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Path loss characteristics at multiple frequency bands from 0.8 to 37 GHz in indoor office
... One set up covered three frequency bands: 6, 10, and 18 GHz, and the second set up five different frequency bands: 0.8, 2.2, 4.7, 26.4, 37.1, and 66.5 GHz. Figure 1 shows two of these setups which cover the frequency ranges from 0.8 to 66.5 GHz (Sasaki et al., 2015;Sasaki et al., 2016;Sasaki et al., 2017a;Sasaki et al., 2017b;Sasaki et al., 2018;Sasaki et al., 2018a;Sasaki et al., 2018b) . ...
The International Telecommunications Union Radiocommunication Sector (ITU‐R) Study Group 3 identified the need for a number of radio channel models in anticipation of the World Radiocommunications Conference in 2019 when the frequency allocation for 5G will be discussed. In response to the call for propagation path loss models, members of the study group carried out measurements in the frequency bands between 0.8 GHz up to 73 GHz in urban low‐rise and urban high‐rise as well as suburban environments. The data were subsequently merged to generate site general path loss models. The paper presents an overview of the radio channel measurements, the measured environments, the data analysis, and the approach for the derivation of the path loss model adopted in Recommendation ITU‐R P.1411‐10 (2019‐08).
... The material for study of indoor office environment is from literature [8]. The office space modeled for measurement and the simulation is showed in Figure 1. ...
... Moreover, the quantitative comparisons of various path loss models for WSN also required distance variable [13], [15] for different frequencies and scenarios. Path loss have different characteristics at multiple frequency which provide more accurate measurement results as it depended on frequency [16]. For many scenarios, path loss exponent distribute in different ways [17], [18] Plus, the different path loss exponent in normal distribution is affected for localization accuracy [9]. ...
Wireless communications in indoor environment such as wireless sensor network and WiFi is slowing becoming the norm of everyday business, especially in industrial indoor settings. Tracking flying objects in an indoor environment controlled via wireless links require proper understanding of the path loss distribution in a 3D environment. Such a setting is rarely discussed-if any-in the open literature where the path loss exponent is generalized over the whole 3D indoor space. This study, however, attempts to address minute changes in path loss exponent distribution in such environment. An extensive measurement campaign was conducted in our university laboratory mimicking an industrial indoor setting where drones are supposed to operate. Our initial study involved a placement of 2.4 GHz transmitter at different heights with 0.00 m, 0.61 m, 1.36m and 1.88 m while varying the receiver antenna location over a 3D grid of 1 meter resolution in x, y, and z-axes directions. The received signal strength indicator (RSSI) readings were recorded to derive the path loss exponent at every grid point. Interestingly, results indicate that path loss exponent is definitely affecting along the z-axis (vertically) but still can be averaged over x-y-axes (horizontally). Increasing the transmitter or receiver height decreases the path loss exponent averaged over the s-x axes grid lines. Furthermore, due to furniture clutter on the floor and the availability of clear LOS components at higher links, the path loss becomes a function of the height. The results confirm further the furniture clutter and the floor proximity do add up to the path loss exponent due to lack of LOS links while higher links experience smaller path loss exponent. This is quite important as it has never been reported in the open literature before.
... [15] analyzed the DS, PL, and frequency selectivity between 5 and 60 GHz in a meeting room. Sasaki et al. [16] proposed a PL model as a function of frequency from 0.8 to 37 GHz. Huang et al. provided a comprehensive comparison between the 11, 16, 28, and 38 GHz bands and presented some preliminary cluster birth-death properties [17]. ...
This paper presents the analysis of geometry-based
cluster frequency dependency at super high frequency (SHF)
bands, which are 3, 10 and 28 GHz. Firstly, multipath components
(MPCs) were extracted from the measured data by using
space alternating generalized expectation maximization (SAGE)
algorithm. Then, geometry-based clusters were estimated by using
the enhanced scattering point-based KPowerMeans (SPKPM)
algorithm. Finally, the frequency dependencies of their scattering
intensities (SIs) were discussed with the assistance of physical
optics (PO). The analysis results showed that SPKPM could
also be applied to get reasonable scattering locations at multiple
frequencies in most cases. Additionally, reflection on a smooth
surface was the dominant mechanism of clusters where there
were no frequency dependence, whereas diffraction, scattering,
and shadowing were significant causes of frequency dependence.
