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1. Outdoor-to-indoor 28 GHz wireless measurements in manhattan: path loss, location impacts, and 90% coverage

   https://doi.org/10.1145/3492866.3549728  

   Kohli, Manav; Adhikari, Abhishek; Avci, Gulnur; Brent, Sienna; Moser, Jared; Hossain, Sabbir; Dash, Aditya; Kadota, Igor; Feick, Rodolfo; Chizhik, Dmitry; et al (January 2022, in Proc. ACM MOBIHOC’22, 2022)

   Outdoor-to-indoor (OtI) signal propagation further challenges link budgets at millimeter-wave (mmWave). To gain insight into OtI mmWaveat28GHz, we conducted an extensive measurement campaign consisting of over 2,000 link measurements in West Harlem, NewYorkCity, covering seven highly diverse buildings. A path loss model constructed over all links shows an average of 30dB excess loss over free space at distances beyond 50m. We find the type of glass to be the dominant factor in OtI loss, with 20dB observed difference between clustered scenarios with low- and high-loss glass. Other factors, such as difference in floor height, are found to have an impact between 5ś10dB. We show that for urban buildings with high-loss glass, OtI data rates up to 400Mb/s are supported for 90% of indoor users by a base station (BS) up to 49m away. For buildings with low-loss glass, such as our case study covering multiple classrooms of a public school, data rates over 2.8/1.4Gb/s are possible from a BS 68/175m away when a line-of-sight path is available. We expect these results to be useful for the deployment of OtI mmWave networks in dense urban environments and the development of scheduling and beam management algorithms. 

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2. Outdoor-to-Indoor 28 GHz Wireless Measurements in Manhattan: Path Loss, Environmental Effects, and 90% Coverage

   https://doi.org/10.48550/arXiv.2205.09436  

   M. Kohli, A. Adhikari (May 2022, ArXivorg)

   Outdoor-to-indoor (OtI) signal propagation further challenges the already tight link budgets at millimeter-wave (mmWave). To gain insight into OtI mmWave scenarios at 28 GHz, we conducted an extensive measurement campaign consisting of over 2,200 link measurements. In total, 43 OtI scenarios were measured in West Harlem, New York City, covering seven highly diverse buildings. The measured OtI path gain can vary by up to 40 dB for a given link distance, and the empirical path gain model for all data shows an average of 30 dB excess loss over free space at distances beyond 50 m, with an RMS fitting error of 11.7 dB. The type of glass is found to be the single dominant feature for OtI loss, with 20 dB observed difference between empirical path gain models for scenarios with low-loss and high-loss glass. The presence of scaffolding, tree foliage, or elevated subway tracks, as well as difference in floor height are each found to have an impact between 5–10 dB. We show that for urban buildings with high-loss glass, OtI coverage can support 500 Mbps for 90% of indoor user equipment (UEs) with a base station (BS) antenna placed up to 49 m away. For buildings with low-loss glass, such as our case study covering multiple classrooms of a public school, data rates over 2.5/1.2 Gbps are possible from a BS 68/175 m away from the school building, when a line-of-sight path is available. We expect these results to be useful for the deployment of mmWave networks in dense urban environments as well as the develop 

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3. Outdoor-to-Indoor 28 GHz Wireless Measurements in Manhattan: Path Loss, Environmental Effects, and 90% Coverage

   Manav Kohli, Abhishek Adhikari (January 2022, https://doi.org/10.48550/arXiv.2205.09436)

   Outdoor-to-indoor (OtI) signal propagation further challenges the already tight link budgets at millimeter-wave (mmWave). To gain insight into OtI mmWave scenarios at 28GHz, we conducted an extensive measurement campaign consisting of over 2,200 link measurements. In total, 43 OtI scenarios were measured in West Harlem, NewYork City, covering seven highly diverse buildings. The measured OtI path gain can vary by up to40dBforagivenlink distance, and the empirical path gain model for all data shows an average of 30dB excess loss over free space at distances beyond 50m, with an RMSfitting error of 11.7 dB. The type of glass is found to be the single dominant feature for OtI loss, with 20dB observed difference between empirical path gain models for scenarios with low-loss and high-loss glass. The presence of scaffolding, tree foliage, or elevated subwaytracks, as well as difference in floor height are each found to have animpact between 5–10dB. Weshowthatforurbanbuildings with high-loss glass, OtI coverage can support 500Mbps for 90% of indoor user equipment (UEs) with a base station (BS) antenna placed up to 49m away. For buildings with low-loss glass, such as our case study covering multiple classrooms of a public school, data rates over 2.5/1.2 Gbps are possible from a BS 68/175m away from the school building, when a line-of-sight path is available. We expect these results to be useful for the deployment of mmWave networks in dense urban environments as well as the development of relevant scheduling and beam management algorithms. 

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4. Dense Urban Outdoor-Indoor Coverage from 3.5 to 28 GHz

   https://doi.org/10.1109/ICC45855.2022.9838919  

   Shakya, Dipankar; Chizhik, Dmitry; Du, Jinfeng; Valenzuela, Reinaldo A.; Rappaport, Theodore S. (May 2022, 2022 IEEE International Conference on Communications)

   In the US, people spend 87% of their time indoors and have an average of four connected devices per person (in 2020). As such, providing indoor coverage has always been a challenge but becomes even more difficult as carrier frequencies increase to mmWave and beyond. This paper investigates the outdoor and outdoor-indoor coverage of an urban network comparing globally standardized building penetration models and implementing models to corresponding scenarios. The glass used in windows of buildings in the grid plays a pivotal role in determining the outdoor-to-indoor propagation loss. For 28 GHz with 1 W/polarization transmit power in the urban street grid, the downlink data rates for 90% of outdoor users are estimated at over 250 Mbps. In contrast, 15% of indoor users are estimated to be in outage, with SNR < −3 dB when base stations are 400 m apart with one-fifth of the buildings imposing high penetration loss (∼ 35 dB). At 3.5 GHz, base stations may achieve over 250 Mbps for 90% indoor users if 400 MHz bandwidth with 100 W/polarization transmit power is available. The methods and models presented can be used to facilitate decisions regarding the density and transmit power required to provide high data rates to majority users in urban centers. 

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5. Millimeter Wave and Terahertz Urban Microcell Propagation Measurements and Models

   Yunchou Xing, Theodore S. (October 2021, IEEE communications letters)

   Abstract—Comparisons of outdoor Urban Microcell (UMi) large-scale path loss models, root mean square (RMS) delay spreads (DS), angular spreads (AS), and the number of spatial beams for extensive measurements performed at 28, 38, 73, and 142 GHz are presented in this letter. Measurement campaigns were conducted from 2011-2020 in downtown Austin, Texas, Manhattan (New York City), and Brooklyn, New York with communication ranges up to 930 m. Key similarities and differences in outdoor wireless channels are observed when comparing the channel statistics across a wide range of frequencies from millimeter-wave to sub-THz bands. Path loss exponents (PLEs) are remarkably similar over all measured frequencies, when referenced to the first meter free space path loss, and the RMS DS and AS decrease as frequency increases. The similar PLEs from millimeter-wave to THz frequencies imply that spacing between cellular base stations will not have to change as carrier frequencies increase towards THz, since wider bandwidth channels at sub-THz or THz carrier frequencies will cover similar distances because antenna gains increase quadratically with increasing frequency when the physical antenna area remain constant. Index Terms—5G; mmWave; 6G; THz; outdoor channel models; UMi; RMS delay and angular spread. 

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