Unit 1
Telephony Background: An overview of telephone networks – Transmission system – Basic switching system – Signaling – Echo cancellation – Working principles of telephone – DC (pulse) and DTMF (tone) – Signaling – Digital Switching Systems. Traffic Analysis: Traffic characterization – Loss systems – Network blocking probabilities – Delay systems (queuing system) – Queues in tandem.
Unit 2
Switching: Single stage – Grading – Progressive grading – Traffic capacity of grading – Applications – Link systems. Space/Time Division Switching: Space switch – Time switch and their design – Hybrid switches – Concentrator and switching components – PBX switches – Digital cross connect – Time division switching: Space and time division switching – General space switches – Time switches – Time division switching networks – Basic networks – Bidirectional pass – Complex switching networks – Concentrators – PBX switches – Digital cross connect units – Grades of services of time division switching networks.