In this thesis, we have modified AODV routing protocol by incorporating link prediction algorithm using a proposed link prediction model. This algorithm predicts the link availability time and even before the link breaks; either it repairs the route locally or sends information to the source nodes to enable them to initiate a new route search well in time. This algorithm improves the quality of service of the network. Simulation results show that AODV routing algorithm with link availability model performs better than the existing AODV.
Advances in wireless technology and hand-held computing devices have brought revolution in the area of mobile communication. The increasing mobility of humans across the globe generated demand for infrastructure-less and quickly deployable mobile networks. Such networks are referred to as Mobile Adhoc Networks (MANET). Usually, nodes in a MANET also act as a router while being is free to roam while communicating each others. Adhoc networks are suited for use in situations where infrastructure is unavailable or to deploy one is not cost-effective.
Frequent changes in network topology due to mobility and limited battery power of the mobile devices are the key challenges in the adhoc networks. The depletion of power source may cause early unavailability of nodes and thus links in the network. The mobility of nodes will also causes frequent routes breaks and adversely affects the required performance for the applications.
Availability of a route in future mainly depends on the availability of links between the nodes forming the route. Therefore, it is important to predict the future availability of a link that is currently available. We have proposed an analytical model for link prediction using Newton divided difference method. This link availability algorithm is incorporated in AODV routing algorithm (AODVLP) to evaluate the performance of AODV routing protocol using the metrics viz. delivery rate, average end-to-end delay, average RTS collisions per node and route failure. In the existing AODV protocol, packets are routed until a link in the existing path fails. This results in degradation of quality of service of network in terms of end-to-end delay and delivery ratio.
Table of Contents
CHAPTER 1 : Introduction
1.1 Mobile Adhoc Networks
1.2 Important Issues
1.3 MAC Protocols
1.4 Routing Protocols
1.4.1 Routing Protocol Strategies
1.4.1.1 Proactive strategy
1.4.1.2 Reactive strategy
1.4.1.3 Hybrid strategy
1.4.2 Destination Sequenced Distance Vector (DSDV) Routing
1.4.3 Adhoc On Demand Distance Vector (AODV) Routing
1.4.4 Dynamic Source Routing (DSR)
1.4.5 Temporally Ordered Routing Algorithm (TORA)
1.5 Cross Layer Design in Mobile Adhoc Networks
1.6 Motivation for the Thesis
1.7 Problem Definition
1.8 Objectives
1.9 Contributions of the Thesis
1.10 Organization of the Thesis
CHAPTER 2 : Wireless MAC, Routing and Cross layer Protocols
2.1 Wireless MAC Protocols
2.1.1 IEEE 802.11b Standard
2.1.2 RTS-CTS-DATA-ACK four way handshake Protocol
2.1.3 Minimum Transmit Power Control Protocols
2.2 Quality of Service Routing
2.2.1 Quality of service in Adhoc Networks
2.2.1.1 Special Issues and Difficulties in MANETS
2.2.1.2 Hard state versus soft state resource reservation
2.2.1.3 Stateful versus Stateless approach
2.2.1.4 Hard QoS versus Soft QoS approach
2.2.2 Classification of QoS Approaches
2.2.3 QoS Models
2.2.3.1 IntServ
2.2.3.2 DiffServ
2.2.3.3 IntServ over DiffServ
2.2.3.4 FQMM
2.2.4 Related Work
2.3 Cross Layer Design
2.3.1 Layered vs Cross Layered approach
2.3.2 Motivations for cross layer design
2.3.3 Cross Layer Protocols
CHAPTER 3 : Link Availability Model
3.1 Link Prediction
3.1.1 Link Prediction Algorithm
3.2 Simulation and Results
3.2.1 Simulation Parameters
3.2.2 Performance Metrics
3.2.3 Simulation Results and Analysis
3.2.3.1 CBR Simulations
3.2.3.2 Energy Simulations
3.2.3.3 TCP Simulations
3.3 Summary and Future Work
CHAPTER 4 : Dynamic Power Control wireless adhoc MAC Protocol
4.1 Dynamic Power Control wireless adhoc MAC Protocol
4.1.1 Proposed Protocol Basics
4.1.2 Model Description
4.1.3 Proposed Protocol Description
4.1.4 Proposed Protocol Algorithm
4.2 Simulation and Results
4.2.1 Simulation Parameters
4.2.2 Performance Metrics
4.2.3 Results and Analysis
4.3 Summary and Future work
CHAPTER 5 : Cross Layer Design for Power Control and Link Availability
5.1 Cross Layer Power Control and Link Availability Prediction
5.1.1 Power Control
5.1.2 Link Availability
5.1.3 Proposed Protocol Algorithm
5.2 Simulation and Results
5.2.1 Simulation Parameters
5.2.2 Performance Metrics
5.2.3 Simulation Results and Analysis
5.3 Summary and Future Work
CHAPTER 6 : Conclusion and Future Work
Bibliography
Objectives and Topics
This thesis focuses on improving the performance and quality of service (QoS) in Mobile Adhoc Networks (MANETs) by addressing the challenges of limited battery life, node mobility, and unpredictable network topology. The primary objective is to develop cross-layer optimization protocols that predict link availability and dynamically manage transmit power to enhance network stability and energy efficiency.
