Data Rate Utility Analysis for Uplink Two-Hop Internet of Things Networks

Abstract

We study the fundamental problem of spectrum allocation and device association in uplink two-hop Internet of Things (IoT) networks under two spectrum allocation schemes: 1) orthogonal spectrum partition (OSP) and 2) full spectrum reuse (FSR). We propose a novel analytical model to estimate the uplink data rate utility function, which takes into account power control fractional and spatial density of aggregators. We then compute the optimal aggregator association bias (for the FSR scheme) and the optimal joint spectrum partition ratio and optimal aggregator association bias (for the OSP scheme) using constraint gradient ascent optimization. Using the above obtained optimal values and the proposed model, we compare the performance of the optimized OSP and FSR schemes with the benchmark maximum-SIR-based association scheme and the minimum-distance association scheme in terms of the cumulative distribution function of device uplink data rate. By optimizing key network parameters, namely the spectrum partition ratio and aggregator association bias, we mitigate interference and enhance the mean uplink per-device data rate for both FSR and OSP. To the best of our knowledge, this paper is the first that proposes an analytical model to estimate the log utility of the uplink data rate of two-hop IoT networks.