Probabilistic model for the analysis of elastic session duration in wireless networks

In wireless networks, the bitrate received by a user session depends not only on the fraction of allocated resources of the base station but also on the number of factors affecting the signal-to-noise ratio. These factors include a distance between a mobile device and the base station, walls, buildings between them, etc. As a result, the bitrate of elastic sessions may differ tenfold. In this paper, we develop a probabilistic model that captures the main specifics of the data transmission through a wireless network by introducing the random serving rate coefficients concept. With the help of the model, we derived the cumulative distribution function of the elastic session duration. © 2021 Institute of Physics Publishing. All rights reserved

Transmission Latency Analysis in Cloud-RAN

Cloud-based Radio Access Network (C-RAN) is a centralized cloud computing architecture for radio access networks (RANs) that provides large-scale deployment, joint support for radio technologies, and real-time virtualization capabilities. By moving signal processing functions to a data center, C-RAN significantly reduces power consumption and deployment cost. The architecture of the cloud radio access network consists of three main components: a pool of base-band units (BBU pool), remote radio heads (RRHs), and a transport network. In C-RAN, base stations are replaced by remote radio heads: data blocks are digitized, transmitted through the fiber-optical infrastructure, and remotely processed in BBU pool. One of the main issues is to control the round-trip delay between the remote radio heads and the BBU pool. In the paper, we describe a C-RAN in terms of queuing network and accurately evaluate all delay components. Besides, we analyze the required computational resources of the BBU pool required to satisfy the strict round-trip delay budget in C-RAN. © 2020, Springer Nature Switzerland AG

Handling overflow traffic in millimeter wave 5G NR deployments using NR-U technology

5G millimeter wave (mmWave) New Radio (NR) base stations (BS) are expected to be deployed in areas with extremely high and drastically fluctuating traffic demands resulting in frequent quality-of-service violations in terms of the provided rate at the access interface, especially, during busy hour conditions. As a cost-efficient countermeasure we consider NR unlicensed (NRU) technology encompassing both NR and WiGiG at a single NR-U BS. To ultimate goal of this study is to determine the required density of these NR-U BSs in an area characterized by a certain density of NR and WiGiG users, where NR users may utilize WiGiG technology as long as their rate requirements are met. Joining the tools of stochastic geometry, queuing theory and Markov chains we characterize the sought metric of interest. We then report the dependency of eventual NR UE session loss probability that can be used to deduce the sought density of NR-U BSs as a function of system parameters. Among other conclusions, we reveal that the effect of the antenna array at NR part of NR-U BS is non-uniform and needs to be taken into account planning NR-U deployments. © 2020 IEEE

Coexistence analysis of 5g nr unlicensed and wigig in millimeter-wave spectrum

The emerging 5G New Radio (NR) cellular systems that may operate in millimeter-wave (mmWave) frequency bands are expected to offer larger bandwidths. They are to be deployed in densely crowded environments, where the traffic load has a high degree of variability, which may introduce capacity bottlenecks. One of the options to alleviate the latter is to concurrently utilize the radio resources available in unlicensedmmWave bands, e.g., at 60 GHz. In thiswork, we address the coexistence ofmmWave-based NRUnlicensed (NR-U) andWiGig technologies and account for the mmWave-specific directionality, propagation, and blockage effects. By further incorporating the features of duty cycling and random access operation, we construct a mathematical framework, which is capable of characterizing the achievable data rates of the NR-U users that operate over both licensed and unlicensed mmWave spectrum simultaneously. Our numerical results demonstrate that the rate attained by such devices is primarily regulated by the initial contention window size that, in its turn, heavily depends on the system and environmental parameters. We report the optimal contention window values for a wide range of blocker and user densities as well as antenna array configurations. © 2021 Institute of Electrical and Electronics Engineers Inc.. All rights reserved