In a method for clients to transmit data via a shared medium network, a schedule assigns time slots to individual clients. A collision avoidance scheme determines an offset time to begin transmitting data, which upon expiration, a client senses if any of the clients is transmitting. If a second client is transmitting, then each client sets a first time slot assigned to the second client on the transmission schedule as a starting time slot. The clients track the schedule and transmit to the access point during the next time slot assigned to each client. If no other client is transmitting, then a client transmits data to the access point, sets the first time slot assigned to it as the starting time slot. The schedule is tracked by the clients and they transmit data to the access point during each successive time slot assigned to them.