Battlefield 3 will feature 4 man squads like in Bad Company 2, however, according to DICE’s Alan Kertz, who once again confirmed some new info via Twitter, squad spawning has changed compared to Bad Company 2.

In Battlefield 3, the squad members can only spawn on the squad leader, while the squad leader can spawn on any squad member. This seems to be the right way to do it, as Kertz points out: “it keeps pace up without tons of spawns”. One of the (minor) problems in Bad Company 2 was that any squad member could spawn on any squad member, meaning, for instance, one player camping behind enemy lines could spawn 3 additional squad mates.

The new system resembles a lot like Battlefield 2, where squad mates could only spawn on the squad leader, while the squad leader had to spawn at the spawn point. on the flip side, this led to a lot of “squad hopping”, whereby a player who died would hop to a squad with a leader closest to the action, and spawn on him. Squad hopping was later fixed in a patch.
http://bf3blog.com/2011/06/new-battl...etails-emerge/