Evaluation of Security-Induced Latency on 5G RAN Interfaces and User Plane Communication

TL;DR

This paper evaluates how security measures impact latency in 5G RAN interfaces and user plane, revealing that security adds overhead but disaggregation still offers latency benefits, though sub-1 ms targets are hard to meet.

Contribution

First testbed implementation of a disaggregated 5G RAN with standardized security, providing empirical latency analysis of security overhead in 5G networks.

Findings

Disaggregated RAN maintains latency advantages over monolithic designs.

Security controls increase latency overhead, but do not negate disaggregation benefits.

Cryptographic overhead can exceed the 1 ms latency target in 5G communications.

Abstract

5G promises enhanced performance-not only in bandwidth and capacity, but also latency and security. Its ultra-reliable low-latency configuration targets round-trip times below 1 ms, while optional security controls extend protection across all interfaces, making 5G attractive for mission-critical applications. A key enabler of low latency is the disaggregation of network components, including the RAN, allowing user-plane functions to be deployed nearer to end users. However, this split introduces additional interfaces, whose protection increases latency overhead. In this paper, guided by discussions with a network operator and a 5G manufacturer, we evaluate the latency overhead of enabling optional 5G security controls across internal RAN interfaces and the 5G user plane. To this end, we deploy the first testbed implementing a disaggregated RAN with standardized optional security mechanisms. Our results show that disaggregated RAN deployments retain a latency advantage over monolithic designs, even with security enabled. However, achieving sub-1 ms round-trip times remains challenging, as cryptographic overhead alone can already exceed this target.