CS-03 Part I — Requirements for Terminal Equipment (TE) and Related Access Arrangements Intended for Direct Connection to Analog Wireline Facilities (sf09841)

4. Special Test Circuits

The special test circuits required to perform the tests described in Section 3 are shown in schematic form in this section.

4.1 Loop Simulator for Loop-start and Ground-start Circuits

Figure 4.1 — Loop Simulator for Loop-start and Ground-start Circuits

Figure 4.1 — Loop Simulator for Loop-start and Ground-start Circuits (the long description is located below the image)
Description

This image shows the schematic for a loop-start and ground-start loop simulator. The tip lead is connected to the A output point via a series combination of a dual switch, S1, a variable resistor and a capacitor, C1. The ring lead is connected to the B output point via a series combination of the other part of the dual switch, S1, a variable resistor and a capacitor, C2. The switch has two positions which are used to reverse the polarity of the DC voltage. The two variable resistors in series with the tip and ring leads are tied together and combine to make the value R. Between the capacitors and variable resistors there is a series connection between the two paths that contains an inductor, a variable DC supply, an ammeter and a second inductor. The total inductance of the two inductors combined is greater than 10 henries and the resistance of the inductors is expressed as RL. C1 plus C2 are equal to 500 microfarads and they are to be matched to 5 percent.

Table 4.1 — Test Conditions for Loop Simulator
ConditionV, voltsSwitch Position for TestR + RL
142.5 to 52.5BothContinuously variable over 400 to 1740 Ω
2105(b)2000 Ω

Notes:

  1. Means shall be employed to generate, at the point of tip and ring connections to the terminal equipment (TE) protective circuitry, the parameters of DC line current and AC impedance which are generated by the illustrative circuits described above (as appropriate for the equipment under test).
  2. In performing the longitudinal balance (Section 3.6), the use of the "DC portion of the loop simulator circuit" is specified.

4.2 Loop Simulator for Reverse Battery Circuits

Figure 4.2 — Loop Simulator for Reverse Battery Circuits

Figure 4.2 — Loop Simulator for Reverse Battery Circuits (the long description is located below the image)
Description

This image shows the schematic for a 2-wire reverse battery loop simulator. The tip lead is connected to the A output point via a series combination of a variable resistor and a capacitor, C1. The ring lead is connected to the B output point via a series combination of a variable resistor and a capacitor, C2. The two variable resistors in series with the tip and ring leads are tied together and combine to make the value R. Between the capacitors and variable resistors there is a series connection between the two paths that contains an inductor, a variable DC supply, an ammeter and a second inductor. The total inductance of the two inductors combined is greater than 10 henries and the resistance of the inductors is expressed as RL. C1 plus C2 are equal to 500 microfarads and they are to be matched to 5 percent.

R + RL = Continuously variable over 400 to 2450 Ω

Notes: 

  1. Means shall be employed to generate, at the point of tip and ring connections to the TE protective circuitry, the parameters of DC line current and AC impedance which are generated by the illustrative circuits described above (as appropriate for the equipment under test).
  2. In performing the longitudinal balance (Section 3.6), the use of the "DC portion of the loop simulator circuit" is specified. In such cases, components C1 and C2 shall be removed.

4.3 Loop Simulator for 4-Wire Loop- and Ground-start Circuits

Figure 4.3 — Loop Simulator for 4-Wire Loop- and Ground-start Circuits

Figure 4.3 — Loop Simulator for 4-Wire Loop- and Ground-start Circuits (the long description is located below the image)
Description

This image shows the schematic for a 4-wire loop-start or ground-start loop simulator. The tip and ring leads are terminated with a series combination of a capacitor, C1, and resistor, R1. In parallel with C1 and R1 are two series inductors, L1 and L2. Terminating the tip_1 and ring_1 leads is the same circuit as terminating the tip and ring leads with component designations of C2, R3, L3 and L4. The capacitors C1 and C2 total 500 microfarads and must be matched to 5 percent. The resistors R1 and R3 must each be 600 Ω. The inductance of L1, L2, L3 and L4 is greater than 5 henries and their resistance is designated as RL1, RL2, RL3 and RL4. An ammeter in series with a variable resistor, R2, and a variable DC supply are connected from the centre of L1/L2 to the centre of L3/L4 through a dual switch with positions "a" and "b". The switch is used to reverse the polarity of the DC voltage.

