PoC Session Establishment

In our OSA-based PoC design, the AS first sets up the callback interface IpAppPoCCallControlManager (see Steps 1 ~ 3 in Figure A.2) and subscribes notifications for specific PoC-related events from the PoC SCF (see Steps 4 and 5 in Figure A.2). With this subscription, when a PoC event (e.g., PoC session establishment request) occurs at the SCS, a notification will be sent to the AS. When receiving an event notification from the PoC SCF (see Step 6 in Figure A.2), the AS starts to initiate a PoC session. In the following example, a PoC session for PoC group with the display name “Lab117” is requested to be established. This group is identified by the SIP URI “sip:[email protected]”, which contains two members: party A and party B. The PoC session establishment procedure is described in the following steps (see Figure A.2).

Step 1. The AS control logic appLogic invokes appPoC function setCallback- ForIpAppPoCCallControlManager. This function instructs appPoC to generate the IpAppPoCCallControlManager interface object and to pass the object reference to the PoC SCF. The IpAppPoCCallControlManager interface provides management functions for PoC service (e.g., function reportMediaNotificationWithGroupID invoked

Figure A.2 Message flow for PoC session establishment

at Step 6, function initiatePoCCallWithMediaRes invoked at Step 19, and function addMemberRes invoked at Step 30).

Step 2. appPoC creates the IpAppPoCCallControlManager object to provide the callback functions to be called by the PoC SCF.

Step 3. appPoC invokes function setCallback to pass the reference of IpAppPoCCall- ControlManager to the PoC SCF. Through this reference, the PoC SCF invokes the callback functions at Steps 6, 19, and 30.

Steps 4 and 5. appLogic invokes the PoC SCF function createMediaNotification through appPoC to request notifications for specific PoC-related events (e.g., the PoC SCF receives a session request for a PoC group).

Step 6. Suppose that PoC party A attempts to establish a PoC session with group Lab117 that has the SIP URI “sip:[email protected]”. The PoC SCF invokes the callback function reportMediaNotificationWithGroupID to notify the AS of this PoC session request. This notification includes the media stream information for party A (e.g., codec, the algorithm for compressing and decompressing voice information, such as G.711, G.723, etc) and the SIP URIs of both party A and group Lab117.

Step 7. IpAppPoCCallControlManager creates the PoCCall object to store information associated with this new PoC session (e.g., SIP URIs of the PoC group and group members, media stream information, the interface object references related to this session in both the PoC SCF and the AS, etc).

Steps 8 and 9. PoCCall generates the IpAppPoCCall object and the IpAppPoCCallLeg object for party A (i.e., IpAppPoCCallLeg (A) in Figures A.2 and A.3). IpAppPoCCall provides the PoC SCF with the session control management functions (e.g., function callEnded invoked at Step 4 in Figure A.3). IpAppPoCCallLeg (A) is used to receive specific events of party A from the PoC SCF.

Steps 10 and 11. Both interface object references generated at Steps 8 and 9 are stored in

PoCCall and passed back to the PoC SCF as the return values of function reportMediaNotificationWithGroupID invoked at Step 6.

Steps 12 and 13. IpAppPoCCallControlManager invokes function newPoCCall through appPoC to notify appLogic of the PoC session request.

Step 14. appLogic retrieves the group member list of the requested group Lab117. The list can be obtained from the GLMS server through the GLMS SCF or from the AS database.

Step 15. After the group member list (i.e., SIP URIs of party A and party B) is obtained, appLogic stores it in PoCCall through function addCallParty.

Step 16. appLogic invokes the PoCCall function start to establish the PoC session.

Steps 17 and 18. PoCCall invokes the PoC SCF function initiatePoCCallWith- MediaReq through appPoC. This function asks the PoC SCF to reserve resources for the PoC session and party A; e.g., reserve a RTP port to transmit media streams to party A.

Steps 19 - 21. When the resources for the PoC session and party A are reserved, PoC SCF invokes the callback function initiatePoCCallWithMediaRes through the IpAppPoC- CallControlManager and appPoC to inform PoCCall that the resources are reserved successfully.

Step 22. PoCCall generates the IpAppPoCCallLeg object for party B (i.e., IpAppPoC- CallLeg (B) in Figures A.2 and A.3). This object is used to receive party B related events from the PoC SCF (e.g., function callLegEnded invoked at Step 1 in Figure A.3).

Step 23. PoCCall invokes function createCallLeg and passes the callback reference of IpAppPoCCallLeg (B) to the PoC SCF.

Step 24. PoCCall invokes the PoC SCF function mediaStreamMonitorReq. This function requests the PoC SCF to report the media stream information of party B to the AS when party B joins in the PoC session (see Steps 26 and 27).

Step 25. To invite party B to join in the session, PoCCall invokes the PoC SCF function routeReqWithGroupID. This function requests the PoC SCF to deliver the invite

message to party B.

Steps 26 and 27. When party B joins in the session, the media stream information of party B is passed to the PoC SCF. The PoC SCF invokes the callback function mediaStream- MonitorRes through IpAppPoCCallLeg (B) to notify PoCCall about the media stream information for party B.

