There’s a huge amount of technological innovation across our network. At one end, you have our vast estate of physical infrastructure – mobile towers, roof-top antennas, and street-level assets like small cells – which deliver EE’s 4G and 5G to millions of devices across the country. At the other is our cloud core, the engine room of our fixed and mobile networks upon which services are built, and customer connectivity requests are almost instantaneously actioned. Mobile backhaul is responsible for the critical middle leg of this journey, transporting data from cell site to core.
As our networks expand, we continue to evolve our backhaul (or transmission) network to ensure the best user experience. This is even more important in the face of increasingly challenging environmental conditions, while also contributing to wider efforts to enhance resilience across our network. Whether in the mountainous Cairngorms, the Norfolk broads, or supporting isolated island communities, every cell site requires backhaul. How we deliver it depends on the varied geography of the UK.
Fibre – the backbone of backhaul
Our fibre-first approach to backhaul is driven by BT Group’s position as the largest provider of fixed services in the UK, with an extensive fibre footprint offering the fastest and most resilient way of backhauling data to our core. Over 6,400 of our 19,000+ mobile sites now have 10Gbit/s fibre backhaul links, especially important in areas where we need to transfer large volumes of data quickly, while an additional 2,000 are connected by unilateral 1Gbit/s fibre. These speeds enable high throughput to support the ever-increasing demand on our network.
We’ve also delivered fibre to some extremely hard-to-reach locations, supporting rural communities and emergency services in those areas. With over 60 per cent of our transmission network on Openreach fibre, we’re able to deliver greater capacity and speeds, boosted further through the activation of advanced RAN features like inter-site carrier aggregation, which increases bandwidth by combining spectrum across multiple sites in the same vicinity – for example, a rooftop mast and a street-level asset.
Microwave
But not everywhere is the same, and our approach in many rural locations is vastly different. While we’re making great progress in our fibre roll-out, in most scenarios where it isn’t viable we look to deploy microwave radio backhaul – notably in difficult to reach locations where laying fibre is logistically challenging and costly.
To ensure these radio links scale to deliver the required capacity, we are deploying solutions which use multiple radio transceivers at each end of the link – either two or four – to increase capacity. This delivers data rates of up to 4Gbps while benefiting from hardware resilience built-in by design, achieving fibre-like results where fibre costs are currently prohibitive
Satellite: A multi-orbital approach
Satellite backhaul provides a viable alternative for hard-to-reach locations. Through our partnership with Eutelsat OneWeb, we achieved an industry first in backhauling a 4G LTE cell site over its Low Earth Orbit (LEO) constellation. With that site smoothly managing live traffic for over a year now, we’re exploring how we can take this further. Alongside Eutelsat OneWeb, we’re also working closely with Starlink in this area, with more rural sites due to go live in the coming months in places like Cumbria, Yorkshire and Shetland.
LEO satellite constellations deliver higher data rates and lower latency than those in geostationary orbit (GEO), and we expect them to augment the range of fibre, microwave, and GEO satellite backhaul solutions available for primary cell site connectivity. Additionally, satellite remains important in providing back-up backhaul to key sites, automatically activated in the event of a terrestrial transmission failure.
Our award-winning network performance underscores the crucial role of mobile backhaul in delivering fast, reliable, and resilient connectivity. As we expand our 5G Standalone services nationwide, our robust backhaul network ensures customers benefit from the full capabilities of our network. This dedication to excellence has earned us recognition from RootMetrics as the UK's best mobile network for 12 consecutive years, as well as a record-breaking score from Umlaut in testing as its best network for the 10th year in a row.
