§ 51.319 Specific unbundling requirements. ( a ) *Local loops.* An incumbent LEC shall provide a requesting telecommunications carrier with nondiscriminatory access to the local loop on an unbundled basis, in accordance with section 251(c)(3) of the Act and this part and as set forth in paragraphs (a)(1) through (8) of this section. The local loop network element is defined as a transmission facility between a distribution frame (or its equivalent) in an incumbent LEC central office and the loop demarcation point at an end-user customer premises. This element includes all features, functions, and capabilities of such transmission facility, including the network interface device. It also includes all electronics, optronics, and intermediate devices (including repeaters and load coils) used to establish the transmission path to the end-user customer premises as well as any inside wire owned or controlled by the incumbent LEC that is part of that transmission path. ( 1 ) *Copper loops.* An incumbent LEC shall provide a requesting telecommunications carrier with nondiscriminatory access to the copper on an unbundled basis in census blocks defined as rural or urban cluster by the Census Bureau. A copper loop is a stand-alone local loop comprised entirely of copper wire or cable. For purposes of this section, copper loops include only digital copper loops (*e.g.,* DS0s and integrated services digital network lines) as well as two-wire and four-wire copper loops conditioned to transmit the digital signals needed to provide digital subscriber line services, regardless of whether the copper loops are in service or held as spares. The copper loop does not include packet switching capabilities as defined in paragraph (a)(2)(i) of this section. The availability of DS1 and DS3 copper loops is subject to the requirements of paragraphs (a)(4) and (5) of this section. ( i ) *Line splitting.* An incumbent LEC shall provide a requesting telecommunications carrier that obtains an unbundled copper loop from the incumbent LEC with the ability to engage in line splitting arrangements with another competitive LEC using a splitter collocated at the central office where the loop terminates into a distribution frame or its equivalent. Line splitting is the process in which one competitive LEC provides narrowband voice service over the low frequency portion of a copper loop and a second competitive LEC provides digital subscriber line service over the high frequency portion of that same loop. The high frequency portion of the loop consists of the frequency range on the copper loop above the range that carries analog circuit-switched voice transmissions. This portion of the loop includes the features, functions, and capabilities of the loop that are used to establish a complete transmission path on the high frequency range between the incumbent LEC's distribution frame (or its equivalent) in its central office and the demarcation point at the end-user customer premises, and includes the high frequency portion of any inside wire owned or controlled by the incumbent LEC. ( A ) An incumbent LEC's obligation, under paragraph (a)(1)(i) of this section, to provide a requesting telecommunications carrier with the ability to engage in line splitting applies regardless of whether the carrier providing voice service provides its own switching or obtains local circuit switching from the incumbent LEC.
( B ) An incumbent LEC must make all necessary network modifications, including providing nondiscriminatory access to operations support systems necessary for pre-ordering, ordering, provisioning, maintenance and repair, and billing for loops used in line splitting arrangements.
( ii ) *Line conditioning.* The incumbent LEC shall condition a copper loop at the request of the carrier seeking access to a copper loop under paragraph (a)(1) of this section or a copper subloop under paragraph (b) of this section to ensure that the copper loop or copper subloop is suitable for providing digital subscriber line services, whether or not the incumbent LEC offers advanced services to the end-user customer on that copper loop or copper subloop. If the incumbent LEC seeks compensation from the requesting telecommunications carrier for line conditioning, the requesting telecommunications carrier has the option of refusing, in whole or in part, to have the line conditioned; and a requesting telecommunications carrier's refusal of some or all aspects of line conditioning will not diminish any right it may have, under paragraphs (a) and (b) of this section, to access the copper loop or the copper subloop. ( A ) Line conditioning is defined as the removal from a copper loop or copper subloop of any device that could diminish the capability of the loop or subloop to deliver high-speed switched wireline telecommunications capability, including digital subscriber line service. Such devices include, but are not limited to, bridge taps, load coils, low pass filters, and range extenders.
( B ) Incumbent LECs shall recover the costs of line conditioning from the requesting telecommunications carrier in accordance with the Commission's forward-looking pricing principles promulgated pursuant to section 252(d)(1) of the Act and in compliance with rules governing nonrecurring costs in § 51.507(e).
