Capacity Analysis of Decoupled Downlink and Uplink Access in 5G Heterogeneous Systems

TL;DR

This paper analyzes the capacity and throughput benefits of decoupling downlink and uplink access in 5G heterogeneous networks using stochastic geometry, simulations, and real-world system verification.

Contribution

It provides a rigorous theoretical analysis of decoupled DL/UL access in 5G systems and validates the results through simulations and real-world system modeling.

Findings

Decoupling increases capacity and throughput in 5G networks.

Simulation results confirm theoretical capacity gains.

Real-world system simulation aligns with theoretical trends.

Abstract

Our traditional notion of a cell is changing dramatically given the increasing degree of heterogeneity in 4G and emerging 5G systems. Rather than belonging to a specific cell, a device would choose the most suitable connection from the plethora of connections available. In such a setting, given the transmission powers differ significantly between downlink (DL) and uplink (UL), a wireless device that sees multiple Base Stations (BSs) may access the infrastructure in a way that it receives the downlink (DL) traffic from one BS and sends uplink (UL) traffic through another BS. This situation is referred to as Downlink and Uplink Decoupling (DUDe). In this paper, the capacity and throughput gains brought by decoupling are rigorously derived using stochastic geometry. Theoretical findings are then corroborated by means of simulation results. A further constituent of this paper is the verification of the theoretically derived results by means of a real-world system simulation platform. Despite theoretical assumptions differing from the very complete system simulator, the trends in the association probabilities and capacity gains are similar. Based on the promising results, we then outline architectural changes needed to facilitate the decoupling of DL and UL.