In most scenarios of wireless sensor networks (WSNs), different traffic types have specific service requirements. None of the previous MAC schemes has been able to provide true pre-emption to the high priority data. This paper introduced a novel data fragmentation scheme for low priority traffic in order to improve the delay performance of high priority traffic in WSN. It is proposed that instead of transmitting the low priority packet as a single unit, it should be transmitted in small fragments with pauses. A MAC protocol FROG-MAC has been designed based on the proposed fragmentation scheme. Simulations over Contiki operating system and testbed experiments over TelosB/Tmote Sky Platform have been performed to evaluate performance of FROG-MAC based on parameters of delay and throughput/packet delivery ratio (PDR). It has been found that FROG-MAC improves the delay and throughput of urgent traffic by reducing its waiting time. For increase in the fragment size, the delay of urgent traffic increases, whereas that of normal traffic reduces. With the increasing network size, the delay for both traffic types increases, and PDR reduces due to the increased network traffic load, collision and retransmissions. The performance of FROG-MAC has also been compared against energy-efficient multi-constrained QoS aware MAC.

在无线传感器网络（WSN）的大多数情况下，不同的流量类型具有特定的服务要求。先前的MAC方案都无法对高优先级数据提供真正的抢占。为了提高无线传感器网络中高优先级业务的延迟性能，本文提出了一种针对低优先级业务的新型数据分片方案。提出代替将低优先级分组作为单个单元发送，而应在具有暂停的小片段中发送。已基于提出的分段方案设计了MAC协议FROG-MAC。已经基于延迟和吞吐量/分组传输率（PDR）的参数执行了Contiki操作系统的仿真和TelosB / Tmote Sky Platform的测试平台实验，以评估FROG-MAC的性能。已经发现，FROG-MAC通过减少等待时间来改善紧急流量的延迟和吞吐量。随着片段大小的增加，紧急流量的延迟增加，而正常流量的延迟减少。随着网络规模的增加，两种流量类型的延迟都会增加，并且由于网络流量负载，冲突和重传的增加，PDR也会减少。FROG-MAC的性能也已与节能多约束QoS感知MAC进行了比较。冲突和重传。FROG-MAC的性能也已与节能多约束QoS感知MAC进行了比较。冲突和重传。FROG-MAC的性能也已与节能多约束QoS感知MAC进行了比较。