Transmission timing of signaling messages in IEEE 802.16 based Mesh Networks

Broadband wireless access becomes more and more important for current and future communication systems. The IEEE 802.16 (WiMAX) standard combines this technology with mesh multihop network topologies. These multihop networks can be deployed for high speed wide-area wireless networks. One key issue of mesh networking is the MAC (Medium Access Control) layer, which is used to share common channel resources (transmission opportunities) among wireless nodes. The scheduling and assignment of transmission opportunities can be realized in centralized or distributed manner. This paper analysis the IEEE 802.16 election based transmission timing (ebtt) mechanism for the coordinated distributed scheduling (C-DSCH). This mechanism is responsible for transmission timing of C-DSCH signaling messages. As the standard defines only a framework of the ebtt-mechanism this paper presents some extensions that are needed in order to guarantee a correct functionality. Furthermore, simulations using the network simulator ns2 show that the standard election mechanism does not perform well and causes a significant delay to data packets. This paper proposes new ideas to solve the problems and to reduce the packet delay.