By Kells Hetherington
With over 11 Wi-Fi devices operating in the average household and the majority of Internet traffic being delivered over Wi-Fi connections, Wi-Fi technology has become so common that we tend to think of it as the only game in town.
But just as Xerox is not the only copier on the market and Kleenex is not the only brand of tissue, Wi-Fi is not the only technology capable of operating within the unlicensed bands we use in our homes, offices, and retail hotspots. Bluetooth is another technology that operates within unlicensed spectrum, as are wireless telephones, baby monitors, and garage door openers.
So far, the vast majority of devices operating within the unlicensed spectrum have been designed to share the spectrum fairly. However, many observers are increasingly concerned about an emerging controversy between the conveyance of Wi-Fi and an emerging wireless technology known LTE-U — with “LTE” being an acronym for “Long-Term Evolution,” commonly known as “4G LTE,” and the “U” standing for “Unlicensed Spectrum.”
From the beginning, Wi-Fi built “politeness” protocols into each device that minimize interference with other devices. For instance, Wi-Fi has a “listen-before-talk” feature to prevent a signal “talking over” another signal. And when another device is detected, Wi-Fi devices “back off” for an increasing amount of time to wait their turn and smooth out the use of the spectrum. LTE-U, however, has been found in tests by CableLabs engineers to take advantage of Wi-Fi’s “politeness” protocols, essentially by taking over Wi-Fi conversations that Wi-Fi devices are too technologically “polite” to interrupt.
LTE-U proponents insist that their new technology is compatible with Wi-Fi, but have so far worked outside the long-successful third-party standard-setting bodies such as the Institute of Electrical and Electronics Engineers (IEEE), which developed the Wi-Fi sharing protocols, or even the telecommunication carriers’ own 3rd Generation Partnership Project (3GPP).
The great advantage of engineers working out technology problems in standard-setting bodies like these is that they operate within the private sector, at an expert level, with the aim of quickly and efficiently solving technological problems.
Another brand of LTE technology called Licensed Assisted Access (LAA) is being developed in the 3GPP standards-setting body, specifically to establish sharing protocols that minimize interference with Wi-Fi. LTE-U, however, is the technology scheduled for deployment in the U.S. markets, where no such robust effort to minimize interference has been undertaken.
Which leads many to wonder – why? The risk-reward seems rather obvious, given that rolling out a new technology that interferes with Wi-Fi would cause unnecessary disruption of shared, unlicensed spectrum, and far worse, would likely lead the FCC to impose a regulatory solution.
It would be far better for the LTE industry to collaborate with the Wi-Fi industry on a private standards-based approach, so that innovation can continue in unlicensed spectrum without regulatory intervention
There is an important theory in economics called the Tragedy of the Commons, which explains how a limited resource owned in common by all – such as a parcel of open grazing land for cattle, or here, a bandwidth of unlicensed spectrum – tempts users of the “free” resource to overuse it, spoiling it for everyone. This danger was explicitly addressed when Wi-Fi sharing protocols were established early on by the IEEE. The result has been an explosion of investment and innovation to the point where most people who read this article will do so on a Wi-Fi device.
The industries who are operating in the unlicensed spectrum can and should continue to rely on private standards-setting organizations like the IEEE and 3GPP to address any problems that might degrade the thriving medium that unlicensed spectrum has become.