Mitel SX-200 DIGITAL Pabx Engineering Information Manual

							Engineering Information 
TABLE 11-7 
ENVELOPE DELAY DISTORTION 
Connection 
Type 
Line to Line 
Line to Trunk 
Trunk to Trunk 
Longitudinal Balance Frequency Band 
(Hz) 
1000 - 3000 
400 - 3200 
1000 - 3000 
400 - 3200 
1000 - 3000 
400 - 3200 Envelope Delay 
Distortion 
(microseconds) 
less than 280 
less than 560 
less than 140 
less than 280 
less than 140 
less than 280 
11.11 All connections meet the longitudinal balance requirements 
outlined in Table 11-8. Note that these apply to OFF-HOOK 
circuits only. 
TABLE 1 l-8 
LONGITUDINAL METALLIC BALANCE 
Longitudinal Metallic palance (dB) 
Minimum Average 
58 63 
58 63 
58 63 
53 58 
System lmpedences 
11.12 System impedences are as follows: 
e 
Station - 9109-010 : 600 ohms I/P impedence 
600 ohms DC loop resistance 
- 9110-110 : 600 ohms I/P impedence 
1200 ohms DC loop resistance. 
l LS/GS Trunk Loop: 600 ohms I/P impedence, 1600 ohms loop 
range. 
0 
LUGS Trunk T/R to ground Resistance: 
- greater than 30 Kohms (ground start) 
- greater than 10 Mohms (loop start) - both in the IDLE state 
a 
Analog type lines: 600 ohms AC input impedence, nominal 
0 
Analog type trunks: 600/900 ohms AC input impedence, nominal 
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							Engineering Information 
Idle Channel Noise - C Message 
11.13 The idle channel C message noise will not exceed the following 
values for any type of interconnection: 
e 
Average: 16 dBrnC 
9 
95% of all interconnections: 20 dBrnC 
Idle Channel Noise - 3 kHr Flat 
11.14 The idle channel noise for 3 kHz flat noise requirements do not 
exceed the following values for any type of interconnection: 
0 95% of all interconnections: 39 dBrn0 
0 
50% of all interconnections: 35 dBrn0 
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							Engineering Information 
12. LOSS AND LEVEL PLAN 
General 
12.01 This Part describes the loss and level plan for North American 
applications of the SX-ZOO@ DIGITAL PABX. 
12.02 A large number of interconnections are possible with the SX- 
ZOO-* DIGITAL PABX, ranging from interconnections between 
on-premises (ONS) line circuits, to the interconnection of remotely 
located satellite PBXs with the SX-ZOO@ DIGITAL PABX. The principles 
of the loss and level plans are described in Part A, their application to 
the SX-200@ DIGITAL PABX is detailed in Part 9, and the arrangements 
for setting the transmission levels are detailed in Pat-t C. 
North American Loss and Level Plans 
12.03 The purpose of a transmission loss and level plan is to provide 
an acceptable transmission grade of service to all subscribers 
in the telephone network. At present, two loss plans exist for the 
public switched network in North America. They are .the VIA NET LOSS 
(VNL) plan and the SWITCHED DIGITAL NETWORK (SDN) plan. 
VNL Plan 
12.04 
(a) 
(b) 
12.05 The VNL plan consists of two parts: a fixed loss portion andra 
variable loss portion; they are as follows: . 
Fixed Portion. A minimum fixed amount of loss is introduced 
into all Toll connections. This loss is equal to 5 dB and is split 
equally between the two end trunks connected to the T.oll 
network. 
Variable Portion. In addition to the fixed portion, a variable loss 
is introduced into all trunks involved in a connection. This loss, 
known as VNL, is proportional to the trunk length and its propa- 
gation delay. The loss ranges from a minimum of 0.5 dB to a 
maximum of 3.0 dB, and covers trunk lengths from 0 to about 
2900 km (0 to 1800 miles). Trunks in excess of this length 
employ echo suppressors and are designed to zero loss. 
The loss objectives for Toll connections using the VNL plan 
range from a minimum of 5.5 dB to a maximum of 8.0 dB 
between end-to-end CO offices (CL5 to CL5). This is illustrated .in 
Figure 12-1. 
SDN Loss Plan 
12.06 The Switched Digital Network (SDN) loss plan was developed to 
meet the needs of the evolving digital public switched network. 
This plan does not assign losses to intermediate links in a connection. 
Under the plan, the local area public network (local CO to local CO).is 
operated at zero loss. This feature eliminates the need to introduce 
digital padding on intermediate digital trunk links and maintains data 
transparency throughout the network. 
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							Engineering i,nformation 
LOCAL TOLL (OR HIGHER) TOLL (OR HIGHER) LOCAL 
+- VNL 9 2.5dB += VNL 
-I.+ VNL + 2SdB -pl 
TOLL- 
CONNECTING 
TRUNK INTER TOLL 
TRUNKS TOLL- 
CONNECTING 
TRUNK 
(2W ANALOG) (4W ANALOG) (2W ANALOG) 
12.07 Control of echo and noise with this plan is achieved by insert- 
ing fixed amounts of loss at the end points where the conver-  Figure 12-1 Local to Local Central. Offices VNL Objectives _ 
sion to analog takes place. A compromise value of 6 dB was selected 
for line-to-line connections over the Toll network. This loss is inserted 
in the receive (RX) direction of transmission (D-A) under software 
control. This is illustrated in Figure 12-2. 
