IEEE 802.16 Mesh networks排程控制訊息成本之效能分析

Abstract

Broadband Wireless Access (BWA) technology is aiming to provide an easy, time-saving, and low-cost method for deployment of next generation network infrastructure. Since 1998, IEEE 802.16 working group has launched a standardization process call Wireless Metropolitan Area network (Wireless MANTM) for BWA. The newly released specification of 802.16 (IEEE Std 802.16-2004)[1] focuses on fixed location wireless access and can support up to 75bps bit rate. There are two mechanisms to schedule data transmission in the IEEE 802.16 Mesh networks: centralized and distributed scheduling. In the centralized scheduling scheme, the BS works like the cluster head and determines time slot allocation of each SS. In order to transmit data packets, the SS is required to submit the request packet to the BS via the control channel. The BS grants the access request by sending the slot allocation schedule call UP_MAP to all SS nodes. In the distributed scheduling scheme, if the SS have data to send, it need to compete with it neighbors. So that it can start data transmission. We’ve proposed a combinational framework in previous works[17], it combine the two advantages of centralized scheduling and distributed scheduling. It has centralized controller BS and it can select a shortest path between source SS and destination SS. In this thesis, we discussed the signaling cost in those two different scheduling schemes of IEEE 802.16 Mesh network and our previous works. We analyzed the effect factors on signaling cost. We also proposed a simple theoretical model in centralized scheduling and proposed framework. In the rest of this thesis, we simulated some scenarios to show those three scheme’s differences.