Abstract:
It's necessary for wireless sensor network(WSN) applications to deal with network congestion, because the channel bandwidth of WSN is usually narrow. However, existing congestion control mechanisms don't run well on WSN platforms. A practical congestion control mechanism for WSN should not only have good network performance but also have little control cost, the proposed EasiCC (EasiNet congestion control mechanism) is such a congestion control mechanism. In EasiCC, the source nodes prorate data packets into several transporting priorities, all the network nodes adjust in-phase packet filtering threshold to adapt network congestion status. With the help of filtering threshold and packet priority, network bandwidth is fairly allotted among data streams. EasiCC uses a stepwise and exponential method to adjust network traffic, so as to reduce control messages between network nodes. EasiCC uses network access waiting time and packet queue overflowing to detect network congestion, uses network admittance and queue dropping simultaneously to ensure the integral network performance. EasiCC has been implemented in wireless sensor network test-bed and costs little on the network bandwidth, communication energy and node memory. Simulation and experimental results indicate that EasiCC can limit transmission delay effectively, reduce packet loss ratio remarkably, and provide bandwidth fairness between data streams at the same time.