( C ) Insofar as it is technically feasible, the incumbent LEC shall test and report troubles for all the features, functions, and capabilities of conditioned copper lines, and may not restrict its testing to voice transmission only.
( iii ) *Maintenance, repair, and testing.* ( A ) An incumbent LEC shall provide, on a nondiscriminatory basis, physical loop test access points to a requesting telecommunications carrier at the splitter, through a cross-connection to the requesting telecommunications carrier's collocation space, or through a standardized interface, such as an intermediate distribution frame or a test access server, for the purpose of testing, maintaining, and repairing copper loops and copper subloops.
( B ) An incumbent LEC seeking to utilize an alternative physical access methodology may request approval to do so from the state commission, but must show that the proposed alternative method is reasonable and nondiscriminatory, and will not disadvantage a requesting telecommunications carrier's ability to perform loop or service testing, maintenance, or repair.
( iv ) *Control of the loop and splitter functionality.* In situations where a requesting telecommunications carrier is obtaining access to the high frequency portion of a copper loop through a line splitting arrangement, the incumbent LEC may maintain control over the loop and splitter equipment and functions, and shall provide to the requesting telecommunications carrier loop and splitter functionality that is compatible with any transmission technology that the requesting telecommunications carrier seeks to deploy using the high frequency portion of the loop, as defined in paragraph (a)(1)(i) of this section, provided that such transmission technology is presumed to be deployable pursuant to § 51.230.
( v ) *Transition period for narrowband loops.* Notwithstanding any other provision of the Commission's rules in this part, an incumbent LEC shall continue to provide a requesting telecommunications carrier with nondiscriminatory access to two-wire and four-wire analog voice grade copper loops, the TDM-features, functions, and capabilities of hybrid loops, or to a 64 kilobits per second transmission path capable of voice grade service over the fiber-to-the-home loop or fiber-to-the-curb loop for 36 months until February 8, 2024, provided such loop was being provided before February 8, 2021.
( vi ) *Transition period for digital copper loops and two-wire and four-wire copper loops conditioned to transmit digital signals.* Notwithstanding the remainder of paragraph (a)(1) of this section, an incumbent LEC shall continue to provide a requesting telecommunications carrier with nondiscriminatory access to copper loops as defined in this section for 48 months until February 10, 2025, provided that the incumbent LEC began providing such loop no later than February 8, 2023. Incumbent LECs may raise the rates charged for such loops by no more than 25 percent during months 37 to 48 of this transition period and may charge market-based rates after month 48.
( 2 ) *Hybrid loops.* A hybrid loop is a local loop composed of both fiber optic cable, usually in the feeder plant, and copper wire or cable, usually in the distribution plant. ( i ) *Packet switching facilities, features, functions, and capabilities.* An incumbent LEC is not required to provide unbundled access to the packet switched features, functions and capabilities of its hybrid loops. Packet switching capability is the routing or forwarding of packets, frames, cells, or other data units based on address or other routing information contained in the packets, frames, cells or other data units, and the functions that are performed by the digital subscriber line access multiplexers, including but not limited to the ability to terminate an end-user customer's copper loop (which includes both a low-band voice channel and a high-band data channel, or solely a data channel); the ability to forward the voice channels, if present, to a circuit switch or multiple circuit switches; the ability to extract data units from the data channels on the loops; and the ability to combine data units from multiple loops onto one or more trunks connecting to a packet switch or packet switches.
( ii ) [Reserved]
( 3 ) *Fiber loops* — ( i ) *Definitions* — ( A ) *Fiber-to-the-home loops.* A fiber-to-the-home loop is a local loop consisting entirely of fiber optic cable, whether dark or lit, serving an end user's customer premises or, in the case of predominantly residential multiple dwelling units (MDUs), a fiber optic cable, whether dark or lit, that extends to the multiunit premises' minimum point of entry (MPOE).
( B ) *Fiber-to-the-curb loops.* A fiber-to-the-curb loop is a local loop consisting of fiber optic cable connecting to a copper distribution plant that is not more than 500 feet from the customer's premises or, in the case of predominantly residential MDUs, not more than 500 feet from the MDU's MPOE. The fiber optic cable in a fiber-to-the-curb loop must connect to a copper distribution plant at a serving area interface from which every other copper distribution subloop also is not more than 500 feet from the respective customer's premises.
