A Payload-Dropping CSMA/CA Protocol for Improving Spatial Reuse of Wireless Local and Personal Area Networks

A Throughput Model for CSMA/CA with a Cross-Layer Payload-Dropping Optimization

“…If subsequently, cell A's idle period i A (t+1) equals 0, the next system state will be that of cell A's (t+1)-th busy period b A (t+1) overlapping b B (t) by (L-o) slots. Because b A (t+1) immediately follows b A (t), cell A will not have exposed slots in these new states: (9) Let x be the duration of i A (t+1). If x is not zero, then cell A will be exposed for the remainder of the header transmission period in cell B.…”

“…To avoid this scenario, different preamble patterns may be used for each cell [7], provided there are enough orthogonal preamble patterns. Alternatively, we could use the following scheme: let CCA indicate the channel as busy when the preamble and header is detected, but remove the indication and stop the frame reception process if signal measurements and/or information obtained during the preamble/header processing stage suggests that the frame is from outside the interference range of the node's cell [8,9]. This allows the CSMA/CA protocol to resume its backoff during the time that would have otherwise been spent receiving the frame's payload ( Fig.1(c)).…”