Using LTE in Unlicensed Bands: Potential Benefits and Co-existence Issues

Use of LTE in unlicensed bands will allow operators to access additional spectrum to meet the increasing demand for mobile services. In this article we provide an overview of the different approaches currently being considered for LTE operation in unlicensed bands and their interaction with WiFi networks. In summary, LTE-Unlicensed (LTE-U) with adaptive transmission (blanking) is likely to be available in the short term, but cannot be used in all regions due to regulatory restrictions. License Assisted Access (LAA) is intended for use more widely and so will include listen before talk and other features required to conform with European and Japanese regulations. However, this will require changes to the LTE standards and so LAA is likely to take longer to deploy. In addition to describing the tradeoffs between these approaches, we also discuss the issue of fair co-existence with existing unlicensed band users, especially WiFi devices.