (in test-suite-friendly.tcl, not yet added to "validate")
• SRM (in test-suite-srm.tcl)
Routing:
• algorithmic routing (test-suite-algo-routing)
23. • hierarchical routing (test-suite-hier-routing.tcl)
• lan routing and broadcast (test-suite-lan.tcl)
• manual routing (test-suite-manual-routing.tcl)
• centralized multicast, DM multicast, not detailedDM, not multicast
over LAN (test-suite-mcast.tcl)
• routing dynamics (test-suite-routed.tcl)
• detailed simulation using virtual classifier (test-suite-vc.tcl)
• mixed-mode session-levels simulation (test-suite-mixmode.tcl)
• session-level simulation (test-suite-session.tcl)
Router Mechanisms (scheduling, queue management, admissions
control, etc.):
• several queue scheduling algorithms: FQ (Fair Queueing), SFQ
(Stochastic Fair Queuing), DRR (Deficit Round Robin), FIFO (with
drop-tail and RED queue management) (test-suite-schedule.tcl)
• CBQ (both in v1 and v2 mode) (test-stuite-cbq{,-v1,-v1a})
• RED queue management (test-suite-red{,-v1,-v1a})
• ECN behavior (and TCP interactions) (test-suite-ecn.tcl)
• admission control algorithms: MS, HB, ACTP, ACTO, parameter-
based (in test-suite-intserv.tcl)
24. Link-layer mechanisms:
• LANs, with CSMA/CD MAC protocols (in test-suite-lan.tcl)
• snoop
Other:
• Error Modules (e.g., in test-suite-ecn.tcl, test-suite-tcp-init-win.tcl,
test-suite-session.tcl, and test-suite-srm.tcl)
In addition there are a number of protocols in the standard ns distribution
which are not covered by validate. Because they cannot be automatically
tested, bit-rot sometimes breaks these protocols.
We attempt to keep non-validated protocols working and welcome
bug reports. Becuase of difficulties maintaining code that we did not write
and for which we may not know ``ground truth'', we cannot promise that
these protocols will remain working. We strongly encourage people using
these protocols in their research to examine their output carefully and
implement test suites for them so that we can move them into the
``validated'' category.
Configure:
25. A simple ./configure will try to auto-detect the packages ns needs to build.
Auto-detection searchs sensible places (like /usr/local) and the directory
above current direcory. If you have packages installed elsewhere you can
explicitly tell ns where something is with options like --with-
tcl=/your/path/to/tcl. Run ./configure --help for a complete list of options
To make this even easier, the make utility has a set of built-in rules so you
only need to tell it what new things it needs to know to build your particular
utility. For example, if you typed in make love, make would first look for
some new rules from you. If you didn't supply it any then it would look at its
built-in rules. One of those built-in rules tells make that it can run the linker
(ld) on a program name ending in .o to produce the executable program.
So, make would look for a file named love.o. But, it wouldn't stop there.
Even if it found the .o file, it has some other rules that tell it to make sure the
.o file is up to date. In other words, newer than the source program. The
most common source program on Linux systems is written in C and its file
name ends in .c.
If make finds the .c file (love.c in our example) as well as the .o file, it
would check their timestamps to make sure the .o was newer. If it was not
26. newer or did not exist, it would use another built-in rule to build a new .o
from the .c (using the C compiler). This same type of situation exists for
other programming languages. The end result, in any case, is that when
make is done, assuming it can find the right pieces, the executable program
will be built and up to date.
The old UNIX joke, by the way, is what early versions of make said when it
could not find the necessary files. In the example above, if there was no
love.o, love.c or any other source format, the program would have said:
make: don't know how to make love. Stop.
Getting back to the task at hand, the default file for additional rules in
Makefile in the current directory. If you have some source files for a
program and there is a Makefile file there, take a look. It is just text. The
lines that have a word followed by a colon are targets. That is, these are
words you can type following the make command name to do various
things. If you just type make with no target, the first target will be executed.
What you will likely see at the beginning of most Makefile files are what
look like some assignment statements. That is, lines with a couple of fields
with an equal sign between them. Surprise, that is what they are. They set
27. internal variables in make. Common things to set are the location of the C
compiler (yes, there is a default), version numbers of the program and such.
This now beings up back to configure. On different systems, the C compiler
might be in a different place, you might be using ZSH instead of BASH as
your shell, the program might need to know your host name, it might use a
dbm library and need to know if the system had gdbm or ndbm and a whole
bunch of other things. You used to do this configuring by editing Makefile.