( ii ) *New builds.* An incumbent LEC is not required to provide nondiscriminatory access to a fiber-to-the-home loop or a fiber-to-the-curb loop on an unbundled basis when the incumbent LEC deploys such a loop to an end user's customer premises that previously has not been served by any loop facility.
( iii ) *Overbuilds.* An incumbent LEC is not required to provide nondiscriminatory access to a fiber-to-the-home loop or a fiber-to-the-curb loop on an unbundled basis when the incumbent LEC has deployed such a loop parallel to, or in replacement of, an existing copper loop facility, except that: ( A ) The incumbent LEC must maintain the existing copper loop connected to the particular customer premises after deploying the fiber-to-the-home loop or the fiber-to-the-curb loop and provide nondiscriminatory access to that copper loop on an unbundled basis unless the incumbent LEC retires the copper loops pursuant to paragraph (a)(3)(iv) of this section.
( B ) An incumbent LEC that maintains the existing copper loops pursuant to paragraph (a)(3)(iii)(A) of this section need not incur any expenses to ensure that the existing copper loop remains capable of transmitting signals prior to receiving a request for access pursuant to that paragraph, in which case the incumbent LEC shall restore the copper loop to serviceable condition upon request.
( iv ) *Retirement of copper loops or copper subloops.* Prior to retiring any copper loop or copper subloop that has been replaced with a fiber-to-the-home loop or a fiber-to-the-curb loop, an incumbent LEC must comply with: ( A ) The network disclosure requirements set forth in section 251(c)(5) of the Act and in § 51.325 through § 51.335; and
( B ) Any applicable state requirements.
( 4 ) *DS1 loops.* ( i ) *Availability of DS1 loops.* ( A ) Subject to the cap described in paragraph (a)(4)(ii) of this section, an incumbent LEC shall provide a requesting telecommunications carrier with nondiscriminatory access to a DS1 loop on an unbundled basis to any building not served by a wire center with at least 60,000 business lines and at least four fiber-based collocators, but only if that building is located in: ( 1 ) Any county or portion of a county served by a price cap incumbent LEC that is not included on the list of counties that have been deemed competitive pursuant to the competitive market test established under § 69.803 of this chapter; or
( 2 ) Any study area served by a rate-of-return incumbent LEC provided that study area is not included on the list of competitive study areas pursuant to the competitive market test established under § 61.50 of this chapter.
( B ) Once a wire center exceeds both the business line and fiber-based collocator thresholds, no future DS1 loop unbundling will be required in that wire center. A DS1 loop is a digital local loop having a total digital signal speed of 1.544 megabytes per second. DS1 loops include, but are not limited to, two-wire and four-wire copper loops capable of providing high-bit rate digital subscriber line services, including T1 services.
( ii ) *Cap on unbundled DS1 loop circuits.* A requesting telecommunications carrier may obtain a maximum of ten unbundled DS1 loops to any single building in which DS1 loops are available as unbundled loops.
( iii ) *Transition period.* Notwithstanding paragraph (a)(4)(i) of this section, an incumbent LEC shall continue to provide a requesting telecommunications carrier with nondiscriminatory access to DS1 loops for 42 months until August 8, 2024, provided the incumbent LEC began providing such loop no later than February 8, 2023.
( 5 ) *DS3 loops.* ( i ) Availability of DS3 loops. ( A ) Subject to the cap described in paragraph (a)(5)(ii) of this section, an incumbent LEC shall provide a requesting telecommunications carrier with nondiscriminatory access to a DS3 loop on an unbundled basis to any building not served by a wire center with at least 38,000 business lines and at least four fiber-based collocators, but only if that building is located in one of the following: ( 1 ) Any county or portion of a county served by a price cap incumbent LEC that is not included on the list of counties that have been deemed competitive pursuant to the competitive market test established under § 69.803 of this chapter; or
( 2 ) Any study area served by a rate-of-return incumbent LEC provided that study area is not included on the list of competitive study areas pursuant to the competitive market test established under § 61.50 of this chapter.
( B ) Once a wire center exceeds the business line and fiber-based collocator thresholds, no future DS3 loop unbundling will be required in that wire center. A DS3 loop is a digital local loop having a total digital signal speed of 44.736 megabytes per second.
( ii ) *Cap on unbundled DS3 loop circuits.* A requesting telecommunications carrier may obtain a maximum of a single unbundled DS3 loop to any single building in which DS3 loops are available as unbundled loops.
