In Chapter 5 we looked at how a Core Transmission Network carries a required capacity between two network nodes. But, how does a network operator determine what capacity is required to be carried? For example, are 90 circuits between Leicester and Coventry sufficient to ensure the expected volume of calls between these exchanges can be carried satisfactorily, or could the operator save money by providing just 60 circuits? Section 6.3 of this chapter considers how the size of traffic route between two exchanges is determined, and how the flow of traffic through a network of many exchanges is routed to give maximum utilisation of the capacity while achieving the appropriate level of resilience (at the switching level). Finally, we consider a simple example of how a network is dimensioned at the switching level, and how this impacts the dimensioning of the Core Transmission Network.

Chapter Contents:

• 6.1 Introduction
• 6.2 Circuit-switching systems
• 6.2.1 Introduction
• 6.2.2 Subscriber switching (local) units
• 6.2.3 Digital telephone switching systems
• 6.2.4 Private automatic branch exchanges
• 6.2.5 Digital exchange structures
• 6.2.6 Integrated services digital network exchanges
• 6.2.7 Non-subscriber digital switching units
• 6.3 Network dimensioning
• 6.3.1 The concept of switched traffic
• 6.3.2 Call distribution
• 6.3.3 Traffic flow
• 6.3.4 Traffic routeing
• 6.3.5 Exchange capacity planning
• 6.4 Summary
• References

Inspec keywords: circuit switching; telecommunication switching; telecommunication traffic

Other keywords: telecommunication traffic; core transmission network; circuit-switching networks; circuit-switching systems

Subjects: Communication switching