Research On QoS Routing In Wireless Multimedia Sensor Network

As derived from traditional sensor networks, wireless multimedia sensor networks can provide rich multimedia information with different granularity and multi-resolution views due to introduce multimedia nodes (i.e. audio, video, image), and is applied to several potential fields such as environment monitoring, industrial control and health care. The distinct features of wireless multimedia sensor networks, such as various media category, great amount of data, the complexity of task processing, make the issue of QoS requirement become an important characteristic that distinguished from traditional sensor networks. The latter tends to lose the quality of service to achieve low power consumption. While the QoS guarantee mechanisms have to be integrated into the design of protocol stack in wireless multimedia sensor networks by the former, as to the application of multimedia, it is presented to give security to the quality of service on timeliness, reliability, bandwidth and packet loss for data communication.By researching deeply to QoS architecture of wireless multimedia sensor networks, and analyzing the strategies of protocol stacks, a new QoS routing algorithm ADSR(Angle based Differentiated Services Routing) is proposed. The main topics in this thesis are as follows:(1) There are three kinds of data coexisting in the network: key frame, ordinary frame of video data, period scalar data, which have different QoS requirements. The model of DiffServ network is used to deal with the hybrid data. In ADSR routing, neighbors are classified based on deviate angle, heterogeneous flows are sent to next hop from different transmission area. Besides that, the influence to route mechanism from the node position, sing-hop communication cost and residual energy is considered in the proposed protocol, which can balance the energy consumption, prolong the network life span while guaranteeing the latency of multimedia.(2) Based on IEEE 802.1 le EDCA, two mechanisms are proposed to implement effective priority access. First, in order to solve the problem of the contention intra nodes, the traffic is classified into two priorities: real time and non real time, and put into two different priority queues with different competitive parameters, respectively. Second, in order to solve the problem of the contention inter nodes, smaller impact factors (such as AIFS, CW) is assigned to the nodes service real time traffic, which make them access the channel in advance.QoS Differentiated Service is implemented by cross-layer protocol design. The experimental results demonstrate that ADSR routing can achieve better performance compared with the current important protocols with the increase of network load, which is more adaptable for large amount of data transfer.