Another pain for the programmer and it also meant that any time you wanted
to install software on a new system you needed to do a complete inventory
of what was where.
As more and more software became available and more and more POSIX-
compliant platforms appeared, this got harder and harder. This is where
configure comes in. It is a shell script (generally written by GNU Autoconf)
that goes up and looks for software and even tries various things to see what
works. It then takes its instructions from Makefile.in and builds Makefile
(and possibly some other files) that work on the current system.
Background work done, let me put the pieces together.
28. • You run configure (you usually have to type ./configure as most
people don't have the current directory in their search path). This
builds a new Makefile.
• Type make This builds the program. That is, make would be executed,
it would look for the first target in Makefile and do what the
instructions said. The expected end result would be to build an
executable program.
• Now, as root, type make install. This again invokes make, make finds
the target install in Makefile and files the directions to install the
program.
This is a very simplified explanation but, in most cases, this is what you
need to know. With most programs, there will be a file named INSTALL
that contains installation instructions that will fill you in on other
considerations. For example, it is common to supply some options to the
configure command to change the final location of the executable program.
There are also other make targets such as clean that remove unneeded files
after an install and, in some cases test which allows you to test the software
between the make and make install steps.
29. 7. Literature review
1. Achieving higher throughput in ieee 802.11 wireless local area
networks with burst transmission methods : As extensions in the
emerging 802.11e for quality-of-service provisioning, burst transmission and
the acknowledgment aggregation are the two important operations to
improve the channel efficiency of IEEE 802.11-based wireless local area
networks (WLANs). However, only a few works have been done on these
operations, and usually assumed the networks to be operated under saturated
traffic conditions and error-free channels. In practice, the assumptions may
not be valid because real-time traffic with proper rate control will not
saturate the networks and the channel is generally error-prone. Thus, the
authors consider two new methods resulted from these operations and
analyse their performance under unsaturated and error-prone WLANs, with
a Markov chain model. The results show that the new methods generally
have better throughput than the conventional IEEE 802.11 medium access
control (MAC) in the WLANs.
30. 2. On the throughput performance of multirate IEEE 802.11 networks
with variable-loaded stations: analysis, modeling, and a novel proportional
fairness criterion: This paper focuses on multirate IEEE 802.11 Wireless
LAN employing the mandatory Distributed Coordination Function (DCF)
option. Its aim is threefold. Upon starting from the multi-dimensional
Markovian state transition model proposed by Malone et.al. for
characterizing the behavior of the IEEE 802.11 protocol at the Medium
Access Control layer, it presents an extension accounting for packet
transmission failures due to channel errors. Second, it establishes the
conditions under which a network constituted by N stations, each station
transmitting with its own bit rate, Rd(s), and packet rate, λs, can be assumed
loaded. Finally, it proposes a modified Proportional Fairness (PF) criterion,
suitable for mitigating the rate anomaly problem of multirate loaded IEEE
802.11 Wireless LANs, employing the mandatory DCF option. Compared to
the widely adopted assumption of saturated network, the proposed fairness
criterion can be applied to general loaded networks. The throughput
allocation resulting from the proposed algorithm is able to greatly increase
the aggregate throughput of the DCF, while ensuring fairness levels among
the stations of the same order as the ones guaranteed by the classical PF
31. criterion. Simulation results are presented for some sample scenarios,
confirming the effectiveness of the proposed criterion for optimized
throughput allocation.
