Multi-Channel Medium Access without Control Channels: A Full Duplex MAC Design

Abstract

We address the problem of improving the throughput and security of multi-channel MAC (MMAC) protocols. We design a protocol called FD-MMAC that exploits recent advances in full duplex (FD) communications to coordinate channel access in a distributed manner. Compared with prior MMAC designs, our protocol eliminates the use of dedicated in-band or out-of-band control channels for resolving contention, discovering the resident channel of destinations, and performing load balancing. The elimination of the control channel improves spectral efficiency and mitigates denial-of-service attacks that specifically target the exchange of control information. Moreover, FD-MMAC enables the operation of multi-channel exposed terminals. To achieve these goals, we integrate an advanced suite of PHY-layer techniques, including self interference suppression, error vector magnitude and received power measurements, and signal correlation. We validate the proposed PHY-layer techniques on the NI USRP testbed. Furthermore, we theoretically analyze the throughput performance of FD-MMAC and verify our analysis via packet level simulations. Our results show that FD-MMAC achieves significantly higher throughput compared with prior art. Finally, we analyze the resilience of FD-MMAC to reactive jamming attacks.