Location Based Services Mobile Computing - CNT 5517-5564

1. Location Based ServicesMobile Computing - CNT 5517-5564 Dr. Sumi Helal Professor Computer & Information Science & Engineering Department University of Florida, Gainesville, FL 32611 helal@cise.ufl.edu

2. Reading Materials • Paolo Bellavista, Axel Küpper and Sumi Helal “Location Based Services – Back to the Future,” the Standards, Tools and Emerging Technologies Department, IEEE Pervasive Computing Magazine, Sumi Helal, Editor, Volume 7, Number 2, April-June 2008 • Roxin, A., Dumez, C., Wack, M., and Gaber, J. 2008. Middleware models for location-based services: a survey. In Proceedings of the 2nd international Workshop on Agent-Oriented Software Engineering Challenges For Ubiquitous and Pervasive Computing (Sorrento, Italy, July 06 - 06, 2008). AUPC '08. ACM, New York, NY, 35-40. • C. Lee, A. Helal and D. Nordstedt, "μJini Proxy Architecture for Impromptu Mobile Service Access," Proceedings of the Workshop on Next Generation Service Platforms for Future Mobile Systems (SPMS 2006). In conjunction with the IEEE/IPSJ International Symposium on Applications and the Internet (SAINT), Phoenix, Arizona, January 2006. (pdf)

3. Overview • What is LBS? What is impromptu LBS? • Examples • Why did LBS not take off for the past 10 years? • LBS Evolution • Today’s LBS classification • LBS Middleware • Mobile Service Discovery • Mobile Service Delivery • Ongoing research

4. Location Based Services • A service whose rendering depends on the location of the service requester, service provider or both • Mobile, networked Applications • Input: geo references from Assisted GPS system • Client/server interaction • Output: Location relevant Information • Example: weather, tourist information, ..

5. Elements of LBS • Querying • Advertisement • Discovery • Delivery • Localization Management • No installs • Lease / Release • Location Privacy

6. Impromptu LBS

7. Impromptu LBS

8. Impromptu LBS

9. Why Difficult to Believe LBS did not take off?

10. Great Phones/ Great B/W2.5-3G Mobile Phones shown • GPRS, EDVO, UMTS, … • 500-800 K speed Who needs Hot Spots!

11. The WiMAX Possibility • Wireless & Mobile Broadband at 10-30 miles range • The Fat Pipe problem. Mobile TV: no thank you!

12. Commoditization Pressure • The Skype Phenomena • VoIP as a cheaper mobile phone service • Signs of commoditization of the Telecom Industry?  pressure on Telecom to explore new sources of revenues (= New Services).

13. Early LBS (1) • Content-Centric • Current LBSs are content-oriented and lack the logic necessary for user interactivity (no user models captured in the service) • Content could be boring! And has limited impact as compared to interactions • Content-centricity was not by choice, it was more of a constraint. Downloading content was what is available, and was challenging enough (e.g. WAP performance)

14. Early LBS (2) • Precision of the Localization subsystem • Cellular triangulation useful for some applications but inadequate for others. • On-board GPS (e.g., Assisted GPS) offers better accuracy, but does not work indoor. • “Locate nearest Pizza place!” era of LBS • Does not need accuracy • Outdoor!

15. Early LBS (3) • Telecom-centric • Localization data owned by Telco; location based information provided by telco; telco partners with other content providers (such as Verizon and Microsoft MSN – never took off, even with a massive publicity campaign). • The centricity and encumbrance by telecom proved to be non-scalable and actually an impedance to the much-anticipated proliferation of the elegant LBS concept

16. The First Fix:From Content to Applications • Redefining LBS to be a framework not an application. • As an application, LBS, gets a location, passes it to an authoritative server (@telco), and then delivers back location relevant information to the target. This is one application – very limiting. • As a framework, LBS gets a location, passes it to servers owned or provided by third party participants (small, medium and large businesses, from a variety of industries), and then delivers back location relevant services (applications) to the target. This is unlimited number of applications. This is very flexible and much more exciting!

17. Requirement to the First Fix:Impromptu (flash) Delivery of Applications. • Middleware and intelligent markup languages should be developed to enable the development of compact size code that takes a few second to download and a couple of seconds to get interpreted and run on a mobile target equipped with the middleware engine. • Code not content: compact code gets interpreted to native computations utilizing native resources. • Net effect: • A few seconds instead of 10’s of seconds or minutes in delivery time • No installation, de-installation or management. • Applications appear & disappear.

18. The Second Fix:Enable Indoor Localization • More investment in indoor localization technology. • Standardizations • Solve Privacy issues • Bluetooth Example: Through the creation of a new “Legalized Snooping” profile • Snoop protocol • Pay customer to snoop • Access to customer profile • On the fly tailored applications • Technologies: Wi-Fi, Ultra wideband, or licensed frequencies.

19. The Third FixAlter LBS Business Model • Telco to sell and profit from basic services only (data pipe, SMS pipe, ..and perhaps application pipe in the future). Telco no longer define LBS. • Empower third party to transact LBS directly with end users, using (and paying for) Telco basic services. This is B2C with B2B embedding. • Any business should be allowed to participate and offer LBS. A business should be able to develop “LBSlets” using simple LBS development kits. • Businesses can host their own LBSs either directly or through a web hosting service. • User to own and sell his/her LBS user profile.

