Battle Communication Structure

[ChrisMOG]

I was wonderring how a group of 20+ people would organize a raid or such against an enemy base and the communication methods used to do this. I can see the need for some sort of group chat, like DAoC, where many people can join at once and chat and give strategic information. I think the voice communication will be at the squad level, since 20+ people trying to talk at once in the heat of battle will result in a bunch of unintelligable crap coming out of your speakers. What do y'all think?