Dynamic Reputation-based Encouragement and Adaptive Mechanism (DREAM) for Personal Networks

Abstract

Recent technological trends and know-how in information and communication technologies have given rise to academic interest and industrial efforts in wide development and implementation of heterogeneous networks. Heterogeneous networks, such as personal networks, relay-based wireless networks, multi-hop cellular networks, and hybrid networks, differ in network infrastructure formation, architecture designs and technical features; however, at the same time, they all have common characteristics and visions, such as providing less infrastructure dependency for network users, improvement of overall system performance and enhancement of network connectivity in a ubiquitous way, anytime and anywhere. The increasing popularity of wireless communications and the rising requirements for data transmissions for various types of service and applications have led to higher demands for communication networks to provide continuous service availability. There are also requirements to lessen the need to consider network users geographical location and technological specifications in the formation of existing network infrastructure. Heterogeneous relay-based communication networks have been seen as an effective way to meet network users requirements for increased data bit rate while still retaining the benefits of dynamics from cellular infrastructure and stability from fixed line communication as well. Personal Networks (PNs) are an emerging concept of heterogeneous networks with a strong focus on the activities and participation of network users in the PNs infrastructure formations. From the architectural point of view, PNs also contain network segments based on relay-based communications. The idea of PN is that several personal computational and communication devices of network users can be organized into secure, private individual networks, regardless of their geographical location. PN includes groups of network users with their computational devices connected to each other in an ad-hoc and dynamic to each other, as well as linked up with fixed-line communications and cellular networks infrastructures. Access to the global communication infrastructure or the Internet may not always be available or may be unstable for network users due to their current locations. Therefore, user-to-user cooperative relaying of communication is a significant factor in proper functionality of a PN. To maintain cooperative relay service in a PN, network users communication devices serve simultaneously as both routers and terminals. Thus, network users have to cooperate in relaying others data packets to support continuous connectivity in PN. The status of network users devices may change from active to standby or disconnected because of their present physical locations or personal reasons. Due to the fact that network users personal portable and mobile devices are usually constrained by limited amount of power, computational resources and memory, the behavior of network users is often selfish in cooperation activities. Selfish network users may be unwilling to spend their own resources in forwarding data packets to other users, since that is not in their direct interests; however, these selfish network users expect other network users to forward their data packets to the requested destinations. This dissertation addresses the selfish behavior of network users in cooperative relay service, which involves forwarding packets for other network users in neighborhood locations. Dynamic Reputation-based Encouragement and Adaptive Mechanism (DREAM) has been developed and proposed to motivate network users to collaborate in relaying data packets of others by awarding them with appropriate incentives, in terms of additional throughput. The incentive rewarding principle of DREAM is based on calculated values of reputation for each relaying network user in a PN. Incentive rewarding is dynamic with compliance to the contribution of each particular network user. Experimental results show that DREAM is appropriate and sustainable for motivating network users to participate in cooperative relay service, particularly for applications characterized by wide coverage and high data rate requirements. To support deployment of the proposed DREAM incentive scheme for cooperative relay service by presently existing mobile network operators, the related service-oriented, self-organized and combined business models have been applied and analyzed. The implications of DREAMs adaptations to policy decision-making have been studied as well.