SX-200@ DIGITAL PABX Loss And Level Plan 
12.08 To illustrate the loss and level plan used for the SX-200@ 
DIGITAL PABX, reference is made to the layout illustrated in 
Figure 12-3. This. layout is not intended to be a typical network, but is 
drawn to show the different types of trunk and line interfaces which 
the SX-200@ DIGITAL PABX will accommodate. The terms used for the 
differ&t types of peripheral interfaces are explained in Table 1 l-1. 
12.09 To implement the required loss objectives (Table 112-l) of the 
plan, combinations of software selectable analog and digital 
transmission pads are provided. All analog padding is provided by 
Mite1 8960 series combined Codec/Filter integrated circuits, over a 7 
dB range in 1 dB increments. Padding is provided in both the Transmit 
(TX) and Receive (RX) directions (see Part C). 
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							Engineering Information 
LOCAL LOCAL 
co co 
PAD 
X 255 PCM 
XI > 
1 LINE TCT INTERTOLL 
TRUNK : TCT LINE 
255 PCM 
x 
PAD 
6dB 
END-END LOSS p-1 
X3467Rl 
Figure 12-2 Local to Local Central Offices Fixed Loss Plan Objectives 
Satellite PBX 
12.10 A satellite PBX (shown in Figure 12-3) is defined as a PBX 
which has no direct connection to the serving central office for 
incomming traffic. It has no directory number, and receives all incom- 
ing calls through the main PBX over satellite trunks. The satellite PBX 
is usually in the same local area as its main PBX. 
Analog Transmission Pad Arrangements - Digital Interfaces 
12.11 The analog transmit pad (A/D) setting defines the input level 
required to produce a 0 dBm0 digital signal, as well as the 
overload point of the interface (approximately 3 dB above the 0 dBm0 
signal level). The TX pad comprises a fixed portion and a variable 
portion. The fixed portion is incorporated into the analog interface to 
the codec/filter. The variable portion (0 to 7 dB) is incorporated into 
the codec/fiIter. 
12.12 The analog receive pad (D/A) defines the output level produced 
by a,digital milliwatt input signal. The Rx pad comprises a fixed 
portion which is part of the analog interface to the codec/filter, and;8 
variable portion (0 to -7 dB) which is incorporated into the codec/fiItee. 
This pad arrangement is illustrated in Figure 12-4. 
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							Engineering information 
Analog Transmission Pad Arrangements - Analog ivterfaces 
12.13 The transmit pads for the analog type cards consist of a vari- 
able or fixed portion on the card itself, a fixed portion on the 
Digital Interface card, and a variable portion in the coder/filter. The 
variable transmit pad on the analog ONS line card may be set to either 
-8.0 dB or -iO.7 dB. The fixed transmit pad on the analog trunk cards is 
set to -8.0 dB. The fixed portion on the Digital Interface card is set to 
1.8 dB while the variable portion in the codecffilter can be set to 
anything between 0 dB and 7 dB, in 1 dB steps. The input signal level 
and overload level are defined by the sum of the fixed and variable 
pads described in the Digital interfaces paragraphs. 
12.14 The receive pads for the analog type cards consist of a fixed 
portion on the analog card itself, a fixed portion on the Digital 
interface card, and a variable portion in the codec/fiiter. The fixed 
portions are set to 5.7 dB and -1.9 dB respectively, while the variable 
portion can be set from 0 to -7 dB in 1 dB steps. The output signal 
level and overload level are defined by the sum of the fixed and 
variable pads as described in the Digital interfaces paragraphs. This 
pad arrangement is illustrated in Figure 12-5. 
Local Switching Loss Plan 
12.15 To maximize the traffic performance of the SX-200m DIGITAL 
PABX, connections between analog interface circuits which are 
in the same analog equipment bay may be made by connecting both 
interfaces to the same analog speech path (junctor), without passing 
through the digital switching network in the digital bays. This type of 
connection is known as a “locally switched connection”. The port- 
to-port losses for locally switched connections are shown in Table 
12-2. 
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							Engineering Information 
. 
TOLL 
OFFICE 
/ AT0 
ONS 
OPS 
SS‘l 
ATN 
sx-208  sx-208 MAIN  MAIN 
PABX  PABX 
NOTE: SEE TABLE 12-l FOR CIRCUIT 
REFERENCE DETAILS 
ANALOG 
0 
CD 
XAOD4BRlE 
Figure 12-3 Types of Trunk and Line Interfaces 
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							Engineering information 
TABLE 12-1 
SX-200s DIGITAL PABX LOSS PLAN 
Page 12-6  
						

							Engineering Information 
TABLE 12-1 (CONT’D) 
$5X-200@) DIGITAL PABX LOSS PLAN 
Originating 
Circuit 
ACO( D) 
ACO(A) Connecting Loss (dB) Loss (dB) 
Circuit TX Direction Rx Direction 
ONS(D) 0 0 
ONS(A) -0.2 -0.2 
OPSS 0 0 
OPSL 0 0 
ACO(D) ,O 0 
ACO(A) -0.2 -0.2 
A-T-W) -2.2 -2.2 
AJ-W) -2.0 -2.0 
ATO -3.2 -3.2 
ATO( D) -3.0 -3.0 
sATT 0 0 
ONS(D) -0.2 -0.2 
ONS(A) -0.4 -0.4 
OPSS -0.2 -0.2 
OPSL -0.2 -0.2 
ACO(D) -0.2 -0.2 
ACO(A) . -0.4 -0.4 
A-WV -2.4 -2.4 
AJ-W) -2.2 -2.2 
ATO -3.4 -3.4 
ATO -3.2 -3.2 
sATi= -0.2 -0.2 
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							Engineering information 
TABLE 12-l (CONT’D) 
SX-200@ DIGITAL PABX LOSS PLAN 
TX Direction Rx Direction 
Page 112-B