tailieunhanh - Mobile Ad Hoc Networks Applications Part 12

Tham khảo tài liệu 'mobile ad hoc networks applications part 12', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 376 Mobile Ad-Hoc Networks Applications destinations that need another description should be assigned the second video description and so on. The main difference between Sequential MDC and Centralized MDC algorithms is that the former does not employ the independent-property of MDC. We evaluate and compare our proposed algorithms under different network conditions. For example network size and multicast group size. Simulation results demonstrate that indeed the way of multicast trees construction and the assignment of MD video can greatly affect the user satisfaction. In addition simulation results show that MDC can achieve higher user satisfaction compared to Layered Coding LC with a small cost in terms of number of pure forwarders nodes bandwidth utilization and aggregate tree delay. Furthermore simulation results show that the independent-description property of MDC can increase the user satisfaction. The rest of this chapter is organized as follows. In the next section we present the related work. In section 3 we present our network model and problem formulation of video multicasting. In Section 4 we describe our proposed algorithms for constructing multiple node-disjoint multicast trees and assigning MD video. In Section 5 we evaluate our proposed algorithms. The complexity analysis of the protocols is presented in Section 6. Finally our conclusions are presented in Section 7. 2. Related work An ad hoc network is a multihop wireless network without a preinstalled infrastructure or centralized administration. It can be deployed in situations where infrastructure is unavailable or where temporary network is needed. In this network nodes are free to move randomly anytime anywhere and arrange themselves as required. Since nodes are often not within the radio transmission range of each other each node operates not only as a host but also as a router forwarding packets for other mobile nodes. In a typical ad hoc environment mobile nodes work as a group to accomplish