Proportional Fair Traffic Splitting and Aggregation in Heterogeneous Wireless Networks

TL;DR

This paper presents a novel, low-complexity traffic splitting and aggregation method for heterogeneous wireless networks, optimizing resource use across macro and small cells with backhaul delay considerations.

Contribution

It introduces a closed-form, water-filling based solution for traffic aggregation that accounts for backhaul delay, improving load balancing in non-collocated AP scenarios.

Findings

Significant throughput gains over existing solutions.

Effective handling of backhaul delay in traffic splitting.

Enhanced performance in heterogeneous network deployments.

Abstract

Traffic load balancing and resource allocation is set to play a crucial role in leveraging the dense and increasingly heterogeneous deployment of multi-radio wireless networks. Traffic aggregation across different access points (APs)/radio access technologies (RATs) has become an important feature of recently introduced cellular standards on LTE dual connectivity and LTE-WLAN aggregation (LWA). Low complexity traffic splitting solutions for scenarios where the APs are not necessarily collocated are of great interest for operators. In this paper, we consider a scenario, where traffic for each user may be split across macrocell and an LTE or WiFi small cells connected by non-ideal backhaul links, and develop a closed form solution for optimal aggregation accounting for the backhaul delay. The optimal solution lends itself to a "water-filling" based interpretation, where the fraction of user's traffic sent over macrocell is proportional to ratio of user's peak capacity on that macrocell and its throughput on the small cell. Using comprehensive system level simulations, the developed optimal solution is shown to provide substantial edge and median throughput gain over algorithms representative of current 3GPP-WLAN interworking solutions. The achievable performance benefits hold promise for operators expecting to introduce aggregation solutions with their existing WLAN deployments.