Millimeter wave (mmWave) communication systems can provide high data rates but the system performance may degrade significantly due to mobile blockers and the user's own body. A high frequency of interruptions and long duration of blockage may degrade the quality of experience. For example, delays of more than about 10ms cause nausea to VR viewers. Macro-diversity of base stations (BSs) has been considered a promising solution where the user equipment (UE) can handover to other available BSs, if the current serving BS gets blocked. However, an analytical model for the frequency and duration of dynamic blockage events in this setting is largely this http URL this paper, we consider an open park-like scenario and obtain closed-form expressions for the blockage probability, expected frequency and duration of blockage events using stochastic geometry. Our results indicate that the minimum density of BS that is required to satisfy the Quality of Service (QoS) requirements of AR VR and other low latency applications is largely driven by blockage events rather than capacity requirements. Placing the BS at a greater height reduces the likelihood of blockage. We present a closed-form expression for the BS density-height trade-off that can be used for network planning.
Apart from static and dynamic blockage, self-blockage plays a key role in mmWave performance. The authors of @cite_12 studied human body blockage through simulation. A statistical self-blockage model is developed in @cite_25 through experiments considering various modes (landscape or portrait) of hand-held devices. The impact of self-blockage on received signal strength is studied in @cite_8 through a stochastic geometry model. They assume the self-blockage due to a user's body blocks the BSs in an area represented by a cone.
@cite_25 @cite_12 @cite_8
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There has been a growing interest in the commercialization of millimeter wave (mmW) technology as a part of the Fifth-Generation New Radio (5G-NR) wireless standardization efforts. In this direction, many sets of independent measurement campaigns show that wireless propagation at mmW carrier frequencies is only marginally worse than propagation at sub-6 GHz carrier frequencies for small-cell coverage --- one of the most important use-cases for 5G-NR. On the other hand, the biggest determinants of viability of mmW systems in practice are penetration and blockage of mmW signals through different materials in the scattering environment. With this background, the focus of this paper is on understanding the impact of blockage of mmW signals and reduced spatial coverage due to penetration through the human hand, body, vehicles, etc. Leveraging measurements with a 28 GHz mmW experimental prototype and electromagnetic simulation studies, we first propose statistical blockage models to capture the impact of the hand, human body and vehicles. We then study the time-scales at which mmW signals are disrupted by blockage (hand and human body). Our results show that these events can be attributed to physical movements and the time-scales corresponding to blockage are hence on the order of a few 100 ms or more. Building on this fundamental understanding, we finally consider the broader question of robustness of mmW beamforming to handle blockage. Network densification, subarray switching in a user equipment (UE) designed with multiple subarrays, fall back mechanisms such as codebook enhancements and switching to legacy carriers in non-standalone deployments, etc. can address blockage before it leads to a deleterious impact on the mmW link margin. In this paper we study the effect of human blockage on a new cellular architecture that incorporates millimeter wave technology for the access link. Assumptions, methodology, and simulation results are discussed to analyze the effect of human blockage on this type of deployment. A statistical model for human blockage and self blockage of the millimeter wave (mmW) signal is presented and analyzed. Our simulations show that even with a simple modulation scheme, an average network throughput of 400 Gbps km2 is achieved. The objective is to propose and demonstrate that such an architecture is capable of providing high throughput services to outdoor users even in heavily crowded areas. The millimeter wave (mmWave) spectrum is a strong candidate carrier frequency for access channels in fifth generation cellular networks. Unfortunately, the human body heavily attenuates mmWave signals. This paper evaluates the impact of self-body blocking (the blocking of the direct link by the handset user's body) in mmWave cellular networks using a stochastic geometric network model. A mathematical model for self-body blocking is proposed, allowing for position changes, and used to compute signal-to-interference-plus-noise ratio (SINR) distributions with two possible user association rules. The results characterize how self-body blocking impacts the SINR coverage. Even including self-body blocking, mmWave cellular systems can still outperform convention systems at lower frequencies, in terms of the achievable rate, due to the larger bandwidth.