- Development of an analytical model for link availability prediction using the Newton divided difference method.
- Modification of the AODV routing protocol to incorporate predictive link-state information (AODVLP).
- Design of a Dynamic Power Control (DPCP) MAC protocol to optimize battery consumption through RTS-CTS-DATA-ACK handshake modifications.
- Integration of power control and link prediction into a comprehensive cross-layer design (DPCPLP).
- Performance evaluation using the ns-2 network simulator, focusing on throughput, packet delivery ratio, end-to-end delay, and energy consumption.
Excerpt from the Book
3.1 Link Prediction
In traditional mobile and wired-network routing algorithms, a change of path happens when a link along the path fails or another shorter path is found. A link failure is costly because multiple retransmission timeouts are required to detect the failure and after that a new path has to be found, leading to delay in restoration. Since paths fail so infrequently in wired networks, this is not an important issue. However, as routing protocols in mobile networks follow this model despite the significantly higher frequency of path disconnections that occur, QoS of route does get affected.
In this section, we propose a link prediction algorithm to predict the time after which an active link will break. This is done by estimating the time at which received signal strength of the data packets will fall below a threshold power. The received power level below the threshold indicates that the two nodes are moving away from each other’s radio transmission range. The prediction of link break warns the source before the path breaks and the source can rediscover a new path in advance.
Chapter Summaries
CHAPTER 1 : Introduction: Provides an overview of MANETs, discusses standard routing protocols, and outlines the motivation for implementing cross-layer design to improve network performance.
CHAPTER 2 : Wireless MAC, Routing and Cross layer Protocols: Details existing MAC and routing protocols, with a specific focus on power-aware mechanisms and various QoS approaches for adhoc environments.
CHAPTER 3 : Link Availability Model: Introduces the novel link prediction model using the Newton divided difference method and presents simulation analysis of the modified AODV (AODVLP) protocol.
CHAPTER 4 : Dynamic Power Control wireless adhoc MAC Protocol: Describes the design and performance evaluation of the proposed DPCP protocol, aimed at minimizing energy usage and maximizing throughput.
CHAPTER 5 : Cross Layer Design for Power Control and Link Availability: Explains the integrated DPCPLP design that combines link prediction and dynamic power control, demonstrating performance improvements over non-cross-layer approaches.
CHAPTER 6 : Conclusion and Future Work: Summarizes the thesis contributions and suggests future research directions, such as evaluating these methods under real-time traffic conditions or incorporating transport layer congestion control.
Keywords
Mobile Adhoc Networks, MANET, Cross Layer Optimization, Link Prediction, AODV, Dynamic Power Control, MAC Protocol, QoS, Energy Efficiency, Network Throughput, Newton Divided Difference, IEEE 802.11, NS-2, Link Availability, Wireless Communication
Frequently Asked Questions
What is the core problem addressed in this thesis?
The thesis addresses the challenges of frequent link failures, limited node battery life, and suboptimal routing performance in Mobile Adhoc Networks (MANETs) due to node mobility.
What are the key themes of the research?
The work focuses on cross-layer interaction, link availability prediction, power-aware MAC protocol design, and Quality of Service (QoS) improvement.
What is the main objective of the thesis?
The goal is to design and implement cross-layer solutions that reduce link failures and optimize power consumption to increase the overall lifetime and capacity of MANETs.
Which methodology is used to evaluate the proposed protocols?
The author uses the ns-2 network simulator to conduct extensive performance evaluations, comparing the proposed models (AODVLP, DPCP, DPCPLP) against existing standard protocols like AODV and IEEE 802.11.
What is covered in the main body of the work?
The main body covers link prediction modeling, power control MAC protocols, and the integration of these features into a unified cross-layer design for improved network stability and performance.
Which keywords best describe the research?
The work is best characterized by terms such as MANET, AODV, cross-layer optimization, power control, link prediction, and network performance evaluation.
How does the link prediction model function?
The model uses the Newton divided difference interpolation method to estimate when the received signal strength will fall below a defined threshold, allowing the system to predict a link break before it occurs.
What is the benefit of the proposed DPCPLP cross-layer design?
The DPCPLP design combines optimum transmit power management with predictive link maintenance, resulting in better throughput, lower energy consumption, and reduced communication interruption times.
- Quote paper
- Anita Yadav (Author), 2016, Cross Layer Optimization for Protocols in Mobile Adhoc Networks, Munich, GRIN Verlag, https://www.grin.com/document/534967
