Two converging trends in wireless data are speeding toward a head-on collision. 

One trend is people's eagerness to watch video on mobile devices. The other is the need for wireless carriers to ration the amount of bandwidth they can provide, given the finite amount of wireless spectrum available. This is a problem with no easy solution.

The growth of smartphones caused a tremendous increase in the amount of wireless data. But text, and even streaming music, is relatively modest consumers of bandwidth. Most music services stream to mobile phones at around 100 kilobits per second; YouTube videos require about five times that amount.

Disqus: Do you think Wi-Fi is the best solution for handling surging video demand?

The proliferation of tablets is causing demand to grow exponentially. Many folks don't care to watch videos on the small screens of a handset, but a 10" tablet is another matter.  However, making video look good on a larger display requires even more data, around a megabit per second or more. That will chew through a gigabyte of data in around two hours.

A study by network management company Allot Communications found that video streaming consumed nearly 40 percent of all mobile bandwidth used in the first half of this year. For now, YouTube is the dominant bandwidth consumer, accounting for roughly half of all use. And with the availability of Netflix and HBO GO on tablets, viewing of bandwidth-gobbling video is sure to grow. Cisco Visual Networking Index predicts that mobile data usage worldwide will grow 26-fold between 2010 and 2015, much of that driven by video.

As a result of surging data use, the carriers have implemented usage caps. Verizon's data plans provide 2 to 10 gigabytes a month, with extra use at $10 per gigabyte.  AT&T's brackets differ slightly, but the pricing is similar.  T-Mobile takes a slightly different approach, throttling the speed once caps are hit rather than charging for overage. Sprint offers truly uncapped data on its limited-coverage 4G network, but imposes caps of 3 to 10 gigabytes for 3G use—and 25 cents per additional megabyte, which works out to $250 per gigabyte.

Both Verizon Wireless and AT&T have also stopped offering unlimited wireless data plans, and AT&T recently informed customers who still have an unlimited plan that they may see data speeds slow if they are among the heaviest users.

AT&T, Comcast, and some other service providers also have caps on wired service, but in general, these are set so high that only online video addicts or heavy file sharers have much chance of encountering them.

Over the long term, the availability of spectrum for wireless data could allow these caps to rise. Spectrum allocation is controlled by governments and, especially in the U.S., freeing spectrum is a long, complex, and highly politicized process.

A second possibility is more efficient use of existing spectrum. In general, each new generation of wireless technology has made it possible to move more data across a given amount of bandwidth. Steve Perlman and Antonio Forenza of Rearden Cos., which has already shown an ability to move more data than anyone thought possible with its OnLive online gaming system, are proposing that a technology called Distributed Input-Distributed Output could dramatically improve the amount of data that can be transmitted through existing wireless spectrum.

For the near term, the best hope for solving the data limitation of wireless devices is to shift more of the work to Wi-Fi. Wireless carriers, realizing the limitations of their own networks, have been building Wi-Fi hotspots to reduce the strain on 3G and 4G systems. Technologies such as Cisco's Service Provider Wi-Fi help carriers optimize their networks.

Most handsets and tablets can use Wi-Fi when available. In your home or office, this is generally simple, but in public places it can be problematic, especially if registration is required to access the network.

In my experience, iPhones, iPads, and BlackBerrys handle public Wi-Fi reasonably well, while Android phones sometimes struggle.  The best thing for both carriers and consumers to ease the wireless crunch would be to make the Wi-Fi alternative more reliable and user friendly.

The contents or opinions in this feature are independent and do not necessarily represent the views of Cisco. They are offered in an effort to encourage continuing conversations on a broad range of innovative technology subjects. We welcome your comments and engagement.

We welcome the re-use, republication, and distribution of "The Network" content. Please credit us with the following information: Used with the permission of http://thenetwork.cisco.com/.