Terminology » Difference between Cellular vs Cell Free Architecture

Difference between Cellular vs Cell Free Architecture

Introduction : In modern wireless communication systems, the way network coverage and connectivity are structured plays a critical role in determining performance, reliability, and user experience. In this page, we wil explore two types of network architectures based on existing wireless systems (e.g. 4G LTE, 5g NR) and emerging ones (6G).

Cellular Architecture : Traditionally, cellular architecture has been the dominant model, where the coverage area is divided into multiple cells, each served by its own base station. Cellular systems are simpler and well established but face challenges such as inter cell interference and limited edge performance.

Cell Free Architecture : With the growing demand for higher data rates, seamless mobility and ultra reliable connections, a new paradigm known as cell free architecture has emerged. In this approach, users are jointly served by many distributed access points (APs) without the concept of fixed cells. Cell free systems offer enhanced spectral efficiency, uniform user experience and better interference management at the cost of increased complexity and coordination.

Key differences

Feature	Cellular Architecture (Current paradigm)	Cell-free architecture (6G concept)
Core concept	The service area is partitioned into distinct geographical areas called “cells,” each managed by a central base station (BS).	The service area is not partitioned; there are no cell boundaries. All users are jointly served by many distributed access points (APs).
User connection	A user is connected to and served by one primary base station at any given time.	A user is simultaneously and coherently served by all access points within their vicinity, or even the entire network.
User Experience	Performance is inconsistent. Users experience high data rates near the cell center and significantly lower rates at the “cell edge.”	Aims to provide a uniformly excellent and consistent quality of experience for all users, regardless of their physical location.
Interference	Interference from neighboring cells (inter-cell interference) is a major performance-limiting factor, especially at the cell edge.	Inter-cell interference is fundamentally eliminated. Signals from other APs are not treated as interference but as a useful part of the desired signal.
Handover	A “handover” process is required when a user moves from one cell to another. This can cause brief interruptions or latency spikes.	There is no concept of handover. The set of serving APs for a user changes continuously and seamlessly as they move.
Network Scalability	Scaling is done by adding more cells (cell splitting), which increases the complexity of interference management.	Scaling is done by deploying more distributed APs. This can improve performance for all users, as more APs contribute to the joint signal.
Backhaul Requirement	The backhaul connection is primarily from each base station to the core network.	Requires a very high-capacity, low-latency “fronthaul” network connecting all APs to a Central Processing Unit (CPU) for joint processing.
Signal Processing	Signal processing (e.g., precoding, decoding) is performed locally at each individual base station.	Signal processing is centralized. The CPU gathers data from all APs to perform large scale, coordinated joint transmission and reception.
Network Control	Control is decentralized, with each base station managing its own cell’s resources.	Control is highly centralized and coordinated. The CPU makes all resource allocation and beamforming decisions for all APs.
Primary Goal	To maximize the capacity of each individual cell while managing interference between them (interference management).	To maximize the performance and quality of service for each individual user, regardless of their location (user-centric design).

Conclusion: In summary, while cellular architecture relies on dividing a network into distinct cells managed by individual base stations, cell free architecture removes these boundaries to create a cooperative and user centric network. As wireless technologies evolve, the shift from cellular to cell free architectures represents a major step toward achieving the seamless, high capacity and energy efficient networks envisioned for future generations.