0RELOH$JHQW6ROXWLRQVIRU$FFRXQWLQJ0DQDJHPHQWLQ0RELOH&RPSXWLQJ Paolo Bellavista, Antonio Corradi, Silvia Vecchi 'LSDUWLPHQWRGL(OHWWURQLFD,QIRUPDWLFD6LVWHPLVWLFD8QLYHUVLW\RI%RORJQD ^SEHOODYLVWDDFRUUDGLVYHFFKL`#GHLVXQLERLW $EVWUDFW 7KHFRQYHUJHQFHRIPRELOHWHOHFRPPXQLFDWLRQVDQGWKH ,QWHUQHWJOREDOV\VWHPIRUFHVWRUHFRQVLGHUWUDGLWLRQDOFOL HQWVHUYHUVROXWLRQVIRUQHWZRUNDQGV\VWHPVPDQDJHPHQW 7KHSDSHUFODLPVWKDWDFFRXQWLQJLQWKHPRELOLW\HQDEOHG ,QWHUQHW UHTXLUHV VXSSRUW LQIUDVWUXFWXUHV KRVWHG LQ WKH IL[HGQHWZRUN7KHVHLQIUDVWUXFWXUHVVKRXOGPRQLWRUFRQ WURODQGUHJLVWHUUHVRXUFHFRQVXPSWLRQORFDOO\ZLWKLQWKH GRPDLQV ZKHUH XVHUVWHUPLQDOV G\QDPLFDOO\ PRYH WR ZLWKRXWUHTXLULQJFRQWLQXRXVFRQQHFWLYLW\ZLWKUHPRWHDQG FHQWUDOL]HG DFFRXQWLQJ KRPH PDQDJHUV ,Q DGGLWLRQ WKH SDSHU VKRZV WKDW WKH 0RELOH $JHQW 0$ WHFKQRORJ\ LV VXLWDEOH WR RYHUFRPH WKH OLPLWV RI WUDGLWLRQDO DFFRXQWLQJ VROXWLRQV LQ VHYHUDO PRELOLW\HQDEOHG XVDJH VFHQDULRV 0$VFDQPD[LPL]HORFDOLW\LQDFFHVVLQJPRQLWRULQJGDWD FDQHQDEOHDFFRXQWLQJHYHQLQFDVHRIWHPSRUDU\GLVFRQ QHFWLRQ FDQ LQVWDOO QHZ PRQLWRULQJFRQWURO EHKDYLRU G\ QDPLFDOO\ DQG FDQ VXSSRUW VHVVLRQGHSHQGHQW VROXWLRQV 7KHSDSHUILQDOO\SUHVHQWVWKHGHVLJQDQGLPSOHPHQWDWLRQ RI WKH 0$EDVHG 0LGGOHZDUH IRU 0RELOLW\ $FFRXQWLQJ 0DQDJHPHQW 0$0  WRJHWKHU ZLWK VRPH XVH FDVHV VKRZLQJWKHDGYDQWDJHVRIWKH0$DGRSWLRQ  ,QWURGXFWLRQ Advances in mobile telecommunications and portable device miniaturization propose new service scenarios where users, access terminals and even service compo- nents can geographically move during provisioning. This forces to face several technical challenges at different lev- els of abstraction, from network connectivity to location tracking, from device-dependent service adaptation to lo- cation-dependent service provisioning. In addition, mobile computing and the Internet are converging and likely to merge, with the aim of providing a unique support infra- structure, capable of hosting network elements, service components, and fixed/mobile access terminals [1]. This mobility-enabled Internet also changes the per- spective of network, systems and service management. Traditional management solutions are tailored to fixed in- frastructures of network elements, and management re- search activities have proposed architectures to deal with geographic distribution and heterogeneity of resources and service components. IETF and OSI have proposed man- agement models based on Client/Server (C/S) interaction [2, 3] and on several variations of it. If one can organize hierarchies of C/S components to achieve decentralization and scalability, the interaction among management entities is usually statically determined for clients and servers in exchanging remote information. These solutions do not fit well global systems in rapid evolution where the enter- ing/exiting of unknown heterogeneous mobile components is usual. These cases ask for the possibility of dynamically installing new management behavior without any service suspension. Some significant management research efforts investigate the support of code mobility in a secure and interoperable way. They have been tagged with different names, such as Management by Delegation [4], Active Networks [5], Programmable Networks [6], Mobile Agent-based management [7, 8]. Among the different activities belonging to the man- agement domain, accounting can be defined as the process of monitoring, controlling and registering the amount of administered resources that an authorized user (or a user group) exploits. Accounting becomes particularly relevant and challenging in mobile computing. Accounting solu- tions require tracking user locations in a global environ- ment and coordinating remote resources, possibly located in different networks with heterogeneous mechanisms for monitoring and access control. Accounting systems should face temporary disconnections and network partitioning. In addition, they should organize control strategies on the base of previous user actions in remote network localities, e.g., to permit the access to one service component if the client has not used up the time quota reserved for that service. The current hardware/software limits of several catego- ries of mobile devices, from personal digital assistants to programmable cell phones, impose an infrastructure over the fixed Internet to support specific issues for their net- work connectivity and service access [1]. In the same way, a support is necessary to provide accounted services in any network locality willing to open its resources to mo- bile accessibility. The paper claims that mobility-enabled accounting management requires a dynamic and extensi- ble support infrastructure, capable of evolving during service provisioning depending on client mobility. The infrastructure should be in charge of monitoring, control- ling and registering resource consumption locally where mobile users/terminals move to, without requiring con- Proceedings of the Seventh International Symposium on Computers and Communications (ISCC’02) 1530-1346/02 $17.00 © 2002 IEEE