The antennas in a wireless network installation must be close to the users. The location of the antennas are not necessarily required to be close to the connected switch or to a computer room. The cable run can be 100 feet or more from the AP or bridge to antenna locations.
RF energy is carried between the antennas and the radio equipment through a coaxial cable. An antenna cable introduces signal loss in the antenna system for both the transmitter and receiver. To reduce signal loss, minimize the cable length and use only low-loss or ultra low-loss antenna cable to connect radio devices to antennas.
RF coaxial cable = loss of signal strength
Loss of signal strength is directly proportionate to the length of the cable segment. As the diameter of the cable increases, signal loss is decreased, but at much higher purchase cost. As signal frequency increases (higher numbered channel) loss increases.
Low-loss cable extends the length between any Cisco Aironet product and its antenna. With a loss of 6.7 dB per 100 feet (30m) for low-loss cable and 4.4 dB for the ultra low-loss cable, these cables provide installation flexibility without a significant sacrifice in range or performance.