AT&T's senior vice president of wireless network architecture and design, Mr. Tom Keathley, revealed in an interview with Fierce Wireless that the company will carry out trials for the LTE-U technology starting either at the end of this year, or early next. He was however non-committal as to when consumers can expect the commercial roll out, saying that the carrier was in no hurry to deploy the fledgling technology any time soon, without learning about its commercial viability, and whether the 5 GHz band can actually be shared in a fair manner with existing dual Wi-Fi equipment that makes use of it. According to Mr. Keathley, "There will be no devices until early next year anyway. So the timing is reasonable".
For the uninitiated, LTE-U or LTE in unlicensed spectrum is a suggestion originally put forth by the San Diego, California-based semiconductor chipmaker Qualcomm Inc. to use unlicensed electromagnetic frequencies like the 5 GHz band commonly used by dual-band Wi-Fi equipment, as an adjunct to licensed bands for LTE communications. While Mr. Keathley said that he does believe fair-use sharing of the 5 GHz band between LTE and Wi-Fi is a definite possibility, he also pointed out that AT&T might actually wait further before considering deploying LAA, or Licensed Assisted Access. LTE-U and LTE-LAA are two competing and often controversial technologies that make use of unlicensed spectrum, but often confused to be one and the same. The major difference between them is that LTE-LAA, under development in accordance with 3GPP standards, incorporates 'listen before talk' capabilities, something that LTE-U does not. 'Listen before talk' ensures that usage of unlicensed spectrum by carriers for LTE communication can co-exist peacefully with other unlicensed uses, like Wi-Fi etc.
It bears mentioning here that AT&T is not a member of the LTE-U forum, unlike its major rivals Verizon and T-Mobile. The later named, has already said that it is eager to launch its services in the 5 GHz spectrum next year by teaming up with fellow members of the LTE-U forum - chipmaker Qualcomm and network equipment major Alcatel-Lucent. Verizon has also indicated its willingness to deploy LTE-U this year itself, over both the 5 GHz as well as 3.5 GHz frequencies. As mentioned already, the usage of the unlicensed 5 GHz band by wireless carriers for commercial usage has got Wi-Fi advocates up in arms, who believe that shared usage of the 5 GHz band will result in the carriers eventually getting to decide how much spectrum is used for LTE and how much gets left over for Wi-Fi, resulting in anything but fair usage.