AFK players here remind me a lot of the "camper" problem of Unreal tournament, but opposite in that situation, it was a player who would sit on a specific weapon or power up spawn and actively keep it out of play for everyone else.
the solution there was to time how long they stood in one place, and once it was too long, all players in the game got a warning about it and could gang up on him, vote the player out of the map, and some servers even banned players for it automatically.
So if the problems are as opposite and they are similar, then the only solution to AFK is to do the same thing, but exactly opposite...
-TL/DR-
count how long a player stays out of combat rang from the rest of the team, or in a required mission zone (like the end room of Stasis), for 60 seconds then everyone playing is warned of the player being afk - if the player doesn't get back with the group after another 30 or seconds, they are flagged as afk.
when a player is flagged as AFK, their cool down time for that STF is doubled - and everyone else in the team has their cool down timer cut in half.
- Using Khitomer in Stasis as the continuing example here, all players would have to stay within combat range of each other all the way until the nodes are cleared, then the player who goes to the room will be exempt.
[SIGPIC][/SIGPIC]
Me playing UT2k4 (red guy) -
http://www.youtube.com/watch?v=Wz0DnP7wXnU0