TR41.1/03-08-065
STANDARDS PROJECT:
TR41.1 PN3-3673-RV4
TITLE:
Proposed changes to ANSI/TIA-464-C, section 6.2.3 - 6.2.5.
ISSUES ADDRESSED:
Proposed changes to ANSI/TIA-464-C loss plan.
SOURCE:
Siemens ICN
CONTACT:
Tailey Tung
Phone: 408-492-5049
Fax:
408-492-2563
Email: tailey.tung@icn.siemens.com
DATE:
August 21, 2003.
DISTRIBUTION TO:
TIA TR41.1
KEYWORDS:
TIA-464-C loss plan
NOTICE: The Contributions in this submission have been formulated to assist TIA TR41.1. The
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This document has been prepared by Contributor to assist the TIA Engineering Committee. It is
proposed to the Committee as a basis for discussion and is not to be construed as a binding
proposal on Contributor. Contributor specifically reserves the right to amend or modify the
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1. Introduction
TR41.9 has advanced the TIA/EIA/IS-968 interim standard to an ANSI approved TIA-968-A
standard on October 29, 2002. They have also made significant changes to the ANSI/TIA968-A loss plan table and the signal power limitation requirements. The new changes in the
form of addendum to ANSI/TIA-968-A-1 standard are now in the process of industry ballot
under SP-3-0016 and expected to be approved in the TR41.9 - 5/2003 meeting.
The new loss plan relaxes the encoded analog content signal power limitations
968-A, section 4.5.10 and the 2-wire and 4-wire lossless tie trunk signal power
4.5.2.1.2. These changes also coordinate with changes to the allowable net
between port requirements in Table 4.6. The result is less allowable net
between some ports and more allowable net amplification between other ports.
in ANSI/TIAlimitations in
amplification
amplification
Because the new ANSI/TIA-968-A loss plan changes impact significantly the ANSI/TIA-464C, section 6.2.5 for PBX loss ranges and TIA/EIA/IS-968 requirements, this contribution
proposes changes to ANSI/TIA-464-C, sections 6.2.3 - 6.2.5 to make them in-line with the
new loss plan changes in ANSI/TIA-968-A standard mandated by FCC for Part 68 product
registration.
2. Propose changes to ANSI/TIA-464-C, section 6.2.3 – 6.2.5
The propose changes to ANSI/TIA-464-C, sections 6.2.3 – 6.2.5 standard are highlighted in
“blue”.
6.2.3
Insertion Loss Criteria for PBX
The nominal values for PBX port-to-port connections are given by the loss plan presented in Table 12.
The PBX interfaces described in the loss plan are given in 4.3 and illustrated in Figure 1.
6.2.3.1
Port-to-Port Loss Table Interpretation
In Table 12, arrows at the row and column designators indicate the transmission direction in which the
coordinate loss values are to be inserted. The negative values in the Port-to-Port loss table denote gain;
e.g., -3 indicates 3 dB gain.
For example, coordinate 1B indicates a nominal port-to-port loss of 3 dB from the ONS interface to the
OPS interface, and coordinate 2A indicates a 3dB loss in the other direction, from the OPS interface to the
ONS interface. The port designations in Table 12 indicate the specific application for which the loss plan
was developed. These ports may, however, be used for other applications, as long as the resulting gains
comply with the TIA/EIA/IS-968 requirements for allowable net amplification between ports. (Ref 42,
Section 4.5.2.5)
6.2.3.2
Port-to-Port Loudness Ratings Table Interpretation
Table 13 is provided to show the relationship between OLR and SLR, Loss, and RLR.
For example, for an ONS to OPS connection, the ONS SLR is 8 dB, the PBX loss is 3 dB (coordinate 1B
in Table 12), and the OPS RLR is –3 dB. The overall loudness ratings is therefore 8 + 3 – 3 = 8 dB. See
Annex B2 for further information on loudness ratings.
Table 12 - PBX Loss Plan
A
B
C
D
E
F
ONS
OPS
DGS
DAL
Loss







AAL(A) AAL(D)
G
ATT
1
ONS

6
3
0
0
0
3
3
2
OPS

3
0
-3
-3
0
0
3
3
4
DGS

9
6
0
0
0
3
3
DAL

9
6
0
0
0
3
3
5
AAL(A)

0
0
-6
-6
0
0
0
6
AAL(D)

3
0
-3
-3
0
0
0
7
ATT

3
0
0
0
0
0
0
Notes:
1.
The units for all Loss values are dB.
2.
Losses have been selected as multiples of 3 dB, in the assumption that this may make
implementation easier.
Table 13 - PBX Loudness Ratings
ONS
OPS
DGS
DAL
RLR
-6
-3
2
2
6
3
-1
SLR
OLR







