User Guide

PAMS
Technical Documentation
NSB–1
System Module
Page 3 – 11
Original 06/98
Functional Description
The DCS 1900 engine consist of a Baseband/RF module with connec-
tions to a separate user interface module. Baseband and RF modules
are interconnected with PCB wiring. The engine can be connected to ac-
cessories via the bottom system connector, the Intelligent Battery Inter-
face (IBI) connector.
The RF submodule receives and demodulates radio frequency signals
from the base station and transmits modulated RF signals to the base
station. It consists of functional submodules Receiver, Frequency Syn-
thesizer and Transmitter.
The Baseband module comprises audio, control, signal processing and
power supply functions. It consists of functional submodules CTRLU
(Control Unit; MCU, DSP, logic and memories), PWRU (Power Supply;
regulators and charging) and AUDIO_RF (audio coding, RF–BB inter-
face).
Modes of Operation
UR4 operates in cellular mode and a local mode for service:
– Cellular mode, phone controlled by OS and partly by base station
– Locals mode, used by Production and After Sales.
– Acting Dead mode
– Power Off mode
– Flash mode
Cellular Mode
In cellular mode phone performs all the tasks to place and release calls.
Also charging and communication between accessories and phone are
done during this mode by OS. Signaling and handover functions are sup-
ported by base station.
Power off
In the power–off mode only CCONT is active. Power–off mode can be left
by pushing the PWR–key, connecting charger to the phone, real time
clock interrupt or intelligent battery interrupt.
Locals Mode
Locals mode is used for testing purposes by Product Development, Pro-
duction and After Sales. The Cellular Software is stopped (no signalling
to base station), and the phone is controlled by MBUS/FBUS messages
by the controlling PC.