Table 4.3 — Test Conditions for Loop Simulator
ConditionV, voltsSwitch Position for TestR2 + RL
142.5 to 52.5(a) and (b)Continuously variable over 400 to 2450 Ω
2105(b)1740 Ω

4.4 Loop Simulator for 4-Wire Reverse Battery Circuits

Figure 4.4 — Loop Simulator for 4-Wire Reverse Battery Circuits

Figure 4.4 — Loop Simulator for 4-Wire Reverse Battery Circuits (the long description is located below the image)
Description

This image shows the schematic for a 4-wire reverse battery loop simulator. The tip and ring leads are terminated with a series combination of a capacitor, C1, and resistor, R1. In parallel with C1 and R1 are two series inductors, L1 and L2. Terminating the tip_1 and ring_1 leads is the same circuit as terminating the tip and ring leads with component designations of C2, R3, L3 and L4. The capacitors C1 and C2 total 500 microfarads and must be matched to 5 percent. The resistors R1 and R3 must each be 600 Ω. The inductance of L1, L2, L3 and L4 is greater than 5 henries and their resistance is designated as RL1, RL2, RL3 and RL4. An ammeter in series with a variable resistor, R2, is connected from the centre of L1/L2 to the centre of L3/L4.

Note:  R2 + RL = Continuous variable over 400 to 2450 Ω.

4.5 DC Conditions to Off‑Premises Stations (OPS) Lines

Figure 4.5 — DC Conditions to Off‑Premises Stations (OPS) Lines

Figure 4.5 — Off-premises Loop Simulator (the long description is located below the image)
Description

This image shows the schematic for an off-premises loop simulator. The tip lead is connected to the A output point via a series combination of a variable resistor and a capacitor, C1. The ring lead is connected to the B output point via a series combination of a dual switch, S1, a variable resistor and a capacitor, C2. The switch has two positions which are used to switch either to a short, in position "a", or to a 24 volt DC supply, in position "b". The two variable resistors in series with the tip and ring leads are tied together and combine to make the value R. Between the capacitors and variable resistors there is a series connection between the two paths that contains two inductors. The total inductance of the two inductors combined is greater than 10 henries and the resistance of the inductors is expressed as RL, which must be minimal in comparison to R. C1 plus C2 are equal to 500 microfarads and they are to be matched to 5 percent.

Note: The minimum DC current present for all resistance ranges of conditions 1 and 2 shall be 16 mA, as per the following table:

Table 4.5 — Resistance Ranges
R + RL Continuously Variable over the Following Range
ConditionSwitch Position for TestClass AClass BClass C
1(a)RL to 200 ΩRL to 800 ΩRL to 1800 Ω
2(b)Not Applicable200 to 2300 Ω900 to 3300 Ω

Notes:

  1. Means shall be used to generate, at the point of tip (T OPS) and ring (R OPS) connections to the PBX, the range of the resistance and impedance which are employed by the illustrative circuit depicted above.
  2. For the longitudinal balance (Section 3.6), the use of the "DC portion of the line simulator" is specified. In such cases, components C1 and C2 shall be removed.

4.6 Alternative Off-hook Termination

Figure 4.6 — Alternative Off-hook Termination

Figure 4.6 — Alternative Off-hook Termination (the long description is located below the image)
Description

This image shows the schematic for the alternative off-hook termination. The alternative termination consists of a 350 Ω resistor, R1, in series with a parallel combination of a 1000 Ω resistor, R2 and a 0.01 microfarad capacitor, C1.

Note:  This alternative termination is used to replace 600 Ω.