( iii ) *Transition period.* Notwithstanding paragraph (a)(5)(i) of this section, an incumbent LEC shall continue to provide a requesting telecommunications carrier with nondiscriminatory access to DS3 loops for 36 months after until February 8, 2024, provided such loop was being provided before February 8, 2021.
( 6 ) *Dark fiber loops.* An incumbent LEC is not required to provide requesting telecommunications carriers with access to a dark fiber loop on an unbundled basis. Dark fiber is fiber within an existing fiber optic cable that has not yet been activated through optronics to render it capable of carrying communications services.
( 7 ) *Routine network modifications.* ( i ) An incumbent LEC shall make all routine network modifications to unbundled loop facilities used by requesting telecommunications carriers where the requested loop facility has already been constructed. An incumbent LEC shall perform these routine network modifications to unbundled loop facilities in a nondiscriminatory fashion, without regard to whether the loop facility being accessed was constructed on behalf, or in accordance with the specifications, of any carrier.
( ii ) A routine network modification is an activity that the incumbent LEC regularly undertakes for its own customers. Routine network modifications include, but are not limited to, rearranging or splicing of cable; adding an equipment case; adding a doubler or repeater; adding a smart jack; installing a repeater shelf; adding a line card; deploying a new multiplexer or reconfiguring an existing multiplexer; and attaching electronic and other equipment that the incumbent LEC ordinarily attaches to a DS1 loop to activate such loop for its own customer. Routine network modifications may entail activities such as accessing manholes, deploying bucket trucks to reach aerial cable, and installing equipment casings. Routine network modifications do not include the construction of a new loop, or the installation of new aerial or buried cable for a requesting telecommunications carrier.
( 8 ) *Engineering policies, practices, and procedures.* An incumbent LEC shall not engineer the transmission capabilities of its network in a manner, or engage in any policy, practice, or procedure, that disrupts or degrades access to a local loop or subloop, including the time division multiplexing-based features, functions, and capabilities of a hybrid loop, for which a requesting telecommunications carrier may obtain or has obtained access pursuant to paragraph (a) of this section.
( b ) *Subloops and network interface devices.* An incumbent LEC shall provide a requesting telecommunications carrier with nondiscriminatory access to subloops on an unbundled basis in accordance with section 251(c)(3) of the Act and this part and as set forth in this paragraph (b), provided that the underlying loop is available as set forth in paragraph (a) of this section. Notwithstanding any other provision of the Commission's rules in this part, an incumbent LEC shall continue to provide a requesting telecommunications carrier with nondiscriminatory access to the subloop for access to multiunit premises wiring and network interface devices on an unbundled basis for 36 months until February 8, 2024, provided such subloop or network interface device was being provided before February 8, 2021. ( 1 ) *Copper subloops.* An incumbent LEC shall provide a requesting telecommunications carrier with nondiscriminatory access to a copper subloop on an unbundled basis. A copper subloop is a portion of a copper loop, or hybrid loop, comprised entirely of copper wire or copper cable that acts as a transmission facility between any point of technically feasible access in an incumbent LEC's outside plant, including inside wire owned or controlled by the incumbent LEC, and the end-user customer premises. A copper subloop includes all intermediate devices (including repeaters and load coils) used to establish a transmission path between a point of technically feasible access and the demarcation point at the end-user customer premises, and includes the features, functions, and capabilities of the copper loop. Copper subloops include two-wire and four-wire analog voice-grade subloops as well as two-wire and four-wire subloops conditioned to transmit the digital signals needed to provide digital subscriber line services, regardless of whether the subloops are in service or held as spares. ( i ) *Point of technically feasible access.* A point of technically feasible access is any point in the incumbent LEC's outside plant where a technician can access the copper wire within a cable without removing a splice case. Such points include, but are not limited to, a pole or pedestal, the serving area interface, the network interface device, the minimum point of entry, any remote terminal, and the feeder/distribution interface. An incumbent LEC shall, upon a site-specific request, provide access to a copper subloop at a splice near a remote terminal. The incumbent LEC shall be compensated for providing this access in accordance with §§ 51.501 through 51.515.
( ii ) *Rules for collocation.* Access to the copper subloop is subject to the Commission's collocation rules at §§ 51.321 and 51.323.
