Investigating small sized metal blockage effects at 60 and 100 GHz using measurements and modeling approaches.

Millimeter wave (mmWave) technologies at 60 GHz and 100 GHz bands are currently gaining significant attention for its potential to meet the demanding needs of next-generation networks. These include ultra-high data rate, ultra-low latency, high spectral efficiency, and high end-to-end reliability. However, mmWave signals' blockage remains a critical issue that affects the reliability of mmWave at 60 GHz and at 100 GHz bands due to the significant attenuations induced by the blockers (BLs). Not only blockers that have the size of a human body or even larger can affect the signal, but also smaller objects with much narrower dimensions, as narrow as 4 cm, can severely affect the signal strength and introduce an attenuation that reaches up to 12 dB at 100 GHz. In this paper we have conducted new measurements and presented results for three small copper sheets at each frequency band, aiming to investigate the blockage effect of small-sized metal objects on signal strength at these two frequency bands. Also, we have examined the performance of the knife-edge diffraction (KED) blockage model of the third-generation partnership project (3GPP) standards body and its evolved version named the mmMAGIC blockage model in such scenarios. Furthermore, we investigated the applicability of the two blockage models in capturing the attenuation characteristics of other materials-such as wood and glass. Experimental results supported by numerical models have shown that the induced peak attenuations are 5(12) dB, 10(23) dB, 23(23) dB for 4 4 cm, 8 8 cm, 16 16 cm copper blockers, respectively, at 60(100) GHz mmWave bands. Also, we have shown that both the 3GPP and mmMAGIC simulation models fail to accurately capture the attenuation characteristics of materials other than copper. The findings of this work highlight the importance of considering the dimensions and types of blockages when deploying reliable mmWave and sub-THz communications.