Research And Implementation Of Quality Of Service Provisioning For Opportunistic Networks

With the development of wireless network communication technology and the popularization of mobile intelligent communication devices, opportunistic networks have been widely used in people's daily life and have brought great convenience to people's life. Due to limited cache capacity and bandwidth, opportunistic networks have larger packet loss rate and longer delivery delay. It is a problem urgent to be solved that how to efficiently use network resources to provide high-quality network communication services.Accounting for these above-mentioned problems, quality of service guarantee for opportunistic networks is analyzed from mobile characteristics of nodes and requirements of quality of service of packets in the network. A quality of service guarantee mechanism based on data transmission probability and a quality of service guarantee mechanism based on traffic class of packets are proposed to solve how to efficiently utilize limited network resources to provide quality of service guarantee for network communication. In order to verify the feasibility of the proposed packet schemes in quality of service provisioning, simulations with opportunistic network environment simulator are carried out.The main works done in the paper are as follows:1. According to mobile characteristics of nodes in opportunistic networks, a new metric, data transmission probability, and a quality of service guarantee mechanism based on data transmission probability are proposed. In order to improve the overall performance of network, the priority order of forwarding and dropping packets are decided by data transmission probability and the size and the time to live of packets. And the feasibility of the quality of service guarantee mechanism is verified by opportunistic network environment simulator.2. Aiming to satisfy different quality of service requirements of different data packets in opportunistic networks, a quality of service guarantee mechanism based on traffic class of packets is proposed. The traffic class of packets are classified based on different quality of service requirements of packets in opportunistic networks; the forwarding and dropping priority of packets are decided by the traffic class of packet and the number of packet copies. Additionally, a new metric called quality of service satisfaction is designed to evaluating the level of quality of service.3. In different application scenarios, the quality of service guarantee mechanisms proposed in this paper are simulated. Simulation results show that quality of service guarantee mechanism based on data transmission probability is more suitable for opportunistic network applying in campus, and quality of service guarantee mechanism based on traffic class of packets is more suitable for opportunistic network applying in post-tsunami relief.