In 2015 I travelled to Shenzhen in China to learn more about 5G mobile technology at Huawei’s headquarters.Huawei’s brand is best known in New Zealand for phone handsets. That is only part of the company’s story. Huawei is also the world’s largest telecoms-equipment-maker and a world-scale economic powerhouse.Spark New Zealand and 2degrees use Huawei kit to power their cellular networks. Moreover, Huawei is leading the charge towards next generation mobile networks.
5G was always going to happen
Everyone in the phone business always knew there would be a generation to follow 4G. Cellular technology is far from done.Yet at the time of my visit 5G was still a new idea only starting to take shape. In 2015 many telcos around the world were still finishing their 4G networks.The hype machine hadn’t kicked in and technologists were still batting ideas around.Some concepts were just that: concepts.
Huawei’s 5G perspective
During the visit I got my first comprehensive overview of the Huawei’s perspective on the technology from Alex Wang, the company’s VP of wireless marketing.This is from the NZ Herald story I wrote about the trip:
“Dealing with more connections is one reason telecommunications companies need 5G. Wang says the formal definition of 5G has yet to be agreed, but one of the items of the list is for it to support massive connectivity.The goal is for cell sites able to cope with one million connections in a square kilometre — effectively that means one mobile device per square metre. By comparison today’s 4G cell sites might handle 1000 to 3000 devices.”
Wang also said the goal was to get latency down to 1 ms and to support data speeds of up to 10 Gbps. This second goal has since been changed to 20 Gbps. Most of the other numbers remain as planned in 2015.
Phones at the speed of light
As any physics student will be able to tell you, light, or radio waves, travels through a vacuum at about 300 kilometres in a millisecond. The speed through air is not much different.The original 5G target speed of 10 Gbps is ten times the speed of today’s fastest home fibre connections. The newer 20 Gbps target is twenty times faster.Without getting deeper into electromagnetic physics or engineering, these goals are ambitious.You can’t push wireless data that fast with the existing mobile radio spectrum. There isn’t enough free bandwidth for three carriers to hit these targets in densely populated areas.
More spectrum needed
Which means carriers need to find new spectrum if they are to deliver 5G. Or, more to the point, government’s have to reorganise existing spectrum allocations. In most cases they then sell it to carriers in an auction.New Zealand’s Radio Spectrum Management, part of the Ministry of Business, Innovation and Employment, is already working on 5G plans.So is the Commerce Commission. Telecommunications Commissioner Dr Stephen Gale said:“We believe the power to regulate remains an important competition safeguard, especially with 5G networks and potential new entrants on the horizon”.
A costly exercise
Spectrum isn’t cheap. Governments usually auction it in blocks at a time. Each block sits in a separate band of spectrum.The last New Zealand government wisely decided not to cash in on the last big spectrum auction for blocks in the 700 Mhz band. That left carriers with the funds to exploit the new bandwidth almost straight away.Contrast this with the UK where bidder spent £1.4 billion buying 5G spectrum. This was more than twice the anticipated cost. The winning bidders spent money they could have used for the capital expense of building a network. It’s likely to mean a slower build and higher costs for users.
In the past different services have run in different frequency bands.One of the features of 5G is that carriers will be able to mash together greater amounts of bandwidth from different bands. Or to use their language: aggregate spectrum.This already happens a little with 4G. Spectrum aggregation is central to 5G. Aggregation opens the door to merging what now may seem like different technologies, in particular cellular and wi-fi. How that works in practice will be interesting.In the next post on 5G we’ll look more at the spectrum issue.
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