Microwave systems
Microwave systems are usually referred to as Microwave Multipoint Distribution Systems (MMDS). These systems do not require wires or cables to transmit the television signal, making them popular choices in areas with low populations where laying cable is expensive, such as parts of Africa or regional Australia.
MMDS transmits information digitally using radio signals in the 2.2 to 2.4 GHz range, and requires a clear line of sight between the transmitter and receiver. The signal can travel reasonable distances, allowing the transmitter and receiver to be more than 50 kilometres apart. These systems support around 33 analogue or more than 100 digital television channels at a time, which is why MMDS is also known in some countries as ‘wireless cable' television.
These systems were originally intended as a one-way cable television system for subscribers in remote areas, or where cables were difficult to install. However, in the late 1990s MMDS technology was expanded to allow two-way transmission. This means that MMDS can now deliver data and internet services as well as cable television services.
|