InterDigital's EdgeHaul antenna uses beam forming to aim the signal, and is a precursor to the antennas that will help speed up 5G networks. Credit: EdgeHaul
If operators are to build 5G mobile networks with download speeds at 10Gbps and above, they are going to need a lot more spectrum -- but getting it won't be easy.
The amount of spectrum allocated to 5G will determine how fast networks based on the technology will eventually become. Until recently, only frequencies below 6GHz have been considered for mobile networks, mostly because they are good for covering large areas. But there's now a growing need to unlock new spectrum bands in the 6GHz to 100GHz range too, attendees at the LTE and 5G World Summit conferences in Amsterdam heard this week.
The use of spectrum in these bands is immensely important for 5G networks to be able to offer multiple gigabits per second, Robert DiFazio, chief engineer at wireless R&D company InterDigital Communications, said. By raising communication speeds, they are also expected to help lower latency in mobile networks.
Even though spectrum from 6GHz to 100GHz won't be used in cellular access networks for at least another five years, vendors are keen to show they can handle all the technical challenges those frequencies present. The development of WiGig, which uses the 60GHz band, has already showed that using such high frequencies works, and on the show floor in Amsterdam, Huawei Technologies and Samsung Electronics both talked up pilot studies of other technologies they have conducted.
For the potential of spectrum above 6GHz to be realized, a new generation of antennas will be required, capable of directing multiple beams of data to different users at the same time. New systems will likely also need new modulation schemes to encode the data on the radio waves more efficiently.
There are ways for mobile networks to increase download speeds using existing spectrum, including using carrier aggregation or sharing spectrum with Wi-Fi networks. But at the end of the day, none of these options come close to the potential that as-yet-unused frequency bands above 6GHz offer. There is nowhere else to go but up, according to Samsung.
Rolling out networks isn't just about hardware and software: Regulators also have their say.
"We have made clear our intention to make large quantities of spectrum available in these frequencies, which is increasingly also the view of other regulators around the world," said Andrew Hudson, director of spectrum policy at British regulator Ofcom, who spoke on the subject on Thursday in Amsterdam.
The current focus of Ofcom's work isn't whether to make spectrum available, but how to identify the best spectrum in this range. This involves finding bands with a combination of good physical characteristics and good prospects for international harmonization, while taking into account current use, according to Hudson.
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