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Reliability of Digital Switching Equipments

Company normally requires that the CO digital switching equipment shall operate with a very high degree of reliability. The effective performance of the telephone exchange is depended on its product specific properties as well as on the properties regarding the operational, environmental and maintenance conditions under which it is used. The objective of this section is to assure that systems meet satisfactory reliability performance standards without imposing undue constraints on the design of the system.… Read More »Reliability of Digital Switching Equipments

Digital Telephone Switching System Design Requirements

Digital Telephone Switching System Design Requirements 3 General Requirements. 4 Design Characteristics. 5 Traffic Handling and Switching. 6 System Capacity 7 Data of Individual Telephone Exchanges 8 Mechanical Design 9 Modular Structure 10 System Maintenance 11 Wiring and Cables 12 Heat Dissipation 13 Grounding 14 Environmental Considerations 15 Memories 16 Programs 17 Line Modules 18 Switching Network. 19 Description of Individual Switching Systems 20 Local Exchange 21 Remote Line Switch (RLS) 22 General Information 23… Read More »Digital Telephone Switching System Design Requirements

Digital Telephone Switching System Codes & Standards

The selection of material and equipment, and the design, construction, maintenance, and repair of equipment and facilities covered by this standards & Codes Digital Telephone Switching System if  shall comply with the latest edition of the references listed below. Digital Telephone Switching System Codes & Standards American National Standards Institute ANSI/NFPA 70 National Electric Code, NEC ANSI C2 National Electrical Safety Code Department of Communications (Canada) CSA C108.8 (CSA: Canadian Standards Association) Radiated Emission Limits… Read More »Digital Telephone Switching System Codes & Standards

Definitions and Terms Digital Telephone Switching Systems

Some of the definitions and terms associated with Central Office (CO) digital telephone switching systems are defined below: Definitions and Terms Digital Telephone Switching Systems Abbreviated Dialing: A subscriber can dial a short code which is converted in the originating exchange into a form which will establish connection with the local, national, or international number required. Alternate Mark Inversion (AMI) signal (bipolar signal): A PCM signal, conveying binary digits, in which successive “marks” (or 1’s)… Read More »Definitions and Terms Digital Telephone Switching Systems

Definitions and Terms Digital Telephone Switching System Part 2

Some of the definitions and terms associated with Central Office (CO) digital telephone switching systems are defined below: Definitions and Terms Digital Telephone Switching System Part 2 CAMA: Centralized Automatic Message Accounting (see also LAMA). CCIS: Common Channel Interoffice Signaling. CCS: A measure of traffic intensity expressed as so many hundred call- seconds per hour. 1 CCS = 36 erlangs. (See also Erlang). Central Office (CO): A facility of the communication common carrier, where the… Read More »Definitions and Terms Digital Telephone Switching System Part 2

Definitions and Terms Digital Telephone Switching System Part 3

Some of the definitions and terms associated with Central Office (CO) digital telephone switching systems are defined below: Definitions and Terms Digital Telephone Switching System Part 3 Delay Distortion: Distortion is an unfaithful reproduction of signals due to changes occurring in the waveform of the original signal. Delay distortion is the delay at one frequency relative to that at another frequency. In a telephone channel, the reference frequency is often taken as 1700 or 1800… Read More »Definitions and Terms Digital Telephone Switching System Part 3

Definitions and Terms Digital Telephone Switching System Part 4

Some of the definitions and terms associated with Central Office (CO) digital telephone switching systems are defined below: Definitions and Terms Digital Telephone Switching System Part 4 Frame Alignment: The state in which the frame of the receiving equipment is correctly phased with respect to that of the received signal. Frequency: Frequency is measured in units called Hertz (Hz). One Hz is one cycle per second. Frequency Diversity: In radio systems the use of one… Read More »Definitions and Terms Digital Telephone Switching System Part 4

Definitions and Terms Digital Telephone Switching System Part 5

Some of the definitions and terms associated with Central Office (CO) digital telephone switching systems are defined below: Definitions and Terms Digital Telephone Switching System Part 5 LAMA: Local Automatic Message Accounting (see also CAMA). Line Code: A code chosen to suit the transmission medium and giving the equivalence between a set of digits generated in a terminal or other processing equipment and the pulses chosen to represent that set of digits for line transmission.… Read More »Definitions and Terms Digital Telephone Switching System Part 5

Definitions and Terms Digital Telephone Switching System Part 6

Some of the definitions and terms associated with Central Office (CO) digital telephone switching systems are defined below: Definitions and Terms Digital Telephone Switching System Part 6 Packet-Mode Operation: The transmission of data by means of addressed packets whereby a transmission channel is occupied for the duration of transmission of the packet only. The channel is then available for use by packets being transferred between different data terminal equipment. Pair-Gain system: A subscriber transmission system… Read More »Definitions and Terms Digital Telephone Switching System Part 6

Definitions and Terms Digital Telephone Switching System Part 7

Some of the definitions and terms associated with Central Office (CO) digital telephone switching systems are defined below: Definitions and Terms Digital Telephone Switching System Part 7 Sidetone: The portion of a talker’s signal that is purposely fed back to the earpiece so that the talker hears his or her own speech. Signaling: The exchange of electrical information (other than by speech) specifically concerned with the establishment and control of connections and management in a… Read More »Definitions and Terms Digital Telephone Switching System Part 7