LTSY for Dispatcher Tutorial

LTSY example

A sample LTSY implementation to dial a voice call is given below.

Implementing MLtsyDispatchCallControlDialVoice::HandleDialVoiceReqL() interface:

virtual TInt HandleDialVoiceReqL(RMobilePhone::TMobilePhoneALSLine aCallLine,
RMobilePhone::TMobileAddress&amp, aDialledParty, 
RMobileCall::TMobileCallParamsV1&amp, aCallParamsV1, TBool aIsIsvCall, 
RMobileCall::TCallParamOrigin aCallOrigin) = 0;

/**
     * The CTSY Dispatcher shall invoke this function on receiving the EEtelCallDial
     * request from the CTSY for dialling a voice call.
     * 
     * It is a request call that is completed by invoking
     * CCtsyDispatcherCallback::CallbackCallControlDialVoiceComp
     * 
     * Implementation of this interface should 
     * dial the requested voice call and complete the callback to indicate
     * that an attempt to dial the call has been made.  The callback function is used
     * to indicate the outcome of this attempt to initiate the dialling process.
     * 
     * @param aCallLine The line to use to dial the call. This parameter can have
     * one of two possible values RMobilePhone::EAlternateLinePrimary to use the 
     * primary voice line or RMobilePhone::EAlternateLineAuxiliary to use the 
     * auxiliary voice line. 
     *  
     * @param aDialledParty Details about the dialled party including the phone
     * number to dial.
     * @param aCallParamsV1 The call parameters of the call to dial. If aIsIsvCall 
     * is set to ETrue, only the field RMobileCall::TMobileCallParamsV1::iIdRestrict 
     * and RMobileCall::TMobileCallParamsV1::iAutoRedial fields are valid.  
     * 
     * @param aIsIsvCall Indicates whether the call originated from a third party
     * application which would have used the CTelephony class to dial the call. 
     * This information is provided in case the LTSY wishes to do special handling
     * for third party calls, for example, not allow third party applications to
     * place emergency calls. See also 
     * MLtsyDispatchCallControlQueryIsEmergencyNumber::HandleQueryIsEmergencyNumberSyncL
     * See also: CTelephony::DialNewCall and RMobileCall::DialISV
     * 
     * @param aCallOrigin The origin of the dial request.  For example, whether the dial  came from an Etel client or the SIM or another source. 
     * 
     * @return KErrNone on success; KErrNotSupported if the LTSY does not  support handling of this request or another error code 
     *indicating the failure otherwise.
     */

Call back function to complete the call dial request:

EXPORT_C void CCtsyDispatcherCallback::CallbackCallControlDialVoiceComp(
    TInt aError, TInt aCallId)

/**
 * Callback function to be used by the Licensee LTSY to complete a pending
 * MLtsyDispatchCallControlDialVoice::HandleDialVoiceReqL
 * 
 * When a dial attempt is made via the above mentioned interface, the LTSY has the 
 * responsibility of allocating a unique Call ID to the call.  For more 
 * information, see the documentation on aCallId below.  
 * 
 * @param aError The error code to be returned to the CTSY Dispatcher by the LTSY
 * indicating the outcome of the attempt to dial the requested call.  This should
 * be KErrNone if the dialling process could be started successfully.  Otherwise
 * another error code to indicate the failure should be returned.
 * 
 * @param aCallId The call ID of the call that the dial attempt refers to which
 * has been allocated by the LTSY.  This should be a number between 1 and 
 * KMaxCallIdValue and should be unique across all call modes (voice, data etc.).  
 * For example, if a request for a voice call is made and the LTSY allocates 
 * this call an ID of 1 and a request for a data call is requested, the LTSY 
 * should allocate a Call ID which is not the same as that already allocated for 
 * the first voice call.
 * 
 */

To indicate call status change notifications, use the following callback:

EXPORT_C void CCtsyDispatcherCallback::CallbackCallControlNotifyCallStatusChangeInd(
    TInt aCauseCode, TInt aCallId, RMobileCall::TMobileCallStatus aMobileCallStatus)

/**
 * Used by an LTSY to indicate to the CTSY that there has been a change in the 
 * status of a call. For example, if the CTSY has previously made a dial request 
 * to make a voice call, the LTSY can call this API to notify the CTSY 
 * of progress of the call through the dialling, connecting and connected states.
 * 
 * The aCauseCode parameter should be used to indicate the reason for the change 
 * in status of a call.
 * 
 * In the case of a call going idle (aMobileCallStatus = RMobileCall::EStatusIdle)
 * specific cause codes need to be returned to the Common TSY to indicate
 * specific causes of status changes:
 * 
 * To indicate that an active call has been released normally by either party,
 * set aCauseCode = KErrGsmCCNormalCallClearing.
 *  
 * To indicate that a mobile originated call that is being dialled has gone
 * idle because the remote party has rejected the call, set
 * aCauseCode = KErrGsmCCCallRejected or another error code (which is != KErrNone)
 * to indicate the reason for rejection.
 *  
 * If a mobile originated call is being dialled and the user cancels dialling,
 * causing the call to go idle, set aCauseCode = KErrGsmCCNormalCallClearing.
 *  
 * When an incoming call goes idle because the client has rejected it
 * (done using RCall::HangUp on the ringing call), set
 * aCauseCode = KErrGsmCCUserBusy.
 * 
 * @param aCauseCode The cause of the change in call status. 
 * 
 * @param aCallId The Call ID of the call whose status has changed.
 * 
 * @param aMobileCallStatus The new status of the call refered to by aCallId.
 * 
 * @see RMobileCall::NotifyMobileCallStatusChange
 */

Implement other functions supported by the baseband and it is the responsibility of the LTSY to return appropriate error code in the call back function if it fails to establish a call.