# Latency Bounds of Packet-Based Fronthaul for Cloud-RAN with Functionality Split

## TL;DR

This paper analyzes latency bounds for Ethernet-based fronthaul in Cloud-RAN, providing insights into reliability-latency trade-offs and guiding architecture design for 5G services like URLL and eMBB.

## Contribution

It introduces a model for latency bounds in packet-based fronthaul, considering different split points and traffic conditions, with numerical and simulation analysis.

## Key findings

- Latency bounds depend on bandwidth and traffic properties.
- Trade-offs exist between reliability and latency in fronthaul design.
- Model supports optimizing Cloud-RAN architecture for 5G services.

## Abstract

The emerging Cloud-RAN architecture within the fifth generation (5G) of wireless networks plays a vital role in enabling higher flexibility and granularity. On the other hand, Cloud-RAN architecture introduces an additional link between the central, cloudified unit and the distributed radio unit, namely fronthaul (FH). Therefore, the foreseen reliability and latency for 5G services should also be provisioned over the FH link. In this paper, focusing on Ethernet as FH, we present a reliable packet-based FH communication and demonstrate the upper and lower bounds of latency that can be offered. These bounds yield insights into the trade-off between reliability and latency, and enable the architecture design through choice of splitting point, focusing on high layer split between PDCP and RLC and low layer split between MAC and PHY, under different FH bandwidth and traffic properties. Presented model is then analyzed both numerically and through simulation, with two classes of 5G services that are ultra reliable low latency (URLL) and enhanced mobile broadband (eMBB).