Carterfone
Encyclopedia
The Carterfone is a device invented by Thomas Carter. It manually connects a two-way mobile radio
system to the public switched telephone network
(PSTN), making it a direct predecessor to today's autopatch
.
The device was acoustic
ally, but not electrically, connected to the public switched telephone network. It was electrically connected to the base station
of the mobile radio
system, and got its power from the base station. All electrical parts were encased in bakelite, an early plastic
. When someone on the CB radio
wished to speak to someone on phone
, or "landline
" (eg, "Central dispatch
, patch me through to McGarrett"), the station operator at the base would dial the telephone number
. When callers on the radio and on the telephone are both in contact with the base station operator
, the handset of the operator's telephone is placed on a cradle
in the Carterfone device. A voice-operated switch in the Carterfone automatically switches on the radio transmitter when the telephone call
er is speaking; when he stops speaking, the radio returns to a receiving condition. A separate speaker
is attached to the Carterfone to allow the base station operator to monitor the conversation, adjust the voice volume, and hang up
his telephone when the conversation
has ended.
This particular device was involved in a landmark
United States
regulatory decision related to telecommunication
s. In 1968, the Federal Communications Commission
allowed the Carterfone and other devices to be connected directly to the AT&T
network, as long as they did not cause harm to the system. This ruling (13 F.C.C.2d 420) created the possibility of selling devices that could connect to the phone system using a protective coupler, and opened the market to customer-owned equipment
. The decision is often referred-to as "any lawful device", allowing later innovation
s like answering machine
s, fax machines, and modem
s (which initially used the same type of manual acoustic coupler as the Carterfone) to proliferate.
In February 2007, a petition
for rulemaking
was filed with the FCC by Skype
, requesting the FCC to apply the Carterfone regulations to the wireless industry — which would mean that OEMs
, portals and others will be able to offer wireless devices and services without the cellular operator
s needing to approve the handset
s. However, on 1 April 2008 FCC chairman Kevin Martin indicated that he would oppose Skype's request.
, there is renewed interest due to a new chairman being selected by the Obama administration, and the opposition to the vendor lock-in
practices which have limited consumer
s' freedom of choice
in both voice and data services. The FCC has indicated that it is unlikely to take action on Wireless Carterfone beyond a possible rule requiring carriers to unlock handsets at the end of their contract periods.
Two-way radio
A two-way radio is a radio that can both transmit and receive , unlike a broadcast receiver which only receives content. The term refers to a personal radio transceiver that allows the operator to have a two-way conversation with other similar radios operating on the same radio frequency...
system to the public switched telephone network
Public switched telephone network
The public switched telephone network is the network of the world's public circuit-switched telephone networks. It consists of telephone lines, fiber optic cables, microwave transmission links, cellular networks, communications satellites, and undersea telephone cables, all inter-connected by...
(PSTN), making it a direct predecessor to today's autopatch
Autopatch
An autopatch, sometimes called a phone patch, is a feature of an amateur radio repeater to access an outgoing telephone connection...
.
The device was acoustic
Acoustic coupler
In telecommunications, the term acoustic coupler has the following meanings:# An interface device for coupling electrical signals by acoustical means—usually into and out of a telephone instrument....
ally, but not electrically, connected to the public switched telephone network. It was electrically connected to the base station
Base station
The term base station can be used in the context of land surveying and wireless communications.- Land surveying :In the context of external land surveying, a base station is a GPS receiver at an accurately-known fixed location which is used to derive correction information for nearby portable GPS...
of the mobile radio
Mobile Radio
This article is about professional equipment. For mobile radios used in amateur radio, see amateur radio mobile operation. Mobile radio or mobiles refer to wireless communications systems and devices which are based on radio frequencies, and where the path of communications is movable on either...
system, and got its power from the base station. All electrical parts were encased in bakelite, an early plastic
Plastic
A plastic material is any of a wide range of synthetic or semi-synthetic organic solids used in the manufacture of industrial products. Plastics are typically polymers of high molecular mass, and may contain other substances to improve performance and/or reduce production costs...
. When someone on the CB radio
Citizens' band radio
Citizens' Band radio is, in many countries, a system of short-distance radio communications between individuals on a selection of 40 channels within the 27-MHz band. Citizens' Band is distinct from the FRS, GMRS, MURS and amateur radio...
wished to speak to someone on phone
Telephone
The telephone , colloquially referred to as a phone, is a telecommunications device that transmits and receives sounds, usually the human voice. Telephones are a point-to-point communication system whose most basic function is to allow two people separated by large distances to talk to each other...
, or "landline
Landline
A landline was originally an overland telegraph wire, as opposed to an undersea cable. Currently, landline 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...
