Running 2 wireless modems make cause some interference with your signals.
MAC filtering
There is a few concerns a person would have when accessing a household wireless device. Some of the concerns a person would have would be interference, security and weather.
Interference - If intermittent and difficult-to-diagnose wireless communication errors occur, interference might be the culprit.
Wireless technology can either be extremely convenient or frustrating. The convenience of using a wireless security camera system is that there is no need to connect long data cables. However, wireless transmission comes with several possible mishaps. For example, a typical wireless cctv system uses standard 2.4 GHz technology, which could cause interference to other wireless devices such as routers and cordless phones. Some cameras may actually have several different frequency variations close to the 2.4 GHz, which could minimize interference. Depending on the antennas of the wireless surveillance system, the operational range may vary, and could even be smaller than standard wired cameras.
Although wireless intercom systems do serve the purpose there are some drawbacks. A wireless intercom system can be vulnerable to both radio interference and security issues. With wireless intercom systems conversations can be picked up by scanners, cordless phones or baby monitors that are on the same frequency.
Traditional security cameras often use lengthy cables that are connected to an external recording device such as DVR or hard drive. Wireless technology has eliminated the long cables, and today's surveillance cameras can transmit videos using standard 2.4 GHz, the same frequency used by routers and other networking equipment such as internet adapters. The only possible downside to wireless technology is interference from other sources such as routers, home phones, and other multi media devices.
People who are looking for affordable security cameras that are also easy to use should install wireless surveillance cameras. These cameras eliminate the lengthy cables and wires that are used in traditional home security cameras. In fact, standard cameras literally have hundreds of feet of wires. Wireless surveillance cameras use the same type of technology as routers, such as 2.4 GHz frequency for transmitting signals. However, the biggest concern with wireless cameras is interference with other wireless devices including routers and cordless phones.
Some potential obstacles to successful wireless transmission and their repercussions include interference and reflection. Both of those can cause problems with wireless transmissions
Many companies have very strict rules about wireless. It's possible that the network was configured in the way you cannot connect your private laptop. If you do not have wireless security policies running, then it's something else. The network might not be compatible with your computer, or there is signal interference, or just firmware problem. There are thousands of reasons. If you want to get a certain answer you need to specify a certain question: including error number, messages and so on.
Interference
Setup your wireless router with the strongest possible security setting (e.g., WPA+PSK or WEP). Although this prevents intruders from joining your network this does not gurantee that some one who is already on your wireless does not snoop.