Google Says Carriers Shouldn't Use LTE in Unlicensed Spectrum Bands
LTE in unlicensed spectrum bands could crowd out WiFi and other services; a better option is for mobile carriers to use underutilized 3.5GHz bands, Google said.Mobile carriers' planned use of unlicensed spectrum bands for Long Term Evolution (LTE) services could crowd out other unlicensed services, such as WiFi, Bluetooth and ZigBee, that operate on the same bands, Google warned in a white paper that it submitted to the FCC last week. The rapid growth of mobile data services and bandwidth-hungry applications has pushed mobile operators to look for more capacity in the 2.4GHz and 5GHz unlicensed frequency bands. Such "WiFi" offloading can benefit carriers by giving them additional capacity. It also helps consumers by enabling better performance, Google hardware engineer Nihar Jindal said in a blog posting. Over the past few months, multiple carriers and suppliers have said they plan to use the unlicensed 5GHz band to deploy LTE services. Typically, such services have been deployed only in licensed frequencies with wireless carriers having the option to use unlicensed frequencies if they needed additional spectrum without the added expense of a license, Jindal said. However, LTE in unlicensed (LTE-U) form poses several co-existence challenges. "LTE over unlicensed has the potential to crowd out unlicensed services," Jindal said. "Holders of licensed spectrum shouldn't be able to convert the unlicensed 5GHz band into a de facto licensed spectrum band, and certainly they should not have the ability to drive out other unlicensed users."
Google's 25-page paper to the FCC reports in, highly technical detail, on what the company said was its investigation of the co-existence between WiFi and LTE technology working across both the licensed and the unlicensed 5GHz spectrum.