Enabling +Application Level Roaming

diff -r 51a74ef9ed63 -r ae94777fff8f Symbian3/SDK/Source/GUID-49205F79-C17B-4126-BDB2-D759B91B5894.dita --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/Symbian3/SDK/Source/GUID-49205F79-C17B-4126-BDB2-D759B91B5894.dita Fri Jun 11 12:39:03 2010 +0100 @@ -0,0 +1,109 @@ + + + + + +Enabling +Application Level RoamingApplication-level roaming (ALR) enables your application to roam +to use the best available data connection while operational. +

To use application-level +roaming:

+ +Initiate an Internet +connection using the Connection Manager API and the Internet destination network. +In this example it is assumed that the best available access point for Internet +is GPRS. +

RConnection handle is returned to the application.

+ + +Register for mobility +API sending NewL(RConnection handle, MMobilityProtocolResp&) to +the Connection Manager API. + +Use Sockets Client +API to open RSockets with RConnection handle. +

RSocket handle is returned to the application.

+ +Initiate normal +socket communication to the Sockets Client API. This data transfer uses GPRS. + A WLAN access point becomes available. The Connection Manager API sends PreferredCarrierAvailable(old +access point, new access point, is upgrade, not seamless) to the +application. The application decides to switch to the better access point. +It closes the old socket using the Sockets Client API. + +Send MigrateToPreferredCarrier() to +the Connection Manager API. Note: The application can also IgnorePreferredCarrier(). +In that case it would just keep using the existing socket. The connection +is moved in the Connection Manager API. The WLAN access point is activated +and RConnection handle is moved from the GPRS interface to WLAN. NewCarrierActive(new +IAP) is returned to the application. The WLAN access point is now +ready to be used. + +Use Sockets Client +API to open RSockets with RConnection handle. This data transfer uses WLAN. + +Transfer data using +the Sockets Client API to confirm that the connection works. + +Send NewCarrierAccepted() to +the Connection Manager API. This is the point of no return. + +Continue transferring +data using the Sockets Client API. This data transfer uses WLAN. + + +

ALR is enabled.

+ +class CALRApplication : public CActive, public MMobilityProtocolResp + { +... + public: // From MMobilityProtocolResp + void PreferredCarrierAvailable( TAccessPointInfo aOldAPInfo, + TAccessPointInfo aNewAPInfo, + TBool aIsUpgrade, + TBool aIsSeamless ); + void NewCarrierActive( TAccessPointInfo aNewAPInfo, TBool aIsSeamless ); + void Error( TInt aError ); + private: // Data + RConnection iConnection; + CActiveCommsMobilityApiExt* iMobility; + }; +// When the connection starts, iMobility is created and it registers the connection to receive mobility messages. +iMobility = CActiveCommsMobilityApiExt::NewL( iConnection, *this );When apreferred access point becomes available, the implementation of CALRApplication::PreferredCarrierAvailable is called. MigrateToPreferredCarrier Mobility message is sent to the middleware in order to roam to this preferred access point. +void CALRApplication::PreferredCarrierAvailable( TAccessPointInfo aOldAPInfo,TAccessPointInfo aNewAPInfo,TBool aIsUpgrade,TBool aIsSeamless ){ + // aOldAPInfo contains the current IAP used by the connection. + // aNewAPInfo contains the newly available IAP that can be used by the connection. + if ( aIsSeamless ) + { + // It is Seamless. E.g. Mobile IP enabled. + } + else + { + // sockets used by the connection should be closed here. + // We ask to migrate to the Preferred Carrier. + iMobility->MigrateToPreferredCarrier(); + } + } +Once the connection roamed to the new access point, the implementation ofCALRApplication::NewCarrierActive is called. The application reopens its sockets on the connection. If the socket connection is fine, the application sends the NewCarrierAccepted Mobility message to the middleware. + +void CALRApplication::NewCarrierActive( TAccessPointInfo aNewAPInfo, TBool aIsSeamless ) + { + // aNewAPInfo contains the newly started IAP used now by the connection. + if ( aIsSeamless ) + { + // It is Seamless. E.g. Mobile IP enabled. + } + else + { + // sockets used by the connection should be reopened here. + // We accept the new IAP. + iMobility->NewCarrierAccepted(); + } + } + \ No newline at end of file