( 2 ) [Reserved]
( 3 ) *Other subloop provisions* — ( i ) *Technical feasibility.* If parties are unable to reach agreement through voluntary negotiations as to whether it is technically feasible, or whether sufficient space is available, to unbundle a copper subloop at the point where a telecommunications carrier requests, the incumbent LEC shall have the burden of demonstrating to the state commission, in state proceedings under section 252 of the Act, that there is not sufficient space available, or that it is not technically feasible to unbundle the subloop at the point requested.
( ii ) *Best practices.* Once one state commission has determined that it is technically feasible to unbundle subloops at a designated point, an incumbent LEC in any state shall have the burden of demonstrating to the state commission, in state proceedings under section 252 of the Act, that it is not technically feasible, or that sufficient space is not available, to unbundle its own loops at such a point.
( c ) *Dedicated transport.* An incumbent LEC shall provide a requesting telecommunications carrier with nondiscriminatory access to dedicated transport on an unbundled basis, in accordance with section 251(c)(3) of the Act and this part, as set forth in paragraphs (d) through (d)(4) of this section. A “route” is a transmission path between one of an incumbent LEC's wire centers or switches and another of the incumbent LEC's wire centers or switches. A route between two points (*e.g.,* wire center or switch “A” and wire center or switch “Z”) may pass through one or more intermediate wire centers or switches (*e.g.,* wire center or switch “X”). Transmission paths between identical end points (*e.g.,* wire center or switch “A” and wire center or switch “Z”) are the same “route,” irrespective of whether they pass through the same intermediate wire centers or switches, if any. ( 1 ) *Definition.* For purposes of this section, dedicated transport includes incumbent LEC transmission facilities between wire centers or switches owned by incumbent LECs, or between wire centers or switches owned by incumbent LECs and switches owned by requesting telecommunications carriers, including, but not limited to, DS1-, DS3-, and OCn-capacity level services, as well as dark fiber, dedicated to a particular customer or carrier.
( 2 ) *Availability.* ( i ) *Entrance facilities.* An incumbent LEC is not obligated to provide a requesting carrier with unbundled access to dedicated transport that does not connect a pair of incumbent LEC wire centers.
( ii ) *Dedicated DS1 transport.* Dedicated DS1 transport shall be made available to requesting carriers on an unbundled basis as set forth in paragraphs (d)(2)(ii)(A) and (B) of this section. Dedicated DS1 transport consists of incumbent LEC interoffice transmission facilities that have a total digital signal speed of 1.544 megabytes per second and are dedicated to a particular customer or carrier. ( A ) *General availability of DS1 transport.* Incumbent LECs shall unbundle DS1 transport between any pair of incumbent LEC wire centers except where, through application of tier classifications described in paragraph (d)(3) of this section, both wire centers defining the route are Tier 1 wire centers. As such, an incumbent LEC must unbundle DS1 transport if a wire center at either end of a requested route is not a Tier 1 wire center, or if neither is a Tier 1 wire center.
( B ) *Cap on unbundled DS1 transport circuits.* A requesting telecommunications carrier may obtain a maximum of ten unbundled DS1 dedicated transport circuits on each route where DS1 dedicated transport is available on an unbundled basis.
( iii ) *Dedicated DS3 transport.* Dedicated DS3 transport shall be made available to requesting carriers on an unbundled basis as set forth in paragraphs (d)(2)(iii)(A) and(B) of this section. Dedicated DS3 transport consists of incumbent LEC interoffice transmission facilities that have a total digital signal speed of 44.736 megabytes per second and are dedicated to a particular customer or carrier. ( A ) *General availability of DS3 transport.* Incumbent LECs shall unbundle DS3 transport between any pair of incumbent LEC wire centers except where, through application of tier classifications described in paragraph (d)(3) of this section, both wire centers defining the route are either Tier 1 or Tier 2 wire centers. As such, an incumbent LEC must unbundle DS3 transport if a wire center on either end of a requested route is a Tier 3 wire center.
( B ) *Cap on unbundled DS3 transport circuits.* A requesting telecommunications carrier may obtain a maximum of 12 unbundled DS3 dedicated transport circuits on each route where DS3 dedicated transport is available on an unbundled basis.
