What telecom policy do the White House, Republican and Democratic Congressional leaders, and all five FCC Commissioners agree on? Bringing consumers more unlicensed airwaves. More unlicensed spectrum is critical for economic growth and innovation. We’ve heard this message loud and clear in the President’s 2014 Economic Report, from both sides of the aisle in the House and Senate, and consistently from Chairman Wheeler and Commissioners Clyburn, Rosenworcel, Pai, and O’Rielly.
How do we accomplish these goals? Consumers and businesses need access to more unlicensed spectrum to meet the demand for popular technologies like Wi-Fi, Bluetooth, and the Internet of Things. Today, creating this access depends on FCC decisions to deliver more spectrum in three important frequency bands – 5 GHz, 3.5 GHz, and 600 MHz. It also depends on ensuring that a diversity of unlicensed technologies can use this shared spectrum – and that having a license for other spectrum doesn’t become a prerequisite for making use of unlicensed bands.
Unlike the 2.4 GHz and 5 GHz unlicensed spectrum bands, where secondary users are not entitled to protection, the FCC has proposed three “tiers” of users for this band. First tier: the incumbents. New users cannot harmfully interfere with them. Second tier: “priority access” users. Users in this tier will have the exclusive right to use particular channels in particular areas, whenever the incumbents aren’t using the spectrum. Third tier: a tier that would work similar to today’s unlicensed bands. In this tier, users would be able to use spectrum wherever and whenever it’s not being used by incumbents or second-tier users.
Now that the FCC has put its plan in place, success will depend on smart and flexible implementation. The unlicensed community is ready to roll up its sleeves and work with the FCC and government users to establish sharing mechanisms. Spectrum Access System providers will assist in making this spectrum available for a variety of commercial use cases, while continuing to protect important federal missions and other incumbent users. By supporting dense small cell networks, this band could provide an important boost to our nation’s wireless capacity needs. It could also support broadband deployment in applications like manufacturing and healthcare.
The FCC is now working hard on the technical rules for the use of unlicensed devices in this band. Adopting rules that enable development of unlicensed devices with reasonable power levels and other operating parameters in at least three unlicensed channels in every market will unleash a huge new resource for American consumers. This low-band spectrum has great coverage and reach and can enable better whole-home Wi-Fi coverage, as well as unlicensed wireless Internet access in rural areas where it is not economical to provide wired broadband. But if the FCC overprotects licensees and incumbents, it will have needlessly squandered a golden opportunity to drive investment and innovation in products, devices and services that help Americans get online and directly contribute to our economy.
In recent months, however, several LTE-based carriers and suppliers have announced plans to build and deploy devices using a new technology called LTE Unlicensed (LTE-U) in the 5 GHz band. LTE-U ties together licensed and unlicensed frequencies using the LTE protocol. But unlike offload into the 5 GHz unlicensed band that uses standard Wi-Fi, the LTE-U approach will introduce new forms of LTE signalling into the 5 GHz band that will interfere with Wi-Fi transmissions. Companies like Verizon, T-Mobile, China Telecom, and Huawei have announced plans to deploy versions of LTE-U technology, despite the fact that the technology will substantially degrade Wi-Fi and other unlicensed use of the band.
To be clear, we believe everyone should have the ability to utilize unlicensed spectrum, including major wireless carriers. Our concern, however, is that carriers deploying LTE-U have considerably less incentive to coexist in unlicensed spectrum as compared to Wi-Fi and other technologies that operate solely in unlicensed spectrum. This is because LTE-U maintains connections in both licensed and unlicensed frequencies, which makes it inherently less sensitive to congestion and collisions in the unlicensed bands. This could lead to LTE-U eventually crowding out Wi-Fi and other technologies that are more sensitive because they operate only in unlicensed spectrum. The Wi-Fi Alliance, the Institute of Electrical and Electronics Engineers, AT&T, Broadcom, Google, the National Cable & Telecommunications Association and many others have expressed concern about the impact of planned LTE-U deployments.
The difference between Wi-Fi and LTE-U
Your Wi-Fi device is polite – it’s designed to allow many users to share the same radio frequencies and therefore to produce the most good for the most people. Wi-Fi is designed to “back off” when it senses another device using a channel. And your Wi-Fi device assumes that other devices in the unlicensed band will treat it in the same polite way. Unfortunately, however, some carriers are rushing to implement LTE-U devices that are designed to take advantage of Wi-Fi’s politeness in a way that could knock consumers off the air. LTE-U likely could be designed to reduce the threat to Wi-Fi, but there has been little incentive to adopt them.
Holders of licensed spectrum shouldn’t be able to convert the unlicensed 5 GHz band into a defacto licensed spectrum band, and certainly they should not the ability to drive out other unlicensed users. The low barriers to entry for accessing this spectrum have fostered the development of innovative technologies that now contribute billions of dollars each year to the U.S. economy. To protect these hotbeds of innovation and promote competition, we must ensure that they remain truly open to all.
FCC Commissioner Jessica Rosenworcel noted recently the Commission is looking closely at any pre-standards deployments of LTE-U that may jeopardize technologies like Wi-Fi. Commissioner Michael O’Rielly likewise explained that, while there was still much to learn about the new LTE-U technology, Wi-Fi’s incredible success should be preserved. The FCC has recently issued a Public Notice seeking comment on this issue.
There is still time for industry-led cooperation to work here – as it has worked with other technologies in the past — to ensure that each new generation of unlicensed technology shares well with other devices so that the unlicensed bands remain fertile ground for permission-less innovation. But those seeking to deploy LTE-U have so far failed to work effectively with other unlicensed users to ensure that this spectrum can be shared among existing users and remain open for innovation. If industry fails to develop workable sharing and coordination mechanisms to preserve the access and innovative use of unlicensed bands, the FCC will need to act.