Heterogeneous Wireless Network Scheduling Algorithm Based On Physical Layer Information

Recently,the low-power,low-cost and reliable ZigBee technology have received significant research attention with the increasing emerging applications such as smart home system,patient monitor in hospitals.Coexisting in the crowed unlicensed ISM band,the throughput and packet reception rate(PRR)of ZigBee can be significantly decreased due to the increasing Wi-Fi devices such as hotspots,mobile phones.Because of the incompatible PHY/MAC layer,ZigBee devices will suffer near 50% packet lost when coexistent with Wi-Fi traffic and the existing mechanism such as CSMA/CA is surprisingly inadequate for solving this problem.We collect the realistic Wi-Fi traffic and find that the size of Wi-Fi frames cluster well follow the power law distribution model.Through the observation,we also find that the Wi-Fi traffic typically appears burst which leads to the channel being free for more than 60% of the time.In this paper,we focus on physical layer and propose a new metric called channel idle indicator(CII)calculated by RSSI that will quantify the channel quality,and based on the CII and logistic regression,we build a channel idle state prediction model and propose a scheduling algorithm which can help ZigBee devices to efficiently use the white space of Wi-Fi channel.Particularly,our approach is light-weight which can be easily implemented on the ability limited commercial off-the-shelf(COTS)ZigBee devices.Extensive experiments show that our scheme can achieve over 91% of the PRR while near 40% higher than the B-MAC protocol and our scheme achieves near 1.5× throughput over B-MAC.Carrying on further,our scheme costs less energy via degrading packet lost in the energy consumption part.