32,115 research outputs found
An evolutionary approach to routing in mobile AD HOC networks using dominating sets.
This thesis presents a new approach to routing in ad-hoc wireless networks using virtual backbones that may be approximated by the graph theoretic concept of dominating sets. · Ad hoc wireless networks provide a flexible and quick means of establishing wireless peer-to-peer communications. Routing remains the main challenging problem in an ad hoc network due to its multihop nature and dynamic network topology. Several protocols based on virtual backbones in ad hoc wireless networks have been proposed that may be used to simplify the routing process. However, little is known about the network routing performance of these protocols and no attempt has previously been made to directly compare them. This thesis is the first research effort to implement, analyze and compare the routing performance of dominating-set-based routing protocols. In this study, we examine four existing routing approaches using a virtual backbone, or spine , imposed on the adÂhoc network. We then propose an evolutionary approach to constructing a stable minimum connected dominating set in an ad hoc wireless network: this employs the use of a genetic algorithm. Since the mobile· nodes that constitute an ad hoc wireless network are constantly in motion, the network configuration is subject to constant change in a manner that resembles the biological process of mutation. This evolution of networks over time lends itself naturally to a model based on genetic algorithms. As part of an in-depth study of the application of genetic algorithms in the field of wireless networks, a scatternet formation protocol for Bluetooth networks was designed, developed and evaluated. This helped to build the knowledge base required to implement new routing protocols using the network simulator ns-2. Simulation studies were then conducted using ns-2 to compare the performance of previously proposed dominatingÂset-based routing approaches. In this thesis, we analyze the performance of our evolutionary routing approach and compare it with the previous approaches. We present our simulation results and show that our evolutionary routing approach outperforms the other routing algorithms with respect to end-to-end packet delay, throughput, packet delivery ratio and routing overhead· across several different scenarios. Thus, we demonstrate the advantages of utilizing a genetic algorithm to construct a backbone that is · used to effectively route packets in an ad-hoc wireless network
Evolutionary Game for Mining Pool Selection in Blockchain Networks
In blockchain networks adopting the proof-of-work schemes, the monetary
incentive is introduced by the Nakamoto consensus protocol to guide the
behaviors of the full nodes (i.e., block miners) in the process of maintaining
the consensus about the blockchain state. The block miners have to devote their
computation power measured in hash rate in a crypto-puzzle solving competition
to win the reward of publishing (a.k.a., mining) new blocks. Due to the
exponentially increasing difficulty of the crypto-puzzle, individual block
miners tends to join mining pools, i.e., the coalitions of miners, in order to
reduce the income variance and earn stable profits. In this paper, we study the
dynamics of mining pool selection in a blockchain network, where mining pools
may choose arbitrary block mining strategies. We identify the hash rate and the
block propagation delay as two major factors determining the outcomes of mining
competition, and then model the strategy evolution of the individual miners as
an evolutionary game. We provide the theoretical analysis of the evolutionary
stability for the pool selection dynamics in a case study of two mining pools.
The numerical simulations provide the evidence to support our theoretical
discoveries as well as demonstrating the stability in the evolution of miners'
strategies in a general case.Comment: Submitted to IEEE Wireless Communication Letter
Coverage Protocols for Wireless Sensor Networks: Review and Future Directions
The coverage problem in wireless sensor networks (WSNs) can be generally
defined as a measure of how effectively a network field is monitored by its
sensor nodes. This problem has attracted a lot of interest over the years and
as a result, many coverage protocols were proposed. In this survey, we first
propose a taxonomy for classifying coverage protocols in WSNs. Then, we
classify the coverage protocols into three categories (i.e. coverage aware
deployment protocols, sleep scheduling protocols for flat networks, and
cluster-based sleep scheduling protocols) based on the network stage where the
coverage is optimized. For each category, relevant protocols are thoroughly
reviewed and classified based on the adopted coverage techniques. Finally, we
discuss open issues (and recommend future directions to resolve them)
associated with the design of realistic coverage protocols. Issues such as
realistic sensing models, realistic energy consumption models, realistic
connectivity models and sensor localization are covered
Optimisation of Mobile Communication Networks - OMCO NET
The mini conference “Optimisation of Mobile Communication Networks” focuses on advanced methods for search and optimisation applied to wireless communication networks. It is sponsored by Research & Enterprise Fund Southampton Solent University.
The conference strives to widen knowledge on advanced search methods capable of optimisation of wireless communications networks. The aim is to provide a forum for exchange of recent knowledge, new ideas and trends in this progressive and challenging area. The conference will popularise new successful approaches on resolving hard tasks such as minimisation of transmit power, cooperative and optimal routing
- …