1. Web Services In M-Commerce cmarinos@netmode.ntua.gr

2. WEB SERVICES & MOBILITY ws-basic activities : describe, publish/unpublish/update, discover, invoke/bind ws-basic roles : provider, requestor, broker issues in using mobile devices : cost, performance, unavailability, bandwidth, devices handicaps (low cpu, memory, small display)

3. Two Different Scenarios : Mobile Device acting as Requestor –ws-aware mobile device (fat client) –ws-agnostic mobile device (thin client) Mobile Device acting as Provider USING WS IN MOBILE DEVICES

4. MOBILE DEVICE (=REQUESTOR) ws-aware mobile device mobile device dispose a ws client application in order to enable services to mobile users interacts with the services provider and the service broker using ws-aware protocols over wireless networks (e.g. WLAN, GSM/GPRS) fat client with XML processing capabilities

5. using ws in fat clients have numerous advantages : 1.enables manufactures to deploy internet solutions built on global standards 2.makes applications more dynamic as they can invoke services based on the users context 3.facilitates the interoperability and integration with enterprise applications and with applications running on other mobile devices MOBILE DEVICE (=REQUESTOR) ws-aware mobile device

6. applicable in cases with multiple companies MOBILE DEVICE (=REQUESTOR) ws-aware mobile device

7. proxy-based architecture : a proxy entity plays the role of the mobile device representative in the fixed network infrastructure proxy interacts via ws-aware protocols with the service provider and the service broker and returns the results using ws-agnostic protocols (e.g. WAP/WML, iMode/cHTML) mobile device does not need to support ws functionality (thin client scenario) MOBILE DEVICE (=REQUESTOR) ws-agnostic mobile device

8. proxy handles the fact that mobile devices non- deterministically lose network connectivity (=keeps the results of service invocation and forward them to the mobile device when the connectivity is re-established) proxy may minimize information flow over low/medium speed wireless links can take care various tasks (e.g. keeping users bookmarks, managing its cache) central entity that controls all user data and decides what services are accessible by the mobile device (single point of failure) MOBILE DEVICE (=REQUESTOR) ws-agnostic mobile device

9. scenario applicable in the case where mobile user moves into unfamiliar environment and obtain services with no previous knowledge (e.g. airport – flight info, duty free offers) MOBILE DEVICE (=REQUESTOR) ws-agnostic mobile device

10. scenario that facilitates the provision of ws that are context sensitive and location based services various applications where the scenario can be used technical issues : 1.mobility of the mobile host (MH – WSP), 2.responsibility for immediate notifications to clients- requestors following the terminal relocation, 3.secure use of registrys update/notification operation MOBILE DEVICE (=PROVIDER)

11. Solutions : 1.mobility (=APIs automatically updates the UDDI service when relocations are experienced) 2.notification(=each provider maintain a table with addresses of known clients) 3.mobility – aware security frameworks (e.g. Wireless Application Protocol PKI introduced to address widely personal trusted devices) MOBILE DEVICE (=PROVIDER)

12. CASE STUDIES Microsoft & Vodafone Mobile Office SMS Nokia & Sun Microsystems Deploying Mobile Web Services using Liberty Alliances Identity Web Services Framework

13. REFERENCES [1] T. Pilioura, A. Tsalgatidou, S. Hadjiefthymiades, Scenarios of using Web Services in M-Commerce, ACM Sidecar Exchanges, Vol. 3, No. 4, January 2003. [2] MAAMAR, Z., MANSOOR, W., YAHYAOUI, H. 2001. E-Commerce through Wireless Devices. In Proceedings of IEEE 10th International Workshops on Enabling Technologies: Infrastructure for Collaborative Enterprises (WETICE'01), IEEE Press, 328-333. [3] Deploying Mobile Web Services using Liberty Alliances Identity Web Services Framework (ID-WSF), White Paper [4] Mobile Web Services, http://www.microsoft.com/serviceproviders/mobilewebservices/default.asp