Does Cellular Replace Wi-Fi?

Seriously – this is a question I recently explored with a seasoned mobile professional. And he made a pretty good case as to why cellular could obviate the need for Wi-Fi – today. But the landscape is changing rapidly, and my long-time contention that the ultimate success of cellular in fact depends upon Wi-Fi remains. Nonetheless, an interesting discussion – but you be the judge.

So I had a very interesting conversation recently with a senior executive of a mobility products company who just happened to mention that he thought cellular would eventually replace Wi-Fi. While I obviously don't agree with that thesis, he did make some pretty good points:

  • Cellular is way more convenient than Wi-Fi. Turn on your cellular-equipped device and it just works (assuming, of course, that you're in an area with coverage), but the Wi-Fi connection process (at present, granted) is clunky and inconvenient.
  • With LTE and particularly LTE-A, the underlying technology is vastly improved in efficiency across the board, meaning higher per-user throughput and improved overall capacity.
  • With Wi-Fi-like small cells clearly pointing the way to the future, capacity should increase even further. Being able to re-use spectrum over shorter distances is clearly a good idea (up to a point; see below) and one that I and others advocated as far back as the original PCS auctions of almost 20 year ago.
  • The Wi-Fi experience is often uneven - my choice of words here, but, let's face it, such can be downright awful, even for customers paying on a daily or other basis, with poor connectivity and throughput that's so painfully slow that the service is, in fact, unusable.

While agreeing with all of the above, I countered, though, with the following:

  • Cellular is severely limited in spectrum, with any given carrier having perhaps 30-50 MHz. of spectrum, more or less, in any given geography. Yes, OFDMA is an efficient bandwidth-allocation mechanism, and, yes, small cells allowing more rapid spectral re-use (over shorter distances) will work where applied. But Wi-Fi offers about a gigahertz of unlicensed spectrum, with small cells fundamental and, in fact, essential. You want capacity? Wi-Fi offers a lot more. And capacity is the key to broadband services, handling large numbers of users and devices, and supporting all applications. Moreover, Wi-Fi spectrum is free, so usage caps, the bane of cellular users everywhere today and a powerful psychological limitation on demand, simply don't exist except in very rare venue-specific installations.
  • Small cells are clearly a great idea, but the installation, power, interconnect, backhaul, and frequency coordination required add cost that carriers simply don't want to absorb today. Adding more capacity, then, will be a slow process in the cellular world, driven more by competitive and financial considerations than the needs of us mere users.
  • Sure, connecting to Wi-Fi can be inconvenient today. But the Wi-Fi Alliance's Passpoint program will address this to a very great degree, enabling connecting to a Wi-Fi network to be as easy as doing so with cellular.
  • And everyone in the Wi-Fi food chain, even those hotels that still offer only .11g service and skimp on coverage and backhaul capacity, have an incentive to improve. Free Wi-Fi that doesn't work well isn't a good value, and paid Wi-Fi that's similarly poor is a rip-off. The existence of such deficits get around.

But, most importantly, the limited spectrum available in the cellular world, coupled with relatively high installation and operating costs, mean that Wi-Fi offload is and will remain essential to the future success of cellular. Look, no one really cares what frequency, technology, or associated other technical details are at work in the service of running an app or accessing the Web while mobile. We just want it to work. And, without Wi-Fi, cellular will become so congested that it will become as unusable as the Wi-Fi typical of bargain motels. And no one wants that to happen.

My bottom line: Wi-Fi will continue to be a fixture in the residence and the enteprise, and will continue to grow in importance to cellular carriers as well. Cellular replacing Wi-Fi altogether? No way!

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