Historically, a new, major generation of wide-area wireless technologies emerges roughly every 10 years.
In the early 1980s, analog cellular, or 1G, went live. There were multiple incompatible technologies, but, hey, we were finally mobile -- at least with voice and dial-up, modem-class data. When 2G went digital in the early '90s, it aimed to improve spectral efficiency, not voice quality or data speeds. Broadband performance was finally reached with 3G, and 4G built on that with even higher-speed data and a gradual push to all-IP-based services.
Now, we're beginning to hear about 5G, which is expected in volume production deployments by 2023 or so. But since we already deploy broadband and all-IP 4G services, what could 5G wireless technology possibly add? More speed, perhaps?
That's the obvious place to start, after all. Advances in networking have always been evaluated primarily by improvements in aggregate or per-user throughput numbers -- and these are, of course, important metrics. But now that 4G can -- in theory, if not contemporary practice -- get us to tens of megabits per second, per user, what could 5G possibly have to offer?
Spectral efficiency, for one. As it turns out, improvements in this key dimension define 5G and the future of mobility overall. These improvements provide the basis for why 5G wireless technology will ultimately be so important to individuals and organizations alike. And it's not really about per-user data speeds. Instead, it's about how efficiently those bits of data can be sent.
Important technologies for 5G
Spectral efficiency is the number of bits per second per unit of bandwidth -- in hertz or cycles per second -- that can be successfully transmitted. Over the last several years, spectral efficiency has been improved, thanks, in part, to advances in modulation -- how information is encoded for transmission through the physically hostile environment that is air -- and beamforming, which focuses energy in a particular direction, thereby improving reliability.
Multiple input, multiple output (MIMO), meantime, takes advantage of not just frequency -- bandwidth -- and time to increase capacity, but also adds a third, spatial dimension. It simultaneously turns historically degrading echoes and reflections of radio transmissions, known as multipath, into assets.
MIMO is based on the concept of a stream -- the more streams and multipath, the better. The math is complex, but MIMO, as we've seen in 802.11n and 802.11ac, truly works. MIMO will likely be at the heart of 5G, yielding unprecedented levels of spectral efficiency. Add in the denser deployment of cellular base stations to reuse spectrum more frequently, and 5G wireless technology is worth both the effort and the wait.
What will 5G be able to do?
With all that spectral efficiency, speeds of 50 Mbps or more aren't out of the question. But the real issue for the 5G era isn't per-user throughput; rather, it is overall system-wide capacity. Capacity is vital, as more users with more devices and more traffic hit the streets. Include the demand from the internet of things clients -- many of which will require megabit-class throughput -- and the ability to handle all of that concurrent, real-time, mission-critical traffic will be what truly defines 5G.
What should IT, then, be doing now with respect to 5G wireless technology? First, don't worry about underlying technologies -- 5G will retain compatibility with IP, so existing and planned services should map over with zero effect on developers or operations. Instead, and really for the first time, we'll have wireless network services that can completely replace landlines. This means there will be no difference between wireline in the services available and the quality of experience users will realize essentially everywhere. I'm expecting greater interworking with Wi-Fi as well -- 5G wireless technology will not replace Wi-Fi, ever -- so no effects there, either. Look for heterogeneous networks, or HetNets, handing off bidirectionally between 5G and Wi-Fi. It will be the best of both worlds.
We'll have uniform, global wireless broadband services, with the capacity -- again, that's the key -- to handle a variety of traffic demands and applications. Due to 5G's capabilities, IT will pay less attention to future wireless generations. In fact, I'm expecting 5G to be so robust that 6G may be delayed well past the early 2030s -- if it's ever needed at all.
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