As we head into the 2020s, mobile phone networks will have to handle much more traffic and many more connections.
There are roughly 6 billion mobile phone users worldwide, and they are upgrading to smartphones. The typical smartphone generates more than 30 times the traffic of the average basic mobile phone. Although the Internet of Things (IoT) is just getting started, it could easily require billions of new connections to sensors and machines.
It’s not too early to start planning for the next-generation wireless technology. 5G wireless is likely to be a constellation of enhancements rather than a single technological breakthrough. As we’ve seen in the past, the wireless industry isn’t going to abruptly switch off 4G and turn on 5G. Instead, expect “4.25G,” “4.5G,” and “4.75G” devices and networks to be gradually introduced over the next several years. Each incremental improvement will create new opportunities for users, enterprises and entrepreneurs.
The never-ending quest for more spectrum
Despite its maturity, the wireless industry continues to invent new ways to squeeze capacity out of existing spectrum. But doubling or even quadrupling capacity won’t be good enough. The wireless industry is literally asking for a 1,000x capacity increase. In addition to basic performance improvements, that is going to require more spectrum and more aggressive reuse of existing spectrum.
The good news is that at really high frequencies, bandwidth is abundant. In part, that’s because it’s easy to find large blocks (say, 500 megahertz) of unused spectrum at frequencies such as 60 gigahertz. Unfortunately, signals at those frequencies don’t travel far or around corners, and electronic components tend to be pricey. Over the short term, expect the mobile phone industry to be granted limited rights to share lower-frequency bands (below 6 gigahertz) that were allocated to other services years ago.
Also expect a big increase in the deployment of small cells. Mobile phone networks were originally built for car phones. Thanks to the development of pocket-size handsets, today’s networks largely serve indoor users. Although outdoor cell sites can often reach users indoors, indoor cells are needed to ensure coverage throughout large buildings and in homes and buildings far from cell sites. Putting small cells indoors ensures that more bandwidth is available for both indoor and outdoor users. Increasingly, mobile network operators are permitting home and business owners to install small cells using the operators’ licensed spectrum — as long as the owners provide the electricity and broadband Internet connections at their own expense.
The technology under the hood
There will be some enhancements to the mobile phone air interface, as well. 5G wireless will make more aggressive use of MIMO technology. MIMO exploits multipath propagation — which until recently was considered about as useful as static — to multiply the maximum transmission rate. Today, MIMO is enabling 4G networks to achieve speeds of hundreds of megabits per second. Tomorrow, it will enable 5G networks to exceed 1 gigabit per second. Unfortunately, radio is a shared medium and individual users almost never experience such high speeds. But there is a MIMO solution for that, too. Multi-user MIMO segregates users so they aren’t all contending for the same resources. Although multi-user MIMO reduces the (theoretical) peak speed, it increases the (real) average speed. Other enhancements to the mobile phone air interface will enable networks to more efficiently serve a mix of high-speed (multimedia) and low-speed (telemetry) applications.
There are some potentially disruptive wireless technologies in the works that could change the course of 5G wireless. Kumu Networks’ self-interference cancellation technology promises to double spectrum capacity and simplify frequency planning. Basically, this technology enables a mobile phone to hear the whisper of distant signals under the roar of its own transmitter. MagnaCom, an Israeli company, has developed a new multidimensional signaling technique that it says provides a 10x performance improvement. And San Francisco-based Artemis Networks claims its personal cell (“pCell”) technology delivers a 35x capacity increase using existing 4G devices. Rather than avoiding interference, the firm’s cloud-based solution puts interference to work. It’s an intriguing but highly controversial idea that has so far only been demonstrated under controlled conditions.
Everyone and everything
There are also some industry trends that could alter the trajectory of 5G wireless. Internet firms are offering mobile services created by stitching together coverage provided by a mix of mobile and Wi-Fi networks. Expect more seamless interoperation between mobile and Wi-Fi networks in the future. Beacons (using Bluetooth or the new Wi-Fi Aware protocol) are attaching information and services to places and objects in the physical world, potentially triggering yet more growth in wireless traffic. With almost as many mobile phones in use as there are people in the world, the next big growth wave will likely be connecting “things,” such as automobiles and parking meters.
5G wireless is important because it will bring us a step closer to a world in which everyone and everything is always connected. The opportunities to observe and manage people, places, and things will multiply, enabling the next successful mashups and shared economy business models.
This commentary by Ira Brodsky first appeared at Computerworld. Brodsky is a Senior Analyst with Datacomm Research and is the author of five books about technology. Brodsky focuses on mobile solutions for payments, retail automation, and health care.