Steps 28 and 29. PoCCall invokes the PoC SCF function addMemberReq through appPoC to reserve resources for party B; e.g., a RTP port to transmit media streams to party B.

Steps 30 - 32. The PoC SCF invokes the callback function addMemberRes through IpAppPoCCallControlManager and appPoC to inform PoCCall that the resources have been reserved for party B.

At this moment, the PoC session is successfully established for parties A and B. To end a PoC session, the PoC session termination procedure is executed (see Figure A.3). The details are given below.

Figure A.3 Message flow for PoC session termination

Steps 1 and 2. When party B leaves the PoC session, the PoC SCF invokes callback function callLegEnded through IpAppPoCCallLeg (B) to notify PoCCall that party B has left.

Step 3. PoCCall invokes the function destroy of IpAppPoCCallLeg (B) to destroy this object.

Steps 4 and 5. When the last party leaves the session (i.e., party A in this example), the PoC SCF invokes the callback function callEnded through IpAppPoCCall to notify PoCCall of the leaving for the last party.

Steps 6 and 7. Since all call parties have left, PoCCall invokes functions destroy of both IpAppPoCCallLeg (A) and IpAppPoCCall to destroy these objects.

Step 8. PoCCall invokes the appPoC function callEnded to notify the end of the PoC session.

Step 9. appPoC invokes the PoCCall function destroy to delete this PoCCall object.

Step 10. appPoC invokes the appLogic function callEnded to notify the end of the PoC session.

Bibliography

[1] 3GPP. Third Generation Partnership Project; Technical Specification Group Services and Systems Aspects; Virtual Home Environment/Open Service Access. 3G TS 23.127 v6.1.0, 2004.

[2] 3GPP. Third Generation Partnership Project; Technical Specification Group Core Network; Open Service Access (OSA); Application Programming Interface (API); Part 1:

Overview; (Release 6). 3G TS 29.198-1 v6.3.1, 2004.

[3] 3GPP. Third Generation Partnership Project; Technical Specification Group Core Network; Open Service Access (OSA); Application Programming Interface (API); Part 3:

Framework. 3G TS 29.198-03 v6.4.0, 2005.

[4] 3GPP. Third Generation Partnership Project; Technical Specification Group Services and Systems Aspects; Service Requirement for the Open Service Access (OSA); Stage 1. 3G TS 22.127 v7.0.0, 2005.

[5] Bargh, M.S., Hulsebosch, R.J., Eertink, E.H., Prasad, A., Wang, H., and Schoo, P. Fast Authentication Methods for Handovers between IEEE 802.11 Wireless LANs. ACM WMASH 2004, 51-60, 2004.

[6] Berndt, H., Hamada, T., and Graubmann, P. TINA: Its Achievements and Its Future Directions. IEEE Communications Surveys and Tutorials, 3(1): 2-11, 2000.

[7] Boneh, D., and Franklin, M. Identity-based Encryption from the Weil Pairing. Advances in Cryptology-CRYPTO’01, 2139: 213–239, 2001.

[8] Chang, M.-F., Wu, L.-Y., and Lin, Y.-B. Performance Evaluation of a Push Mechanism for WLAN and Mobile Network Integration. IEEE Transactions on Vehicular Technology, 55(1): 380-383, 2006.

[9] Chen, J.-H., Pang, A.-C., Sheu, S.-T., and Tseng, H.-W. High Performance Wireless

Switch Protocol for IEEE 802.11 Wireless Networks. ACM Mobile Networking and Applications, 10(5): 741-751, 2005.

[10] Eastlake, D., and Jones, P. US Secure Hash Algorithm 1 (SHA1). IETF RFC 3174, 2001.

[11] Hankerson, D., Menezes, A., and Vanstone, S. Guide to Elliptic Curves Cryptography.

Springer-Verlag, 2004.

[12] Haverinen, H., and Salowey, J. Extensible Authentication Protocol Method for Global System for Mobile Communications (GSM) Subscriber Identity Modules (EAP-SIM).

RFC 4186, 2006.

[13] Hung, H.-N., Lin, Y.-B., Lu, M.-K., and Peng, N.-F. A Statistic Approach for Deriving the Short Message Transmission Delay Distributions. IEEE Transactions on Wireless Communications, 3(6): 2345-2352, 2004.

[14] Hwu, J.-S., Chen, R.-J., and Lin, Y.-B. An Efficient Identity-based Cryptosystem for End-to-end Mobile Security. IEEE Transactions on Wireless Communications, 5(9):

2586-2593, 2006.

[15] IEEE. IEEE Standard for Information Technology - Telecommunications and Information Exchange between Systems - Local and Metropolitan Area Networks - Specific Requirements Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications Amendment 2: Fast Basic Service Set (BSS) Transition. IEEE Standard 802.11r, 2008.

[16] ITU-T Recommendation X.509. Information Technology - Open Systems Interconnection - the Directory: Public-key and Attribute Certificate Frameworks. ITU-T, 2000.

[17] Kassab, M., Belghith, A., Bonnin, J.-M., and Sassi, S. Fast Pre-Authentication based on Proactive Key Distribution for 802.11 Infrastructure Networks. ACM Wireless Multimedia Networking and Performance Modeling, October 2005.

