Differences between Wireless and Fixed Telephone Networks
Fixed Telephone Networks
- Transfer of information in the public switched telephone network (PSTN) takes place over landline trunked lines (called trunks) comprised of fiber optic cables, copper cables, microwave links, and satellite links.
- The network configurations in the PSTN are virtually static, since the network connections may only be changed when a subscriber changes residence and requires reprogramming at the local (CO) of the subscriber
- In the fixed telephone network, each subscriber loop is fixed, and a twisted pair connection is provided between a subscriber and the central office CO, or in some cases, several subscribers are connected to the concentrator, which is connected via a trunk connection to thecentral office CO
- Fixed networks are difficult to change, and require a substantial investment to accommodate any new subscriber.
- The available channel bandwidth for fixed networks can be increased by installing high capacity cables (fiber optic or coaxial cable
- The only fixed connections are between BSs and the MSC, and between the MSC and the PSTN
- Wireless networks are highly dynamic, with the network configuration being rearranged every time a subscriber moves into the coverage area of a different BS.
- There are several limitations to WN, like bandwidth allocation, interference, multipath propagation, Doppler spread, which will be discussed later in the course.
- Both modern PSTNs and second generation WNs use separate signalling channels, according to common channel Signalling System SS 7.