IEEE Consumer Electronics Magazine - November/December 2020 - 35

Table 1. Summary of damage caused by RF fields.

as CO2 due to proliferation in the ICT industry 4
and mobile communication systems, which is
expected to be 51% (179 Mt CO2 e) by 2020.5
In humans, eyes, skin tissues, and brain are
the most vulnerable areas and the power density
exposure is maximum.7 There are concerns
regarding planning of the 5G networks in a way as
to abide by the EMF limits and constraints.
Various 5G enabling technologies have been discussed in the literature to provide new opportunities for reducing the exposure and for EMF
aware network planning to plan the future communication networks.8 In,9 the authors discussed
the EM radiation reduction techniques for mobile
communication systems, such as Massive MIMO,
which increases the spatial diversity by transmitting parallel streams of information channels
known as spatial multiplexing. Various other
techniques discussed include electromagnetic
shielding, beamforming, coordinated multipoint,
spectrum sharing. In, 10 an algorithm to achieve
better quality of experience and service in the 5G
systems is proposed. In addition, zonal based
approach is followed in 11 to prolong battery lifetime of users in a spectrum-shared network contemplating Green Communication.

HALF-DUPLEX RADIO: ROADMAP
FOR THERMAL RADIATION MODE

In the Ultra dense network deployment, there
are a large number of interference issues, such as

November/December 2020

UL-to-DL (Uplink-to-Downlink) interference, DLto-DL interference between user equipment, and
UL-to-UL interference at the base stations. These
are a result of "always ON" signals in the current
mobile communication systems. In Figure 1, a
proposal has been presented to reduce the EM
radiation impact and improve the SINR for mobile
communication systems. A "Thermal radiation
(TR)" mode is proposed in the mobile handset to
introduce half-duplex communication in the
mobile network. When the "TR mode" is switched
ON in the mobile device, only the low bandwidth
requiring applications are supported by the network. These services are denoted as ½A1 ¼
Text; A2 ¼ Conversational Voice: The applications having high data rate requirement, such
as video are not supported. The uplink information transfer for these applications is suspended. The active signals in the network
include the reference signals required for
downlink information transfer and the base station detection signals for maintaining a stable
connection throughout.
The TR mode operation is depicted in
Figure 1 with respect to the active and nonactive signals. The cell depicting the current communication scenario is denoted by letter "A",
i.e., Active mode zone. The TR mode zone is
denoted by "T". A device can also transit into
TR mode by adapting switching. The adaptive
switching takes place when the mobile equipment does not have the appropriate signal
strength to support applications requiring high
bandwidth. The stages of the device transitioning from active mode to TR mode are denoted
by X, Y and Z. Stage X depicts good signal
strength received by the device when there is
line of sight phenomenon or favorable channel
conditions. Stage Y denotes poor signal
strength received by the device, i.e., low Signal-to-Noise (SNR) ratio. In this stage, the
device cannot support high bandwidth applications as the received SNR falls below a
threshold value required to support other
applications. At this stage, the device adaptively transitions to TR mode and only supports applications A1 and A2 : The "always-ON"
signals are suspended in this stage and
resumed when the received signal strength is
above the threshold.

IEEE Consumer Electronics Magazine - November/December 2020

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