Novel CSMA/CA MAC structure with interference mitigation and error tolerance

Abstract

In this dissertation, we propose an accurate analytical model for the IEEE 802.15.4 CSMA/CA MAC protocol. We consider the non-backoff state in modeling the Markov chain for IEEE 802.15.4 CSMA/CA MAC and obtain accurate analysis models on throughput and power consumption. We also investigate the operation of PCA devices under the presence of DRP devices in a WiMedia MAC environment and formulate a mathematical model based on a Markov chain to represent the behavior of PCA devices. We propose a defer operation reflection mechanism, which mathematically supplements a Markov chain-based analysis, to reflect the effect of the existence of DRP periods on the probabilities of successful transmissions, collisions, and idle state of a device. Specifically, this mechanism can overcome the limitation of a Markov chain model, which is caused by the dependency among PCA devices under the presence of DRP devices. Analytical results obtained from our proposed mathematical model agree well with simulation results and show that the saturated throughput of PCA devices decrease as the proportion of DRP periods or the number of DRP period groups increase. We mathematically analyze the association procedure of IEEE 802.15.4 ZigBee devices and propose an efficient association algorithm which associate ZigBee devices with a piconet coordinator (PNC) with changing CSMA/CA MAC parameters adaptively to the number of unassociated ZigBee devices. The proposed analysis model is based on Markov chain and order statistics concepts and the proposed algorithm is based on a dynamic estimation concept. We considered total association time of ZigBee devices as a performance measure. The maximum number $N_{max}$ of ZigBee devices, with which pre-given association time requirement is satisfied, is also investigated. Numerical results show that analytical results match well with simulation results and the proposed association algorithm shortens total association time compared to the conv...