User Glossary

ADSL (Asymmetric Digital Subscriber Line)

A form of DSL, data communications technology that enables faster data transmission over copper telephone lines than a conventional modem can provide.


BT 21CN (BT 21st Century Network)

BT’s £10bn programme to upgrade the analogue network to their next generation IP infrastructure called BT 21st Century Network or 21CN. Over the next 5 years BT will migrate over 30 million end user phone lines on to a fully integrated IP system transmitting voice and Internet traffic over a common system. The programme has implications for many traditional signalling systems.



Process to ensure that the alarm panel is recognised and can communicate on both paths with the ARC across the Emizon Service Platform.


DHCP (Dynamic Host Configuration Protocol)

Dynamic Host Configuration Protocol. Allows a device i.e. the alarm control panel to automatically request and obtain an IP address.


DNS IP Address

This is what a system uses to translate a web name i.e. to an IP address (Domain Name System).


DSL (Digital Subscriber Line)

A family of technologies that provide digital data transmission over the wires of a local telephone network.


DTMF (Dual Tone Multi Frequency)

Used for telephone signalling over the line in the voice frequency band to the call switching centre.



The ability to protect data from being read or edited during transmission.


ESP (Emizon Service Platform)

Platforms hosted in secure locations that are built and managed to BS5979 – maintaining strict requirements for secure alarm signaling


Ethernet hub

Device that is used with a router to extend the number of ports or connections available to the IP network.


FEP (Front End Processor)

A processor which authenticates, monitors and manages the data security across the IP networks to prevent technological attacks from succeeding


GPRS (General Packet Radio Service )

A mobile data service available to users of GSM mobile phones. It provides moderate speed data transfer, by using unused channels in the GSM network.


GPRS Module (General Packet Radio Service)

Provides connectivity for the secondary GPRS communications path for Emizon 21 on the TCD.


GSM (Global System for Mobile)

A widely used digital mobile phone standard.



An individual customer premise connected to the Emizon 21 service via the hardware or TCD (Emizon 21’s equivalent of a Digi or STU) in the alarm panel..


IP Address

Internet protocol. A number that identifies each sender or receiver of information that is sent in packet across the Internet.


IP Module

Provides connectivity for the primary IP/Broadband communication path for Emizon 21 on the TCD.


IPR (Intellectual Property Right)

An umbrella term for various legal entitlements which attach to certain types of information, ideas, or other intangibles in their expressed form.


LED (Light Emitting Diode)

A semiconductor device that emits incoherent narrow-spectrum light when electrically biased in the forward direction


MAC Address

The unique address which every device that connects to a network is given at manufacturing stage.


MSANS (Multi Service Access Nodes)

The facility to combine telephony data into a structured voIP service


NVM (Non Volatile Memory)

Memory with the capability to store information, recover the power & the chip will retain the memory



A poll is an encrypted and sequenced message transmitted by the signalling system and acknowledged by the receiver. A loss of the polling sequence during a specified time constitutes an alarm.


Port Number

In the Internet suite of protocols, the identifier for a logical connector between an application entity and the transport service.


POTS (Plain Old Telephone Service)

The standard, analog telephone service that remains the basic form of residential and small business telephone service nearly everywhere in the world


PSTN (Public Switch Telephone Network)

The concentration of the world’s public circuit-switched telephone networks, in much the same way that the Internet is the concentration of the world’s public IP-based packet-switched networks.



The router at the customer premises is the gateway into the global IP network and the benefits that it brings. It is the router that enables the alarm control panel to communicate with the Emizon platform and then onwards to the ARC.


SDSL (Symmetric Digital Subscriber Line)

A Digital Subscriber Line (DSL) variant. It runs over one pair of copper wires, with a maximum range of about 3 kilometers. The main difference between ADSL and SDSL is that SDSL has the same upstream data transfer rate as downstream (symmetrical), whereas ADSL always has smaller upstream bandwidth (asymmetrical).


SIM (Subscriber Identification Module)

A smart card containing the telephone number of the subscriber, encoded network identification details etc.


SSL (Secure Socket Layer)

Protocols which provide secure communications on the Internet for facilities such as e-mail, internet faxing & data transferring.


Subnet Mask

A piece of data which checks if the device is sending data within the local area network or outside of it.


TCD (Telemetry Communication Device)

Emizon’s equivalent of a Digital Communicator or STU.


TCD Serial Number (Telemetry Communication Device)

The unique reference number for the TCD. This number allows the alarm equipment at the customer’s premises to be matched to the installation number at the ARC installation and on the Emizon service platform.


UDL (Upload Download)

The ability to connect to an alarm panel, retrieve the log information and change the configuration of the alarm panel remotely.


USB (Universal Serial Bus)

A serial bus standard to interface devices.


VoIP (Voice Over IP)

The routing of voice conversations over the Internet or through any other IP-based network.


WAN (Wide Area Network)

The scientific and engineering discipline concerned with communication between computer systems. Such networks involves at least two computers.