Performance Comparison of Multichannel MAC Protocols for Low-power and Lossy Networks: TSCH versus EM-MAC

Abstract

The Medium Access Control (MAC) protocol proposed by the evolving IEEE 802.15.4 standard for Low-power and Lossy Networks (LLNs) includes a multichannel mode known as Time-Slotted Channel Hopping (TSCH). TSCH, published in 2015, is part of the most recent version of the IEEE 802.15.4 standard. In this paper, we present a performance comparison between TSCH (with Orchestra scheduling algorithm) and EM-MAC, a contention-based multichannel MAC protocol for LLNs, in terms of average packet delivery ratio, power consumption and latency after network start-up phase. Results obtained from experiments on a testbed with Z1 nodes sending traffic to the sink in an environment with negligible external interference, follow the same trend as the ones obtained through a simulation study. TSCH/Orchestra outperforms EM-MAC or performs equally well for all considered loads. A point of attention though for TSCH, is the significant time required by newly joining nodes to associate to the TSCH network and to join the tree created by the IPv6 Routing Protocol for LLNs (RPL).