Laser Communications

The presence of Bullarum in the atmosphere has a tendancy to advertise the general location of radio transmitters. Even low-energy short-range transmissions will cause an umbrella of bullarum to appear a hundred meters above the transmitter. Line-of-Sight Laser communications were adopted to circumvent this predicament.
Lasers used for communications use near-ultraviolet light and are not visible to the eyes of humans or most debees (if any).

Utility

Manually-targetable lasercom devices come in two varieties. First is as a feature on a multi-optic sight. Focus the sight on the intended receiver, press the button, and speak. The second is as an option on a laser weapon. Aim the weapon at the intended receiver, press the transmit trigger and speak. Each variety has its advantages.
Coalition Scout units will often carry a man-portable repeater. These lightweight relay units allow scout units to establish long range lasercom communications around and through obstacles that would otherwise make line of sight communication impossible. There is no feasible limit to the number of relay units that can be chained together in this manner.
The territory within the coalition states is slowly being filled with a network of lasercom tower repeaters.

Complexity

Because the beamwidth of a lasercom device is narrow, it must be aimed directly at the intended receiver. Man-portable lasercom devices typically must be aimed by hand.
Most robot vehicles and communication hub installations (portable as well as stationary) are equipped with automatic tracking on their lasercom devices, enabling them to maintain constant alignment with a designated lasercom receiver. The larger the vehicle or installation, the more transmitters it has, enabling it to maintain a web of lasercom nodes and even retransmitting lasercom signals from other units that are unable to establish a line of sight to their intended recipients.