ONS
8

8
8
10
10
14
14
10
OPS
11

8
8
10
10
17
14
13
DGS
8

11
11
10
10
14
14
10
DAL
8

11
11
10
10
14
14
10
AAL(A)
20

14
17
16
16
26
23
19
AAL(D)
17

14
14
16
16
23
20
16
ATT
13

10
10
15
15
19
16
12
Notes:
1.
The units for all SLR, RLR and Loss values are dB.
2.
The SLR and RLR values include the following network losses:
AAL(A) and AAL(D) include a nominal 3 dB central office loss
ATT includes a 2 dB line loss.
AAL(A) AAL(D)
ATT
6.2.4
PBX Loss Plan Assumptions
The port-to-port losses for PBXs were developed based on the loss plans for public and private networks.
The PBX loss plan is intended to provide satisfactory Grade-of-service (GoS) performance and
compatibility with the public and private network loss plans. The following assumptions were the prime
considerations:
(1)
The transmission loss and level plan of the PSTN, which is primarily an all-digital network
with some fixed loss as described in ANSI T1.508-1998 (Ref 8), forms a basis for the private
network loss plan.
(2)
Central offices insert the following variable losses on analog trunks connections to ensure
network stability:
Connection Type
CO Loss
Note
Local Call
Regional Call
Long Distance Call
0 dB
3 dB
6 dB
1
Note:
(3)
(4)
(5)
(6)
1. This is the assumed nominal loss for planning purposes.
Transmission facilities to be used have losses compatible with the PBX port-to-port losses.
PBX port-to-port losses associated with analog interfaces apply to any trunks with analog
terminations at the PBX.
PBX port-to-port losses associated with digital interfaces apply to any trunks with digital
terminations at the PBX.
Non-proprietary PBX stations have the following loudness ratings:
Station
SLR
RLR
Notes
OPS
ONS
DGS
11
8
8
-3
-6
2
1
2
3
Notes:
1. The OPS (off premises station) ratings are representative of 2500-type sets operating on
26 gauge / 2.75 km loops with normal battery feed and impedance characteristics, as
measured at a PSTN end office or PBX OPS port.
2. The ONS (on premises station) ratings are representative of 2500-type sets operating on
short loops with the typical current-limited battery feed and 600  impedance
characteristics of PBX ONS ports. See ANSI/TIA-470-110-C (Ref 2) for further details.
3. The DGS (digital station) ratings are chosen to improve interoperability with the ITU-T
standard SLR/RLR levels for digital sets of 8 and 2. See ANSI/TIA-810-A (Ref 16) for
further details.
6.2.5
PBX Loss Ranges and ANSI/TIA-968-A Requirements
6.2.5.1
Recommended Loss Ranges
The port-to-port losses in Table 12 are the recommended nominal values.
Although there are no mandatory loss ranges associated with these values, it is desirable that the average
1 kHz loss fall within +0.5 dB of the nominal loss values given in Table 12.
6.2.5.2
ANSI/TIA-968-A Requirements
Tables 14, 15, 16 and 17 provide a cross reference from the Table 12 loss values to the equivalent limits
for the ANSI/TIA-968-A defined ports.
Tables 14 and 15 show the allowable amplification (gain) and equivalent loss respectively.
Table 16 shows the losses recommended in this standard, and Table 17 shows the difference between the
allowable and recommended losses.
It should be noted that a number of analog connections have a zero tolerance between the Table 12 values
and the ANSI/TIA-968-A requirements.
