Modem Call Control

API Reference

The Modem Call Control (mcc) API functions of this API are provided by the modemService service.

IPC interfaces binding

Here's a code sample binding to modem services:

   clientExe.clientComponent.le_mcc -> modemService.le_mcc

Starting a Call

To initiate a call, create a new call object with a destination telephone number calling the le_mcc_Create() function.

le_mcc_Start() must still initiate the call when ready.

The le_mcc_Start() function initiates a call attempt (it's asynchronous because it can take time for a call to connect). If function failed, the le_mcc_GetTerminationReason() API can be used to retrieve the terminal reason.

It's essential to register a handler function to get the call events. Use le_mcc_AddCallEventHandler() API to install that handler function. The handler will be called for all calls' events (incoming and outgoing).

The le_mcc_RemoveCallEventHandler() API uninstalls the handler function.

The following APIs can be used to manage incoming or outgoing calls:

When finished with the call object, call le_mcc_Delete() to free all the allocated resources associated with the object.

Multi-threading/multi-application behaviour: the callRef is linked to a specific client (i.e. connection with the mcc service). Each client will have its own callRef for a same call. That is, if a call event handler is registered by one thread but le_mcc_Create() is called by another thread, they will each get different call references for the same call. So, when multiple threads are being used to work with the same call, a comparison of the call references themselves can't be used to tell whether or not they refer to the same call.

Answering a call

Receiving calls is similar sending calls. Add a handler through le_mcc_AddCallEventHandler() to be notified of incoming calls.

To answer, call le_mcc_Answer(). To reject it, call le_mcc_HangUp().

Ending all calls

A special function can be used to hang-up all the ongoing calls: le_mcc_HangUpAll(). This function can be used to hang-up any calls that have been initiated through another client like AT commands.

Supplementary service.

Calling Line Identification Restriction (CLIR) can be activated or deactivated by le_mcc_SetCallerIdRestrict API. The status is independent for each call object reference. Status can be read with the le_mcc_GetCallerIdRestrict() API. Default value is LE_OFF (Enable presentation of own phone number to remote).

Call waiting and call hold are not yet managed. The event Le_MCC_EVENT_WAITING warns the application for an incoming call, but there's no way to put the current call in hold.

Sample codes

A sample code that implements a dialing call can be found in le_mccTest.c file (please refer to Sample code of Modem Call control page).

Copyright (C) Sierra Wireless Inc. Use of this work is subject to license.