I‘m not yet in the military but in the application process. I‘ve worked in the North for a communications company who did occasionaly contracts with DND. Indirectly, I have some familiarity with some aspects of the ATIS, and less with the LCIS techs.
From my experience, the ATIS and LCIS work on the electronics and communciations systems not found in the aircraft or within land vehicals. On base, they repair service and maintain HF, VHF, UFH, X-band based communication systems usually this is hand-held or base station transceivers. They set-up and maintain satellite earth stations, computer networks, datacom systems, to the more mundane paging, order wires, intercom and telephone systems. In the field, they‘d be setting up satellite earth stations, radio systems, and the general electronics techs on a case by case basis.
The ATIS techs may be more involved with travel here and there to FOL sites, radar/remote/repeater site s(manned and unmanned), verifying contractor work in various locations, commissioning of comm systems, and verifying system integrities. ATIS may be attached to land and sea elements depending. I don‘t know about the LCIS techs in this regard.
I‘d expect alot of non-MOC duties too like general cleaning, duty NCO, security detailing and monitoring, help desk, cafeteria help as the higher ranks order.
Anyone who may know Bill Self (Selfcom) from travels in the North, he sends his regards.