Virgin Media O2 has tested a Nokia RAN running on an Nvidia GPU at a busy site in Paddington, central London, Light Reading reported on 28 October. Rob Joyce, VMO2's director of mobile access engineering, said AI-based channel quality estimation raised spectral efficiency by 20%. He also said a GPU is not required to do this and described Ericsson's silicon as very good. Ericsson CEO Per Narvinger has said about 60,000 base stations operated by its customers already run an AI successor to link adaptation on existing ASICs, with a gain of around 10%.
VMO2 has no GPU RAN in the £700 million tranche of network spending announced earlier this year, and Joyce favours a distributed RAN. Centralising GPU baseband would require CPRI or eCPRI links of 25 Gbit/s each, about 3 of them or 75 Gbit/s, to a site that has 10 Gbit/s of fibre today. In his words, a distributed deployment means putting additional baseband GPU resources at each site, which is the cost that has to be weighed against the gain.
The 20% and the 10% cannot be compared. They come from different vendors, different algorithms and different scales: 1 trial site against a deployed base of 60,000. Light Reading's report gives no baseline, test duration or site count for the 20%. I made the case in Ericsson and Nokia at odds on AI-RAN silicon that the decision to use AI in the RAN is separate from the decision to buy GPUs, and VMO2's engineering lead now says the same. That keeps the position from Is AI-RAN the future of telco? intact: the commercial case for GPU RAN depends on benefits beyond radio algorithms that ASICs can also run, and no operator has published a baseline or a cost per site to show it. For Nokia customers the choice is narrower than the technology case suggests, because Nokia is no longer developing new technology with Marvell and its roadmap runs through GPUs.

