US Patent 7773576 Slotted Aloha congestion control

A slotted Aloha communication system is provided according to one embodiment of the invention. The system may include a hub and a plurality of RCSTs. According to one embodiment, congestion control may occur at the RCST based in part on the number of segments received at the hub, the number of retransmission segments received at the hub and the number of successful collision retransmission segments received at the hub. The hub may communicate information regarding received segments. Congestion control may include calculating a transmission probably, performing a skewed probability measure with a probability equal to the transmission probability. If the results of the probability measure is positive the RCST may transmit or retransmit a segment within a first time prior, if the probability measure is negative then the RCST waits a set time period and reperforms the skewed probability measure.