[18] Kleinrock, L. Queueing System Volume 1: Theory. John Wiley & Sons, 1976.

[19] Lin, Y.-B. Performance Modeling for Mobile Telephone Networks. IEEE Network, 11(6):

63-68, 1997.

[20] Lin, Y.-B., and Chlamtac, I. Wireless and Mobile Network Architectures. John Wiley and Sons, 2001.

[21] Lin, Y.-B., and Pang, A.-C. Wireless and Mobile All-IP Networks. Wiley, 2005.

[22] Ma, W., Fang, Y., and Lin, P. Mobility Management Strategy based on User Mobility Patterns in Wireless Networks. IEEE Transactions on Vehicular Technology, 56(1):

322-330, 2007.

[23] Madson, C., and Glenn, R. The Use of HMAC-SHA-1-96 within ESP and AH. IETF RFC 2404, 1998.

[24] Moerdijk, A.-J., and Klostermann, L. Opening the Networks with Parlay/OSA: Standards and Aspects behind the APIs. IEEE Network, 17(3):58-64, 2003.

[25] Open Mobile Alliance. Push to Talk over Cellular (PoC) – Architecture. OMA-AD-PoC- V2_0-20080507-C, 2008.

[26] Open Mobile Alliance. PoC User Plane. OMA-TS-PoC_UserPlane-V2_0-20080507-C, 2008.

[27] Pang, A.-C., and Chen, Y.-K. A Study on Availability of Mobility Databases.

International Conference on Information Networking (ICOIN), 195-200, 2004.

[28] Pyarali, I., and Schmidt, D.C. An Overview of the CORBA Portable Object Adapter.

ACM StandardView Magazine, 6(1):30-43, 1998.

[29] Qian, Y., Hu, R.-Q., and Chen, H.-H. A Call Admission Control Framework for Voice over WLANs. IEEE Wireless Communications, 13(1): 44-50, 2006.

[30] Revest, R., Shamir, A., and Aldeman, L. A Method for Obtaining Digital Signature and Public Key Cryptosystems. Communication of the ACM, 21(2): 120-126, 1978.

[31] Rong, B., Qian, Y., Lu, K., Chen, H.-H., and Guizani, M. Call Admission Control Optimization in WiMAX Networks. IEEE Transactions on Vehicular Technology, 57(4):

2509-2522, 2008.

[32] Ross, S.M. Stochastic Processes. John Wiley & Sons, 1996.

[33] Rosenberg, J., Schulzrinne, H., Camarillo, G., Johnston, A., Peterson, J., Sparks, R., Handley, M., and Schooler, E. SIP: Session Initiation Protocol. IETF RFC 3261, 2002.

[34] Schulzrinne, H., Casner, S., Frederick, R., and Jacobson, V. RTP: A Transport Protocol for Real-Time Applications. IETF RFC 3550, 2003.

[35] Shamir, A. Identity-based Cryptosystems and Signature Schemes. Advances in Cryptology–CRYPTO’84, 196: 47-53, 1984.

[36] Stallings, W. Cryptography and Network Security. Prentice Hall, 1999.

[37] Walkden, M., Edwards, N., Foster, D., Jankovic, M., Odadzic, B., Nygreen, G., Moiso, C., Tognon, S.M., de Bruijn, G. Open Service Access: Advantages and Opportunities in Service Provisioning on 3G Mobile Networks Definition and Solution of Proposed Parlay/OSA Specification Issues. Project P1110 Technical Information EDIN 0266-1110, 2002.

[38] WiMAX Forum. WiMAX Forum Network Architecture, Stage 3: Detailed Protocols and Procedures. WiMAX Forum, Release 1.1.0, 2007.

[39] Yang, S-R. Dynamic Power Saving Mechanism for 3G UMTS System. ACM/Springer Mobile Networks and Applications (MONET), 12(1): 5-14, 2007.

Publication List

z Journal Publications

1. Chou, C.-M., Hsu, S.-F., Lee, H.-Y., Lin, Y.-C., Lin, Y.-B., and R.S. Yang. CCL OSA: A CORBA-based Open Service Access System. International Journal of Wireless and Mobile Computing, 1(3/4): 289-295, 2006.

2. Hwu, J.-S., Hsu, S.-F., Lin, Y.-B., and Chen, R.-J. End-to-end Security Mechanisms for SMS. International Journal of Security and Networks, 1(3/4): 177-183, 2006.

3. Hsu, S.-F., Lin, Y.-C., and Lin, Y.-B. An OSA Application Server for Mobile Services. International Journal of Pervasive Computing and Communications, 3(1/2): 102-113, 2007.

4. Hsu, S.-F., and Lin, Y.-B. Selecting Transition Process for WLAN Security. Wireless Communications and Mobile Computing, 8(7): 921-925, 2008.

5. Hsu, S.-F., and Lin, Y.-B. A Key Caching Mechanism for Reducing WiMAX Authentication Cost in Handoff. Accepted and to appear in IEEE Transitions on Vehicular Technology.