LOS discovery for highly directional full duplex RF/FSO transceivers

In-Band LOS Discovery Between Drones Using Highly Directional Transceivers

“…Accordingly, we calculated the received power P r cv of a node's transceiver from the following relations [17]: −(P t + P r ) < 10 log 10 e −σ R cos δ + 10 log 10 ζ γ + 200βR cos δ 2 (12) P r cv = P r × cos δ (13) where, R is the distance between the nodes in meters, δ is the radial distance of a node from its neighbor's beam's axis of propagation, P t is the transmitter's source power in dBm, P r is the received power along beam normal in dBm, γ is the transmitter radius in cm, ζ is the receiver radius in cm, β is the divergence angle of transmitter in mRad. The messages used for the three-way handshake 'Hello', 'H-Ack' and 'Ack' were considered to be 38 bytes and data rate was 1Mbps, which gives packet transmission time of ≈300µs [1]. Assuming a processing delay of 100µs, from (4), we calculated τ = 3 × 300 + 2 × 100 = 1100µs.…”

“…Only the highly directional transceivers can be used for communication. The nodes simultaneously transmit and receive over the same channel 1 . v) Asynchronous algorithm: The nodes run the proposed discovery algorithm in a distributed manner without any synchronization mechanism.…”

“…It uses an optimal value of probability that depends on the node density of the network for transmitting beacon messages at random directions. In [2], [15] and [1], different LOS discovery protocols are presented for nodes in a 2D scenario. These protocols also assume no clock synchronization among the nodes.…”