{"data":{"id":"us/47-cfr-appendix-to-part-36","jurisdiction":"us","citation":"47 CFR Appendix to Part 36","heading":"Appendix to Part 36—Glossary","body":"The descriptions of terms in this glossary are broad and have been prepared to assist in understanding the use of such terms in the separation procedures. Terms which are defined in the text of this part are not included in this glossary.\nAccess Line\nA communications facility extending from a customer's premises to a serving central office comprising a subscriber line and, if necessary, a trunk facility, e.g., a WATS access line.\nBook Cost\nThe cost of property as recorded on the books of a company.\nCable Fill Factor\nThe ratio of cable conductor or cable pair kilometers in use to total cable conductor or cable pair kilometers available in the plant, e.g., the ratio of revenue producing cable pair kilometers in use to total cable pair kilometers in plant.\nCategory\nA grouping of items of property or expense to facilitate the apportionment of their costs among the operations and to which, ordinarily, a common measure of use is applicable.\nCentral Office\nA switching unit, in a telephone system which provides service to the general public, having the necessary equipment and operations arrangements for terminating and interconnecting subscriber lines and trunks or trunks only. There may be more than one central office in a building.\nChannel\nAn electrical path suitable for the transmission of communications between two or more points, ordinarily between two or more stations or between channel terminations in Telecommunication Company central offices. A channel may be furnished by wire, fiberoptics, radio or a combination thereof.\nCircuit\nA fully operative communications path established in the normal circuit layout and currently used for message, WATS access, or private line services.\nCircuit Kilometers\nThe route kilometers or revenue producing circuits in service, determined by measuring the length in terms of kilometers, of the actual path followed by the transmission medium.\nCommon Channel Network Signaling\nChannels between switching offices used to transmit signaling information independent of the subscribers' communication paths or transmission channels.\nComplement (of cable)\nA group of conductors of the same general type (e.g., quadded, paired) within a single cable sheath.\nComplex\nAll groups of operator positions, wherever located, associated with the same call distribution and/or stored program control unit.\nConcentration Equipment\nCentral office equipment whose function is to concentrate traffic from subscriber lines onto a lesser number of circuits between the remotely located concentration equipment and the serving central office concentration equipment. This concentration equipment is connected to the serving central office line equipment.\nConnection—Minute\nThe product of (a) the number of messages and, (b) the average minutes of connection per message.\nConversation—Minute\nThe product of (a) the number of messages and, (b) the average minutes of conversation per message.\nConversation—Minute—Kilometers\nThe product of (a) the number of messages, (b) the average minutes of conversation per message and (c) the average route kilometers of circuits involved.\nCost\nThe cost of property owned by the Telephone Company whose property is to be apportioned among the operations. This term applies either to property costs recorded on the books of the company or property costs determined by other evaluation methods.\nCurrent Billing\nThe combined amount of charges billed, excluding arrears.\nCustomer Dialed Charge Traffic\nTraffic which is both (a) handled to completion through pulses generated by the customer and (b) for which either a message unit change, bulk charge or message toll charge is except for that traffic recorded by means of message registers.\nCustomer Premises Equipment\nItems of telecommunications terminal equipment in Accounts 2310 referred to as CPE in § 64.702 of the Federal Communication Commission's Rules adopted in the Second Computer Inquiry such as telephone instruments, data sets, dialers and other supplemental equipment, and PBX's which are provided by common carriers and located on customer premises and inventory included in these accounts to be used for such purposes. Excluded from this classification are similar items of equipment located on telephone company premises and used by the company in the normal course of business as well as over voltage protection equipment, customer premises wiring, coin operated public or pay telephones, multiplexing equipment to deliver multiple channels to the customer, mobile radio equipment and transmit earth stations.\nCustomer Premises Wire\nThe segment of wiring from the customer's side of the protector to the customer premises equipment.\nDSA Board\nA local dial office switchboard at which are handled assistance calls, intercepted calls and calls from miscellaneous lines and trunks. It may also be employed for handling certain toll calls.\nDSB Board\nA switchboard of a dial system for completing incoming calls received from manual offices.\nData Processing Equipment\nOffice equipment such as that using punched cards, punched tape, magnetic or other comparable storage media as an operating vehicle for recording and processing information. Includes machines for transcribing raw data into punched cards, etc., but does not include such items as key-operated, manually or electrically driven adding, calculating, bookkeeping or billing machines, typewriters or similar equipment.\nDial Switching Equipment\nSwitching equipment actuated by electrical impulses generated by a dial or key pulsing arrangement.\nEqual Access Costs\nInclude only initial incremental presubscription costs and initial incremental expenditures for hardware and software related directly to the provision of equal access which would not be required to upgrade the switching capabilities of the office involved absent the provisions of equal access.