LAN
Local area network.
A computer network that spans a relatively small area. Most LANs are confined to a single building or group of buildings. However, one LAN can be connected to other LANs over any distance via telephone lines and radio waves. A system of LANs connected in this way is called a wide-area network (WAN). See also WLAN.

Last mile
The topology denotes the operator’s ownership of the access network.

Layered architecture
The concept of layered network architecture divides a network at any specific point into layers, each of which adds value to the physical medium of communication.

LDCs
Least developed countries.
These are the 49 least developed countries recognized by the United Nations.

Leased line
A point-to-point communication channel or circuit that is committed by the network operator to the exclusive use of an individual subscriber. Under national law, leased lines may or may not be permitted to interconnect with the public switched network.

LF
Low frequency.

Licensing
An administrative procedure for selecting operators and awarding franchises for the operation of particular telecommunication services, for instance cellular radio.

Line sharing
A form of network unbundling that allows a competitive service provider to offer ADSL using the highfrequency portion of a local loop at the same time that an incumbent continues to offer standard switched voice service over the low-frequency portion of the same loop.

LLU
Local loop unbundling.
The process of requiring incumbent operators to open the last mile of their legacy networks to competitors. See ULL.

Local loop
The system used to connect the subscriber to the nearest switch. It generally consists of a pair of copper wires, but may also employ fibreoptic or wireless technologies.

LRIC
Long-run incremental costs.

LTE
Long-term evolution.