| Unidirectional Links in Mobile Ad Hoc Networks |
| The project deals with investigating the occurrence and impact of unidirectional links in a MANET. The conventional routing protocols are not tailored to handle the existence of such links and often treat them as non existent, in making their routing decisions. In this project, two approaches are used to overcome the problems caused by unidirectional links. Firstly, a routing algorithm which takes into account the directionality of the links between nodes has been developed. Secondly, a framework based on Layer 2 tunneling has been developed, to enable existing routing protocols to effectively use the unidirectional links. |
| Distributed Configuration Management in Mobile Ad Hoc Networks |
| This project deals with enabling nodes in a MANET to dynamically configure themselves upon entry into a network. Since, centralized servers are unavailable in an ad hoc network, this service discovery needs to be done in a distributed manner. Also, the addressing of nodes in an ad hoc network needs to be configured to allow effective internetworking with nodes on the Internet. Distributed algorithms to effectively configure the mobile nodes with service related information are being developed as a part of this project. |
| Characterization of Bursty Traffic and its Effect in Multihop Networks |
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1. The effects of Pareto and merged Pareto interarrival times
in single server queues. 2. Relative effects of high variance and long range dependence in interarrival times. 3. Relative effects of merged Pareto interarrival times and merged queue outputs in a multihop network. 4. The generation and study of effects of traffic with rates corresponding to approximate fractional Brownian noise. |
| Routing and Performance Optimization in Multihop Networks Fielding Bursty Traffic |
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1. Development of a combined model for route discovery, maintenance
and performance optimization. 2. Adaptive operation to deal with burstiness and variations in network structure and traffic. 3. Applications of the above techniques in ad hoc networks. |
| Medium Access Control and Optimization |
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1. Development of analytically tractable models. 2. Invariance of the model to traffic types. 3. Optimizations over multiple channels. |
| Pattern Recognition and Link Level Communication |
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1. Blind and semiblind parameter estimation in finite mixtures. 2. Parameter estimation for hidden Markov systems. 3. Applications in mobile wireless communication. |
| Channel Allocation in Cellular/Rapidly Deployable Networks |
| Distributed algorithms to allocate channels for calls in cellular and rapidly deployable networks are being developed as a part of this project. The channels are treated as a resource which can be held by only one call at a time. Thus, the approach used tailors distributed mutual exclusion to allocate channels to contending base stations, in a conflict-free manner. The base stations are stationary in the case of cellular systems, but are in mobile in the case of rapidly deployable networks. |
| Transport Layer Issues in Mobile Ad Hoc Networks |
| The dynamic nature of ad hoc networks renders TCP in its current form, ineffective for delivering reliable data streams. TCP is tailored to work under the assumption that the main reason for packet loss in congestion, and not due to the unreliability of the link. TCP responds by reducing its throughput in response to packet losses. However, in ad hoc networks, the major reason for packet losses is the high error rate and constant flux of the wireless links. TCP needs to be tailored to use information regarding the breakage and formation of links in order to effectively transmit data. Algorithms to achieve these characteristics are being developed as a part of this project. |
| Location Management in Mobile Ad Hoc Networks |