Network Quality Measurements of LTE Drones

Network Quality Measurements of LTE Drones

Cellular-connected drones can provide beyond line-of sight control (BVLOS), low latency, real time communication, robust security, and wide range coverage. Cellular-connected drones have several key potential applications in enhanced LTE and 5G networks. The objective of the study is to evaluate field measurement data collected during drone flights in the KT Long-Term Evolution (LTE) networks in Seoul and Jeju, Korea. The multicopter drones are developed with LTE modem and LTE test smart phone for field measurements. The radio network quality between drones and LTE base transceiver stations (BTS) is evaluated by measuring downlink metrics such as the serving cell RSRP, RSRQ, SINR, modulation types of downlink, the downlink and uplink throughputs, and LTE PUSCH Tx Power on reference signal. In the existing LTE networks, field measurements show that there is no problem in C&C of BVLOS operations in the flight height up to 150m but the data rate requirements for video transmission does not meet at high flight altitudes.

The existing LTE networks can support BVLOS operations of low altitude drones. Enhanced LTE and 5G networks can support the reliable command and control (C&C) as well as the reliable application data including video (streaming), images, other sensor data, etc. Enhanced LTE and 5G networks can provide heights target up to 300m and data rates for C&C up to 60 ~100 kbps and application data up to 50 Mbps for UL. The objective of the study is to eval uate the radio network quality between drones and LTE BTS by mea suring downlink metrics such as the serving cell RSRP, RSRQ, SINR on reference signal. The modulation types of downlink, CQI, PCIs (physical cell identifiers), the downlink and uplink data rate, and LTE PUSCH Tx Power are also measured to to eval uate the radio network quality. Field measurements show that the radio network quality degrades at the heights higher than 120m as the effect of substantial interference from neighbor cells. The numbers of observed neighbor cells are i ncreased as the radio path clearance at the higher flight heights. Field measur ements show that there is no problem in C&C of BVLOS operations in the existing LTE networks in the flight height up to 150m but the data rate requirements for video tran smission does not meet at high flight altitudes. In enhanced LTE and 5G networks, interfe rence cancellation and beam forming antenna techniques can be used for cellular -connected drones.