Agilent Technologies 8960 10 Series Reference Manual page 173

Determining if a Call Connect/Disconnect Process is Completed
The most common technique used by control programs to determine if a call connect/disconnect process has
completed (either successfully or unsuccessfully), is to repeatedly query the call state using the
CALL:STATus:STATe? query command inside a program loop. The return value from each query is checked to
determine if the connect/disconnect process is proceeding or has reached the desired state.
There are, however, some inherent problems associated with this technique:
• The rapid polling of the instrument increases bus traffic and places increased demand on the instrument's
processors to respond to the constant stream of queries.
• The control program must handle failure conditions. For example: if a call origination process is started but
the call never leaves the Idle state, the control program must incorporate some technique to prevent the
program from staying in the loop forever waiting for a transition out of the Idle state.
The test set implements a set of commands designed specifically for call connect/disconnect synchronization.
(see "Step 8: Disconnect the Mobile Station from the BSE" on page 196
These commands directly address many of the inherent problems discussed above. When properly used these
commands eliminate the need for rapid polling of the instrument, and relieve the programmer of many of the
tasks associated with error handling.
Call Connect/Disconnect Synchronization Commands
Call Connected State Query Command The call-connected-state query command is used to query the
connected state of a call. This command allows the control program to determine if a call is connected (that is,
in the Connected state) or disconnected (that is, in the Idle state), with a built-in provision to automatically
wait if the call is in one of the transitory states.
The basic operation of this query is:
• If the call is in the Connected state when the query is received by the test set, the query immediately
returns a 1.
• If the call is in the Idle state (that is, disconnected) when the query is received by the test set, the query
immediately returns a 0.
• If the call is in one of the transitory states (that is, Setup Request, Proceeding, Alerting, or Disconnecting)
when the query is received by the test set, the query hangs (that is, does not return an answer) until the
call state changes to either Idle or Connected and then behaves as above.
The call-connected-state query command can be used at any time to determine the connected state of a call.
The built-in provision to automatically wait if the call is in one of the transitory states eliminates the need for
rapid polling when the call-connected-state query command is used to synchronize to a call connect/disconnect
process.
NOTE If repeat paging is on, a call origination process can stay in one of the transitory states until the
mobile either answers the page or until the user stops the paging process. This means that if a
call-connected-state query command is sent to the test set with repeat paging set to on, the query
could hang "forever".
S:\Hp8960\E1960A GSM Mobile Test Application\A.04 Release\Reference_Manual\Chapters\prog_prog_guide_step4.fm
Step 4: Establish an Active Link with Mobile Station
for call disconnect synchronization).
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