Disconnected from halo 3 everytime playing?

[haffy]

I play halo 3 and most of the time I am getting disconnected and it annoys me because i want to rank up but i lose exp so i feel like theres no point to play it. but everytime i play by myself its fine i usually turn off all the wireless internet connections on the laptops in my home and it works but everytime my brother joins my games or if we play together we will disconnect almost everytime even if the computers wireless networks are turned off. I dont know if anyone else gets this problems or knows how to fix it but i was just wondering