Automatic Message Accounting
Encyclopedia
Automatic message accounting (AMA) provides detail billing for telephone calls. When direct distance dialing
(DDD) was introduced in the US, message registers no longer sufficed for dialed telephone calls. The need to record the time and phone number of each long distance call was met by electromechanical data processing equipment.
In centralized AMA (CAMA) the originating Class 5 telephone switches
used automatic number identification
(ANI) and multi-frequency
(MF) to send the originating and dialed phone numbers to the Class 4
toll connecting office. The Class 4 office had punched tape
machines to record this information on a long strip of paper the width of a hand. Each day a technician cut the paper tapes and sent them to the accounting center to be read and processed into phone bills. Each punch recorder was responsible for 100 trunks, and its associated call identity indexer (CII) identified the trunk for an initial entry on connecting the call, an answer entry when the called party
answered, and a disconnect entry when the call was cleared
.
In Bell System
exchanges (particularly 5XB switches) information from the marker
told the sender that the call required ANI, and stored the calling equipment number in reed relay
packs in the sender. The sender used the transverter connector (TVC) to seize a transverter (TV), which was a bay of a few hundred flat spring relays that controlled all AMA functions. TV looked in the AMA translator (AMAT) that took care of these particular few thousand lines. AMAT was a rack of ferrite ring cores with cross-connect wires passing through holes of 3 × 4 inches or about a decimeter square, one wire per line. The wire was terminated on a wire wrap
peg representing that particular line, and passed through a ring that represented the NNX digits of the billing number, then the M, C, D and finally Units of that number. When queried, AMAT sent a high-current pulse through the wire for that particular line, inducing pulses in the appropriate rings which were amplified by a cold cathode
tube amplifier and then by a relay, and sent back to the transverter which supplied it to the Sender for transmission by ANI to the tandem office.
In case of billing complaint, a test apparatus allowed scanning through all the lines in an office at the rate of about a hundred per minute, to find which ones were translated to a particular billing number.
In some electromechanical offices in the 1970s, the paper tape punch recorders were replaced by magnetic tape
recorders. Most punches remained in service until the exchange switch itself was replaced by more advanced systems. Stored program control exchange
s, having computers anyway, do not need separate AMA equipment. They sent magnetic tapes to the Accounting Center until approximately 1990, when data link
s took over this job.
BAF is administered by Telcordia Technologies
, with the Billing AMA Format Advisory Group (BAFAG) playing a central role in the overall approval and administration of BAF records. The BAFAG consists of subject matter experts and representatives from the Telcordia Consulting Services Business Group who review and authorize proposed BAF elements, as well as subject matter experts from AT&T, Qwest, and Verizon.
The BAFAG uses GR-1100, billing automatic message accounting format (BAF), as the document that defines the BAF recordings generated for call scenarios. It describes the possible groupings of BAF structures and modules that form BAF records, the connection between service/technology and call type, how call type and call conditions determine what structure and modules (if any) are selected for generation of a BAF record, and how the characteristics of the calling/called addresses as well as the services provided are factors in module generation.
es and similar exchanges installed in the early and middle 20th century. The metering pulse
s were generated in a junctor circuit, at a rate set by the sender, usually one pulse every few minutes. Every month a worker wrote down the indicated number of message units, similar to a gas meter
. In the middle 20th century it became customary to photograph the meters, about a hundred per film frame, for examination in comfort. Since they were only used on local calls, and most residential lines didn't pay for local calls, American message registers generally showed four digits.
Despite the arrival of STD
, Europe continued making and using message registers in the 1970s, designing ones that could register more than one click per second on a trunk call and display five or six digits.
Direct distance dialing
Direct distance dialing or direct dial is a telecommunications term for a network-provided service feature in which a call originator may, without operator assistance, call any other user outside the local calling area. DDD requires more digits in the number dialed than are required for calling...
(DDD) was introduced in the US, message registers no longer sufficed for dialed telephone calls. The need to record the time and phone number of each long distance call was met by electromechanical data processing equipment.
