Wireless turf wars: How can LTE-U and Wi-Fi co-exist?

Dirk Gates, founder and executive chairman of Wi-Fi solutions provider Xirrus, argues that LTE should not be allowed to operate in Wi-Fi frequency bands without regulation and employing a listen-before-talk protocol

Wireless turf wars: How can LTE-U and Wi-Fi co-exist?

Over the past few months, the wireless and telecoms industries have seen multiple articles on the advantages of LTE-U (LTE in the unlicensed spectrum) operating in the 5Ghz spectrum alongside Wi-Fi. At face value it sounds like a reasonable proposition but the results of extensive testing have shown that an LTE-U network will supersede any Wi-Fi signal in public locations.

LTE-U is designed to let mobile networks improve their data speed over short distances without the need for a Wi-Fi network. It uses unlicensed spectrum, such as the 5GHz band used by Wi-Fi, to boost coverage of 4G and, because there are no additional rights to be purchased, allows carriers to extend their networks at a fraction of the cost.

However, these networks also create enough ‘noise’ to interfere with nearby corporate networks and public Wi-Fi hotspots and this level of interference will only increase unless LTE carriers agree to share the 5GHz spectrum fairly. Those advocating LTE-U argue it should be allowed to operate in the same spectra as Wi-Fi technology as a legitimate competitor.

However, I disagree and here are my reasons why:

Additional costs to the user: LTE offers a 3G or 4G connection as part of a user’s data plan. This means that whenever a user connects outside of a public hotspot, it eats into their data allowance. Once this allowance is consumed, the cost of connecting to LTE-U adds up quickly.

Wi-Fi is a better fit for businesses: Why would a company want to pay what could be an extortionate bill for mobile-based connectivity when they can run a cost-efficient corporate Wi-Fi network?

Wi-Fi can be secure: Whilst public Wi-Fi has had some security problems in the past, LTE-U doesn’t necessarily offer better security. IT administrators can now provide separate encryption keys for each user for creating a secure, private network at any location.

Using the spectrum efficiently: Five years ago, supporters could talk about LTE’s increased efficiency in using the spectrum. Now, the capabilities of 802.11ac - and the forthcoming 802.11ax – far outstrip the efficiency of LTE.

Not to mention, users will need to buy a device that is LTE-U compatible.

Co-operation and co-existence?

A debate at the Federal Communications Commission (FCC) in the US is already brewing, which is likely to turn into a full-blown regulatory tussle over a person’s device. Similarly, the WiFi Alliance in the UK wants to set standards, conduct tests and issue its own approvals. While the arguments and debates are sure to continue for some time, there are legitimate questions about how this extra LTE traffic affects Wi-Fi.

The UK has already successfully conquered the co-existence problem by regulating the 5GHz spectrum and employing a listen-before-talk (LBT) protocol. However, carriers in the US are rushing LTE-U to market before the FCC can implement similar regulations.

If this continues, not only will consumers become frustrated with problems such as latency on their devices, but traditional Wi-Fi vendors will be forced to look for clean spectrum. Similar to the European model, the FCC and industry leaders need to take steps now to regulate the 5GHz band.



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