Local area networks are independent fixed wire networks that make up your fixed network. Cables and wires connect each device to your servers. LANs are the most common type of networks used, but this may not be the case for long - wireless local area networks are becoming more popular.

A network of computers within a home, office or group of buildings. Often connected via Cat-5 cables (the `blue computer network cables`) or by local wireless connections (eg. wireless routers).

Also called a Fixed Line service, Fixed Wire service, Wired service, Telephone line, POTS (Plain Old telephone Service) Phone line, Land Line, CO Line, Central Office Line and Copper Connection. These are the traditional copper telephone connections, from an exchange (CO) to a premises. Today landlines also describe fibre optic telephony lines. Generally speaking, a landline is a non-wireless telephone line.

A flat display used in electrical equipment. Early versions were two-toned, but today LCDs are colour. LCDs are used on handsets; both mobile (including PDA, etc.) and landline handsets.

Programming of a PABX to use different lines or override codes to obtain the best call rate for differing call types or time of day calling. For example: When calling a mobile phone, a PABX which has been LCRed may use an alternate (cheaper) carrier for that call. This is simply done by prefixing the dialled number with a four digit override code. The user does not see or notice the LCR taking place.

A dedicated telephone line assigned from one location to another. Set up by a telecommunications carrier, the connection is said to be a leased line. Typically used by businesses to connect geographically distant offices, leased lines are more expensive than other methods available today (eg. VPNs). Leased lines offer an inherently secure, fast and always-on connection.

Small, bright, light source that uses very little power and does not burn out. LEDs may emits visible, UV or IR.

LEO satellites are more common than GeoSats because it is cheaper to place them in LEO and they need less powerful amplifiers for transmitting. LEO is an orbiting height of between 200 and 2000 kms and the satellites travel at about 27,400 kmph to maintain their orbit - providing a period of orbit of around 1 hour and 30 minutes. This means that constant coverage to an area on Earth must be provided using a network of LEO satellites. (This is unsuitable for some communications requirements and so geostationary orbit satellites are also used - see Geosynchronous Satellite.)

The number of lines of text which can be displayed on a handset without scrolling. Not to be confused with CND (Calling Number Display).

The fee charged by a telephone carrier for the connection to their network. Distinct from usage charges, this fee is a flat access fee.

A stationary wireless broadband link which must be operated in line-of-sight. 3-5km ranges are expected.

Calls made between standard telephone services within the same charging zone or to adjacent standard charging zones, and charged at a flat rate. However, local calls from ISDN services are timed and do not have a flat charging structure.

A charging arrangement that allows dial-up internet users to access their (ISP) Internet Service Provider for the cost of a local call, irrespective of their distance from the physical point of presence (PoP). See 019 numbers.

The telephone exchange (see CO) which a standard telephone service is physically connected to. This is usually the closest exchange, but not always.

The ability for a customer to retain their existing landline number when changing service providers. This may occur in two circumstances: either the number is retained by the carriage service provider and simply rebilled, or the number is actually ported from one carrier to another. As with mobile number porting, the approximate time where the number is unavailable through either of the carriers is 15 minutes.

Long distance calls are also called STD calls, NDD (National Direct Dialled) Calls or Trunk Calls. (Technically, international calls are also long distance calls, but this is not a common use of the term.) These are domestic calls which extend beyond local billing zones.

Refers to a communication medium which must have an unimpeded (or nominal) line-of-sight between transmitter and receiver.