Nortel DMS-100 Series General Description Manual page 20

1-4 DMS-100 ringing overview
Figure 1-2 Normal versus immediate ringing on 1FR line
Ringing request received
Normal
ringing
(immediate
ringing
disabled)
Immediate
ringing
enabled
The effects of immediate ringing on the power ringing signal differ between
LME and LCE. In LME, when immediate ringing is enabled, the DMS-100
schedules power ringing during the next available time slot in the ringing
portion of the ringing cycle. Ringing is removed at the end of the last time slot
in the ringing portion of the ringing cycle.
For example, in Figure 1-2, "Normal versus immediate ringing on 1FR
line." immediate ringing is enabled on the LME, the first power ringing burst
applies at the start of time slot 1 and continues to the end of time slot 3. This
results in a ringing burst truncated to 1.5 s rather than a complete 2-s burst.
In LCE, like LME, when immediate ringing is enabled, the DMS-100
schedules power ringing during the next available time slot in the ringing
portion of the ringing cycle. Ringing is removed when the 2-s burst has
completed.
297-1001-131 Standard 06.01 October 2000
Ringing cycle 1
Ringing
applied
0 1 2 3 4 5
Time slot 0 not available.
Try cycle 2.
0 1 2 3 4 5
6-s delay
Time slot 0 not available. Try time slot 1. Time slot 1
available. Apply power ringing at slot 1.
0 1 2 3 4 5
0.5-s delay
Apply power ringing
Ringing
applied
6 7 8 9 10 11 0 1 2 3 4 5
Time slot 0 available. Apply
power ringing at Time slot 0.
6 7 8 9 10 11 0 1 2 3 4 5
Apply power ringing
6 7 8 9 1011 0 1 2 3 4 5
Ringing cycle 2
6 7 8 9 1011
6 7 8 9 1011
6 7 8 9 1011