UBC Theses and Dissertations
Protocol enhancement and network formation techniques in IEEE 802.15.3 WPANs Yin, Zhanping
Designed for high rate wireless personal area networks (WPANs), the IEEE 802.15.3 protocol enables peer-to-peer communications between devices (DEVs) with quality of service (QoS) support. This thesis presents several performance enhancement methods and scatternet formation techniques for 802.15.3 networks. Considering piconet coverage and multi-rate carriers, we first propose a Third-Party Handshake Protocol (3PHP) for fast peer discovery and connection reestablishment. With the active involvement of the piconet coordinator (PNC), 3PHP guarantees full piconet connectivity, and achieves faster peer discovery by removing the peer discovery overhead and eliminating costly upper layer routing between directly unreachable DEVs by a more reliable and efficient MAC layer forwarding. Second, we develop intra-piconet route optimization algorithms in the PNC with application awareness through self-learning the achievable data rates between DEVs, which significantly increase the system performance in terms of reducing transmission time and increasing effective data rate, and thus reduce power consumption and increase piconet capacity. Furthermore, we propose a frame aggregation strategy for efficient frame transmissions in 802.15.3 Contention Period (CPs), and model the CP in each superframe as a contention resolution problem. We further propose a novel Adaptive CP Suspend (ACS) scheme that significantly shortens the effective region in a CP, thus greatly reducing the system energy cost by allowing DEVs to sleep during the suspended parts of the CPs. ACS adapts to varying channel traffic and collision situations by employing a CP counter at the PNC. Finally, we investigate the 802.15.3 scatternet formation problem. Configuration of scatternets needs to consider the piconet size and channel reuse, given the number of logical channels available. We first evaluate the effect of piconet size on the expected scatternet connection rate, and show that a medium sized piconet radius yields the best scatternet connection data rate taking into account of channel reuse. Moreover, we propose a stochastic scattenet formation algorithm to avoid neighbor information gathering in 802.15.3 networks. With only 20% more piconets than the ideal but impracticable greedy algorithm, the stochastic method scales well with network size, achieves better connectivity, requires less maintenance and is robust and stable with respect to changes in the WPAN.
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