Modeling of Multi-Link Synchronous Access with Threshold of Waiting Time in Wi-Fi 7

Multi-link operation (MLO) is one of the key features of 802.11be, which can achieve higher throughput, and lower latency than single-link operation in a heavily loaded network. For a nonsimultaneous transmit and receive (NSTR) multi-link device (MLD), synchronous transmissions across multiple links are required to avoid the in-device coexistence (IDC) interference. Compared to legacy access mechanisms of single-link, the modeling and performance theoretical analysis of synchronous multi-link access mechanisms face some new challenges. The two-dimensional Markov performance analysis model for single-link cannot be applied to multi-link scenarios. In this paper, we present an analytical model to compute the multi-link synchronous access probability and the saturation throughput in the assumption of ideal channel conditions. The proposed Markov model combines the distributed coordination function (DCF) mechanism with the process of multi-link synchronous access based on the threshold of waiting time. Different from other proposed MLO models, we consider the stochastic state of channel during the synchronous access backoff procedures of each link, and define the concept of waiting time threshold. Comparison with simulation results show that the proposed model is accurate in predicting the multi-link synchronous access probability, as well as system saturation throughput.