Care should be taken to ensure that no analog connection violates the ANSI/TIA-968-A Standard for
allowable net amplification between ports (Ref 42: ANSI/TIA-968-A, Section 4.5.2.5). In general this is
achieved by offsetting the nominal loss by amount equal to the maximum expected component tolerance
and measurement error.
The recommended losses are based on a desirable port-to-port OLR of 10 dB. The change in the RLR of
digital ports from 0 dB to 2 dB requires a corresponding decrease in loss for some of the analog stations
to digital trunk connections, in order to maintain an optimum OLR.
Unfortunately, some of the desirable ONS and OPS losses would violate the ANSI/TIA-968-A
requirements for through-gain transmission. In these cases the losses have been set to levels compliant
with the ANSI/TIA-968-A requirements, even though this results in a less than optimum OLR of 13 dB.
Table B2 in Annex B2.4 - ‘Optimum Overall Loudness Ratings’ contains the desirable ONS and OPS to
digital trunk connection losses required to meet the optimum OLR of 10 dB. These are provided as a
reference for future versions of this standard, or in the event that the ANSI/TIA-968-A Standard changes
during the life of this standard.
Until such time that the ACTA changes the requirements in ANSI/TIA-968-A Standard, users should
ensure that they comply with the current ANSI/TIA-968-A requirements for through-gain transmission.
Table 14 – ANSI/TIA-968-A-1, Section 4.5.2.5, Allowable Net Amplification Between Ports
To
From (E)
Tie trunk type ports
Lossless
2/4-wire
Subrate
1.544 Mb/s
Satellite 4W
Subrate
1.544 Mb/s
Tandem 4W
ATT
DAL
DAL
Integrated
services
trunk
OPS ports
(2-wire)
Analog Public
switched network ports
(2-wire)
Subrate
1.544 Mb/s
Digital PBX-CO
Trunk Port
(4-wire)
DAL
OPS
AAL(A)
AAL(D)
DAL
8
9
10
1
2
3
4
7
1
ATT
Lossless Tie Trunk Port
(2/4-wire)
0 dB
2 dB
2 dB
2 dB
2 dB
2
DAL
Subrate 1.544 Mb/s Satellite
4W Tie
1 dB
3 dB
3 dB
3 dB
3
DAL
Subrate 1.544 Mb/s Tandem
4W Tie
-2 dB
0 dB
0 dB
0 dB
0 dB
4
DAL
Integrated Services Trunk
-2 dB
0 dB
0 dB
0 dB
0 dB
5
DGS
Approved Digital TE
-2 dB
0 dB
0 dB
0 dB
0 dB
0 dB
0 dB
0 dB
6
ONS
ONS Port with Approved TE
-2 dB
0 dB
0 dB
0 dB
0 dB
0 dB
0 dB
0 dB
7
OPS
OPS Port (2-wire)
2 dB
4 dB
4 dB
4 dB
4 dB
4 dB
4 dB
4 dB
8
AAL(A)
Analog Public Switched
Network Port (2-wire)
3 dB
3 dB
3 dB
9
AAL(D)
Analog Public Switched
Network Port (2-wire)
3 dB
3 dB
3 dB
10
DAL
Subrate 1.544 Mb/s Digital
PBX-CO Trunk Port (4-wire)
0 dB
Note: Positive values denote gain. Negative (-) values denote loss.
Table 15 - ANSI/TIA-968-A-1, Section 4.5.2.5, Allowable Net Loss Between Ports
To
From (E)
Tie trunk type ports
Integrated
services
trunk
OPS ports
(2-wire)
DAL
DAL
OPS
AAL(A)
AAL(D)
DAL
3
4
7
8
9
10
-2 dB
-2 dB
-2 dB
-3 dB
-3 dB
-3 dB
Lossless
2/4-wire
Subrate
1.544 Mb/s
Satellite 4W
Subrate
1.544 Mb/s
Tandem 4W
ATT
DAL
1
2
-2 dB
Analog Public
switched network ports
(2-wire)
Subrate
1.544 Mb/s
Digital PBX-CO
Trunk Port
(4-wire)
1
ATT
Lossless Tie Trunk Port
(2/4-wire)
0 dB
2
DAL
Subrate 1.544 Mb/s Satellite
4W Tie
-1 dB
3
DAL
Subrate 1.544 Mb/s Tandem
4W Tie
2 dB
0 dB
0 dB
0 dB
0 dB
4
DAL
Integrated Services Trunk
2 dB
0 dB
0 dB
0 dB
0 dB
5
DGS
Approved Digital TE
2 dB
0 dB
0 dB
0 dB
0 dB
0 dB
0 dB
0 dB
6
ONS
ONS Port with Approved TE
2 dB
0 dB
0 dB
0 dB
0 dB
0 dB
0 dB
0 dB
