Link State Routing in Wireless Ad-Hoc Networks

International audienceLink state has been the dominating IGP routing technology in IP networks for more than a decade. With the advent of wireless ad-hoc networking, the need for light, efficient and robust routing makes it a good candidate to be also used in this constrained environment. One of the key issue in ad-hoc networking is the lack of bandwidth. Thus, in this paper we examine the overhead due to link state routing in an ad-hoc network. More precisely we study the classic link-state protocol OSPF and OLSR, a link state protocol that was developed specifically for ad-hoc networks. Further, we study how this overhead evolves when the node density increases. The last part of the paper presents directions towards extending OSPF for wireless and ad-hoc networks, which would make it a favorite to seamlessly unify wired and mobile IP networks

Simulation of Networked Control Systems Using TrueTime

This paper gives a brief introduction to the TrueTime simulator and then gives several examples on how TrueTime can be used to simulate networked control systems. Among the examples are time-triggered and event-based networked control and AODV routing in wireless ad-hoc networks

Cooperative routing in wireless ad hoc networks.

Cheung, Man Hon.Thesis (M.Phil.)--Chinese University of Hong Kong, 2007.Includes bibliographical references (leaves 89-94).Abstracts in English and Chinese.Abstract --- p.iAcknowledgement --- p.iiiChapter 1 --- Introduction --- p.1Chapter 1.1 --- Rayleigh Fading Channels --- p.1Chapter 1.2 --- Ultra-Wideband (UWB) Communications --- p.2Chapter 1.2.1 --- Definition --- p.2Chapter 1.2.2 --- Characteristics --- p.3Chapter 1.2.3 --- UWB Signals --- p.4Chapter 1.2.4 --- Applications --- p.5Chapter 1.3 --- Cooperative Communications --- p.7Chapter 1.4 --- Outline of Thesis --- p.7Chapter 2 --- Background Study --- p.9Chapter 2.1 --- Interference-Aware Routing --- p.9Chapter 2.2 --- Routing in UWB Wireless Networks --- p.11Chapter 2.3 --- Cooperative Communications and Routing --- p.12Chapter 3 --- Cooperative Routing in Rayleigh Fading Channel --- p.15Chapter 3.1 --- System Model --- p.16Chapter 3.1.1 --- Transmitted Signal --- p.16Chapter 3.1.2 --- Received Signal and Maximal-Ratio Combining (MRC) --- p.16Chapter 3.1.3 --- Probability of Outage --- p.18Chapter 3.2 --- Cooperation Criteria and Power Distribution --- p.21Chapter 3.2.1 --- Optimal Power Distribution Ratio --- p.21Chapter 3.2.2 --- Near-Optimal Power Distribution Ratio β´ة --- p.21Chapter 3.2.3 --- Cooperation or Not? --- p.23Chapter 3.3 --- Performance Analysis and Evaluation --- p.26Chapter 3.3.1 --- 1D Poisson Random Network --- p.26Chapter 3.3.2 --- 2D Grid Network --- p.28Chapter 3.4 --- Cooperative Routing Algorithm --- p.32Chapter 3.4.1 --- Cooperative Routing Algorithm --- p.33Chapter 3.4.2 --- 2D Random Network --- p.35Chapter 4 --- UWB System Model and BER Expression --- p.37Chapter 4.1 --- Transmit Signal --- p.37Chapter 4.2 --- Channel Model --- p.39Chapter 4.3 --- Received Signal --- p.39Chapter 4.4 --- Rake Receiver with Maximal-Ratio Combining (MRC) --- p.41Chapter 4.5 --- BER in the presence of AWGN & MUI --- p.46Chapter 4.6 --- Rake Receivers --- p.47Chapter 4.7 --- Comparison of Simple Routing Algorithms in ID Network --- p.49Chapter 5 --- Interference-Aware Routing in UWB Wireless Networks --- p.57Chapter 5.1 --- Problem Formulation --- p.57Chapter 5.2 --- Optimal Interference-Aware Routing --- p.58Chapter 5.2.1 --- Link Cost --- p.58Chapter 5.2.2 --- Per-Hop BER Requirement and Scaling Effect --- p.59Chapter 5.2.3 --- Optimal Interference-Aware Routing --- p.61Chapter 5.3 --- Performance Evaluation --- p.64Chapter 6 --- Cooperative Routing in UWB Wireless Networks --- p.69Chapter 6.1 --- Two-Node Cooperative Communication --- p.69Chapter 6.1.1 --- Received Signal for Non-Cooperative Communication --- p.69Chapter 6.1.2 --- Received Signal for Two-Node Cooperative Communication --- p.70Chapter 6.1.3 --- Probability of Error --- p.71Chapter 6.2 --- Problem Formulation --- p.75Chapter 6.3 --- Cooperative Routing Algorithm --- p.77Chapter 6.4 --- Performance Evaluation --- p.80Chapter 7 --- Conclusion and Future Work --- p.85Chapter 7.1 --- Conclusion --- p.85Chapter 7.2 --- Future Work --- p.86Chapter 7.2.1 --- Distributed Algorithm --- p.87Chapter 7.2.2 --- Performance Analysis in Random Networks --- p.87Chapter 7.2.3 --- Cross-Layer Optimization --- p.87Chapter 7.2.4 --- Game Theory --- p.87Chapter 7.2.5 --- Other Variations in Cooperative Schemes --- p.88Bibliography --- p.8

Link State Routing in Wireless Ad-Hoc Networks

Link state has been the dominating IGP routing technology in IP networks for more than a decade. With the advent of wireless ad-hoc networking, the need for light, efficient and robust routing makes it a good candidate to be also used in this constrained environment. One of the key issue in ad-hoc networking is the lack of bandwidth. Thus, in this paper we examine the overhead due to link state routing in an ad-hoc network. More precisely we study the classic link-state protocol OSPF and OLSR, a link state protocol that was developed specifically for ad-hoc networks. Further, we study how this overhead evolves when the node density increases. The last part of the paper presents directions towards extending OSPF for wireless and ad-hoc networks, which would make it a favorite to seamlessly unify wired and mobile IP networks

Fine-grained reputation-based routing in wireless ad hoc networks

Ad hoc networks are very helpful in situations when no fixed network infrastructure is available. They are especially important in emergency situations such as natural disasters and military conflicts. Most developed wireless ad hoc routing protocols are designed to discover and maintain an active path from source to destination with an assumption that every node is friendly and cooperative. However, it is possible that the participating nodes are selfish or malicious. A mechanism to evaluate reputation for each node is essential for the reliability and security of routing protocol in ad hoc networks. We propose a fine-grained reputation system for wireless ad hoc routing protocols based on constantly monitored and updated first and second-hand reputation information. The nodes in the network monitor their neighbors and obtain first-hand information based on the perceived behavior. Second-hand information is obtained by sharing first-hand information with nodes’ neighbors. Our system is able to distinguish between selfish and malicious nodes and take appropriate actions in either case. We employ the moving-window mechanism which enables us to assign more weight to more recent observations and adjust responsiveness of our reputation system to changes in nodes’ behavior. We show that our fine-grained reputation system is able to improve both reliability and security of an ad hoc network when compared to a reputation system that does not distinguish between selfish and malicious nodes