  Beam management in 5G NR involves the transmission and reception of control
signals such as Synchronization Signal Blocks (SSBs), crucial for tasks like
initial access and/or channel estimation. However, this procedure consumes
energy, which is particularly challenging to handle for battery-constrained
nodes such as RedCap devices. Specifically, in this work we study a mid-market
Internet of Things (IoT) Smart Agriculture (SmA) deployment where an Unmanned
Autonomous Vehicle (UAV) acts as a base station "from the sky" (UAV-gNB) to
monitor and control ground User Equipments (UEs) in the field. Then, we
formalize a multi-variate optimization problem to determine the optimal beam
management design for RedCap SmA devices in order to reduce the energy
consumption at the UAV-gNB. Specifically, we jointly optimize the transmission
power and the beamwidth at the UAV-gNB. Based on the analysis, we derive the
so-called "regions of feasibility," i.e., the upper limit(s) of the beam
management parameters for which RedCap Quality of Service (QoS) and energy
constraints are met. We study the impact of factors like the total transmission
power at the gNB, the Signal-to-Noise Ratio (SNR) threshold for successful
packet decoding, the number of UEs in the region, and the misdetection
probability. Simulation results demonstrate that there exists an optimal
configuration for beam management to promote energy efficiency, which depends
on the speed of the UEs, the beamwidth, and other network parameters.
