As shown in FIG. 10, the secondary device may also transmit a beacon beam 24 while performing the secondary search pattern 700, such that the primary device may establish a communication link with the secondary device when beacon beam 24 from the secondary device is detected. The second communication device 200b transmits beacon beam 24b while the first communication device 200a transmits beacon beam 24a. In the same way as described above for the secondary device, the primary device may also acquire frames via the receiver 240 and the first optical system 250 of the primary device while primary device is at each beacon beam location and detect, using the one or more processors 210 of the primary device, a beacon beam 24 of the secondary device in one or more of the acquired frames.

For example, while the first communication device 200a is at beacon position 0, a plurality of frames may be acquired at the first communication device 200a at the rate of 5000 frames per second. As the secondary device rotates through the frame positions of the secondary search pattern 700, the beacon beam position of the beacon beam 24 transmitted from the secondary device may also rotate with the frame positions, centered at the same location as the frame positions. When the one or more processors 210 of the primary device detects the beacon beam 24 of the secondary device, no further rotation according to the primary and secondary search patterns 700, 800 are performed, and the primary device may establish a communication link 22 with the secondary device. The primary device may also track the beacon beam location as described above with respect to the secondary device.