LTE PRINCIPLES AND OPTIMIZATION (A 4G WIRELESS TECHNOLOGY)

LTE brings new technologies like Multiple Input Multiple Output (MIMO) transmission, multiband carrier aggregation, small cells and a number of new uses cases like Voice over LTE (VoLTE). The optimization of Key Performance Indicators (KPI) is still important in LTE including setup success rates, handover success rates and call retainability. LTE uses frequency reuse one without any soft handover which makes the interference management more challenging than in legacy radio networks. Signalling message coding and packet scheduling are example solutions in LTE optimization together with the traditional RF optimization. Capacity optimization focuses on the high traffic areas and mass event. It is not only about user plane dimensioning but also interference management, signalling solutions and connectivity dimensioning are important. Many mass events are uplink limited while the networks in general are downlink limited, which adds further complexity on the high capacity optimization. Voice has been Circuit Switched in 2G and in 3G networks while voice in LTE is VoIP (VoLTE). A number of optimization steps are required to provide similar or better drop rates with VoLTE as with CS voice. Also the handover from VoIP to CS voice requires optimization. That is called Single Radio Voice Call Continuity (SRVCC). LTE will be running in parallel with 2G and 3G network. The interworking between these radios need to be considered as well as the usage of multiple LTE bands. Many operators have already deployed three LTE frequencies and will deploy even five or six frequencies in the long term