Methods to implement communication in natural and humanmade disasters have been
widely discussed in the scientific community. Scientists believe that unmanned aerial vehicles (UAVs)
relays will play a critical role in 5G public safety communications (PSC) due to their technical superiority.
They have several significant advantages: a high degree of mobility, flexibility, exceptional
line of sight, and real-time adaptative planning. For instance, cell edge coverage could be extended
using relay UAVs. This paper summarizes the sidelink evolution in the 3GPP standardization associated
with the usage of the device to device (D2D) techniques that use long term evolution (LTE)
communication systems, potential extensions for 5G, and a study on the impact of circular mobility
on relay UAVs using the software network simulator 3 (NS3). In this simulation, the transmitted
packet percentage was evaluated where the speed of the UAV for users was changed. This paper also
examines the multi-input multi-output (MIMO) communication applied to drones and proposes a
new trajectory to assist users experiencing unfortunate circumstances. The overall communication is
highly dependent on the drone speed and the use of MIMO and suitable antennas may influence
overall transmission between users and the UAVs relay. When the UAVs relaying speed was configured
at 108 km/h the total transmission rate was reduced to 55% in the group with 6 users allocated
to each drone.