Performance of 2-dimensional sloppy-slotted ALOHA random access signaling

Theoretical and simulated performance results are presented and compared for 2-dimensional sloppy-slotted-ALOHA (2DSSA) random access signaling. 2DSSA is useful for multi-channel random access signaling with severe timing and frequency errors. It is shown that the increase in capacity over conventional multi-channel slotted-ALOHA, multi-channel unslotted-ALOHA, or 2-dimensional unslotted-ALOHA can range from a factor of 1 to 4, depending on the timing and frequency error distributions encountered.<>