\nEquivalent Gauge\nA standard cross section of cable conductors for use in equating the metallic content of cable conductors of all gauge to a common base.\nEquivalent Kilometers of 104 Wire\nThe basic units employed in the allocation of pole lines costs for determining the relative use made of poles by aerial cables and by aerial wire conductors of various sizes. This unit reflects the relative loads of such cable and wire carried on poles.\nEquivalent Pair Kilometers\nThe product of sheath Kilometers and the number of equivalent gauge pairs of conductors in a cable.\nEquivalent Sheath Kilometers\nThe product of (a) the length of a section of cable in kilometers (sheath kilometers) and (b) the ratio of the metallic content applicable to a particular group of conductors in the cable (e.g., conductors assigned to a category) to the metallic content of all conductors in the cable.\nExchange Transmission Plant\nThis is a combination of (a) exchange cable and wire facilities (b) exchange central office circuit equipment, including associated land and buildings and (c) information origination/termination equipment which forms a complete channel.\nHolding Time\nThe time in which an item of telephone plant is in actual use either by a customer or an operator. For example, on a completed telephone call, holding time includes conversation time as well as other time in use. At local dial offices any measured minutes which result from other than customer attempts to place calls (as evidenced by the dialing of at least one digit) are not treated as holding time.\nHost Central Office\nAn electronic analog or digital base switching unit containing the central call processing functions which service the host office and its remote locations.\nInformation Origination/Termination Equipment\nEquipment used to input into or receive output from the telecommunications network.\nInterexchange Channel\nA circuit which is included in the interexchange transmission equipment.\nInterexchange Transmission Equipment\nThe combination of (a) interexchange cable and wire facilities, (b) interexchange circuit equipment and, (c) associated land and buildings.\nInterlocal Trunk\nA circuit between two local central office units, either manual or dial. Interlocal trunks may be used for either exchange or toll traffic or both.\nIntertoll Circuits\nCircuits between toll centers and circuits between a toll center and a tandem system in a different toll center area.\nLocal Channel\nThe portion of a private line circuit which is included in the exchange transmission plant. However, common usage of this term usually excludes information origination/termination equipment.\nLocal Office\nA central office serving primarily as a place of termination for subscriber lines and for providing telephone service to the subscribers on these lines.\nLoop\nA pair of wires, or its equivalent, between a customer's station and the central office from which the station is served.\nMessage\nA completed call, i.e., a communication in which a conversation or exchange of information took place between the calling and called parties.\nMessage Service or Message Toll Service\nSwitched service furnished to the general public (as distinguished from private line service). Except as otherwise provided, this includes exchange switched services and all switched services provided by interexchange carriers and completed by a local telephone company's access services, e.g., MTS, WATS, Execunet, open-end FX and CCSA/ONALs.\nMessage Units\nUnit of measurement used for charging for measured message telephone exchange traffic within a specified area.\nMetropolitan Service Area\nThe area around and including a relatively large city and in which substantially all of the message telephone traffic between the city and the suburban points within the area is classified as exchange in one or both directions.\nMinutes-of-Use\nA unit of measurement expressed as either holding time or conversation time.\nMinutes-of-Use-Kilometers\nThe product of (a) the number of minutes-of-use and (b) the average route kilometers of circuits involved.\nMulti-Center Exchange\nAn exchange area in which are located two or more local central office buildings or wire centers.\nOperations\nThe term denoting the general classifications of services rendered to the public for which separate tariffs are filed, namely exchange, state toll and interstate toll.\nOperator Trunks\nA general term, ordinarily applied to trunks between manually operated switchboard positions and local dial central offices in the same wire center.\nPrivate Line Service\nA service for communications between specified locations for a continuous period or for regularly recurring periods at stated hours.\nRemote Access Line\nAn access line (e.g., for WATS service) between a subscriber's premises in one toll rate center and a serving central office located in a different toll rate center.\nRemote Line Location\nA remotely located subscriber line access unit which is normally dependent upon the central processor of the host office for call processing functions.\nRemote Trunk Arrangement (RTA)\nArrangement that permits the extension of TSPS functions to remote locations.\nReservation\nThat amount or quantity of property kept or set apart for a specific use.\nReserved\nKept or set apart for a specific use.\nSeparations\nThe process by which telecommunication property costs, revenues, expenses, taxes and reserves are apportioned among the operations.\nService Observing Unit\nA unit of work measurement which is used as the common denominator to express the relative time required for handling the various work functions at service observing boards.\nSheath Kilometers\nThe actual length of cable in route kilometers.\nSpecial Services\nAll services other than message telephones, e.g., private line services.