Example: Establishing Logical Channels Without Parameter Negotiation; Figure 13: Establishing The Multiplexer Control Channel And The Logical Channel - Siemens Mux_guide_v06 User Manual

Multiplexer User's Guide
Confidential / Released
4.4 Example: Establishing logical channels without parameter
negotiation
•
Send AT+CMUX=0; wait for the response
•
Send Request SABM for DLCI = 0; wait for the response
•
Send Request SABM for all requested DLCIs; wait for the response
As a result the multiplexer is established and information / data can be transmitted
(⇒ ready for Information Transfer).
Customer
µC
Closed Down
Disconnected
Disconnected
DLCI = 0
Connected
DLCI = 0
Disconnected
DLCI = 1
Connected
DLCI = 1

Figure 13: Establishing the multiplexer control channel and the logical channel

Mux_guide_v06
Serial
interface
RequestStartUp
ResponseStartUp
ConfirmStartUp
RequestSABM
DLCI = 0
ConfirmUA
DLCI = 0
RequestSABM
DLCI = 1
ConfirmUA
DLCI = 1
Page 32 of 36
GSM engine µC
Closed Down
IndicationStartUp
Disconnected
Disconnected
DLCI = 0
IndicationSABM
DLCI = 0
ResponseUA
DLCI = 0
Connected
DLCI = 0
Disconnected
DLCI = 1
IndicationSABM
DLCI = 1
ResponseUA
DLCI = 1
Connected
DLCI = 1
s
m
o b i l e
30.06.2004