APPENDIX 5
Glossary of Terms (continued)
Digital PSTN
Digital Public Switched Telephone Network.
The digital national telephone system. Service is available to customers on
twisted-pair wires that carries a DC supply provided from the network tel-
ephone exchange, on optical fibre or other digital transmission medium. The
digital service may be in ISDN format or another digital format.
DTMF
Dual Tone Multi Frequency
The series of tones used by telephones to send dialling information to an
analogue PSTN exchange. These tones are also used by the DTMF Fast
Format and Contact ID alarms reporting protocols.
DTMF Fast Format
Alarms Reporting Protocol
A protocol that is a sequence of analogue DTMF tones that are used to send
via telephone lines a transmission to receiving equipment at an ARC, and to
receive checking and acknowledgement replies from that receiving equip-
ment. 8 or 16 channel DTMF Fast Format protocol is commonly used in
burglar or intruder alarm equipment.
Dualcom96
Alarms Reporting Protocol
This protocol is used by DualCom GSM to send transmissions to receiving
equipment at an ARC, and to receive checking and acknowledgement re-
plies from that receiving equipment. This is a Modem type protocol
Earth Loop Calling
An older type of analogue PSTN or analogue PABX extention line. Normally
provided with no DC voltage present on the line. Requires the line to be
connected to earth to obtain a ‘dial tone’. DualCom and Control Panel Digi-
Modems can not be used with this type of telephone line.
EEPROM
Electrically Erasable Programmable Read Only Memory.
A type of NVM. See NVM
GSM
Global System for Mobile Communications.
Digital telephone service particularly (but not exclusively) for users that may
be mobile for carrying digital data, speech or fax, where the path from the
user is by a radio link to one (or more) fixed sites.
Hybrid Line
A line that carries digital data and analogue signals simultaneously. Most
commonly this is an ADSL digital service and an analogue telephone serv-
ice on one line from a Service Provider to a subscriber.
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