\nStation-to-Station Basis\nThe term applied to the basis of toll rate making which contemplates that the message toll service charge (telephone) covers the use made of all facilities between the originating station and the terminating station, including the stations, and the services rendered in connection therewith.\nStudy Area\nStudy area boundaries shall be frozen as they are on November 15, 1984.\nSubscriber Line or Exchange Line\nA communication channel between a telephone station or PBX station and the central office which serves it.\nSubtributary Office\nA class of tributary office which does not have direct access to its toll center, but which is connected to its toll center office by means of circuits which are switched through to the toll center at another tributary office.\nTandem Area\nThe general areas served by the local offices having direct trunks to or from the tandem office. This area may consist of one or more communities or may include only a portion of a relatively large city.\nTandem Circuit or Trunk\nA general classification of circuits or trunks between a tandem central office unit and any other central office or switchboard.\nTandem Connection\nA call switched at a tandem office.\nTandem Office\nA central office unit used primarily as an intermediate switching point for traffic between local central offices within the tandem area. Where qualified by a modifying expression, or other explanation, this term may be applied to an office employed for both the interconnection of local central offices within the tandem area and for the interconnection of these local offices with other central offices, e.g., long haul tandem office.\nToll Center\nAn office (or group of offices) within a city which generally handles the originating and incoming toll traffic for that city to or from other toll center areas and which handles through switched traffic. The toll center normally handles the inward toll traffic for its tributary exchanges and, in general, either handles the outward traffic originating at its tributaries or serves as the outlet to interexchange circuits for outward traffic ticketed and timed at its tributaries. Toll centers are listed as such in the Toll Rate and Route Guide.\nToll Center Area\nThe areas served by a toll center, including the toll center city and the communities served by tributaries of the toll center.\nToll Center Toll Office\nA toll office (as contrasted to a local office) in a toll center city.\nToll Circuit\nA general term applied to interexchange trunks used primarily for toll traffic.\nToll Connecting Trunk\nA general classification of trunks carrying toll traffic and ordinarily extending between a local office and a toll office, except trunks classified as tributary circuits. Examples of toll connecting trunks include toll switching trunks, recording trunks and recording-completing trunks.\nToll Office\nA central office used primarily for supervising and switching toll traffic.\nTraffic Over First Routes\nA term applied to the routing of traffic and denoting routing via principal route for traffic between any two points as distinguished from alternate routes for such traffic.\nOperator System\nA stored program electronic system associated with one or more toll switching systems which provides centralized traffic service position functions for several local offices at one location.\nTributary Circuit\nA circuit between a tributary office and a toll switchboard or intertoll dialing equipment in a toll center city.\nTributary Office\nA local office which is located outside the exchange in which a toll center is located, which has a different rate center from its toll center and which usually tickets and times only a part of its originating toll traffic, but which may ticket or time all or none, of such traffic. The toll center handles all outward traffic not ticketed and timed at the tributary and normally switches all inward toll traffic from outside the tributary's toll center to the tributary. Tributary offices are indicated as such in the Toll Rate and Route Guide.\nTrunks\nCircuit between switchboards or other switching equipment, as distinguished from circuits which extend between central office switching equipment and information origination/termination equipment.\nTSPS Complex\nAll groups of operator positions, wherever located, associated with the same TSPS stored program control units.\nWeighted Standard Work Second\nA measurement of traffic operating work which is used to express the relative time required to handle the various kinds of calls or work functions, and which is weighted to reflect appropriate degrees of waiting to serve time.\nWide Area Telephone Service WATS\nA toll service offering for customer dial type telecommunications between a given customer station and stations within specified geographic rate areas employing a single access line between the customer location and the serving central office. Each access line may be arranged for either outward (OUT-WATS) or inward (IN-WATS) service or both.\nWideband Channel\nA communication channel of a bandwidth equivalent to twelve or more voice grade channels.\nWorking Loop\nA revenue producing pair of wires, or its equivalent, between a customer's station and the central office from which the station is served.","path":["Title 47—Telecommunication","CHAPTER I—FEDERAL COMMUNICATIONS COMMISSION","SUBCHAPTER B—COMMON CARRIER SERVICES","PART 36—JURISDICTIONAL SEPARATIONS PROCEDURES; STANDARD PROCEDURES FOR SEPARATING TELECOMMUNICATIONS PROPERTY COSTS, REVENUES, EXPENSES, TAXES AND RESERVES FOR TELECOMMUNICATIONS COMPANIES 1"],"source_url":"https://www.ecfr.gov/api/versioner/v1/full/2026-08-25/title-47.xml","current_through":"2026-08-25","vintage":"","retrieved_at":"2026-08-27T02:26:28Z","sha256":"7d4cdc2b6bbd8d114bbb6ea465f8bd1be3669be52fc1b75b028adb168823e153","source_id":"us-cfr","stale":true,"prev":"us/47-cfr-36.507","next":"us/47-cfr-42.01"},"notice":"GroundRules: Original legal text. Not legal advice."}