Low Latency Techniques for Mobile Backhaul over DOCSIS

TL;DR

This paper presents an implementation and optimization of a method to reduce end-to-end latency in mobile backhaul over DOCSIS networks by coordinating LTE and HFC scheduling, demonstrating consistent latency improvements.

Contribution

It implements and optimizes a previously proposed latency reduction method on a real testbed combining LTE and DOCSIS networks.

Findings

Latency improved under all traffic loads

Effective coordination reduces end-to-end delay

Testbed validates practical applicability

Abstract

The mobile network operators (MNOs) are looking into economically viable backhaul solutions as alternatives to fiber, specifically the hybrid fiber coaxial networks (HFC). When the latencies from both the wireless and the HFC networks are added together, the result is a noticeable end-to-end system latency, particularly under network congestion. In order to decrease total system latency, we proposed a method to improve upstream user- to-mobile core latency by coordinating the LTE and HFC scheduling in previous papers. In this paper, we implement and optimize the proposed method on a custom LTE and DOCSIS end-to-end system testbed. The testbed uses the OpenAirInterface (OAI) platform for the LTE network, along with Cisco's broadband router cBR-8 that is currently deployed in the HFC networks around the world. Our results show a backhaul latency improvement under all traffic load conditions.