The wireless industry is considering 5G performance targets of 10 Gbps and 1 millisecond-latency, said the senior director of technology for wireless association GSMA on an investor conference call organized by Bernstein financial analysts last week. Those targets will require the use of higher frequency spectrum, along with considerable innovation in antenna technology and the use of new signaling and modulation schemes, said senior director Dan Warren.
“Ten gigabits per second requires a lot of spectrum and a lot of antennas,” said Warren in a transcript of the conference call shared with Telecompetitor. Because of these challenges and because carriers worldwide are still making considerable investment in LTE, Warren doesn’t expect 5G deployment to occur until 2025, with some trial deployments occurring sooner.
5G Network Requirements
The portion of the radio spectrum where there is sufficient spectrum available for 5G is in the high-frequency millimeter wave band – and that frequency band is challenged to provide long-distance coverage, Warren said.
“To get decent range out of the millimeter wave, you need to have… one antenna per individual pointing at a very specific individual endpoint,” explained Warren. If, for example, a network operator wanted to support 200 connections on a cellsite, it would need 200 antennas on top of that cellsite.
Warren noted that some fixed wireless equipment already supports service over comparatively long distances by tightly focusing antenna beams. But what will complicate matters for 5G will be the need to provide that capability in a mobile environment.
“The kind of technologies which vendors are working on at the moment are ways of tracking or predicting where a device is going to move next and then pointing the beam so it remains focused on the individual device,” Warren explained.
The GSMA currently envisions two specific applications that are likely to require the high bandwidth and low latency of 5G, Warren said. These include autonomous driving and augmented or immersive Internet.
Autonomous driving could eliminate the need for drivers, with technology handling vehicle navigation. Such cars are likely to have in-car entertainment, and ubiquitous coverage along roadways will be critical, Warren said.
“Otherwise there’s a rather awkward handover experience where your car tells you that you need to grab hold of the wheel again,” said Warren.
Augmented or immersive Internet would be similar to virtual reality technology that enables users to see a virtual 3-D world by donning special goggles. In addition relevant pieces of information would be displayed for the end user. “So if I was looking at an individual, it might have their name and their Facebook status,” Warren said.
Augmented Internet is one of the applications that could drive the need for low latency as a means of preventing what Warren called “cyber sickness” – a form of motion sickness. “The human eye and the human brain are sensitive on a visual basis to anything where latency is more than one or two milliseconds,” Warren explained. Without that he said, “the experience where an individual moves their head wearing an augmented reality display is that the image doesn’t keep up with their movement and it essentially makes them feel nauseous.”
Meeting the latency target will be challenging because of the laws of physics, Warren said. But he added that “it’s much easier to do if you’re doing it very close to the end users, which then means that you have to really rethink the way that content is delivered… It’s actually a change in network topology.”
Because augmented Internet screen size would be relatively small, however, bandwidth requirements would be relatively low, Warren noted.
Wi-Fi and the IoT
Other interesting points from the conference call with Warren include:
- 5G and unlicensed wireless technology such as advanced Wi-Fi will be coupled more tightly from the start, unlike with what occurred with 4G
- The Internet of Things could drive the need for the “antithesis” of 5G – a low-power network with very large range capable of delivering very small amounts of bandwidth in order to support sensor networks.