Assuming that the line-of-sight (LOS) is obstructed, diffraction,
scattering, and shadowing accounted for 30-40 percent of the
whole channel in terms of power which was not negligible and
thus the channel was largely frequency dependent. The analysis
results are expected to provide crucial insights for multiplefrequency
channel modeling for the 5th generation (5G) wireless
system.
This paper presents the frequency dependence of the path loss exponent (PLE) based on measurement results of multiple frequency bands in indoor environments and explains the propagation mechanisms that cause frequency dependence. Path loss measurements from 0.8 GHz to 66.5 GHz in two indoor open office environments were used to derive the parameters of a close-in free space reference distance model (CI model) and an alpha-beta-gamma model (ABG model). We revealed that the PLE of the single-frequency CI model tended to decrease with increasing frequency, while the frequency coefficient of the ABG model was smaller than that of the free space loss (FSPL), indicating a different frequency dependence than FSPL in these environments. Furthermore, the propagation mechanisms of the waveguide effect and the first Fresnel zone shielding cause this frequency dependence. Ray-tracing simulations revealed that the PLE becomes large and small in the low- and high-frequency bands, respectively, when the ceiling height is low, consistent with the measurements. The PLE becomes small regardless of the frequency band when the ceiling height is high, indicating frequency dependence along the propagation mechanism in both the ray-tracing simulation and measurement results.
Novel empirical path loss and root mean square delay spread (RDS) models for smart office scenarios are proposed. The effects of person density on the path loss and RDS are investigated based on the extensive measurements at 2.3-2.5GHz. Firstly, both of the measured path loss and RDS data are modeled as the dual log-distance functions. It is caused by the regular structure and furniture in the office environment. Secondly, in the proposed path loss model, the path loss exponents and the additional attenuation factor are modeled as quadratic functions of the person density. Meanwhile, the RDS is found to be uncorrelated with the person density. These phenomena reveal that the persons in the environments can be regarded as absorbers rather than scatters. rgb0.00,0.00,0.00Then, the accuracy of the proposed models is validated by the measured data and compared with two traditional models. Finally, the effect of the persons’ movements on the path loss and RDS are investigated, and the proposed models are extended to millimeter wave bands by ray tracing technology. The proposed models and results can provide necessary information for link budget and algorithm design for the Internet of Things smart office scenarios.
The millimeter-wave (mmWave) is expected to deliver a huge bandwidth to address the future demands for higher data rate transmissions. However, one of the major challenges in the mmWave band is the increase in signal loss as the operating frequency increases. This has attracted several research interests both from academia and the industry for indoor and outdoor mmWave operations. This paper focuses on the works that have been carried out in the study of the mmWave channel measurement in indoor environments. A survey of the measurement techniques, prominent path loss models, analysis of path loss and delay spread for mmWave in different indoor environments is presented. This covers the mmWave frequencies from 28 GHz to 100 GHz that have been considered in the last two decades. In addition, the possible future trends for the mmWave indoor propagation studies and measurements have been discussed. These include the critical indoor environment, the roles of artificial intelligence, channel characterization for indoor devices, reconfigurable intelligent surfaces, and mmWave for 6G systems. This survey can help engineers and researchers to plan, design, and optimize reliable 5G wireless indoor networks. It will also motivate the researchers and engineering communities towards finding a better outcome in the future trends of the mmWave indoor wireless network for 6G systems and beyond.
Indoor Ultra‐high Broadband Access with high traffic densities inside office buildings brings the indoor office channel into the focus. Whereas in the past decade the indoor office channel in the UHF range was subject to intense channel modeling and channel characterization approaches, with the advent of 5G mmWave channels are raising attention. After introducing the key characteristics and main differences of propagation in the UHF and mmWave frequency range, respectively, the first part of the article indoor office channels describes empirical, semiempirical, and deterministic path loss models for both the UHF and the mmWave frequency range. A detailed description is provided for the semiempirical Motley–Keenan model and its various extensions. These models allow a narrowband channel characterization and provide the large‐scale characteristics. These models are relevant for the planning and optimization of radio access points as well as an enabler for system‐level simulations. The second part introduces channel models capable of providing temporal and spatial channel characteristics. This includes approaches to derive models for double‐directional channels, which are required to simulate and investigate multi‐antenna systems and beam‐forming algorithms especially in the mmWave range. Furthermore, an approach to describe the impact of human blockage is provided. As exemplary approaches, the extended Saleh–Valenzuela model and the TGad channel model are described.