7
OPS
OPS Port (2-wire)
-2 dB
-4 dB
-4 dB
-4 dB
-4 dB
-4 dB
-4 dB
-4 dB
8
AAL(A)
Analog Public Switched
Network Port (2-wire)
-3 dB
-3 dB
-3 dB
9
AAL(D)
Analog Public Switched
Network Port (2-wire)
-3 dB
-3 dB
-3 dB
10
DAL
Subrate 1.544 Mb/s Digital
PBX-CO Trunk Port (4-wire)
0 dB
Note: Positive values denote loss. Negative (-) values denote gain.
Table 16 – ANSI/TIA-464-C Recommended Net Loss Between Ports
To
From (E)
Tie trunk type ports
Integrated
services
trunk
OPS ports
(2-wire)
DAL
DAL
OPS
AAL(A)
AAL(D)
DAL
3
4
7
8
9
10
Lossless
2/4-wire
Subrate
1.544 Mb/s
Satellite 4W
Subrate
1.544 Mb/s
Tandem 4W
ATT
DAL
1
2
Analog Public
switched network ports
(2-wire)
Subrate
1.544 Mb/s
Digital PBX-CO
Trunk Port
(4-wire)
1
ATT
Lossless Tie Trunk Port (2/4wire)
0 dB
0 dB
0 dB
0 dB
0 dB
0 dB
0 dB
0 dB
2
DAL
Subrate 1.544 Mb/s Satellite
4W Tie
3 dB
0 dB
0 dB
0 dB
6 dB
0 dB
3 dB
0 dB
3
DAL
Subrate 1.544 Mb/s Tandem
4W Tie
3 dB
0 dB
0 dB
0 dB
6 dB
0 dB
3 dB
0 dB
4
DAL
Integrated Services Trunk
3 dB
0 dB
0 dB
0 dB
6 dB
0 dB
3 dB
0 dB
5
DGS
Approved Digital TE
3 dB
0 dB
0 dB
0 dB
6 dB
0 dB
3 dB
0 dB
6
ONS
ONS Port with Approved TE
3 dB
0 dB
0 dB
0 dB
3 dB
0 dB
3 dB
0 dB
7
OPS
OPS Port (2-wire)
3 dB
-3 dB
-3 dB
-3 dB
0 dB
-3 dB
0 dB
-3 dB
8
AAL(A)
Analog Public Switched
Network Port (2-wire)
0 dB
-6 dB
-6 dB
-6 dB
0 dB
0 dB
0 dB
-6 dB
9
AAL(D)
Analog Public Switched
Network Port (2-wire)
0 dB
-3 dB
-3 dB
-3 dB
0 dB
0 dB
0 dB
-3 dB
10
DAL
Subrate 1.544 Mb/s Digital
PBX-CO Trunk Port (4-wire)
3 dB
0 dB
0 dB
0 dB
6 dB
0 dB
3 dB
0 dB
Note: Positive values denote loss. Negative (-) values denote gain.
Table 17 - Difference between ANSI/TIA-968-A-1, Section 4.5.2.5 and ANSI/TIA-464-C Port Loss
To
From (E)
Tie trunk type ports
Lossless
2/4-wire
Subrate
1.544 Mb/s
Satellite 4W
Subrate
1.544 Mb/s
Tandem 4W
ATT
DAL
DAL
Integrated
services
trunk
OPS ports
(2-wire)
Analog Public
switched network ports
(2-wire)
Subrate
1.544 Mb/s
Digital PBX-CO
Trunk Port
(4-wire)
DAL
OPS
AAL(A)
AAL(D)
DAL
8
9
10
1
2
3
4
7
1
ATT
Lossless Tie Trunk Port (2/4wire)
0 dB
2 dB
2 dB
2 dB
2 dB
2
DAL
Subrate 1.544 Mb/s Satellite
4W Tie
4 dB
3 dB
3 dB
9 dB
3
DAL
Subrate 1.544 Mb/s Tandem
4W Tie
1 dB
0 dB
0 dB
0 dB
6 dB
4
DAL
Integrated Services Trunk
1 dB
0 dB
0 dB
0 dB
6 dB
5
DGS
Approved Digital TE
1 dB
0 dB
0 dB
0 dB
6 dB
0 dB
3 dB
0 dB
6
ONS
ONS Port with Approved TE
1 dB
0 dB
0 dB
0 dB
3 dB
0 dB
3 dB
0 dB
7
OPS
OPS Port (2-wire)
5 dB
1 dB
1 dB
1 dB
4 dB
1dB
4 dB
1 dB
8
AAL(A)
Analog Public Switched
Network Port (2-wire)
3 dB
3 dB
3 dB
9
AAL(D)
Analog Public Switched
Network Port (2-wire)
3 dB
3 dB
3 dB
10
DAL
Subrate 1.544 Mb/s Digital
PBX-CO Trunk Port (4-wire)
6 dB
Note: Positive values denote loss relative to ANSI/TIA-968-A-1.
Notes:
1.
The ANSI/TIA-968-A-1 limits in Table 15 are only provided as a convenience to users of this
standard. Users should consult the latest ANSI/TIA-968-A-1 Standard to ensure that they are
in compliance.
2.
The ONS ports with approved TE are for 2-wire on-premises station ports to separately
approved terminal equipment.
3.
Subrate 1.544 Mb/s Digital PBX-CO trunk ports are for 4-wire 1.544 Mb/s High Capacity
Circuit digital ports.
4.
The numbers in the first column of each table are used in the first row of each table as
references to the ANSI/TIA-968-A port nomenclature.