" (eg, "Central dispatch
Dispatch (logistics)
Dispatch is a procedure for assigning employees or vehicles to customers. Industries that dispatch include taxicabs, couriers, emergency services, as well as home and commercial services such as maid services, plumbing, HVAC, pest control and electricians.With vehicle dispatching, clients are...
, patch me through to McGarrett"), the station operator at the base would dial the telephone number
Telephone number
A telephone number or phone number is a sequence of digits used to call from one telephone line to another in a public switched telephone network. When telephone numbers were invented, they were short — as few as one, two or three digits — and were given orally to a switchboard operator...
. When callers on the radio and on the telephone are both in contact with the base station operator
Telephone operator
A telephone operator is either* a person who provides assistance to a telephone caller, usually in the placing of operator assisted telephone calls such as calls from a pay phone, collect calls , calls which are billed to a credit card, station-to-station and person-to-person calls, and certain...
, the handset of the operator's telephone is placed on a cradle
Cradle
Cradle may refer to:Mechanical devices:*Bassinet, a small bed, often on rockers, in which babies and small children sleep* Ship cradle, supports a ship that is dry docked...
in the Carterfone device. A voice-operated switch in the Carterfone automatically switches on the radio transmitter when the telephone call
Telephone call
A telephone call is a connection over a telephone network between the calling party and the called party.-Information transmission:A telephone call may carry ordinary voice transmission using a telephone, data transmission when the calling party and called party are using modems, or facsimile...
er is speaking; when he stops speaking, the radio returns to a receiving condition. A separate speaker
Loudspeaker
A loudspeaker is an electroacoustic transducer that produces sound in response to an electrical audio signal input. Non-electrical loudspeakers were developed as accessories to telephone systems, but electronic amplification by vacuum tube made loudspeakers more generally useful...
is attached to the Carterfone to allow the base station operator to monitor the conversation, adjust the voice volume, and hang up
On-hook
In telephony, the term on-hook has the following meanings:# The condition that exists when a telephone or other user instrument is not in use, i.e., when idle waiting for a call. Note: on-hook originally referred to the storage of an idle telephone receiver, i.e., separate earpiece, on a switchhook...
his telephone when the conversation
Conversation
Conversation is a form of interactive, spontaneous communication between two or more people who are following rules of etiquette.Conversation analysis is a branch of sociology which studies the structure and organization of human interaction, with a more specific focus on conversational...
has ended.
Landmark regulatory decision
This particular device was involved in a landmark
Landmark
This is a list of landmarks around the world.Landmarks may be split into two categories - natural phenomena and man-made features, like buildings, bridges, statues, public squares and so forth...
United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
regulatory decision related to telecommunication
Telecommunication
Telecommunication is the transmission of information over significant distances to communicate. In earlier times, telecommunications involved the use of visual signals, such as beacons, smoke signals, semaphore telegraphs, signal flags, and optical heliographs, or audio messages via coded...
s. In 1968, the Federal Communications Commission
Federal Communications Commission
The Federal Communications Commission is an independent agency of the United States government, created, Congressional statute , and with the majority of its commissioners appointed by the current President. The FCC works towards six goals in the areas of broadband, competition, the spectrum, the...
allowed the Carterfone and other devices to be connected directly to the AT&T
AT&T
AT&T Inc. is an American multinational telecommunications corporation headquartered in Whitacre Tower, Dallas, Texas, United States. It is the largest provider of mobile telephony and fixed telephony in the United States, and is also a provider of broadband and subscription television services...
network, as long as they did not cause harm to the system. This ruling (13 F.C.C.2d 420) created the possibility of selling devices that could connect to the phone system using a protective coupler, and opened the market to customer-owned equipment
Customer-premises equipment
Customer-premises equipment or customer-provided equipment is any terminal and associated equipment located at a subscriber's premises and connected with a carrier's telecommunication channel at the demarcation point...
. The decision is often referred-to as "any lawful device", allowing later innovation
Innovation
Innovation is the creation of better or more effective products, processes, technologies, or ideas that are accepted by markets, governments, and society...
s like answering machine
Answering machine
The answering machine or message machine, also known as the telephone answering machine in the UK and some Commonwealth countries) and previously known as an ansaphone, ansafone, or telephone answering device is a device for answering telephones and recording callers' messages.Unlike voicemail,...
s, fax machines, and modem
Modem
A modem is a device that modulates an analog carrier signal to encode digital information, and also demodulates such a carrier signal to decode the transmitted information. The goal is to produce a signal that can be transmitted easily and decoded to reproduce the original digital data...
s (which initially used the same type of manual acoustic coupler as the Carterfone) to proliferate.
