Backhauling Many Devices: Relay Schemes for Massive Random Access Networks

The number of devices connected to Internet of Things (IoT) and massive machine-type communication (mMTC) networks is expected to increase exponentially in the next generation of wireless communication systems, resulting in a new type of “massive” random access network. However, most of the work in this emerging field considers the single-hop setting with direct communication between the users and a fully-equipped base station. In contrast, this work explores the massive random access problem in a two-hop relay setting where users access the network through a femto- or pico-cell relay which itself only has a limited amount of bandwidth/power. We present two low-complexity relaying schemes designed to minimize power consumption and discuss their tradeoffs using numerical simulations.