Design of a Prioritized Error Control Scheme based on Load Differentiation for Time Sensitive Traffic on the Wireless LAN

This paper proposes and analyzes the performance of a prioritized error control scheme for time sensitive application on the wireless sensor network. As a modified version of IEEE 802.11 WLAN, the proposed scheme further divides DCF into H-DCF and L-DCF without changing PCF, aiming at maximizing the successful retransmission of a packet that carries critical data. While channel estimation elminates the unnecessary polls to the sensor node currently unreachable during PCF, two DCF subperiods enable prioritized error recovery by making only the high priority packet be retransmitted via H-DCF. A good chop value, which distributes the retransmission to each period, can maximize recovered weight, or criticality, minimizing the possible degradation of network throughput. The simulation results show that the proposed scheme can improve recovered weight by 8% while showing 97% successful transmission at maximum for the given simulation parameter.