
			Telephone Terminolgy
	              Written by Elric of Imrryr
		        Lunatic Labs UnLimited

A & A BUREAU:   Abuse & Annoyance Bureau. The personal in this line of
work spend their time helping customers get rid of nuts, obscene callers,
harassing collectors, etc.
 
ACCESS:         The existence of paths within a network from an input terminal
to a set of output terminals in the absence of traffic is indicated by the
term, ACCESS. Full access permits
connecting to all output terminals by unique paths; multiple access indicates
that all output terminals can be reached in more than one way; partial access
refers to the ability to reach only a fraction of the output terminals
 
ACCESSIBILITY--(availability):  The number of trunks of the required route
in a switching network which can be reached from an inlet.
 
ADAPTOR:        A device designed to switch a number of voice-frequency
telephone channels coming from a non-time-division switching system to a
time-division multiplex highway.
 
ALIASING:       The occurrence of spurious frequencies in the output of a
PCM system that were not present in the input, due to foldover of higher
frequencies.
 
ALTERNATE ROUTING:      A procedure by which several routes involve different
switching stages or networks. Usually the route having the fewest switching
stages is tested first.
 
ANALOG TRANSMISSION:    The transmission of continuously variable signals
rather than descretely variable signals. Prior to the use of digital encoding
and PCM, it was the only way of
transmitting voice signals over telephone channels
 
ASYNCHRONOUS SYSTEM:    A system in which the transmission of each
information character is individually synchronized usually by the use of
start and stop elements.
 
AUTOVON:	AUTOmatic VOice Network
 
AVERAGE HOLDING TIME:   The average duration of a call expressed in seconds
or minutes.
 
BIT:    The smallest binary unit of information. A contraction of the word
binary digit.
 
BIT RATE:       The rate or speed at which bits are transmitted. Bits per
second is a common measure.
 
BLOCKING (CONGESTION):  A condition where the immediate establishment of a
new connection is impossible due to the lack of available paths, or the
inability to interconnect two idle network terminals because some of the
applicable links between them are used for other connections.
 
BORSCHT:        An acronym for the functions that must be performed in the
CO when digital voice transmission occurs: Battery, Overvoltage, Ringing,
Supervision, Coding, Hybrid, and Test
 
Business Office Supervisor (BOS):The boss of the service representatives
 
BROADBAND EXCHANGE (BEX):       Public switched communication system featuring
full duplex (FDX) connections of various bandwidths. A Western Union facility.
 
BUSINESS SERVICE INSTRUCTOR (BSI):      A traffic employee who will come out
and teach you how to use your phone system.
 
BUSY HOUR:      An uninterrupted period of 60 minutes in which the total
traffic of a sample is maximum.
 
BYTE:   A unit of information in electronic computer terminology
consisting of 8 bits, referred to as extended binary coded decimal
information of an EBCDIC code.
 
CALL CONGESTION RATIO:  The ratio of the time during which congestion exists
to the total time considered. It is an estimate of the probability that an
external observer will find a system in
a congested condition.
 
CALLING RATE:   Average calls per subscriber per hour.
 
CALL STORE:     The memory section of a stored program control switching system
in which temporary information used in the processing of calls through the
exchange is contained. It is also referred to as the Process Store.
 
CELL:   In cellular mobile telephony, the geographic area served by one
transmitter. Subscribers may move from cell to cell.
 
CENTRAL OFFICE: Exchanges where subscriber lines and PBX lines
terminate. There they are switched to provided the "desired" connection with
other subscribers. Such an exchange is called an end office and is designated
as a Class 5 office in the U.S.
 
CENTRAL OFFICE SWITCH:  (CO SW) This term is used to describe a connection
point which gives access to the DDD network.
 
CENTRAL PROCESSOR:      The main computer element of a stored program
control switching system, which under the direction of the stored program
establishes switching network
connections and also monitors and analyzes the system to insure proper
operation. Routine process testing, maintenance and administrative funtions
are also carried out.
 
CENTREX:        A PBX system in which the switching equipment is located
centrally and away from the location being served. Direct inward dialing
(DID) and direct outward dialing (DOD)
as well as automatic number identification (ANI) are provided by
such a system.
 
CHANNEL:        An electronic commications path, usually of 4,000 Hz (voice) bandwidth.
 
COMMON BATTERY: A system of supplying direct current for the telephone set
from the central office.
 
CONCENTRATORS:  Equipment used to connect a large number of path, for
example:
        ANSWERING SERVICE CONCENTRATORS: Equipment provided in local central
        offices which, together with identifying equipment at the answering
        service location makes it possible to answer a large number of
        customer lines on a few pairs
 
CROSSBAR SWITCH:An electromechanical switching machine utilizing a relay
mechanism with horizontal and vertical input lines (usually 10 by 20), using
a contact matrix to connect any vertical to any horizontal.
 
CROSSPOINT:     The element that actually performs the switching
functions in a telephone system. May be mechanical using metal contacts, or
solid-state using integrated circuits.
 