20. LBS Evolution Integration of location data into social network services Merging of outdoor and indoor LBS applications LBS features and supporting services Location-based dating • Introduction of finder LBSs • Restaurants • Filling stations • ATMs • … Google launches GoogleMaps First Child tracking services First commercial Proactive LBSs Application-oriented LBSs First location-based Mobile gaming 1996 2000 2004 2008 2012 FCC passed E-911 mandate Emergence of RFID Mass market penetration of GPS-capable mobiles Deadline phase 1 of E-911 Launch of Galileo First commercial WLAN fingerprinting systems New middleware features for spam avoidance and privacy preservation Key technologies & activities Intro- duction of Android handset Introduction of 3G networks First handset Supporting Java Location API Deadline phase 2 of E-911 First GPS capable iPhone GPS works indoors Emergence of common middleware for proactive, cross-referencing, and multi-target LBSs

21. LBS Evolution community orientation cross-referencing multi-target self-referencing single-target operator-centric positioning device-centric positioning content-oriented application-oriented user centrality reactive proactive proactivity degree

22. Mobile Service Discovery • Impromptu service discovery and delivery • Widespread use of diverse mobile devices • Wireless hotspots and broadband coverage • Location-based and other context-relevant services • Most importantly: the Business Opportunity • Challenges of impromptu mobile services • User mobility • Service portability across a wide range of mobile devices • Relevance and suitability: avoiding the morass of the Web • User Manageability • Acceptable quality of service • An effective infrastructure is a key to realize this vision • Context-aware service discovery • Device-independent service delivery

23. Service Discovery Protocols • Service discovery is relatively new (late 1990s). • IETF SLP, Sun Jini, UPnP, and Salutation • Announce-listen model (Soft state model) • Ad-hoc Service Discovery • IBM DEAPSpace • Konark Service Gossip Protocol [LHD+03][HDV+03] • Wide-area Service Discovery • Wide-area extension to SLP (WASRV) • Berkeley Secure Service Discovery Service (SSDS)

24. Sever Selection Mechanisms • Selection of the best among replicated services • Availability, fault-tolerance, load-balance, and scalability • Server-side approach • HTTP redirect • Network-side approach • DNS round-robin, DNS LOC RR, DNS GL RR • IP Anycast, Cisco DistributedRouter • IETF RSerPool (Reliable Server Pooling) • Client-side approach • SmartClient

25. Three-tier Mobile SDP(Choonhwa Lee et al) • Provide the most appropriate service to mobile users by exploiting any meaningful context information • Service classification by coverage

26. Services Contexts Service Profile Device Description Other Context Information BA GSR ProximityServices Domain Services Profile Server at home Global Services Conceptual Model of the Three-tier Discovery Architecture • Different selection criteria • Guided selection • User transparency • Scalability (Performance)

27. campus … CSE Bld MSL Bld … Printer serivce 4th floor 3rd floor Printer? … E467 E 451 Domain Discovery Sub-system • On-campus registry hierarchy example

28. Global Service Discovery … Domain hierarchy GSR-capable registry BA-capable registry GSR BA … Domain-3 GSR Domain-2 BA service BA BA Client Domain-1

29. Service Delivery Technologies • Over the Air Downloads (OTA) • UI tailored to work on target device downloading the service • Universal Interactions • Device-Independent UI Languages • W3C XForms, INCITS/V2 URC, XIML, UIML, CMU PUC • UI Remoting Approaches • UPnP Remote UI, Jini Proxy Architecture • UI Authoring Styles (W3C DI) • Single Authoring • A single generic description (all-in-one approach) • Multiple Authoring • A UI for each type of client devices (Jini ServiceUI project) • Flexible Authoring • Customized UIs for popular platforms and automatically generated interfaces for rare platforms

30. Java for Mobile Services • Java technologies for service portability and dynamic service discovery • J2ME • Java runtime environments optimized for mobile devices • Configurations: CLDC and CDC • Profiles: MIDP, FP, PP, and other optional packages • Jini • Dynamic service discovery framework on top of Java RMI • Jini Surrogate Architecture for resource-poor devices • Jini requires J2ME CDC/RMI Profile as the minimal runtime environment

31. JiniProxy Architecture VTC-Based Service Delivery Jini Protocol Jini Proxy (VTC Service Delivery) Mobile Clients Standard Jini Protocol Context-Aware Service Discovery Enhanced Jini Protocol Context-aware Jini Lookup Service Service Providers

32. JiniProxy Architecture • Jini Proxy • functions as a proxy to a Jini network w.r.t. service discovery • serves client devices as VTC servers for service delivery • Three delivery mode to bring discovered services to resource-constrained mobile devices • Client executable mode • VTC MIDlet emulation mode • VTC J2SE emulation mode • Capable of selecting the best adaptation depending on the service context

33. Thin-Client Approach to Service Delivery • VTC (Virtual Thin Client)-based adaptation • Three delivery modes: Client executable, MIDlet service emulation, J2SE service emulation • Built on top of Sun Jini and AT&T VNC • Smart-phone client (J2ME capable phone) • Four main components • Jini Protocol • Resident Client • VTC • Jini Proxy

34. Jini System Architecture

35. (4) Display update KVM event (3) KVM event (3) KVM event X11 input event MIDlet runner (2) Jini protocol Jini Proxy • (1) VNC server • pool VNC desktop pool MIDlet Emulator

36. VTC non-MIDlet Emulation Mode ZOOM

37. Performance Measurement