US 12,483,329 B2
Relayed ground-to-satellite free-space-optical communications
Sayed Hasan Hariq, Germantown, MD (US); and Rohit Iyer Seshadri, Gaithersburg, MD (US)
Assigned to Hughes Network Systems, LLC, Germantown, MD (US)
Filed by Hughes Network Systems, LLC, Germantown, MD (US)
Filed on Apr. 6, 2023, as Appl. No. 18/296,436.
Prior Publication US 2024/0340083 A1, Oct. 10, 2024
Int. Cl. H04B 10/11 (2013.01); H04B 10/112 (2013.01); H04B 10/118 (2013.01); H04B 10/29 (2013.01)
CPC H04B 10/118 (2013.01) [H04B 10/1127 (2013.01); H04B 10/29 (2013.01); H04B 10/11 (2013.01); H04B 10/112 (2013.01); H04B 10/1129 (2013.01)] 18 Claims
OG exemplary drawing
 
1. A communication system for providing free space optical (FSO) ground-to-satellite communications, the communication system comprising:
an optical ground station;
a plurality of FSO relays, each being either a tropospheric FSO relay or a stratospheric FSO relay, the plurality of FSO relays comprising:
a first FSO relay to communicate with the optical ground station via a first FSO sub-link; and
a second FSO relay to communicate with a satellite via a second FSO sub-link, wherein:
the optical ground station is communicatively coupled with the satellite optically via the plurality of FSO relays by communicating with the satellite via a ground-to-satellite FSO communication link that comprises at least three FSO sub-links including the first FSO sub-link and the second FSO sub-link;
each of the plurality of FSO relays is deployed at a respective altitude thereby defining a path length for each of the FSO sub-links of the ground-to-satellite FSO communication link; and
the respective altitude for at least one of the plurality of FSO relays is optimized based on decreasing an outage probability associated with at least one of the FSO sub-links in presence of predetermined attenuation factors.