1 Dms-100 Ringing Overview; Introduction - Nortel DMS-100 Series General Description Manual

1 DMS-100 ringing overview

Introduction

The DMS-100 ringing system performs automatic number identification
(ANI) and coin functions and supports the following three ringing systems
used in North America:
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The DMS-100 ringing signal is based on a 6-second (s) cycle. The cycle is
divided into 12 time slots, which are the smallest divisions of the ringing cycle.
The duration of each time slot is software controlled and is typically set to 0.5
s. In many DMS-100 peripherals, the ringing cycle is further divided into
larger divisions consisting of one or more time slots.
The DMS-100 line module equipment (LME), line concentrating equipment
(LCE), and Subscriber Carrier Module (SCM) each use a distinctive ringing
cycle format. For example, each subdivides the ringing cycle differently.
The ringing cycle in the LME is divided into 12 time slots, which are typically
set to 0.5 s each. The ringing cycle in the Line Concentrating Module (LCM),
like the LME, is also divided into 12 time slots. However, the LCM ringing
cycle is further divided into four subcycles. The subcycles consist of one or
more time slots.
The ringing cycle in the SCM, like the LME and LCM, is divided into 12 time
slots. It is further subdivided into three phases consisting of four time slots of
2 s each.
A diagram of each of the DMS-100 ringing cycle formats is shown in the
following figure.
Bell Canada
Bell operating company (BOC)
Rural Electrification Association (REA)
DMS-100 Family DMS-100 Ringing System BASE15 and up
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