( iv ) *Dark fiber transport.* Dark fiber transport consists of unactivated optical interoffice transmission facilities. Incumbent LECs shall unbundle dark fiber transport between any pair of incumbent LEC wire centers except where, through application of tier classifications described in paragraph (d)(3) of this section, both wire centers defining the route are either Tier 1, Tier 2, or a Tier 3 wire center identified on the list of wire centers that has been found to be within a half mile of alternative fiber pursuant to the Report and Order on Remand and Memorandum Opinion and Order in WC Docket No. 18-14, FCC 19-66 (released July 12, 2019). An incumbent LEC must unbundle dark fiber transport only if a wire center on either end of a requested route is a Tier 3 wire center that is not on the published list of wire centers. Notwithstanding any other provision of the Commission's rules in this part, an incumbent LEC shall continue to provide a requesting telecommunications carrier with nondiscriminatory access to dark fiber transport for eight years until February 8, 2029, provided such dark fiber transport was being provided before February 8, 2021.
( 3 ) *Wire center tier structure.* For purposes of this section, incumbent LEC wire centers shall be classified into three tiers, defined as follows: ( i ) Tier 1 wire centers are those incumbent LEC wire centers that contain at least four fiber-based collocators, at least 38,000 business lines, or both. Tier 1 wire centers also are those incumbent LEC tandem switching locations that have no line-side switching facilities, but nevertheless serve as a point of traffic aggregation accessible by competitive LECs. Once a wire center is determined to be a Tier 1 wire center, that wire center is not subject to later reclassification as a Tier 2 or Tier 3 wire center.
( ii ) Tier 2 wire centers are those incumbent LEC wire centers that are not Tier 1 wire centers, but contain at least 3 fiber-based collocators, at least 24,000 business lines, or both. Once a wire center is determined to be a Tier 2 wire center, that wire center is not subject to later reclassification as a Tier 3 wire center.
( iii ) Tier 3 wire centers are those incumbent LEC wire centers that do not meet the criteria for Tier 1 or Tier 2 wire centers.
( 4 ) *Routine network modifications.* ( i ) An incumbent LEC shall make all routine network modifications to unbundled dedicated transport facilities used by requesting telecommunications carriers where the requested dedicated transport facilities have already been constructed. An incumbent LEC shall perform all routine network modifications to unbundled dedicated transport facilities in a nondiscriminatory fashion, without regard to whether the facility being accessed was constructed on behalf, or in accordance with the specifications, of any carrier.
( ii ) A routine network modification is an activity that the incumbent LEC regularly undertakes for its own customers. Routine network modifications include, but are not limited to, rearranging or splicing of cable; adding an equipment case; adding a doubler or repeater; installing a repeater shelf; and deploying a new multiplexer or reconfiguring an existing multiplexer. They also include activities needed to enable a requesting telecommunications carrier to light a dark fiber transport facility. Routine network modifications may entail activities such as accessing manholes, deploying bucket trucks to reach aerial cable, and installing equipment casings. Routine network modifications do not include the installation of new aerial or buried cable for a requesting telecommunications carrier.
( d ) *911 and E911 databases.* An incumbent LEC shall provide a requesting telecommunications carrier with nondiscriminatory access to 911 and E911 databases on an unbundled basis, in accordance with section 251(c)(3) of the Act and this part.
( e ) *Operations support systems.* An incumbent LEC shall provide a requesting telecommunications carrier with nondiscriminatory access to operations support systems on an unbundled basis only when it is used to manage other unbundled network elements, local interconnection, or local number portability, in accordance with section 251(c)(3) of the Act and this part. Operations support system functions consist of pre-ordering, ordering, provisioning, maintenance and repair, and billing functions supported by an incumbent LEC's databases and information. An incumbent LEC, as part of its duty to provide access to the pre-ordering function, shall provide the requesting telecommunications carrier with nondiscriminatory access to the same detailed information about the loop that is available to the incumbent LEC.
[68 FR 52295, Sept. 4, 2003, as amended at 68 FR 64000, Nov. 12, 2003; 69 FR 54591, Sept. 9, 2004; 69 FR 77953, Dec. 29, 2004; 70 FR 8953, Feb. 24, 2005: 78 FR 5746, Jan. 28, 2013; 86 FR 1673, Jan. 8, 2021; 86 FR 8872, Feb. 10, 2021]