In February 2007, a petition
Petition
A petition is a request to do something, most commonly addressed to a government official or public entity. Petitions to a deity are a form of prayer....
for rulemaking
Rulemaking
In administrative law, rulemaking refers to the process that executive and independent agencies use to create, or promulgate, regulations. In general, legislatures first set broad policy mandates by passing statutes, then agencies create more detailed regulations through rulemaking.By bringing...
was filed with the FCC by Skype
Skype
Skype is a software application that allows users to make voice and video calls and chat over the Internet. Calls to other users within the Skype service are free, while calls to both traditional landline telephones and mobile phones can be made for a fee using a debit-based user account system...
, requesting the FCC to apply the Carterfone regulations to the wireless industry — which would mean that OEMs
Original Equipment Manufacturer
An original equipment manufacturer, or OEM, manufactures products or components that are purchased by a company and retailed under that purchasing company's brand name. OEM refers to the company that originally manufactured the product. When referring to automotive parts, OEM designates a...
, portals and others will be able to offer wireless devices and services without the cellular operator
Mobile network operator
A mobile network operator , also known as mobile phone operator , carrier service provider , wireless service provider, wireless carrier, or cellular company, or mobile network carrier is a telephone company that provides services for mobile phone subscribers.One essential...
s needing to approve the handset
Handset
On a telephone, the handset is a device the user holds to the ear to hear the audio sound. Modern-day handsets usually contain the phone's microphone as well, but in early telephones the microphone was mounted directly on the telephone itself, which often was attached to a wall at a convenient...
s. However, on 1 April 2008 FCC chairman Kevin Martin indicated that he would oppose Skype's request.
, there is renewed interest due to a new chairman being selected by the Obama administration, and the opposition to the vendor lock-in
Vendor lock-in
In economics, vendor lock-in, also known as proprietary lock-in or customer lock-in, makes a customer dependent on a vendor for products and services, unable to use another vendor without substantial switching costs...
practices which have limited consumer
Consumer
Consumer is a broad label for any individuals or households that use goods generated within the economy. The concept of a consumer occurs in different contexts, so that the usage and significance of the term may vary.-Economics and marketing:...
s' freedom of choice
Free market
A free market is a competitive market where prices are determined by supply and demand. However, the term is also commonly used for markets in which economic intervention and regulation by the state is limited to tax collection, and enforcement of private ownership and contracts...
in both voice and data services. The FCC has indicated that it is unlikely to take action on Wireless Carterfone beyond a possible rule requiring carriers to unlock handsets at the end of their contract periods.
See also
- AutopatchAutopatchAn autopatch, sometimes called a phone patch, is a feature of an amateur radio repeater to access an outgoing telephone connection...
- Hush-a-Phone v. United States
- InterconnectionInterconnectionIn telecommunications, interconnection is the physical linking of a carrier's network with equipment or facilities not belonging to that network...
- ModemModemA modem is a device that modulates an analog carrier signal to encode digital information, and also demodulates such a carrier signal to decode the transmitted information. The goal is to produce a signal that can be transmitted easily and decoded to reproduce the original digital data...
- Cordless telephoneCordless telephoneA cordless telephone or portable telephone is a telephone with a wireless handset that communicates via radio waves with a base station connected to a fixed telephone line, usually within a limited range of its base station...
- Terminal equipmentTerminal equipmentIn telecommunication, the term terminal equipment has the following meanings:* Communications equipment at either end of a communications link, used to permit the stations involved to accomplish the mission for which the link was established....
- TelephoneTelephoneThe telephone , colloquially referred to as a phone, is a telecommunications device that transmits and receives sounds, usually the human voice. Telephones are a point-to-point communication system whose most basic function is to allow two people separated by large distances to talk to each other...
- RadioRadioRadio is the transmission of signals through free space by modulation of electromagnetic waves with frequencies below those of visible light. Electromagnetic radiation travels by means of oscillating electromagnetic fields that pass through the air and the vacuum of space...
- Citizens' band radioCitizens' band radioCitizens' Band radio is, in many countries, a system of short-distance radio communications between individuals on a selection of 40 channels within the 27-MHz band. Citizens' Band is distinct from the FRS, GMRS, MURS and amateur radio...
External links
- Full text of FCC Carterfone decision
- Full text of Skype petition
- Cybertelecom :: Customer Premises Equipment - FCC Regulations concerning attachment and marketing of CPE
- Timeline from NPR
- ArsTechnica: Any lawful device - 40 years after the Carterfone decision (includes picture of the Carterfone)
- Carterfone: My Story, by Nicholas Johnson, FCC Commissioner, 1966-73