NTT Access Network Service Systems Laboratories and NTT DOCOMO have been carrying out joint research and development (R&D) toward construction of the fifth-generation mobile communications system (5G). This article presents a path loss model developed as one of our R&D activities.
This paper proposed that a path loss model for outdoor-to-indoor corridor is presented to construct next generation mobile communication systems. The proposed model covers the frequency range of millimeter wave bands up to 40 GHz and provides three dimensional incident angle characteristics. Analysis of path loss characteristics is conducted by ray tracing. We clarify that the paths reflected multiple times between the external walls of buildings and then diffracted into one of the buildings are dominant. Moreover, we also clarify how the paths affect the path loss dependence on frequency and three dimensional incident angle. Therefore, by taking these dependencies into consideration, the proposed model decreases the root mean square errors of prediction results to within about 2 to 6 dB in bands up to 40 GHz. © 2017 The Institute of Electronics, Information and Communication Engineers.
A path loss model based on the Rec. ITU-R P.1411 model, which can cover the frequency range from microwave to millimeter-wave bands, is presented. The path loss characteristics are analyzed on the basis of measurement results obtained using the 2 to 37 GHz band in street microcell environments. It is clarified that the characteristics depend on distance from transmitter to intersection and frequency dependency. By taking these dependencies into account, the proposed model can decrease the root mean square error of prediction results to within about 5 dB in the 2 to 37 GHz band.
The global bandwidth shortage facing wireless carriers has motivated the exploration of the underutilized millimeter wave (mm-wave) frequency spectrum for future broadband cellular communication networks. There is, however, little knowledge about cellular mm-wave propagation in densely populated indoor and outdoor environments. Obtaining this information is vital for the design and operation of future fifth generation cellular networks that use the mm-wave spectrum. In this paper, we present the motivation for new mm-wave cellular systems, methodology, and hardware for measurements and offer a variety of measurement results that show 28 and 38 GHz frequencies can be used when employing steerable directional antennas at base stations and mobile devices.
This paper presents and analyzes the results of millimeter-wave 60-GHz frequency range propagation channel measurements that are performed in various indoor environments for continuous-route and direction-of-arrival (DOA) measurement campaigns. The statistical parameters of the propagation channel, such as the number of paths, the RMS delay spread, the path loss, and the shadowing, are inspected. Moreover, the interdependencies of different characteristics of the multipath channel are also investigated. A linear relationship between the number of paths and the delay spread is found, negative cross correlation between the shadow fading and the delay spread can be established, and an upper bound exponential model of the delay spread and the path loss is developed to estimate the worst case of the RMS delay spread at given path loss. Based on the DOA measurements that are carried out in a room [line of sight (LOS)] and in a corridor with both LOS and nonline-of-sight (NLOS) scenarios, radio-wave propagation mechanisms are studied. It is found that considering the direct wave and the first-order reflected waves from smooth surfaces is sufficient in the LOS cases. Transmission loss is very high; however, diffraction is found to be a significant propagation mechanism in NLOS propagation environments. The results can be used for the design of 60-GHz radio systems in short-range wireless applications.
Millimeter-wave (mm-wave) radio is attracting attention as one of the key enabling physical layer technologies for the fifth-generation (5G) mobile access and backhaul. This paper aims at clarifying possible roles of mm-wave radio in the 5G development and performing a comprehensive literature survey on mm-wave radio channel modeling essential for the feasibility study. Emphasis in the literature survey is laid on grasping the typical behavior of mm-wave channels, identifying missing features in the presently available channel models for the design and evaluation of the mm-wave radio links within the 5G context, and exemplifying different channel modeling activities through analyses performed in the authors' group. As a key technological element of the mm-wave radios, reduced complexity beamforming is also addressed. Design criteria of the beamforming are developed based on the spatial multipath characteristics of measured indoor mm-wave channels.
Because of the potential implementation of indoor wireless local
area networks (LANs) and personal communication networks (PCNs) it is
important to understand propagation of signals in the UHF band inside
buildings. The authors explore features of office buildings of modern
construction that influence propagation between transmitter and receiver
located on the same floor. One feature is the clear space between
ceiling and furnishings or floor that results in excess attenuation of
the signal. A second feature is reflection and transmission at interior
and exterior walls. Diffraction at corners and propagation along the
exterior wall are also shown to be a significant means for radiation to
reach the receivers. The influences of the first two features are
combined into a computer program that evaluates the sector average
signal, which is then compared with measurements
Path Loss Characteristics at 800 MHz to 37 GHz in Urban Street Microcell Environment
- M Sasaki