Both AT&T and Verizon have had recent press releases about how they are currently testing 5G cellular data technology, and touting how wonderful it’s going to be. The AT&T Press release on 5G included the following statements:
Technologies such as millimeter waves, network function virtualization (NFV), and software-defined networking (SDN) will be among the key ingredients for future 5G experiences. AT&T Labs has been working on these technologies for years and has filed dozens of patents connected with them. . . . We expect 5G to deliver speeds 10-100 times faster than today’s average 4G LTE connections. Customers will see speeds measured in gigabits per second, not megabits.
AT&T went on to say that they are testing the technology now and plan to start applying it in a few applications this year in Austin, TX.
This all sounds great, but what are the real facts about 5G? Consider some of the following:
Let’s start with the standard for 5G. It has not yet been developed and is expected to be developed by 2018. The Next Generation Mobile Network Alliance (the group that will be developing the standard) states that the standard is going to be aimed at enabling the following:
- Data rates of several tens of megabits per second should be supported for tens of thousands of users;
- 1 gigabit per second can be offered simultaneously to workers on the same office floor;
- Several hundreds of thousands of simultaneous connections to be supported for massive sensor deployments
How does this stack up against AT&T’s claims? First, let’s talk about how 4G does today. According to OpenSignal (who studies the speeds from millions of cellular connections), the average LTE download speeds in the 3rd quarter of last year for the major US carriers was 6 Mbps for Sprint, 8 Mbps for AT&T, and 12 Mbps for both Verizon and T-Mobile.
The standard is going to be aimed to improve average speeds for regular outdoor usage to ‘several tens of megabits per second’ which means speeds of maybe 30 Mbps. That is a great data speed on a cellphone, but it is not 10 to 100 times faster than today’s 4G speeds, but instead a nice incremental bump upward.
Where the hype comes from is the part of the standard that talks about delivering speeds within an office. With 5G that is going to be a very different application, and that very well might achieve gigabit speeds. This is where the millimeter waves come into play. As it turns out, AT&T and Verizon are talking about two totally different technologies and applications, but are purposefully making people think there will be gigabit cellular data everywhere.
The 5G standard is going to allow for the combination of multiple very high frequencies to be used together to create a very high bandwidth data path of a gigabit or more. But there are characteristics of millimeter wavelengths that limit this to indoor usage inside the home or office. For one, these frequencies won’t pass through hardly anything and are killed by walls, curtains, and to some extent even clear windows. And the signal from these frequencies can only carry large bandwidth a very short distance – at the highest bandwidth perhaps sixty feet. This technology is really going to be a competitor to WiFi but using cellular frequencies and standards. It will allow the fast transfer of data within a room or an office and would provide a wireless way to transmit something like Google’s gigabit broadband around an office without wires.
But these millimeter waves are not going to bring the same benefits outdoors that they can do indoors. There certainly can be places where somebody could get much faster speeds from 5G outdoor – if they are close to a tower and there are not many other users. But these much faster speeds are not going to work, for example, for somebody in a moving car. The use of multiple antennas for multiple high frequencies is going to require an intricate and complicated antenna array at both the transmitter and the receiver. But in any case the distance limitations and the poor penetration ability of millimeter frequencies means this application will never be of much use for widespread outdoor cellphone coverage.
So 5G might mean that you will be able to get really fast speeds inside your home, at a convention center or maybe a hotel, assuming that those places have a very fast internet backbone connection. But the upgrade to what you think of as cellular data is going to be a couple-fold increase in data speeds for the average user. And even that is going to mean slightly smaller coverage circles from a given cell tower than 4G.
The problem with this kind of hype is that it convinces non-technical people that we don’t need to invest in fiber because gigabit cellular service is coming very soon. And nothing could be further from the truth. There will someday be gigabit speeds, but just not in the way that people are hoping for. And both big companies make this sound like it’s right around the corner. There is no doubt that the positive press over this are is great for AT&T and Verizon. But don’t buy the hype – because they are not promising what people think they are hearing.