Telephone Network Components and Concepts

Posted on Nov 26, 2024 in Computers

Central Types

Central Local (CL)

Connects subscribers within a defined geographic area.

Central Elementary (CP)

Interconnects local exchanges, linking to a higher-order central.

Central School (CS)

Connects primary centrals, linking to a higher-order central.

Central Tertiary or Nodal (CT)

High-power interconnects, linking to other tertiary plants. Only six exist.

Network Sections

Subscriber Line

Connects the terminal to the subscriber central.

Primary Section

Each union power circuit consists of individual links, each capable of carrying one communication at a time.

Secondary Section

Connects a power station with a primary school.

Tertiary Section

Connects a secondary to a tertiary center.

Quaternary Section

Connects two tertiary centrals, also known as “Great National Routes.”

Network Concepts

Hierarchical Network

The set of subscriber stations and automatic exchanges.

End Sections

Connections between central hierarchical networks.

Final Route

Unique path for two subscribers to connect through the hierarchical network.

Direct Section

Links connecting two exchanges not hierarchically linked.

Tandem Central

Complementary central in urban areas, handling traffic between exchanges.

Central Variations

Central Sector (CS)

Primary central sector header, connecting subscribers and local exchanges.

Traffic Central Sector (CTS)

Primary head of central sector, connecting local exchanges to a secondary central.

Central Terminal (CT)

Local central in rural areas, connecting subscribers to a primary central.

Central Sub (CSS)

Similar to a sector but not the head of the sector.

Main Central Sector (CSP)

Primary central for transit traffic within a sector.

Regular City Central (CUO)

Central for a unicentral or multicenter area, connecting subscribers to a primary central.

Central City No Ordinary (CUNO)

Central for a multicenter area, connecting subscribers to a tandem central.

Central City Tandem (CTU)

Connects urban core to the primary hierarchical network.

Tandem Central Interurban (CTI)

Acts as both tandem and central sector.

CAI, CAN, CAP

Centrals for high traffic, national transit, and provincial transit respectively.

CN

Connects secondary stations to a nodal region, directing traffic.

Telephone Components

Microphone

Converts sound vibrations into a variable current.

Receiver

Transforms variable current into sound waves.

Induction Coil

Separates transmit and receive circuits.

Ringer

Provides an audible warning tone.

Condenser

Allows AC power to pass to the ring circuit.

Hook Switch

Extends the circuit to the plant when the receiver is lifted.

Disc/DTMF

Signals the desired call route to the central automatic.

Network Types and Technologies

Circuit-Switched Network

Dedicated connection network, either analog or digital.

PSTN

Public Switched Telephone Network, using circuit-switching.

SDH

Synchronous Digital Hierarchy, primary transmission protocol for PSTN.

Space Switching

Physical transfer of a multiplex to another.

Switching Time

Content storage in a memory channel for a short time.