Applying genetic algorithm for optimizing broadcasting process in ad-hoc network

Optimizing broadcasting process in mobile ad hoc network (MANET) is considered as a main challenge due to many problems, such as Broadcast Storm problem and high complexity in finding the optimal tree resulting in an NP-hard problem. Straight forward techniques like simple flooding give rise to Broadcast Storm problem with a high probability. In this work, genetic algorithm (GA) that searches over a population that represents a distinguishable ‘structure’ is adopted innovatively to suit MANETs. The novelty of the GA technique adopted here to provide the means to tackle this MANET problem lies mainly on the proposed method of searching for a structure of a suitable spanning tree that can be optimized, in order to meet the performance indices related to the broadcasting problem. In other words, the proposed genetic model (GM) evolves with the structure of random trees (individuals) ‘genetically’ generated using rules that are devised specifically to capture MANET behaviour in order to arrive at a minimal spanning tree that satisfies certain fitness function. Also, the model has the ability to give different solutions depending on the main factors specified such as, ‘time’ (or speed) in certain situations and ‘reachability’ in certain others.

MAR : message-aware routing for opportunistic wireless ad hoc networks

In this paper we study the problem of routing in opportunistic wireless network, and propose a novel routing mechanism, message-aware routing (MAR). Using MAR, the messages can be prioritized at mobile nodes and the resources will be allocated accordingly. The MAR uses the message-aware socializing model to classify mobile nodes into different social groups. In MAR, nodes only maintain up-to-date routing information for the nodes in the same social group and the messages for the nodes in the same social group will have higher priority to be delivered. The MAR improves the routing efficiency in terms of reduced traffic and a higher delivery success rate. Further, MAR is constructed in decentralized way and does not require any centralized infrastructure. Experiments using NS2 simulator show that the MAR achieves higher delivery rate than the Epidemic and Prophet routing.

Ad infinitum (a curious, repetitive melody)

Ad Infinitum is an instrumental piece using mallet instruments that repeats to create suspense with a crescendo in the middle.

Multicast lifetime maximization using network coding in lossy wireless ad-hoc networks

In traditional stop-and-wait strategy for reliable communications, such as ARQ, retransmission for the packet loss problem would incur a great number of packet transmissions in lossy wireless ad-hoc networks. We study the reliable multicast lifetime maximization problem by alternatively exploring the random linear network coding in this paper. We formulate such problem as a min-max problem and propose a heuristic algorithm, called maximum lifetime tree (MLT), to build a multicast tree that maximizes the network lifetime. Simulation results show that the proposed algorithms can significantly increase the network lifetime when compared with the traditional algorithms under various distributions of error probability on lossy wireless links.