Modem User Manual

LZT 123 1834 13
SIM
SIM
GSM
ENGINE
GSM
ENGINE
DCE
DCE
DTE
DTE
SYSTEM INTERFACE
STATUS &
RESPONSE
COMMAND
& CONTROL
MS
GSM
NETWORK
DC
POWER
GR64
SIM
SIM
GSM
ENGINE
GSM
ENGINE
DCE
DCE
DTE
DTE
SYSTEM INTERFACE
STATUS &
RESPONSE
COMMAND
& CONTROL
MS
GSM
NETWORK
DC
POWER
GR64
Figure 2.2-2 Main Blocks in a Wireless System (external micro-controller)
In accordance with the recommendations of ITU-T (International Telecommunication
Union - Telecommunications Standardization Sector) V.24, the TE communicates with
the MS over a serial interface.
The functions of the wireless modem follow the recommendations provided by 3GPP
(3rd Generation Partnership Project) and ITU-T. 3GPP is a collaboration agreement
that was established in December 1998. The collaboration agreement brings
together a number of telecommunications standards bodies which are known as
Organizational Partners . The current Organizational Partners are ARIB, CCSA, ETSI,
ATIS, TTA, and TTC.
3GPP specifies a set of AT commands for controlling the GSM element of the wireless
modem; these commands are supplemented by Sony Ericsson specific commands.
To find out how to work with AT commands, see the AT Commands Manual.