First, the boys are only allowed to camp 3 nights during the year, enough to meet the requirements for their first class rank. Each trip should be a one night trip, and is held separate from the rest of the troop. In other activities, including weekly meetings, the 11 year old patrol would meet separately from the remainder of the troop, and would not participate in most normal events, with the exception of Court of Honor ceremonies, etc.
When he turns 12, he can become a part of a patrol within the larger part of the troop. Administratively, this may seem unusual to non LDS members, but a large amount of significance is placed on the 12th birthday within that church, thus their reasoning behind the way the 11 year old patrol is handled separately from the rest.
At ages 12-13, they are members of the troop, and for the most part other than the prohibition about travelling to/from campsites on Sundays, there are not a lot of major differences for boys in an LDS troop.