Jyrki T. J. Penttinen and Juha Kallio
The transmission lines form the base for practically all types of networks, transporting the contents of the user to the destination in the core part of the networks. This applies to voice service as well as data services and signaling. As the data rates tend to increase and the applications and services are constantly becoming more demanding, as for data consumption, transport networks need to support very high data rates and quality of service requirements. Among the fixed data network evolution, especially the wireless data networks take major leaps towards very high data rates, and the transmission of the core should be at least as efficient so that it does not create bottlenecks.
9.2 Physical Transmission Systems
Transmission can be built up, for example, by utilizing good old copper wires, or more advanced lines such as fiber optics, radio links, or via satellite connections. For each one of these, there is an optimal environment that can be balanced between the cost of the deployment and operating expenditures, bit rates, length of transmission line, easiness to install the equipment, availability of power, presence of interferences, and other technical and nontechnical parameters. Although in general, the role of copper wires is getting less significant along with the deployment of fiber optics, to mention one example, the copper is still useful in some areas.
The transmission line capacity ...