Human Electromagnetic Field Exposure in Wearable Communications: A Review <s> VI. HUMAN EMF EXPOSURE IN WERABLE COMMUNICATIONS OPERATING IN MMW SPECTRUM A. Motivation <s> A promising way of realizing the fifth generation (5G) wireless systems is to operate 5G deployments at higher frequency bands, specifically in the millimeter-wave (mmW) spectrum (30-300 GHz). Access to such spectrum bands will enable future 5G wireless systems to meet the 5G requirements of peak rate greater than 10 Gb/s, and cell edge rate of up to 1 Gb/s. However, the emerging 5G systems will need to coexist with a number of incumbent systems in these bands. This paper provides an extensive study of the co-channel coexistence of 5G in two critical mmW bands, 27.5-28.35 GHz (28 GHz) and 71-76 GHz (70 GHz) bands, where fixed satellite service (FSS) and fixed service (FS), such as wireless backhaul, are the predominant incumbent users. In the 28-GHz study, we show that interference from 5G into the FSS space stations can be kept below the FSS interference protection criterion. We also characterize the minimum separation distance between the FSS earth stations (ESs) and 5G in order to protect the 5G system from interference due to the ESs transmissions. In the 70-GHz study, we show that the 5G-to-FS interference could be a potential issue in certain scenarios, but we introduce techniques to significantly suppress this interference, while maintaining acceptable performance of the 5G systems. For each study, we suggest appropriate deployment strategies for a 5G system based on our results. <s> BIB001 </s> Human Electromagnetic Field Exposure in Wearable Communications: A Review <s> VI. HUMAN EMF EXPOSURE IN WERABLE COMMUNICATIONS OPERATING IN MMW SPECTRUM A. Motivation <s> As wearable devices become more ingrained in our daily lives, traditional communication networks primarily designed for human-being-oriented applications are facing tremendous challenges. The forthcoming fifth-generation (5G) wireless systems look to support unprecedented high capacity, low latency, and massive connectivity. In this article, we examine key challenges facing wearable communication devices. A cloud/edge communication architecture that integrates the cloud radio access network (CRAN), software-defined network (SDN), device-to-device (D2D) communications, and cloud/edge technologies is presented. Computation offloading enabled by this multilayer communications architecture can offload computation-excessive and latency-stringent applications to nearby devices through D2D communications or to nearby edge nodes through cellular or other wireless technologies. Critical issues faced by wearable communications, e.g., short battery life, limited computing capability, and stringent latency, can be greatly alleviated by this cloud/edge architecture. Together with the presented architecture, current transmission and networking technologies [including nonorthogonal multiple access (NOMA), mobile edge computing (MCE), and energy harvesting] can greatly enhance the performance of wearable communications in terms of spectral efficiency, energy efficiency, latency, and connectivity. <s> BIB002 </s> Human Electromagnetic Field Exposure in Wearable Communications: A Review <s> VI. HUMAN EMF EXPOSURE IN WERABLE COMMUNICATIONS OPERATING IN MMW SPECTRUM A. Motivation <s> This paper studies the feasibility of Wi-Fi and 5G technologies in the unlicensed 60 GHz band for humanitarian assistance and disaster relief (HA/DR) operations. Building a wireless communications system in the 60 GHz band can benefit HA/DR activities for two reasons: (i) no license is needed; (ii) a wide bandwidth is available. Our simulation results show that both of Wi-Fi and 5G can achieve data rates exceeding the requirements for most of the HA/DR missions, which proves the feasibility of the two wireless technologies for operation of high-data-rate HA/DR activities such as real-time video streaming. <s> BIB003
The potential of mmW frequencies for wearable communications is enormous for applications requiring Gbps throughput. Such networks might use wireless standards including 5G BIB001 or IEEE 802.11ad/ay BIB003 , based on which commercial products are already available. As have been observed in Eq. (3), the major concern regarding wearable communications in mmW is higher SAR due to the extremely small penetration depth, δ, as shown in Eq. (3). Moreover, some tissues (e.g., eyes) are especially vulnerable to mmW radiation-induced heating and require more attention BIB002 . It is necessary to continually update regulations based on new materials, frequencies, device types, and transmitted powers. Additionally, manufacturers must be educated with the newest research/regulations to better address consumer concerns and promote this new technology. Out of various spectrum bands, this paper focuses unlicensed bands, which enable cheaper and less complex devices (as well as longer battery life), all of which are desirable for wearable communications and networking BIB002 . The 2.4 GHz industrial, scientific, and medical (ISM) band has already long been coveted by numerous unlicensed communications systems. The FCC recently opened up an additional 7 GHz of spectrum available for unlicensed use through 64-71 GHz, which now provides a historic 14 GHz of contiguous chunk through 57-71 GHz-also known as the 60 GHz band BIB001 . Therefore, this paper considers a wearable communications environment with two different carrier frequencies-i.e., 2.4 GHz and 60 GHz. It enables a comparison of the impacts of carrier frequency on the human EMF exposure. Adopting two different operating frequencies differentiates wearable communications environments. The adopted parameters for the two scenarios are summarized in Table III .