Improved Handover Through Dual Connectivity in 5G mmWave Mobile Networks

TL;DR

This paper introduces a dual connectivity protocol for 5G mmWave networks that enhances handover reliability by enabling simultaneous connections to 4G and 5G cells, with rapid switching capabilities.

Contribution

It presents a novel dual connectivity protocol with uplink control signaling and a local coordinator, providing the first comprehensive evaluation of mmWave handover mechanisms.

Findings

Significant reduction in handover latency.

Improved connection stability during blockage events.

Enhanced throughput and reliability metrics.

Abstract

The millimeter wave (mmWave) bands offer the possibility of orders of magnitude greater throughput for fifth generation (5G) cellular systems. However, since mmWave signals are highly susceptible to blockage, channel quality on any one mmWave link can be extremely intermittent. This paper implements a novel dual connectivity protocol that enables mobile user equipment (UE) devices to maintain physical layer connections to 4G and 5G cells simultaneously. A novel uplink control signaling system combined with a local coordinator enables rapid path switching in the event of failures on any one link. This paper provides the first comprehensive end-to-end evaluation of handover mechanisms in mmWave cellular systems. The simulation framework includes detailed measurement-based channel models to realistically capture spatial dynamics of blocking events, as well as the full details of MAC, RLC and transport protocols. Compared to conventional handover mechanisms, the study reveals significant benefits of the proposed method under several metrics.