BT, Nokia boast breakthrough in 5G carrier aggregation

BT says it’s the first operator in Europe to conduct a carrier aggregation (CA) trial using four carrier components (4CC) in a 5G standalone (SA) live network.

Conducted on its EE mobile network with Nokia, the achievement marks another step in its migration to an all-5G core.  

“As we migrate to a 5G standalone core network, this technology milestone is vital to giving our customers the best experience,” said BT’s Managing Director of Service Platforms Greg McCall.

Specifically, the network team combined four radio channels – 2.1, 2.6, 3.4 and 3.6 GHz – using Nokia’s 5G Radio Access Network technology in EE’s live network spectrum.

The first stage of the trial was conducted in BT’s lab in Bristol; the second part involved an outdoor radio mast at BT’s Adastral Park in Suffolk, where they achieved 4CC on 5G SA using EE’s spectrum.

Not only is it the first time that a network operator in Europe achieved 4CC on 5G SA using commercial spectrum, but it’s also the first time it was achieved outside a lab in Europe, according to the operator.  

Most 5G networks today are non-standalone (NSA), which means the core still relies on 4G LTE. BT said 5G carrier aggregation over a standalone network represents a major leap forward in the evolution of 5G infrastructure, effectively combining several transmission bands into one connection. Every new carrier added allows for higher capacity and speed directly to customer devices.

Of course, the devices are needed in order for consumers to get the benefits. For example, AT&T’s Gordon Mansfield told Fierce in May that it will activate its 5G core – aka 5G SA – when the devices are ready.

Elsewhere in the U.S., T-Mobile has claimed a lot of firsts when it comes to 5G. It was the first in the world in 2020 to deploy a nationwide standalone network and remains the only carrier in the U.S. to have commercially launched SA.

In June of this year, T-Mobile announced it was able to aggregate three channels of mid-band 5G spectrum using a commercial device – the Samsung Galaxy S22. In that case, the “un-carrier” merged two channels of 2.5 GHz and one channel of 1900 MHz spectrum, effectively creating a 210 MHz 5G channel. Speeds reached over 3 Gbps.

Back in February, T-Mobile President of Technology Neville Ray tweeted about how they were able to reach ~2 Gbps using 4 CA on low and mid-band spectrum with Nokia and MediaTek.  

In its June 2022 Mobility Report, Ericsson said more than 20 service providers had launched public 5G SA networks by the end of 2021, and that number is expected to double in 2022.