A buddy of mine is an LCIS Tech with 1RCR.
He lives in the shacks with the rest of the RCR guys, as well as the other techs that are attached to 1RCR. He normally does PT with the 1RCR Signals Platoon, which is mostly other LCIS techs, Sigops, and Linemen. In garrison an LCIS Tech is usually too busy with his regular work to undertake any serious infantry training. On Battalion exercises he'll go out to the field, but he'll usually be doing the same thing he does in garrison - fix comms gear. Overseas the LCIS Techs rotated in and out of the FOBs which is usually alright, unless you're getting mortared regularly. The upside to this is you'll probably be in a static position so you'll have more chances to shower, hook up an xbox, and horde spunkmeyer muffins. If things go bad you'll be expected to fight like anyone else, but they'll try and put you where you'd be of most use - just behind "the front".
Overall I think its a pretty cool job. If I were to OT out of the infantry I'd seriously consider being an LCIS Tech. I like to work with radios, and I'd be interested in the more technical side of things.
Hope that helps!