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An Analytical Model for CBAP Allocations in IEEE 802.11ad



Nada Golmie, Tanguy Ropitault, Michele Zorzi, Chiara Pielli


The IEEE 802.11ad standard extends WiFi operation to the millimeter wave frequencies, and introduces novel features concerning both the physical (PHY) and Medium Access Control (MAC) layers. However, while there are extensive research efforts to develop mechanisms for establishing and maintaining directional links for mmWave communications, fewer works deal with transmission scheduling and the hybrid MAC introduced by the standard. The hybrid MAC layer provides for two different kinds of resource allocations: Contention Based Access Periods (CBAPs) and contention free Service Periods (SPs). In this paper, we propose a Markov Chain model to represent CBAPs, which takes into account operation interruptions due to scheduled SPs and the deafness and hidden node problems that directional communication exacerbates. We also propose a mathematical analysis to assess interference among stations. We derive analytical expressions to assess the impact of various transmission parameters and of the Data Transmission Interval configuration on some key performance metrics such as throughput, delay and packet dropping rate. This information may be used to efficiently design a transmission scheduler that allocates contention-based and contention-free periods based on the application requirements.
IEEE Transactions on Wireless Communications


mmWave, data transmission, wireless communications, 802.11ad networks, 5G


Golmie, N. , Ropitault, T. , Zorzi, M. and Pielli, C. (2021), An Analytical Model for CBAP Allocations in IEEE 802.11ad, IEEE Transactions on Wireless Communications, [online], (Accessed April 17, 2024)
Created January 14, 2021, Updated January 19, 2021