A landline (or land line) was originally an overland telegraph wire,[1] as opposed to an undersea cable. Currently, landline (or land phone or main line or fixed-line) refers to a telephone line which travels through a solid medium, either metal wire or optical fibre, as distinguished from a mobile cellular line, where transmission is via radio waves. In 2003, the CIA reported approximately 1.263 billion main telephone lines worldwide. China had more than any other country, at 350 million, and the United States was second with 268 million. The UK has 23.7 million residential fixed landlines.[2] In 2008 there were 1.27 billion fixed line subscribers in the world.[3]
Contents |
A fixed phone line (a line that is not a mobile phone line) can be hard-wired or cordless.
Fixed wireless refers to the operation of wireless devices or systems in fixed locations such as homes and offices. Fixed wireless devices usually derive their electrical power from the utility mains electricity, unlike mobile wireless or portable wireless which tend to be battery-powered. Although mobile and portable systems can be used in fixed locations, efficiency and bandwidth are compromised compared with fixed systems. Mobile or portable, battery-powered wireless systems can serve as emergency backups for fixed systems in case of a power blackout or natural disaster.
The term landline is also used to describe a connection between two or more points that consists of a dedicated physical cable, as opposed to an always-available private link that is actually implemented as a circuit in a wired switched system (usually the public switched telephone network). So-called leased lines are invariably of the latter type; the implications of a landline in this context are security and survivability. For example, a military headquarters might be linked to front-line units "by landline" to ensure that communication remains possible even if the conventional telephone network is damaged or destroyed. .
|
||||||||||||||