## 1 Introduction  
The spectrum with a range of 1-100 mm (3-300 GHz band) wavelengths can be classified as millimetre-Wave (mm-Wave) bands [1; 2]. There is an excellent interest in short range communications using mm Waves (mmWave) [3; 4; 5; 6]. Because of their mainly unaccredited or light-licensed bandwidth, these bands are now promising applicants for next-generation wireless communication, such as device-to-device (D2D) communications [7]. Millimeter wave spectrum bands for 5G were also identified by the World Radio Conference (WRC) 2015 [8], and are expected to be finalized by WRC 2019. Many researchers have studied the characteristics of the wideband channel in different frequency bands in order to meet high data-rate demands. For a wideband channel at a low frequency band, in the early 2000s, [PERSON] et al. [9] studied angle delaying and dispersion characteristics in the case of an indoor peer-to-peer (P2P) channel centered at 1920 MHz. In the work, the omnidirectional and directional antennas for measuring the angles of arrival and delay propagation statistics have been used. The typical results for the root mean square (RMS) delay spreads were 17-219 ns for the outdoor cross-campus measurements, and three indoor-to-indoor locations exhibited 27-34 ns RMS delay spreads and normalized angular spreads of multipath power between 0.73 and 0.90 [9]. Recent measurement campaigns were conducted to obtain propagation measurements and channel modeling at 28, 38, 60, and 73 GHz in an urban microcell, urban macrocell, rural area, indoor hotspot, and vehicle scenarios, respectively [10; 11; 12; 13]. In the literature [14], the measurements were carried out in rural and urban locations at frequency bands of 50 MHz-6 GHz. [PERSON] et al. [15] used an indoor radio channel over a range of 1-9 GHz, using omnidirectional antennas and four environments (line-of-sight (LOS), soft non-LOS (NLOS), hard NLOS, and a corridor). The path loss exponents (PLEs) with verity reference distances were high in the hard-NLOS scenario compared with the others [13; 15; 16]. Additionally, [PERSON] et al. studied indoor propagation measurements at 2-73 GHz in LOS and NLOS for offices and shopping malls, and the measured path loss as a function of distances [13]. They have carried through measured information and ray tracking of 28 to 73.5 GHz in the mmWave frequency bands, comparing trajectory models. Their work revealed that the studied path-loss models were very comparable in their prediction accuracy, given large datasets, even though some of these models required more model parameters and lacked a physical basis for their floating intercept value. Indoor channel propagation studies are reported in [17; 18; 19], while outdoor channel propagation studies are reported in [20; 21; 22], as listed in Table 1. [PERSON] et al. [16] carried out 26 GHz open office LOS measurements of the wideband channel. In the literature [18], the first sounding channel and the original outcomes are provided for synthesized omnidirectional findings of the 28 GHz band. In the literature [19], in a line-of-sight (LOS) situation, mmWave propagation features were studied in 6.5, 10.5, 15, 19, 28, and 38 GHz bands in the indoor corridor setting. For outdoor cellular propagation, the world's first empirical measurements were conducted at 28, 38, and 73 GHz in New York [20; 21; 22].