3. Enhancing quality of service in MANETS by effective routing :
This paper evaluates the performance evaluation by combining Network
layer and MAC layer protocols with Transport layer congestion control
mechanisms operating in a mobile adhoc network. In Adhoc networks,
certain QoS parameters like error rate, delay and packet loss are increased
and certain parameters like throughput and delivery ratio are decreased in
Transport layer is due to MAC problems and disconnection is also possible
due to mobility because the network layer is not able to detect the path to
deliver the packets. So, combine the mechanisms of these three layers to
improve the QoS drastically. We examine the effects of two different MAC
protocols - IEEE 802.11and IEEE802.11e with AODV and DSR of routing
algorithms with Slow start and Arithmetic Increase and Multiplicative
Decrease (AIMD) mechanism of TCP.IEEE802.11 uses distributed
coordination function (DCF) where IEEE802.11e uses enhanced distributed
coordination function (EDCF). Specifically, we access the impact of
multiple wireless hops and node mobility on the throughput performance of
32. TCP on each MAC protocol with two routing algorithms. Additionally the
other QoS parameters of delay, Bandwidth delay product, delivery ratio and
packet loss is also investigated. Results show that in all instances, the QoS
parameters 15-20% improvement in throughput, 40-45% improvement in
bandwidth-delay product, 10-15% improvement in delivery ratio, packet loss
is reduced drastically to 40-50% in IEEE802.11e with AODV algorithm in
network layer and slow start mechanism in transport layer. Similarly Results
shows, the QoS parameters 35-40% improvement in throughput, 25-30%
improvement in bandwidth-delay product, 15-20% improvement in delivery
ratio, packet loss is reduced drastically to 20-25% in IEEE802.11e with
AODV algorithm in network layer and AIMD mechanism in transport layer.
But if DSR algorithm is used in the network layer instead of AODV it
affects the QoS parameters. In both cases DSR algorithm increases the -
packet loss which in turn affects the throughput and packet delivery ratio.
The reason is analyzed and suggests the suitable mechanisms implemented
in each layer to enhance QoS parameters.
33. 5. A distributed contention control mechanism for power saving in
random-access Ad-hoc wireless local area networks: The power
consumption of mobile computers connected to wireless networks is
negatively affected by the congestion level of the channel, and
significantly depends on the medium access control (MAC) protocol
policy. This paper illustrates the design and the performance evaluation
of a new mechanism for the distributed contention control of the
random accesses to the shared transmission channel of a wireless LAN
(WLAN). The aim is the design of a distributed access scheme where
each frame transmission leads to an optimal power consumption level,
from the network interface (NI) viewpoint. To achieve this goal, we
present a new analytical model to define the optimal average power
consumption required by the NI for a frame transmission, and for a
given random-access scheme. Specifically, we considered the Standard
IEEE 802.11 Distributed Coordination Function (DCF) access scheme
for WLANs. By exploiting the optimal values analytically derived, we
define a parametric and adaptive power-save, distributed contention
control (PS-DCC) mechanism. The proposed mechanism has been
investigated via simulation. The power consumption of the proposed
mechanism approximates the analytically defined optimal level,
34. outperforming the Standard 802.11 DCF access scheme. To confirm
the absence of overheads introduced, the channel utilization still results
closely approximating the optimal values
6. A Protocol Enhancement for IEEE 802.11 Distributed Power Saving
Mechanisms No Data Acknowledgement: Mobile devices including
wireless LAN functionality are becoming increasingly popular in society.
The wide range of products available in the market target different customer
needs but most of them should meet two main requirements: QoS support
for differentiating real-time services from non real-time and power saving
functionality to achieve an operating time according to users' expectations.
The devices presenting the most challenging technical issues to meet these
two requirements are dual-mode handsets (cellular/WLAN) because of their
mandatory support of a strict QoS demanding application, VoIP, and their
small device size which severely limits the battery capacity. The focus of our
work in this paper is the design and evaluation of an enhancement of the
distributed wireless LAN power saving mechanisms defined in the IEEE
802.11 and 802.11e standards, no data acknowledgment (NDACK). The
objective of NDAck is to increase the battery lifetime of wireless LAN
mobile devices while providing the required QoS. The protocol
35. improvement designed has been implemented in OPNET to evaluate the
performance enhancements obtained. Our results show that (i) NDAck
significantly reduces the power consumption of stations running real-time
applications, (ii) the larger the power consumption due to the congestion in
the wireless channel the larger the power consumption reduction with
NDAck and (iii) NDAck results in a considerable QoS improvement for
real-time applications.
8 Conclusion & Future Enhancements
8.1 Conclusion
The performance analysis with saturated traffic does not apply to nodes that
do not originate traffic but may forward it in on behalf of others. Sometimes,
these relay stations may not have any packet to forward. Another challenge
is the fact that not all relay stations receive the same amount of data to
forward. This amount is determined by the upper layer routing protocol.
