GTE Omni Si Database Technical Practices Issue 1 Manual

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TL-130500-1001Blockage10.3.2 Blockage can only occur when the number of voice
Occurrencetraffic line and trunk circuits in a PCMUS group exceeds the
number of available time slots. Since it is unlikely that all the
time slots in a PCMUS group will be busy simultaneously for any
length of time, blockages rarely happen. To further reduce the
possibility of blockage, a simple traffic study (traffic engineering)
should be done. This will prevent putting too much hardware into
a group. Traffic engineering is...

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TL.-130500-1001
Determining10.3.5 (Figure 10.4) To calculate the estimated usage of a
CCS UsagePCMUS group:
of a System1. Multiply the number of lines by the letermined CCS value.
2. Multiply the number of trunks by the determined CCS value.
NOTE: Because DID and DOD trunks are one way, they can be
considered low traffic.
3. Add these totals together.
(L X 
CCS/L) + (T X CCS/T) = CCSigroupL = total lines in the group
T=total trunks in the group
NOTE: Calculate all circuits on a line or trunk...

TL-4 30500-l 001Dedicated10.4 Certain equipment must have a time slot reserved for its
Time Slots
use at all times (this is called a dedicated time slot). Each
dedicated time slot is effectively removed from the pool of time
slots associated with a PCMUS group.
The Attendant Console requires a dedicated time slot because
the attendant must be accessible at all times. Dedicated time
slots affect the traffic handling capacity of a PCMUS group.
Table 10.2 lists the equipment that uses dedicated time slots....

TL-130500-1001Progress Tone10.4.1 Access to a PPTR (FB-17280-A) card circuit is
Recognizerrequired for stations allowed to access an SCC through MEW(Most Economical Route Selection).
The system supports a maximum of two cards with four circuits
per card. Each circuit of the PPTR requires a dedicated time
slot.The number of stations using the feature determines the
number of circuits used (Table 10.3).
Table 10.3Required PCM Progress Tone Recognizer PCBs
Number of PCM Progress
Tone Recognizer
Circuits...

TL-130500-1001
l CAS Branch system with DTMF stations- DTMF receivers should be provided for each E&M Tie trunk
(FB-17201 -A or FB-51267-A)
- Each Tie line (E&M circuit) will be counted as two more
DTMF stations
- Each Tie line (E&M trunk circuit) that sends PDTMF signals
to the PABX will be counted as two more PDTMF stations
To determine additional 
PDTMFs required for release link trunks
in the CAS Branch option, see Table 10.4.
Table 10.4
Required PRLT CircuitsPRLTPRLT
PDTMF
CircuitsRequired...

TL-130500-1001Table 10.5Required PDTMF Receivers
Number of PDTMFsFB-17203-A
Maximum Number of
(TCR Circuits)PDTMF 
PCBs RequiredPDTMF Stations
2717
3
156
4
1111
52176
62250S-l 60
NOTES:
0 This table is based on 3.75 originating calls per PDTMF
station, and eight seconds holding time.
l This table is used only to determine the number of circuits
used by telephones.
The total quantity of PDTMF receivers is established by adding
all PDTMFs required for stations, CAS Tie trunks, PRLTS (PCM
release link...

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One additional receiver must be provided with each of the first
two 
RLTs if the CAS Branch option is used. These DTMF
receivers are dedicated to the 
RLTs. The remaining RLTs share
the pooled DTMF traffic with the lines and trunks, and the 
RLTsmust be considered in sizing the receiver pool. Any receiver can
be used for line and trunk DTMF receiver traffic use, but by
reserving two receivers (for 
RLTs), lines and trunks cannot
exhaust the available supply of receivers.
Determine...

TL-130500-1001Table 10.6DTMF Receivers Required to Provide aP=
0.01 Grade of Service
Traffic In CCSDTMF Receivers Required
5.32
17.03
33.44
53.05
75.06
99.0
7
124.08
NOTES:l The actual probability of a delay greater than 3 seconds =
0.005.l The 
CCSlline and CCSitrunk values used in this example are
assumed; actual value will vary from system to system.
0 The Eight-Party Conference card uses up to eight time slots
when fully loaded, but typically requires five time slots.
0 The typical busy-hour...