How much signal are you getting, tosaman? You may not have enough to keep a connection going?
You may want to look at the DHCP Address Reservation i pictured up above- adding the PS3's MAC Address there and setting a custom Ip address should help.
Next thing to look at would be possibly port forwarding- the PlayStation network uses specific ports that are sometimes closed by default. The ones to open are:
• TCP Ports: 80, 443, 5223, and 10070 - 10080
• UDP Ports: 3478, 3479, 3658, and 10070