Many Wireless Sensor Network (WSN) applications heavily rely on information being transmitted in a timely manner. In such sensor networks, packet scheduling plays a vital role in reducing end-to-end data transmission delays. It also helps in reducing sensors energy consumptions, thus increasing the lifetime of the wireless sensor network. Most of the existing packet-scheduling mechanisms of wireless sensor networks use First Come First Serve (FCFS). It is the most simplest and traditional packet scheduling scheme which process packets as they arrive.