Often, someone will call requesting a "wireless solution" for their security cameras. Some things you may want to be aware of when planning this.
1. Wireless... Still needs power, and batteries will not last long.
2. Range can be affected by a number of things. Walls, elevation changes, transmission power, broadcasting frequency of transmission, other wireless devices in the area, humidity and general atmospherics.
3. Anyone else can see your video.. Not very private.
4. Sometimes your wireless device can interfere with WiFi devices such as routers, etc..
Typically Interference symptoms from spread spectrum cordless phones will be seen as a line through the video. It may pulse a little as well. Symptoms of a router interfering will be pulsing consistently.
Best results for wireless installations can be made by considering the following.
1. Keep the antenna cables short lowers the RF loss.
2. Keep the transmission as close to the same plane. (about the same height) as the receiving device.
3. Remove any spread spectrum phone devices from the wireless path.
4. Keep the receive and transmit points over any motion activity.
5. Use Directional antennas when possible.
I hope this helps you if you have wireless cameras, or are considering installing them.