Centralized AMA
Class 5 telephone switches
A Class 5 telephone switch is a telephone switch or telephone exchange in the Public Switched Telephone Network located at the local telephone company's central office, directly serving subscribers. Class 5 switch services include basic dial-tone, calling features, and additional digital and data...
used automatic number identification
Automatic number identification
Automatic number identification is a feature of telephony intelligent network services that permits subscribers to display or capture the billing telephone number of a calling party. In the United States it is part of Inward Wide Area Telephone Service . ANI service was created by AT&T for...
(ANI) and multi-frequency
Multi-frequency
In telephony, multi-frequency signaling is an outdated, in-band signaling technique. Numbers were represented in a two-out-of-five code for transmission from a multi-frequency sender, to be received by a multi-frequency receiver in a distant telephone exchange...
(MF) to send the originating and dialed phone numbers to the Class 4
Class 4 telephone switch
A Class 4, or Tandem, telephone switch is a U.S. telephone company central office telephone exchange used to interconnect local exchange carrier offices for long distance communications in the Public Switched Telephone Network....
toll connecting office. The Class 4 office had punched tape
Punched tape
Punched tape or paper tape is an obsolete form of data storage, consisting of a long strip of paper in which holes are punched to store data...
machines to record this information on a long strip of paper the width of a hand. Each day a technician cut the paper tapes and sent them to the accounting center to be read and processed into phone bills. Each punch recorder was responsible for 100 trunks, and its associated call identity indexer (CII) identified the trunk for an initial entry on connecting the call, an answer entry when the called party
Called party
The called party is a person who answers a telephone call. The person who initiates a telephone call is the calling party....
answered, and a disconnect entry when the call was cleared
Clearing (telecommunications)
Clearing, in telecommunications means:* A sequence of events used to disconnect a call and return to the ready state. It is sometimes, particularly in the context of common channel signaling, called teardown....
.
In Bell System
Bell System
The Bell System was the American Bell Telephone Company and then, subsequently, AT&T led system which provided telephone services to much of the United States and Canada from 1877 to 1984, at various times as a monopoly. In 1984, the company was broken up into separate companies, by a U.S...
exchanges (particularly 5XB switches) information from the marker
Marker (telecommunications)
A marker is a type of special purpose control system that was used in electromechanical telephone central office switches. Central office switches are the large devices that telephone companies use to make the connections that support telephone calls...
told the sender that the call required ANI, and stored the calling equipment number in reed relay
Reed relay
A reed relay is a type of relay that uses an electromagnet to control one or more reed switches. The contacts are of magnetic material and the electromagnet acts directly on them without requiring an armature to move them...
packs in the sender. The sender used the transverter connector (TVC) to seize a transverter (TV), which was a bay of a few hundred flat spring relays that controlled all AMA functions. TV looked in the AMA translator (AMAT) that took care of these particular few thousand lines. AMAT was a rack of ferrite ring cores with cross-connect wires passing through holes of 3 × 4 inches or about a decimeter square, one wire per line. The wire was terminated on a wire wrap
Wire wrap
Wire wrap is a technology used to assemble electronics. It is a method to construct circuit boards without having to make a printed circuit board. Wires can be wrapped by hand or by machine, and can be hand-modified afterwards. It was popular for large-scale manufacturing in the 60s and early 70s,...
peg representing that particular line, and passed through a ring that represented the NNX digits of the billing number, then the M, C, D and finally Units of that number. When queried, AMAT sent a high-current pulse through the wire for that particular line, inducing pulses in the appropriate rings which were amplified by a cold cathode
Cold cathode
A cold cathode is a cathode used within nixie tubes, gas discharge lamps, discharge tubes, and some types of vacuum tube which is not electrically heated by the circuit to which it is connected...
tube amplifier and then by a relay, and sent back to the transverter which supplied it to the Sender for transmission by ANI to the tandem office.
In case of billing complaint, a test apparatus allowed scanning through all the lines in an office at the rate of about a hundred per minute, to find which ones were translated to a particular billing number.
