1. 1 An overview Always Best Connected Networks Dênio Mariz Igor Chaves Thiago Souto {denio,igor,mouse}@gprt.ufpe.br Aug, 2004

2. 2 Agenda  Motivation  ABC concept  ABC scenario  ABC actors  ABC reference model  Solution components  Conclusions

3. 3 Global Connectivity  Over the last few years, we have experienced a variety of access technologies being deployed 2G  3G cellular systems Worldwide coverage  Wireless LAN (WLAN) solutions have been extensively deployed to provide hot spots access Airports, hotels, conference centers High-bandwidth Internet access  Fixed access tied to WLAN in office and home environments  DSL + Bluetooth + WLAN + Cellular +... Connectivity (almost) everywhere Environments of multiple access technologies

4. 4 The ABC concept  Always Best Connected (ABC) refers to Being not only always connected But also being connected in the best possible way at all times  ABC Networks concept allows a personalized connectivity to the devices and access technologies that best suit his or her needs Example: Combining worldwide coverage of GSM with high bandwidth of WLAN hot spots  Depending on the application and user preferences, a user can be connected over multiple accesses in parallel  ABC concept include all types of access technologies: Fixed and wireless Existing and future technologies

5. 5 What is Best Connected ?  The definition of Best depends on different aspects Personal preferences Size and capabilities of the device Application requirements Security Operator or corporate policies Available network resources Networks coverage Price (Other ?)

6. 6 Challenges  When realizing the ABC scenario Relationships and agreements between access operators and service providers The user experience of the ABC Technical solutions for network and terminal

7. 7 ABC Scenario 1. Maria gets up in the morning and checks her e-mail in her laptop using a DSL connection. She will have a meeting soon and starts downloading a huge document. 1

8. 8 ABC Scenario 2. Maria unplug her laptop and heads for the office. The laptop automatically checks for other available accesses and finds 3G coverage. The download resumes. 2

9. 9 ABC Scenario 3. Maria takes the subway and join to the already started meeting using her PDA. The conference tool adapts to the limited capabilities of the access technology (sound only). 3

10. 10 ABC Scenario 4. Maria leaves the subway and walks to her office. The meeting continues on her PDA now with video (B&W). 4

11. 11 ABC Scenario 5. Maria gets to the office and transfers the conference to her desktop which is connected to the WLAN. The conference tool now enables full video. 5

12. 12 ABC Actors  A number of people and organizations are involved in providing ABC service ABC user Access operator ABC service provider Application service provider The corporation the user works (allowing corporate access to the user)  One corporation can play several roles  there may be several corporations with business agreements among them  A common AAA infrastructure is needed

13. 13  The technical aspects involved in ABC solutions are distributed along several components  Integrated terminal: The ABC terminal and Access device are one and the same  Personal Area Network (PAN) scenario: Several ABC terminals using the same access device ABC Reference Model Access network ABC service provider network Application server Corporate network Correspondent terminal ABC terminal Access devices PAN or combined device

14. 14 User Experience  Subscription  Seamless information delivery  Mobility support  User interaction and perception

15. 15 Solution Components  Content adaptation  Profile handling  Mobility management  AAA support  Access selection  Access discovery Content adaptation Profile handling Mobility Management AAA support Access selection Access discovery

16. 16 Access Discovery  Terminal must discover available networks and access devices At boot up Also periodically to find out if a better option is available  Key issues To define a generic set of parameters describing access networks and devices  Operator, QoS, cost, type of access device How the information about access networks should be collected (statistics, measurements, operator info, …) To handle the dynamics of PAN devices

17. 17 Access Selection1/2  Access selection is the process of deciding over which access network to connect at any point in time Terminal-based selection Network-based selection User intervention  Network-based Allows for load balancing May reduce signaling over radio interface Can maximize total system throughput Seems will be dominant (my bet )

18. 18 Access Selection2/2  Aspects to consider: User profile (preferences) must be taken in consideration  There may be a set of preferences (at home, at work, …) Application requirements Network characteristics (available bandwidth, Cost, …) Device capabilities  Key issues in Access Selection On line Algorithms to select the access subsystem among several available options and restrictions How to provide a easy-to-understand tool for the user to show him his current ABC options

19. 19 AAA Support1/2  Authentication, Authorization, and Accounting (AAA)  Purpose Verify user identity (authentication) Verify the service to which ABC user is entitled (authorization) Collect data to present the bill (accounting)  AAA is a key component in ABC scenario PAN Access network ABC service Corporate network Several corporations providing pieces of an entire solution

20. 20 AAA Support2/2 ACME AAA Server 3G access network Access operator and ABC service provider: ACME Hotspot AAA Server WLAN access network Access operator: hotspot Business agreement 1) user moves into WLAN coverage 2) Authentication request 3) Authentication request

21. 21 Mobillity Management  Mobility is one of the key issues in ABC may be provided as part of ABC service Mobility enhancements to provide: 1) Session continuity; 2) Session transfer; 3) Reachability (or Presence)  Session continuity To maintain a session when terminal moves between different access networks Mobile IP can help on this  Session transfer To maintain a session when terminal moves between different devices (PAN)  Reachability The ability to reach an ABC user at his current access network and device Session Initiation Protocol (SIP) can help on this

22. 22 Profile Handling  ABC service providers can offer various services to different users  User profile contains user personal preferences Choice of access Application adaptation VPN solutions AAA information  The user profile is stored by ABC service provider Can be updated by the user  Security is a key issue handling user profiles!

23. 23 Content Adaptation  Approaches for content adaptation The application to detect changes in network characteristics (or terminal capabilities) and request application server to adapt contents accordingly The terminal to provide information about the access network to the application and application server The access network to provide information to the application server and/or terminal regarding QoS changes on network  Key issues Signaling among application, terminal, access network Support for dynamic reconfiguration depending on a variety of external factors: media formats, mobility, QoS matching the access network characteristics

24. 24 Conclusions  ABC concept offers the user connectivity over multiple access technologies optimized application performance seamless mobility session management  It is a new paradigm for network integration PAN, WPAN, LAN, WLAN, 2.5G, 3G, 4G … New business relationships  Introduces new challenges Access discover Access selection Mobility, signaling, session stability Content adaptation AAA and other security aspects Others

25. 25 References  E. Gustafsson and A. Jonsson, Always Best Connected, IEEE Wireless Communications, Vol. 10, No. 1, pp. 49-55, Feb 2003.