8.2 Future Enhancements
Enhancing the protocol from IEEE802.11 from IEEE802.11 e /
IEEE802.16
36. 9 Appendix
9.1 Source Code
set val(chan) Channel/WirelessChannel
set val(prop) Propagation/TwoRayGround
set val(netif) Phy/WirelessPhy
set val(mac) Mac/802_11
set val(ifq) Queue/DropTail/PriQueue
set val(ll) LL
set val(ant) Antenna/OmniAntenna
set val(x) 800
set val(y) 800
set val(ifqlen) 1500
set val(seed) 1.0
set val(adhocRouting) AODV
set val(nn) 10
set val(stop) 15.0
set val(energymodel) EnergyModel ;
set val(radiomodel) RadioModel ;
set val(initialenergy) 1000 ;# Initial energy in Joules
37. set ns_ [new Simulator]
set topo [new Topography]
set tracefd [open out.tr w]
set namtrace [open out.nam w]
$ns_ trace-all $tracefd
$ns_ namtrace-all-wireless $namtrace $val(x) $val(y)
$topo load_flatgrid $val(x) $val(y)
set god_ [create-god $val(nn)]
$ns_ node-config -adhocRouting AODV
-llType $val(ll)
-macType $val(mac)
-ifqType $val(ifq)
-ifqLen $val(ifqlen)
-antType $val(ant)
38. -propType $val(prop)
-phyType $val(netif)
-channelType $val(chan)
-topoInstance $topo
-agentTrace ON
-routerTrace ON
-macTrace ON
for {set i 0} {$i < $val(nn) } {incr i} {
set node_($i) [$ns_ node]
}
set X1(0) 130.32
set X1(1) 235.55
set X1(2) 336.499
set X1(3) 147
set X1(4) 488.23
set X1(5) 374.881
set X1(6) 246.766
set X1(7) 167.161
set X1(8) 419.979
set X1(9) 532.0
set Y1(0) 539.172
39. set Y1(1) 476.86
set Y1(2) 532.92
set Y1(3) 774.801
set Y1(4) 455.623
set Y1(5) 344.034
set Y1(6) 664.992
set Y1(7) 326.676
set Y1(8) 754.081
set Y1(9) 619.0
for {set i 0} {$i < $val(nn) } {incr i} {
$node_($i) set X_ $X1($i)
$node_($i) set Y_ $Y1($i)
$node_($i) set Z_ 0.0
}
puts "Loading scenario file..."
for {set i 0} {$i < $val(nn) } {incr i} {
$ns_ initial_node_pos $node_($i) 30
40. }
for {set i k} {$i < $val(nn) } {incr i} {
$ns_ at $val(stop).0 "$node_($i) reset";
}
puts "-----------------------------------------------"
puts "Routing table"
puts "-----------------------------------------"
puts "|Node | one hop neighbour|"
puts "-----------------------------------------"
for {set i 0} {$i < $val(nn) } {incr i} {
for {set j 0} {$j < $val(nn) } {incr j} {
set a [ expr $X1($j)-$X1($i)]
set b [ expr $a*$a]
set c [ expr $Y1($j)-$Y1($i)]
set d [ expr $c*$c]
set e [ expr $b+$d]
41. set f 0.5
set g [expr pow($e,$f)]
if {$g <= 200 && $i != $j} {
puts "| Node($i) | ($j) |"
}
}
puts "-----------------------------------------"
}
set udp_(0) [new Agent/UDP]
$ns_ attach-agent $node_(0) $udp_(0)
set null1_(0) [new Agent/Null]
$ns_ attach-agent $node_(4) $null1_(0)
set cbr1_(0) [new Application/Traffic/CBR]
$cbr1_(0) set packetSize_ 1000
$cbr1_(0) set interval_ 0.01
$cbr1_(0) set random_ 1
$cbr1_(0) set maxpkts_ 1000
$cbr1_(0) attach-agent $udp_(0)
42. $ns_ connect $udp_(0) $null1_(0)
$ns_ at 1.00 "$cbr1_(0) start"
$ns_ at 5.3 "$cbr1_(0) stop"
$ns_ at 0.0 "$node_(0) setdest 589 732 5"
$ns_ at 0.0 "$node_(1) setdest 294 670 5"
$ns_ at 0.0 "$node_(2) setdest 395 726 5"
$ns_ at 0.0 "$node_(3) setdest 405 765 5"
$ns_ at 0.0 "$node_(4) setdest 147 649 5"
$ns_ at 0.0 "$node_(5) setdest 733 537 5"
$ns_ at 0.0 "$node_(6) setdest 605 758 5"
$ns_ at 0.0 "$node_(7) setdest 426 520 5"