4.7 E&M Signalling

4.7.1 TE on Side "A"

Figure 4.7.1 — E&M Types I & II Signalling (TE Originates on M Lead)

Figure 4.7.1 — E&M Types I & II Signalling (TE Originates on M Lead) (the long description is located below the image)
Description

This image shows the schematic of the signalling interfaces of an E & M type one or type two interfaces on the A side. The image is displayed in two parts. First is the E & M "type one" schematic. On the terminal equipment A side, the tip and ring leads are connected to the tip and ring leads of the tie trunk channel side via 600 Ω isolation transformers. The tip_1 and ring_1 lead (if the terminal is a 4-wire interface) are connected to the tip_1 and ring_1 leads of the tie trunk channel side. The E lead of the terminal equipment is connected from ground, through a switch to the E lead of the tie trunk channel side, which contains a detector and current limiter connected to a negative DC voltage supply. There is a contact protection device in parallel with the detector. The M lead on the terminal equipment side is connected from ground, through a detector to the M lead on the tie trunk channel side, which contains a surge protection to ground and a switch with two positions. Position one is to ground and position two is to a current limiter and a negative DC voltage supply.

Second is the E & M type two schematic. The tip, ring, tip_1 and ring_1 leads of a type two are the same connections as the type one. The E lead and the SG lead of the terminal equipment are connected via a switch. The E lead is connected to the E lead of the tie trunk channel side, which is connected to a detector and current limiter to a negative DC voltage. There is a contact protection circuit in parallel with the limiter. The SG lead is connected to the SG lead of the tie trunk channel side, which is connected to ground. The M lead on the terminal equipment side is connected from ground, through a detector to the M lead on the tie trunk channel side. There is a contact protection circuit from the M lead to ground. On the tie trunk channel side the M lead and the SB lead are connected via a switch. The SB lead of the tie trunk channel side is connected to the terminal equipment SB lead, which is connected through a current limiter to a negative DC voltage.

4.7.2 TE on Side "B"

Figure 4.7.2 — E&M Types I & II Signalling (TE Originates on E Lead)

Figure 4.7.2 — E&M Types I & II Signalling (TE Originates on E Lead) (the long description is located below the image)
Description

This image shows the schematic of the signalling interfaces of an E&M type one or type two interface on the B side. The image is displayed in two parts. First is the E&M type one schematic. On the terminal equipment B side, the tip and ring leads are connected to the tip and ring leads of the tie trunk channel side via 600 Ω isolation transformers. The tip_1 and ring_1 lead (if the terminal is a 4-wire interface) are connected to the tip_1 and ring_1 leads of the tie trunk channel side. The E lead of the terminal equipment is connected from a negative DC voltage source through a detector and current limiter, which has a contact protection circuit in parallel to the E lead of the tie trunk channel side that is connected to ground via a switch. The M lead on the terminal equipment side is connected from a negative DC voltage source through a current limiter to a switch with two positions. Position one is to ground and position two, the current limiter. The output of the switch contains a surge protection to ground and is then connected to the M lead on the tie trunk channel side to ground, through a detector.

Second is the E&M type two schematic. The tip, ring, tip_1 and ring_1 leads of a type two are the same connections as the type one. The E lead and the SG lead of the tie trunk channel side are connected via a switch. The E lead is connected to the E lead of the terminal equipment side, which is connected to a detector and current limiter to a negative DC voltage. There is a contact protection circuit in parallel with the limiter. The SG lead is connected to the SG lead of the terminal equipment side which is connected to ground. The M lead on the tie trunk channel side is connected from ground, through a detector to the M lead on the terminal equipment side. There is a contact protection circuit from the M lead to ground. On the terminal equipment side, the M lead and the SB lead are connected via a switch. The SB lead of the terminal equipment side is connected to the tie trunk channel side SB lead, which is connected through a current limiter to a negative DC voltage.

4.8 Reference Information

4.8.1 Reverse Battery Trunk Interface

Direct inward dialing (DID) TE interface functions are interpreted as follows:

Table 4.8.1 — DID TE Interface Functions
TonesAnswer SupervisionFailure Mode Supervision
TE Response/Condition for Incoming CallsBusy 60 IPMReorder 120 IPMRequiredNot RequiredReverse Battery or Control Circuit Interface
If the station answersX
If the call is answered by an attendant, a recorded announcement or other meansX
If the number is busyXX
If all transmission paths in the TE are busyXX
If the TE returns ring back tone to the callerX
If all incoming trunks to the TE are busyN/AThe network will indicate all-trunks-busy to the caller N/A.N/A
If the TE is out of service due to: maintenance, power failure, power disconnected or other malfunctions or conditionsThe network will indicate all-trunks-busy to the caller. (See Footnote Note 1.)X
If the terminal TE returns dial tone to the caller (see Footnote Note 2)X

Footnotes

Footnote 1

This condition is the result of failure mode supervision from the TE.

