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| S/N. | Parameters | Description |
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| 1 | 3D UE dropping | Earlier channel models specified that the UE is at 1.5 m in height. In this case, the propagation distance determines the elevation characteristics of the direction of the LoS. The closer the UE to the BS, the higher the elevation, relative to the direction of the LoS. As a result, users experiencing related slow fading channel conditions would display closely related elevation in the direction of the LoS, and it will be challenging to distinguish vertically. Fortunately, TSG-RAN WG1 [214] has given a 3D UE drop to ease the vast limitations. The latest UE drop allows users to be outside in only 20 percent of the cases, where their height is maintained at 1.5 m. |
| 2 | Outdoor to indoor users for UMa and UMi | According to ITU’s modeling specifications, the outdoor to indoor relationship demonstrates a propagation mode specified in the urban-microcell scenario in [213] to help UEs located within buildings. The latest 3GPP channel model has expanded this to UMa as well. |
| 3 | High-rise scenario | The high-rise case was suggested to characterize the UE channel on very high floors (more than 20), following the report [214]. Also, indoor distributed antenna systems can be implemented to assist users in such buildings. Still, this solution cannot always be extended to high residences, and improved results have been suggested for uptilt beams. |
| 4 | A new expression for the path loss | The path loss is dependent on the frequency of transmission, the distance of the UE from the BS, and the heights of the antennas used for radio signal transmission and reception. Following the results of comprehensive measurements, the working group, TSG-RAN-WG1 [214], updated the ITU channel model’s path loss expression to accommodate UE height’s effects in the NLoS scenario. Finally, the path loss expression used a 3D distance to replace the 2D distance. |
| 5 | Distance-dependent large-scale parameters | At the meeting, 3GPP [214] suggested modeling elevation characteristics as lognormal random variables with specified parameters for UMa scenarios. |
| 6 | The policy used for UE attachment | In addition to estimating the path loss for the reference signal received power (RSRP), an agreement was also reached at the meeting to account for fast fading. The RSRP estimation depends only on slow fading components and path loss before this decision [214]. |
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