With an eye on the coming millimeter wave auction, NBN Co is preparing to add 5G to its technology mix. The Australian broadband wholesaler has what it says is one of the biggest fixed wireless networks in the world, with 2,500 TD-LTE base stations and 600,000 homes passed.
The wireless network is part of the NBN's "multi-technology mix," along with fiber, copper, HFC and satellite. It serves 350,000 customers, or around 4% of the 7.3 million premises currently connected.
Sam Stephens, general manager of wireless technologies, says the biggest challenge is ensuring capacity. "You are always limited by spectrum," he told the recent Light Reading Next-Gen Broadband APAC conference.
"It's the busy hour peaks that really require the extreme capacity and the dimensioning to meet that and deliver a good enough service during the busy period." He said the NBN FWA network achieves around 4 bits-per-hertz over the air – "as good as many LTE networks out there."
It had held up well during the pandemic lockdowns, aided by a well-timed tweak just before the pandemic arrived.
"We changed our frame rate configuration at the start of 2020 – something that had been in planning for a long time. That was extremely fortuitous timing because it unlocked about 30% additional downlink capacity and gave us headroom to be able to cope with the covid traffic during 2020."
Five reasons why
Now Stephens' team is looking ahead to 5G. With its network portfolio heavily weighted to old-school tech like DSL and HFC, the company can't afford not to take advantage of a high-capacity low-cost option like 5G.
It has good business reasons as well. Telstra and Optus are already running 5G FWA services of their own, aimed at customers the NBN can't reach or those who appreciate the simplicity and portability of broadband wireless.
The other major wireless player, TPG Telecom, has calculated that it can save A$50 million ($38.2 million) for every 100,000 NBN-hosted FWA customers it can migrate to its own network.
Stephens said NBN Co had been working for the last three years on trying to stretch the capabilities of mmWave so that it becomes "a viable technology for remote and rural customers" as well as for urban small cells.
In January, NBN Co and Ericsson announced a world record for long-range 5G transmission over mmWave, transmitting close to 1 Gbit/s over 7.3km.
"The big thing that we've demonstrated is: If you get a clear line of sight, it will work at 7km or even a bit further. We're doing some more work and we expect it out even a little bit further." But he notes that while deployments in 3.5GHz or 2.3GHz don't require line of sight, mmWave certainly will.
The aim would be to determine which users needed upgrading and to strike a balance with 4G.
"Our 4G network is comparable to a 5G network in many ways and if we were to remove some of the capacity and move that onto a higher speed layer then we'd be able to deliver similar high speeds across both networks."
The ACMA auction of 26GHz frequencies for 29 cities takes place in April. Each bidder will be limited to up to 1GHz in spectrum.
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— Robert Clark, contributing editor, special to Light Reading