LTE Carrier Aggregation and Unlicensed Access
Daniel Chew, Andrew L. Adams, Jason Uher · 2021
Long-term evolution (LTE) market share is likely to increase in the near future due to a couple of factors. This chapter covers the paradigm shift from voice to data traffic in LTE. While LTE and the other 3GPP standards are clearly designed to be deployed in scenarios where the operator has full control over the spectrum, there has been an increasing push to adopt some basic coexistence methods to take advantage of all possible spectrum opportunities. 3GPP began a feasibility study into the direct use of unlicensed spectrum in 2015. There are four primary technologies added to the 3GPP specifications that support spectrum flexibility for a mobile operator: small cells, dual connectivity, carrier aggregation, and licensed-assisted access (LAA). The chapter discusses the evolved packet core, radio access network, and air interface details necessary to motivate the discussion on LTE-LAA.