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Integrated Use of Licensed- and Unlicensed-Band mmWave Radio Technology in 5G and Beyond

Research output: Contribution to journalArticle

Xi Lu, Eduard Sopin, Vitaly Petrov, Olga Galinina, Dmitri Moltchanov, Kirill Ageev, Sergey Andreev, Yevgeni Koucheryavy, Konstantin Samouylov, Mischa Dohler

Original languageEnglish
Article number8643932
Pages (from-to)24376-24391
Number of pages16
JournalIEEE Access
Issue number1
Publication statusPublished - 19 Feb 2019


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The 3GPP standardization rapidly moves forward with studies of a wider bandwidth waveform as well as adaptation of the emerging 5G New Radio (NR) based access to the unlicensed spectrum (NR-U). One of the basic architectures for NR-U involves carrier aggregation of an anchor licensed – NR carrier and a secondary carrier in unlicensed spectrum, which altogether allows for seamless traffic offloading in scenarios where multi-gigabit data rates are required. While today’s research on NR-U addresses mostly physical- and protocol-layer aspects, a system-level performance of NR-U offloading mechanisms has not been investigated thoroughly. In this work, we develop a mathematical queuing theoretic framework that is mindful of the specifics of millimeter-wave (mmWave) session dynamics
and may serve as a flexible tool for the analysis of various strategies for the integrated use of licensed and unlicensed mmWave bands in terms of the session drop probability and system utilization. To illustrate this, we select three distinct strategies (based on sequential service, probabilistic offloading, or proportional splitting) and complement our mathematical models with a detailed performance evaluation in a representative massive augmented / virtual reality (AR/VR) scenario. Based on this quantitative analysis of the selected schemes, we conclude that proportional splitting of traffic between the two mmWave bands leads to better performance.We believe that the contributed mathematical analysis can become an important building block in further system development and service optimization across many usage scenarios.

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