Return to footnote 1 referrer

Footnote 2

Applicable to a TE that is arranged to return a dial prompt to the calling party for the purpose of accepting further dialled digits that may be used to re-route the incoming call to another destination.

Return to footnote 2 referrer


See also Section 3.5.4 for more information on direct inward dialing.

5. Terminal Equipment (TE) Installation Wiring

Note:

This section is for information purposes only and does not form part of the mandatory requirements.

5.1 Scope

This section provides guidelines for the installation and wiring of technical equipment (TE) when the installation of such equipment requires inside or in-building wiring that is not an integral part of the equipment as registered. Such installation shall be carried out under the supervision of qualified personnel and shall be in accordance with the guidelines of this section to ensure that registration requirements are met once the TE is connected to the network.

5.2 General

TE and all associated installation wiring could, under certain circumstances, become exposed to extraneous voltages, current and surges from the network and from connections to other equipment. For example, they could be subjected to lightning-induced voltage surges of up to a 1000 V peak. The average rise time of such a surge is 100 μs. The minimum rise time can be less than 10 μs. The customer is responsible for ensuring that TE is normally connected to inside or in-building wiring.

There may also be times when the TE and all associated installation wiring may be subjected to voltages and current resulting from contact with commercial power facilities under fault conditions. There should be sufficient high impedance between the tip and ring and ground reference to allow the metallic and longitudinal voltages to rise at approximately the same rate as a lightning surge. TE and the associated installation wiring should be capable of safely withstanding these extraneous voltages, currents, and surges. It shall be installed in a manner that ensures continued compliance with the network protection requirements described in Section 3.

5.3 Safety Requirements

The installation of the TE and associated wiring shall be in accordance with the most recent version of the Canadian Electrical Code — Part I (issued by the Canadian Standards Association, which is the standard used to specify safety requirements for electrical installations).

5.4 Technical Requirements

5.4.1 Demarcation Point

The demarcation point, as defined in the CRTC Telecom Decision 99-10, is the physical location ("point") where the wires and facilities on one side of the point are under the responsibility and control of one party, while the wires and facilities on the other side of the point are under the responsibility and control of a different party. For single residences, the demarcation point is at the carrier-provided jack which shall be installed at an accessible location mutually agreed upon by the carrier and the customers. For multiple-dwelling units, in-building wiring may be owned by a telecommunications service provider or the property owner. Installation practices may vary depending on the type of building.

5.4.2 Type of Wiring

Wires, cables and connecting devices used in the installation shall be of a type designed for use in telecommunications applications and shall be suitable for the location and conditions under which they are used. The manufacturer's published recommendations of either the wiring or TE shall be considered sufficient indication of suitability. Examples of good installation practices may be found in CSA Standards T525-94 (R1999), Residential Wiring for Telecommunications, and T568.1-05 (R2010), Telecommunications Cabling Systems in Commercial Buildings.

5.4.3 Limitations on Wiring

The total loss of the TE and the wiring from the demarcation point to the furthest TE should be limited by the following conditions:

  1. if TE is intended for connection to CO lines:
    1. added resistance of 50 Ω; and
    2. transmission loss of 0.5 dB.
  2. if TE is intended for connection to trunks:
    1. no added resistance; and
    2. transmission loss of 2.5 dB.

Where the above limits are insufficient to meet the customer's requirements, the customer shall contact the service provider to determine jointly whether the particulars of the proposed installation will ensure minimum transmission specifications. In the event that transmission compensation is required, the customer may incur additional charges.

5.4.4 Communications Ground

In order to minimize the introduction of noise, TE requiring a communication ground separate from the safety (green wire) ground shall have a low-impedance path to the main building ground source, independent of that provided by the carrier for its equipment.

Note:

In locations where the local building ground potential may be expected to rise to hazardous levels relative to a remote ground, due to the proximity of an electric power station or similar installation, engineering coordination with the carrier shall be required.

5.5 Qualifications of Installation Supervision

The person responsible for the direct supervision of the personnel performing the installation shall have the necessary qualifications outlined in the appropriate documents.