Research On The MAC Protocol Of High-Rate Wireless Personal Area Network

With the development of personal communication technology, Wireless Personal Area Network (WPAN) has received more and more attention. It is composed of personal wireless devices which work in ad-hoc mode. IEEE 802.15.3 standard has been defined for the high-rate WPAN. The MAC and PHY protocol are specified in the standard, but the schedule scheme is undetermined for flexibility. The IEEE 802.15.3 MAC specification is described in the paper and its content contains the structure of super-frame, channel access protocol, channel time management, the communication procedure between devices, and so on.In the third chapter of this paper, the challenge when multi-media services are applied in IEEE 802.15.3 environment is presented. It is known that, the number of packets which belong to the Variable Bit Rate (VBR) flow in a superframe varies with time. Thus, it is difficult to assign appropriate Channel Time Allocation (CTA) for each service previously. According to the statistical property of VBR flow, an effective schedule scheme is proposed in the paper. The scheme is described as follows: firstly, the CTA for each service flow is assigned based on its average traffic load; then, the CTA is adjusted dynamically by using the Relinquish signaling to get better performance. In other words, if the CTA for a VBR flow with large packet number of packets is not enough for transmission, it can occupy the free airtime which belongs to another VBR flow. Simulation work shows that both delay and jitter of VBR flows are reduced considerably when using the proposed scheme.In the fourth chapter, the two PHY drafts of IEEE 802.15.3a are described and they can provide the transmission speed of 480Mb/s in...