# Learning-based Resource Optimization in Ultra Reliable Low Latency HetNets

## TL;DR

This paper introduces a learning-based resource optimization framework for ultra-reliable low latency communications in HetNets, effectively reducing delay and costs through joint user offloading and resource allocation.

## Contribution

It proposes a novel low complexity heuristic method combining SVM-based user association and convex optimization for URLLC resource management in HetNets.

## Key findings

- Significantly reduces spectrum access delay by ~93%.
- Reduces bandwidth and power costs by ~33%.
- Demonstrates effectiveness of learning-based approach in URLLC HetNets.

## Abstract

In this paper, the problems of user offloading and resource optimization are jointly addressed to support ultra-reliable and low latency communications (URLLC) in HetNets. In particular, a multi-tier network with a single macro base station (MBS) and multiple overlaid small cell base stations (SBSs) is considered that includes users with different latency and reliability constraints. Modeling the latency and reliability constraints of users with probabilistic guarantees, the joint problem of user offloading and resource allocation (JUR) in a URLLC setting is formulated as an optimization problem to minimize the cost of serving users for the MBS. In the considered scheme, SBSs bid to serve URLLC users under their coverage at a given price, and the MBS decides whether to serve each user locally or to offload it to one of the overlaid SBSs. Since the JUR optimization is NP-hard, we propose a low complexity learning-based heuristic method (LHM) which includes a support vector machine-based user association model and a convex resource optimization (CRO) algorithm. To further reduce the delay, we propose an alternating direction method of multipliers (ADMM)-based solution to the CRO problem. Simulation results show that using LHM, the MBS significantly decreases the spectrum access delay for users (by $\sim$ 93\%) as compared to JUR, while also reducing its bandwidth and power costs in serving users (by $\sim$ 33\%) as compared to directly serving users without offloading.