What is with my wireless xbox live connection? Please help.?

I have xbox live, i have my xbox 360 like 10 steps away from my router, and im NOT aloud to go wired, so i use the xbox 360 wireless adapter. I look at network settings and i have 4 bars connecting to my router, then when i go play COD 4, or COD 5 i will get 1-2-3 bars up and down all game, though never 4 full bars. Also frick everyone sais oh sorry but its the host, WELL ITS NOT THE HOST!!!! This happens sometimes during the day, this usually happens around 11 am, to 12 pm, to 2 pm usually, in the morning like 8 am i get 3 bars allways, then at night i get 3 bars allways. When its in the middle of the day which is when i get bad connection, i look and im the only one in the room with a screwed up connection. Please dont say its the host because it is not the host!!! Please help, also i can't go wired or move my 360 closer to my router. Also if you say "oh the middle of the day is when everyone plays so your connection will suck", then why do my friends who are also wireless never go lower then 3 bars no matter when they play?