Survivable free space optical mesh network using high-altitude platforms

Beam Size Optimization for High-Altitude Platforms to Ground Links in FSO Communications

“…Substituting ( 3) and ( 6) into (2), we obtain the following formula for the daily energy consumption E consum of a HAP with payload Figure 4 depicts the total daily energy consumption of a HAP versus ground coverage radius. The energy consumption is calculated by (7) with n HAPi FSO = 0, ∀i = 1..K and ρ avion = 2 W/kg. A solar energy level between the minimum harvested at York and Enugu allows a 500 kg HAP covering a ground radius of 5000 − 20000 meters.…”

“…Based on this observation, the topology design is broken in two steps: first, ground nodes are clustered by the smallest number of clusters to minimize K; second, HAPs, which locate at the centres of clusters but at an elevation of 20 km, are interconnected by the fewest number of inter-HAP links. An algorithm designing such a topology has been proposed in [7] where clusters are equal and the cluster radius must be given as an input parameter.…”

“…A communication model using a HAP network is described in [7] and illustrated in Figure 1. According to this model, FSO transceivers on the ground (so call ground FSO nodes) are regrouped into clusters.…”

“…An end-to-end data-switching model for this HAPbased FSO network was also proposed in [7]. A serving Dieu Linh Truong is with School of Information and Communication Technology, Hanoi University of Science and Technology, Vietnam.…”

“…The study in [7] designed a HAP network to cover a set of ground FSO nodes where beam sizes are equal and fixed for all serving FSO transceivers. Different to that study, in the current research, individual beam size are tuned for each serving FSO transceiver in order to reduce the number of HAPs and thus the HAP network cost.…”