License-Assisted Access Considerations

Abstract

With mobility as the dominant theme in the emerging fabric of IoE (Internet of Everything), a prolific demand for capacity is a natural consequence. Throughput, latency reduction, availability and reliability are elemental attributes of experientially attractive and robust mobile multimedia services. These elemental attributes drive the demand for spectrum. The use of E-UTRA (Enhanced-Universal Terrestrial Radio Access) technologies, specified under the LTE project, over the 5 GHz unlicensed spectrum, is being considered as a forward-looking approach for standardization to meet the growing capacity demands to support mobile multimedia services. The 5 GHz spectrum band also includes the ISM (Industrial, Scientific, and Medical) band, which is utilized by the IEEE 802 family of technologies. LAA (license assisted access) refers to the use of LTE technologies over unlicensed spectrum, with assistance using a licensed radio frequency carrier. A significant challenge in the standardization of LAA for interoperability is the management of co-channel and adjacent channel interference, when both E-UTRA and the IEEE family of technologies share the same unlicensed spectrum. These challenges are compounded by the differences in the regulations across the three different global ITU (International Telecommunication Union) regions (Europe, Americas, and Asia.) This article will identify strategies and corresponding trade-offs to mitigate the coexistence challenges between the E-UTRA and the IEEE family of technologies, utilizing forward-looking and interoperable enablers. In conclusion, the article will delineate recommendations for a realization of CA (carrier aggregation) between licensed and unlicensed spectrum for downlink and uplink, to accomplish deployment-specific capacity enhancements.