Verizon, SK Telecom join T-Mobile in testing unlicensed LTE, but Wi-Fi Alliance urges caution

Ericsson (NASDAQ: ERIC) is working with Qualcomm (NASDAQ:QCOM) and several major carriers to trial unlicensed LTE service in the 5 GHz band. The carriers, including Verizon Wireless (NYSE: VZ), T-Mobile US (NYSE:TMUS) and SK Telecom, are at the vanguard of deploying what is known as License Assisted Access (LAA) or LTE-Unlicensed (LTE-U).

However, the Wi-Fi Alliance, which certifies Wi-Fi-enabled products and represents the interests of Wi-Fi players, expressed concerns that LAA will harm Wi-Fi users in the 5 GHz band.

Ericsson said in a statement that LAA is "live in Ericsson labs and is now supporting the aggregation of licensed and unlicensed spectrum for peak rates up to 450 Mbps and enabling fair sharing of spectrum between mobile and Wi-Fi devices."

Ericsson's lab trials of both LAA "fair sharing" and licensed-unlicensed aggregation, which used 20 MHz on a licensed band and 40 MHz on an unlicensed 5 GHz band, were demonstrated in cooperation with Qualcomm.

Qualcomm has been championing LTE-U since at least November 2013, before the 3GPP switched to the term "License Assisted Access." 3GPP chose the LAA moniker to stress the point to government spectrum regulators that the use of LTE on a secondary carrier in an unlicensed band would be accompanied by a licensed primary carrier.

Ericsson added that its implementation of LAA incorporates "fair sharing" within the 5 GHz band to accommodate traditional Wi-Fi users. "Fair sharing works on the principle that Wi-Fi and LAA users would have equal access to the spectrum," Ericsson said.

However, some in the Wi-Fi community, including unlikely allies like cable MSOs and public interest groups, worry that the control and scheduling in LAA will always be run over the licensed channel since it is centrally-scheduled, meaning that carriers will hold the balance of power over how much spectrum is devoted to LTE and how much to unlicensed Wi-Fi. In effect, they worry that unlicensed Wi-Fi will be relegated to the status of a second-class citizen in the 5 GHz band.

The Wi-Fi Alliance urged caution and cooperation with Wi-Fi users. "There is a risk that LAA, and especially pre-standard systems deployed ahead of coexistence work being done in the industry, will negatively impact billions of Wi-Fi users who rely on 5 GHz today for networking and device connectivity," the group said in a statement. "It is generally agreed in principle that fair sharing is required, but there needs to be further work from all parties to address this risk in practice."

In its statement, the alliance noted that "the future value of unlicensed spectrum is dependent upon good stewardship by all technologies that share the resource. The LTE and Wi-Fi communities must work toward a mutually understood fair and effective use of the 5 GHz band and ensure that there are no adverse effects to the installed base and future users of Wi-Fi. Wi-Fi Alliance is planning collaboration with 3GPP, and is eager to work with those planning pre-standard deployments to help them continue to satisfy the expectations of Wi-Fi users."

The Wi-Fi Alliance added that it may speak out on the topic if necessary. "We plan to work with regulators and industry stakeholders toward an industry-led outcome that avoids heavy regulation and ensures that users are able to benefit from Wi-Fi well into the future," the group said.

Ericsson, Qualcomm, Verizon, T-Mobile and SK Telecom are all members of the Wi-Fi Alliance, along with hundreds of other companies, including Apple (NASDAQ: AAPL), Broadcom, Cisco, Comcast (NASDAQ: CMCSA), LG Electronics, Intel, Microsoft (NASDAQ: MSFT), Nokia (NYSE:NOK), Samsung Electronics, Sprint (NYSE: S) and Sony.

For more:
- see this Ericsson release
- see this Wi-Fi Alliance release

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