A landline telephone (also known as land line, land-line, main line, home phone, landline, fixed-line, and wireline) refers to a phone that uses a metal wire telephone line for transmission as distinguished from amobile cellular line, which uses radio waves for transmission.

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 United Kingdom has 23.7 million residential fixed homephones. In 2008, the world had 1.27 billion fixed line subscribers.

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. 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 be used as emergency backups for fixed systems in case of a power blackout or natural disaster.

Panasonic Fixed line telephone

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 land line 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. Another example of this is in airports. All air traffic control towers have dedicated lines connected to the police, fire department, hospitals, army, etc. Deployed as a precaution in case of emergency, these can be used at any time.

In recent years, the landline telephone has seen major decline due to the advancement of mobile network technology and the obsolescence of the old copper wire networking. In the coming years, the use of these networks will be deemed completely out of date and replaced with the use of more efficient broadband and fiber optic connection extending to rural areas and places where telecommunication was much more sparse. Some see this happening as soon as the year 2025.[3]

In 2004, only about 45% of people between the ages of 12 and 17 owned cell phones. As a means of communication in that time, they had to rely on the use of landline telephones. In just 4 years' time, that percentage reached a total of about 71%. That same year, 2008, about 77% of adults owned a mobile phone.[4] In the year 2013, 91% of adults own a mobile phone. Of that 91%, almost 60% have a smart phone.[5]

After Hurricane Sandy, Verizon refused to install landline copper wire in Mantoloking, NJ because of its high cost. Instead, Verizon proposed to local customers to install Verizon Link, which is a wireless home phone system that does not require the phone to be connected to landline copper wire, but instead receives its signal from the towers. Landlines work by transmitting voice and data signals by copper wire through electric pulses. This means landline phones would still work even if there was a blackout or a satellite disturbance, causing interference with mobile phones.[7]

The effect decreasing landlines have had on contacting emergency services is also a big safety issue. On September 11, 2001, when disaster struck New York City, tens of thousands of people were calling 911 emergency and the volume of calls flooded mobile towers. The calls would not go through because of the lack of frequency, so the network crashed. The overload of data signals not only delayed communications, but it also slowed down the response time of police and fire departments because they could not properly communicate.

Another issue is the lack of data and voice coverage in some parts of the world. For example, the majority of the United States has mobile coverage, but some places still do not. This is a concern because in those are very isolated places, if there were an emergency, there would be no means of communication without landlines in place. Also, the decrease in landlines has had an effect on the accuracy of locating someone who called 911. When a landline is used to call emergency services, a nearly exact location can be found; however, when a mobile phone is used, the location differs and has a radius of 10 to 300 meters.[10] This variation in location could potentially be the difference between life and death for someone who calls 911.

Bruce Kushnick, Executive Director of New Networks Institute, has argued that reports of the landline's decline have been exaggerated.[11] In a 2013 Huffington Post article, Kushnick accepted the notion that Americans were dropping landlines but also noted that many journalists and phone company providers have relied too much on limited statistics released by the Center for Disease Control (CDC).[11] Kushnick criticized the CDC's methodology, stating that "the CDC statistics are really the Voice Link of data. The customers who have data applications, like grandma's Life Alert, or a small business using an ATM machine or DSL service or anything over the wire that is not a residential voice call, has NOT been counted."[11]