When it comes to wireless networks, there are two major options on the table, cellular and Wi-Fi. With the explosive growth in the smartphone market, fueled largely by the immensely popular Apple and Android-powered devices, the network focus has shifted decidedly in favor of the cellular option and developments like 4G LTE offerings that can now support downstream bursts close to 50 Mbps; average data rates are in the range of 3.5 Mbps to 14 Mbps. However, there has also been a lot happening on the Wi-Fi front though it doesn't seem to generate the same buzz.
Despite its role in in-building infrastructure, Wi-Fi has essentially been a side-show in the mobile revolution. This is rather strange given the fact that Wi-Fi delivered widespread enterprise mobility for laptops and in a small number of cases, voice devices, years before the smartphone revolution got under way. However, with users demanding to bring their beloved mobile devices into the enterprise and marketing departments scrambling to get customer-facing applications into the public app stores, Wi-Fi continued to be an "infrastructure play" and generated all the excitement of Cat 6 cable!
However, the Wi-Fi Alliance continues to press forward with new certifications, the Wi-Fi equipment manufacturers continue to innovate, and used correctly, Wi-Fi can play an increasingly important role in delivering mobile UC.
Blazing Radios
The IEEE 802.11n radio link standard is rapidly becoming universal, and chipsets to support 802.11ac are just hitting the market; those will push data rates close to the 1 Gbps mark. These new radio links make use of more bandwidth-efficient coding schemes (i.e. more bits per second per hertz) and wider channels. Where the original 802.11a and g (data rates up to 54 Mbps) operated in 20 MHz channels, 802.11n introduced the option of 40 MHz channels; 802.11n delivers data rates up to 288.9 Mbps in a 20 MHz channel and 600 Mbps in a 40 MHz channel. With 802.11ac, channels up to 80 and 160 MHz will be added. Those wider channels will only be supportable in the 5 GHz U-NII band.
This does present a problem for smartphones. Part of what allows those newer 802.11 radio links to achieve such high data rates is multiple input-multiple output (MIMO) antenna systems that allow several independent transmissions (up to 4) to be sent simultaneously on the same channel. Multiple transmissions call for multiple radios, which taxes the battery power of a smartphone. To compensate for that, smartphone implementations of 802.11n limit the transmitter to one transmission channel, yielding a maximum data rate of 72.2 Mbps in a 20 MHz channel and 150 Mbps in a 40 MHz channel; most are limited to 20 MHz operation. As with all Wi-Fi implementations, actual throughput is roughly half those rates.
In any case, with Wi-Fi we can typically achieve average data rates far in excess of what we can get from LTE, and there are no "usage charges" for Wi-Fi. In the higher ed market, Wi-Fi has essentially replaced wired Ethernet for the student population, so Ethernet jacks are disappearing from dorm rooms much the way wired telephones were yanked when students started showing up with cell phones.
UC over Wi-Fi
Those sorts of data rates can easily support voice, video, and collaboration applications, assuming the Wi-Fi networks are configured properly for the volume of traffic; there are lots of systems integrators out there who know how to do that. There is indeed a cost involved in building that infrastructure, but Wi-Fi should certainly be one of the essential building blocks we look for in deploying a mobile UC capability.
Frankly it is surprising that more organizations have not made more extensive use of Wi-Fi up until now. For years we have had voice handsets from companies like Polycom/SpectraLink, Cisco, and Vocera that would operate over Wi-Fi, but they found little acceptance beyond a few specialized verticals like health care (Note: In May, Polycom announced it was selling SpectraLink to an affiliate of Sun Capital Partners, Inc. for $110 million. See Dave Michels' recent blog for more on this and other issues surrounding Wi-Fi phones).
I actually published a book about the how-to's of voice over wireless LANs some years back and I have fielded inquiries from countless users over the years regarding the possibility of shifting some of their cellular usage onto Wi-Fi. However, very few have followed through on the idea. The general feeling seems to be that the infrastructure upgrades would be too costly and they are getting a "good enough" deal on their cellular contracts.
The bigger problem seems to be that the managers in charge of "mobility" are not in charge of "Wi-Fi", so "mobility" becomes a synonym for "cellular"--it's the old story that "to a hammer, every problem looks like a nail".
Nevertheless, UC involves bringing a number of disparate communications technologies under one tent, and if mobility is going to be part of that, it is foolhardy to ignore one of the most prevalent mobile technologies we have.
