5G is not just about upgrading the handsets, radios, and antennas that together comprise the Radio Access Network (RAN). Offering 5G mobile services also requires substantial upgrades to packet-optical wireline networks that connect cell sites to each other and to data centers hosting accessed content, and everything in between. This means that for Mobile Network Operators (MNO) to achieve the 5G improvements over 4G LTE of 100x more devices, 100x faster data rates, 10x lower latency, and 1000x higher data volumes, everything in the end-to-end mobile service path must eventually be scaled and modernized. This applies to connect, storage, and compute resources resulting in multi-year modernization journey that will start in the RAN and network edge and steadily move inwards, which has already started in several countries.
Unlike previous introductions of mobile networking technology (2G, 3G, 4G) where the new generation of was intended to replace the old generation – but never did – 5G is not intended to replace 4G. 5G is intended to complement and coexist alongside 4G (and 2G and 3G mobile services in many cases) meaning they must coexist by sharing as much connect, storage, and compute resources as possible if MNOs are to support multiple generations of mobile services in a cost-effective manner. 4G will also continue to evolve over time from existing Long-Term Evolution (LTE) deployed today, to future LTE Advanced and LTE Advanced Pro, which are enhancements to 4G that bring it closer to expected 5G performance.
Holistically speaking, a mobile network is a massive wireline network with radios hanging off its edges. In most cases, the only wireless part of the end-to-end journey of data flowing between users and accessed content is between from User Equipment (UE) and cell site antennae. The rest of the end-to-enFd journey is predominantly over packet-optical wireline networks, although wireless backhaul does exist.
In short, this means the move to offering 5G mobile services is about far more than just a wireless upgrade.