A Deadlock-Free High-Throughput Tree Algorithm for Random Access over Fading Channels

We recently proposed a random access scheme which combines the widely used binary exponential backoff (BEB) algorithm with a cross-layer tree algorithm (TA), which relies on successive interference cancellation (SIC) with first success (FS). It was shown that BEB and SICTA/FS complement each other nicely and the proposed protocol can afford a maximum stable throughput (MST) as high as 0.6 without packet loss. However, although BEB-SICTA/FS avoids the deadlock problem caused by the error propagation of successive interference cancellation (SIC), it may still suffer from deadlock effects induced by the "level skipping" under harsh wireless channels. In this paper, we develop a novel BEB-SICTA/F1 protocol, which is a modified version of BEB-SICTA/FS. Our analysis and simulations demonstrate that this simple modification can afford high-throughput random access while completely avoiding deadlock problems.