Local AMA
In local AMA (LAMA) all this equipment was located at the Class 5 office. In this case, it also recorded the completion of local calls, thus obviating message registers. For detail billed calls, the punch recorded both calling and called numbers, as well as time of day. For message rate calls, only the calling number and time of day.In some electromechanical offices in the 1970s, the paper tape punch recorders were replaced by magnetic tape
Magnetic tape
Magnetic tape is a medium for magnetic recording, made of a thin magnetizable coating on a long, narrow strip of plastic. It was developed in Germany, based on magnetic wire recording. Devices that record and play back audio and video using magnetic tape are tape recorders and video tape recorders...
recorders. Most punches remained in service until the exchange switch itself was replaced by more advanced systems. Stored program control exchange
Stored Program Control exchange
Stored Program Control exchange is the technical name used for telephone exchanges controlled by a computer program stored in the memory of the system. Early exchanges such as Strowger, panel, rotary, and crossbar switches were electromechanical and had no software control...
s, having computers anyway, do not need separate AMA equipment. They sent magnetic tapes to the Accounting Center until approximately 1990, when data link
Data link
In telecommunication a data link is the means of connecting one location to another for the purpose of transmitting and receiving information. It can also refer to a set of electronics assemblies, consisting of a transmitter and a receiver and the interconnecting data telecommunication circuit...
s took over this job.
Billing automatic message format (BAF)
Around the same time period, the billing AMA format (BAF) was developed to support the full range of local exchange carrier services. BAF is now the preferred format for all AMA data generated for processing by a LEC Revenue Accounting Office (RAO). BAF supports the complete spectrum of services and technologies, including local and network interconnection services, operator services, toll-free services, Intelligent Network database services, wireline and wireless call recording, IP addressing, and broadband data services.BAF is administered by Telcordia Technologies
Telcordia Technologies
Telcordia Technologies, formerly Bell Communications Research, Inc. or Bellcore, is a telecommunications research and development company based in the United States created as part of the 1982 Modification of Final Judgment that broke up American Telephone & Telegraph...
, with the Billing AMA Format Advisory Group (BAFAG) playing a central role in the overall approval and administration of BAF records. The BAFAG consists of subject matter experts and representatives from the Telcordia Consulting Services Business Group who review and authorize proposed BAF elements, as well as subject matter experts from AT&T, Qwest, and Verizon.
The BAFAG uses GR-1100, billing automatic message accounting format (BAF), as the document that defines the BAF recordings generated for call scenarios. It describes the possible groupings of BAF structures and modules that form BAF records, the connection between service/technology and call type, how call type and call conditions determine what structure and modules (if any) are selected for generation of a BAF record, and how the characteristics of the calling/called addresses as well as the services provided are factors in module generation.
Message register
Electromechanical pulse counters counted "message units" for message rate service lines, in panel switchPanel switch
The panel switching system was an early type of automatic telephone exchange, first put into urban service by the Bell System in the 1920s and removed during the 1970s...
es and similar exchanges installed in the early and middle 20th century. The metering pulse
Metering pulse
In telecommunications signalling, metering pulses are signals sent by telephone exchanges to metering boxes and payphones aimed at informing the latter of the cost of ongoing telephone calls....
s were generated in a junctor circuit, at a rate set by the sender, usually one pulse every few minutes. Every month a worker wrote down the indicated number of message units, similar to a gas meter
Gas meter
A gas meter is used to measure the volume of fuel gases such as natural gas and propane. Gas meters are used at residential, commercial, and industrial buildings that consume fuel gas supplied by a gas utility. Gases are more difficult to measure than liquids, as measured volumes are highly...
. In the middle 20th century it became customary to photograph the meters, about a hundred per film frame, for examination in comfort. Since they were only used on local calls, and most residential lines didn't pay for local calls, American message registers generally showed four digits.
Despite the arrival of STD
Subscriber trunk dialling
Subscriber trunk dialling is a term for a telephone system allowing subscribers to dial trunk calls without operator assistance.- Terminology :...
, Europe continued making and using message registers in the 1970s, designing ones that could register more than one click per second on a trunk call and display five or six digits.