Opportunistic MAC protocol for co-existence of M2M and Wi-Fi network
Ajinkya Rajandekar, Biplab Sikdar · 2018
Internet-of-Things is expected to increase the number of connected devices to billions. The major share of these devices will not be user operated, rather they will be machines communicating with other machines without any human intervention. In M2M communication, the network access to such high density of M2M devices is real bottleneck because of limited spectrum. The unlicensed spectrum is affordable choice for M2M networks but presence of existing technologies like Wi-Fi makes network access even more difficult problem to address. We present a MAC protocol design for coexistence of M2M and WiFi network in which high density M2M nodes can be served along with WiFi traffic. The MAC protocol uses opportunistic medium access technique which utilizes WiFi white spaces to serve M2M traffic using a hybrid contention-transmission MAC scheme. The hybrid MAC is optimized to utilize the varying lengths of white spaces effectively. We also present the effect of such opportunistic M2M communication on existing Wi-Fi network in terms of throughput and delay performance of Wi-Fi traffic. We show that proposed protocol can serve large number of M2M devices without significant impact on Wi-Fi networks.