$ns_ at 0.0 "$node_(8) setdest 378 647 5"
$ns_ at 0.0 "$node_(9) setdest 490 612 5"
$ns_ at 0.05 "$node_(0) label M0"
$ns_ at 0.05 "$node_(1) label M1"
$ns_ at 0.05 "$node_(2) label M2"
$ns_ at 0.05 "$node_(3) label M3"
$ns_ at 0.05 "$node_(4) label M4"
$ns_ at 0.05 "$node_(5) label M5"
$ns_ at 0.05 "$node_(6) label M6"
$ns_ at 0.05 "$node_(7) label M7"
$ns_ at 0.05 "$node_(8) label M8"
43. $ns_ at 0.05 "$node_(9) label M9"
$ns_ at 0.05 "$node_(0) add-mark m blue circle"
$ns_ at 0.05 "$node_(1) add-mark m gray circle"
$ns_ at 0.05 "$node_(2) add-mark m gray circle"
$ns_ at 0.05 "$node_(3) add-mark m gray circle"
$ns_ at 0.05 "$node_(4) add-mark m green circle"
$ns_ at 0.05 "$node_(5) add-mark m gray circle"
$ns_ at 0.05 "$node_(6) add-mark m gray circle"
$ns_ at 0.05 "$node_(7) add-mark m gray circle"
$ns_ at 0.05 "$node_(8) add-mark m gray circle"
$ns_ at 0.05 "$node_(9) add-mark m gray circle"
$ns_ at 15.0 "finish"
$ns_ at $val(stop).0002 "puts "NS EXITING..." ; $ns_ halt"
puts $tracefd "M 0.0 nn $val(nn) x $val(x) y $val(y) rp $val(adhocRouting)"
puts $tracefd "M 0.0 prop $val(prop) ant $val(ant)"
puts "Starting Simulation..."
proc finish {} {
#exec nam out.nam &
exit 0
}
52. REFERENCES
[1] Y. D. Barowski and S. Biaz, “The performance analysis of ieee-802.11
under unsaturated traffic conditions,” Tech. Rep. CSSE04-09, Auburn
University, Aug. 2004.
[2] V. Bharghavan, A. Demers, S. Shenker, and L. Zhang, “MACAW: A
media access protocol for wireless LANs,” in ACM SIGCOMM, London,
U.K, pp. 212–225, Oct. 1994.
[3] G. Bianchi, “Performance analysis of the IEEE802.11 distributed
coordination function,” IEEE Journal in Selected Areas: Communication,
vol. 18, pp. 535–547, March 2000.
[4] L. Bononi, M. Conti, and L. Donatiello, “A distributed mechanism for
power saving in IEEE 802.11 wireless lans,” Mobile Networks and
Applications, vol. 6, no. 3, pp. 211–222, 2001.
[5] F. Cali, M. Conti, and Gregori, “IEEE802.11 wireless lan: Capacity
analysis and protocol enhancement,” in INFOCOM ’98 Seventeenth Annual
Joint Conference of the IEEE Computer and Communications Societies.
Proceedings. IEEE, 1998.
53. [6] M. M. Carvalho and J. J. Garcia-Luna-Aceves, “Delay analysis of the
IEEE802.11 in single-hop networks,” in 11th IEEE International Conference
on Network Protocols (ICNP’03), Atlanta, Georgia, USA, Nov. 2003.
[7] H. S. Chhaya and S. Gupta, “Performance modeling of asynchronous
data transfer methods of IEEE802.11 mac protocol,” Wirel. Netw., vol. 3,
no. 3, pp. 217–234, 1997.
[8] D. S. J. De Couto, D. Aguayo, B. A. Chambers, and R. Morris,
“Performance of multihop wireless networks: Shortest path is not enough,”
in Proceedings of the First Workshop on Hot Topics in Networks (HotNets-
I), (Princeton, New Jersey), ACM SIGCOMM, October 2002.
[9] L. M. Feeney and M. Nilsson, “Investigating the energy consumption
of a wireless network interface in an ad hoc networking environment,” in
IEEE INFOCOM, Anchorage, AK, USA, 2001.
[10] L. Huang and T.-H. Lai, “On the scalability of IEEE802.11 ad hoc
networks,” in Proceedings of the 3rd ACM international symposium on
Mobile ad hoc networking & computing, pp. 173–182, ACM Press, 2002