3G is turning out to be an unusually troublesome technology for Vodafone UK. The operator, which spent about £6 billion (US$8.3 billion, at today's exchange rate) to acquire its original 3G license in 2000, is in a hurry to shift customers off the ageing service so that it shut down the network, re-farm spectrum and save money. Crucially, it also needs 3G out of the way before it can rely heavily on open RAN.
Vodafone is building an open RAN network to replace about 2,500 sites currently supplied by Huawei, having been ordered by government authorities to evict the controversial Chinese vendor by 2028. It has already named its key partners, handing a prominent role to South Korea's Samsung. But its new suppliers do not offer support for 3G.
"Part of the challenge is that open RAN is not geared up to 3G," said Ker Anderson, Vodafone UK's head of radio and performance, during a media roundtable in London this week. "Do I leave part of the Huawei kit running 3G and put in open RAN serving 2G, 4G and 5G and then create a dog's dinner of capabilities so that managing traffic … becomes a performance nightmare?"
Vodafone's headquarters in the town of Newbury.
Anderson admits 3G is "holding us back from introducing open RAN," a technology that Vodafone hopes will inject new competition into the market for radio access network technologies. In a traditional network, all the software and components for a particular site come from the same vendor (mainly Ericsson, in Vodafone UK's case). The big idea with open RAN is to redesign interfaces so that operators can mix and match suppliers.
Vodafone, accordingly, is buying software and radios from Samsung, more radios from Japan's NEC, Intel-based hardware servers from Dell, cloud infrastructure from Wind River as well conformance and interoperability testing services from Keysight and Capgemini.
To free up spectrum, and support the open RAN shift, it has now moved all its 2100MHz spectrum – including the frequencies it bought for 3G back in 2000 – over to its 4G network. A similar process is underway for 900MHz spectrum. Vodafone has already carved out a contiguous 10MHz block in this band for its 4G services, allowing it to provide better in-building coverage for any 4G devices.
The plan is to phase out 3G entirely. "As we move forward, we expect 3G to go down and it continues to go down weekly as more people buy and upgrade handsets, and we will gradually evolve 900MHz to move to 5G and ultimately there will not be a need for it on 3G," says Anderson.
Unfortunately, he cannot move as quickly as he would like because lots of Vodafone customers still rely on 3G technology. While 90% of data traffic now runs on the 4G network, the installed base includes "people not interested in technology" who have not upgraded their handsets for years, explains Anderson. Others have 4G-capable phones but only 3G plans. An additional problem is old firmware on 4G-capable devices, tying users to a 3G service. It all means 3G may be around for several years – much longer than analysts were expecting.
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Given his remarks about a "dog's dinner of capabilities," Anderson seems unwilling to run a Huawei 3G network in parallel to the open RAN one. "The costs of operating two parallel networks are so high (tower rent, energy and other costs) that the high uptake of 2G and 3G is open RAN's biggest challenge," said John Strand, the CEO of Danish advisory group Strand Consult, in emailed comments.
He points out that millions of people in Africa, Latin America and Asia still use phones that only support 2G and 3G. Open RAN technologies, he says, "are not solutions that can replace existing networks in Europe, Africa and Latin America."
Anderson says Vodafone UK invests between £600 million ($698 million) and £700 million ($815 million) in capital expenditure annually and that he could easily spend more this year, if he were allowed, given the long list of technical activities. Besides the Huawei swap-out, those include Vodafone's 5G deployment, rollout of mobile edge computing, investment in the Redstream transport network, decoupling from O2 (with which it has previously shared some active network equipment) and shift from Nokia to Ericsson in London and parts of the southeast.
The longevity of 2G
Samsung's earlier lack of support for 2G technology was raised as a concern by Howard Watson, BT's chief technology officer, during a parliamentary committee last year. "The key point is the single RAN concept and the 2G and 3G legacy," he told politicians. "Right now, 50% of my voice calls still use the 2G and 3G network … My view right now is that for a replacement technology today, 2G has to be a critical part of the solution."
However, Samsung appeared to have addressed this shortcoming when it was unveiled as Vodafone's main open RAN partner. The system it is building will include 2G as well as 4G and 5G technologies, Vodafone said back in June. Other open RAN vendors are also now boasting support for older network standards. Just last week, Mavenir announced the commercial readiness of a 2G architecture, while Parallel Wireless, a rival company, has long insisted that it can provide both 2G and 3G products to its customers. Both companies have featured in Vodafone trials, although Samsung was ultimately preferred as the UK software supplier.
Anderson told Light Reading that he expects 2G to outlast 3G and still be around when he retires (something that does not look imminent). That technology is needed, according to Vodafone spokespeople, because it remains the only option for global roaming and is still used for machine-to-machine connectivity.