Chapter 3: AT Commands Reference
June 30, 2008 AT Commands Reference Manual 3-449

Multiple Channel Configuration

The configurations listed below are recommended to achieve maximum use of parallel channels
with minimum conflicts.
Two Channel Configuration
DLC1 – Data channel dedicated to CDS
DLC2 – ACCH (AT command channel; includes all AT commands except CDS related
commands)
Figure 3-21: Two-channel Configuration
Note: Between data sessions, DLC1 is IDLE (in command mode).
Four-channel Configuration
DLC1 – GRLC or Logger
DLC2 – ACCH
DLC3 – CSD
DLC4 – GPRS
Figure 3-22: Four-Channel Configuration
Note: Between sessions, the Data and GPRS channels are IDLE (in command mode).
Two virtual channelsG24
D
L
C
1
App 1
External Modem
D
L
C
2
App 2
AT comm ands
GPRS CSD