CUSTOMER:The person, firm, or corporation which orders service and is
reponsible for the payment of charges and compliance with Telephone Company
regulations.
 
CUSTOMER-PROVIDED EQUIPMENT (CPE):      This includes any equipment provided by
the customer and connecting to the Telephone Company facilities. This
equipment may be customer-provided and maintained (CPM) or customer-provided
and telephone maintained (CPT).
 
CUT-OFF FREQUENCY: The frequency above or below which signals are blocked by a
circuit or network.
 
DATA SET:       Telephone company term for a modem.
 
DIAL PULSING:   A system of dc pulsing in which the digits are transmitted by
the interruption of the dc circuit a number of times, one to ten
interruptions corresponding 
 
DIAL TONE:A tone used in dial telephone systems to indicate that the equipment
is ready for the dialing operation. This tone is 600Hz modulated by 120Hz when
 supplied by a tone alternator of 133Hz when supplied by an interrupter. The
modulating frequency gives this tone its low-pitched sound. Interrupted low
tone is used for line busy reorder, and no ciruit tone signals reached by the
customer
 
DIRECT DISTANCE DIAL (DDD) NETWORK:     All Bell and Independent Telephone
Company equipment and facilities used to permit customers to dial their own
long distance (toll) calls.
 
DTMF:   Dual-Tone-Multi-Frequency; Use of two simultaneous voice-bandsb tones
for dialing.
 
ESS:    Electronic Switching System; A telephone switching machine using
electronics, often combined with electromechanical crosspoints, and
usually with a stored-program computer
as the control element.
 
EXCHANGE AREA:  The territory within which telephone service is provided
without extra charge. Also calling Local Calling Area or just Exchange.
 
JUMPER: Two wires (a pair) twisted together and used on the frame to
connect equipment and cables which provide customer service.
 
LINE:   Any type of circuit terminated in a telephone or equivalent at one end
and a switching machine at the other end.
 
LINESIDE:       Refers to the portion of the central office that connects to
the local loop.
 
LOADED CABLE:	Cable designed with LOAD POTS at designated intervals to
balence tranmission characteristics of the voice frequencies, 300 to 3200 Hz.

LOAD POTS (LOAD COILS): Load Poits are indutance coils arranged at designed
intervals to balence transmission characteristics of the voice frequen-
cies 300 to 3200Hz.
 
LOCAL CHANNEL:  The local Channel is the cable, or the outside wire, used to
connect the serving CO to the customer location
 
LOCAL LOOP:The voice-band channel connecting the subscriber to the
central office
 
LOSS:	The decrease in energy, expressed in dB, between two points in a
circuit.

MESSAGE TELEPHONE SERVICE (MTS):        The official name for long distance or
toll service.
 
NON-LOADED CABLE (NL):  Cable without LOAD POTS to balence the transmission
characteri
 
OFF-HOOK:       The condition that indicates the active state of a
customer telephone circuit. The opposite condition is On-Hook.
 
On-Hook:	The condition that indicates the idle state (loop open) of

a station line on other circuit.

PABX or PBX:    A private (automatic) branch telephone exchange system
providing telephone switching in an office or building.
 
PADS:	A resistance network of value needed to introduce a specific
transmission loss.

Protector:	A device used to prevent damage to lines or equipment by
dangerously high voltages or currents. The device may be a sparkgap, varistor,
thermistor, etc. The device usually has a very high resistance to ground until
the presence of an abnormal voltage or current causes the resistance to
decrease. The device will then conduct and eliminate thhe dangerous condition.

PULSE CODE MODULATION:  (PCM) A communication system technique of
 coding signals with binary codes to carry informations.
 
RADIO COMMON CARRIER:   (RCC) A company that provides mobile telephone service,
but is not a telephone company.
 
Repeat Coil:	Two or more windings, each magnetically coupled to all other
windings.
	Used for impedance matching facilities and equipment, simplexing and
isolation. In signaling equipment repeat coils are used to pass VF(ac) while
blocking dc.

Repeater:	An electronic device used on long circuits to amplify voice
signals and/or repeat supervision, (D.C.) signals. (One of those often seen
on telepone poles.

RING:   The alerting signal to the subscriber or terminal equipment; the
name for one conductor of a wire pair, designated by R.
 
Station (STA):	Denotes transmitting and/or receiving equipment at any
location on a customer's premises.

SUBSCRIBER LINE INTERFACE CIRCUIT:      (SLIC) In digital transmission of voice
, the circuit which performs some or all of the interface functions at the
central office. See BORSCHT.
 
TIE PAIRS:	TIE PAIRS are terminations on a frame block which will
provide connections between frames. These connections are a wire path from
one piece of equipment to another. Their only purpose is to tie equipment that
is not located on the same frame or floor together. TIE PAIRS function as an
extension cord.

TOLL CALL:	Any call for a destination outside of the local service
area of the calling station.

TRUNK CABLE:	Trunk Cable, sometimes called Exchange Cable, is used to
connect one central office to another. Trunk Cable is inventoried in the
Facility System therefore the assignments are on the Circuit Layout
Record (CLR).

