System-Level Models and Methods for Improving Session Service Reliability in Millimeter-Wave Cellular Systems
Samuylov, Andrey (2025)
Tampere University
2025
Tieto- ja sähkötekniikan tohtoriohjelma - Doctoral Programme in Computing and Electrical Engineering
Informaatioteknologian ja viestinnän tiedekunta - Faculty of Information Technology and Communication Sciences
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Väitöspäivä
2025-04-22
Julkaisun pysyvä osoite on
https://urn.fi/URN:ISBN:978-952-03-3867-1
https://urn.fi/URN:ISBN:978-952-03-3867-1
Tiivistelmä
Utilizing the millimeter wave (mmWave) band promises to deliver extraordinary rates to the air interface of fifth generation (5G) systems. This technology will enable many novel applications, such as holographic communications, virtual and extended reality, high data-rate streaming, and others.
Although 5G mmWave systems have already been standardized by 3rd Generation Partnership Project (3GPP), their deployment is hampered by several factors, with dynamic human body blockage being one of the most impactful. A mobile crowd around the user dynamically occludes the propagation path between user equipment (UE) and base station (BS), which may lead to a temporal loss of connectivity. Thus, it is necessary to develop new system-level blockage mitigation techniques that can improve service reliability in 5G mmWave systems.
This thesis evaluates methods for improving service reliability in 5G mmWave systems. To this aim, it starts by proposing models for dynamic human body blockage. Then, by utilizing the methods of stochastic geometry and queueing theory, a general mathematical methodology capable of capturing the mmWave band propagation and session service specifics at the mmWave BS is developed. Equipped with this tool, two mechanisms for improving service reliability are considered and evaluated: (i) bandwidth reservation and (ii) multi-connectivity.
The thesis results demonstrate that the use of bandwidth reservation offers a way to improve session continuity at the expense of slight performance degradation in resource utilization. It was also shown that multi-connectivity significantly improves both user- and network-centric performance. The average gains made available by preferring advanced multi-connectivity strategies are modest on top of the baseline performance and come at the cost of additional signaling overhead. Finally, it was shown that multi-connectivity or bandwidth reservation alone are not sufficiently flexible in isolation. A joint implementation of the considered mechanisms is recommended to maintain efficient system performance.
Although 5G mmWave systems have already been standardized by 3rd Generation Partnership Project (3GPP), their deployment is hampered by several factors, with dynamic human body blockage being one of the most impactful. A mobile crowd around the user dynamically occludes the propagation path between user equipment (UE) and base station (BS), which may lead to a temporal loss of connectivity. Thus, it is necessary to develop new system-level blockage mitigation techniques that can improve service reliability in 5G mmWave systems.
This thesis evaluates methods for improving service reliability in 5G mmWave systems. To this aim, it starts by proposing models for dynamic human body blockage. Then, by utilizing the methods of stochastic geometry and queueing theory, a general mathematical methodology capable of capturing the mmWave band propagation and session service specifics at the mmWave BS is developed. Equipped with this tool, two mechanisms for improving service reliability are considered and evaluated: (i) bandwidth reservation and (ii) multi-connectivity.
The thesis results demonstrate that the use of bandwidth reservation offers a way to improve session continuity at the expense of slight performance degradation in resource utilization. It was also shown that multi-connectivity significantly improves both user- and network-centric performance. The average gains made available by preferring advanced multi-connectivity strategies are modest on top of the baseline performance and come at the cost of additional signaling overhead. Finally, it was shown that multi-connectivity or bandwidth reservation alone are not sufficiently flexible in isolation. A joint implementation of the considered mechanisms is recommended to maintain efficient system performance.
Kokoelmat
- Väitöskirjat [5265]