1、Location Based ServicesMobile Computing - CNT 5517-5564,Dr. Sumi Helal Professor Computer 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 encumbran

2、ce by telecom proved to be non-scalable and actually an impedance to the much-anticipated proliferation of the elegant LBS concept,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 se

3、rver (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 the

4、n delivers back location relevant services (applications) to the target. This is unlimited number of applications. This is very flexible and much more exciting!,Requirement to the First Fix:Impromptu (flash) Delivery of Applications.,Middleware and intelligent markup languages should be developed to

5、 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

6、 few seconds instead of 10s of seconds or minutes in delivery time No installation, de-installation or management. Applications appear & disappear.,The Second Fix:Enable Indoor Localization,More investment in indoor localization technology. Standardizations Solve Privacy issues Bluetooth Example: Th

7、rough 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.,The Third FixAlter LBS Business Model,Telco to sell and profit from basic services o

8、nly (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

9、 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.,1996,2000,2004,2008,2012,Key technologies & activities,FCC passed E-911 mandate,Deadlin

10、e phase 1 of E-911,Deadline phase 2 of E-911,First handset Supporting Java Location API,Mass market penetration of GPS-capable mobiles,Launch of Galileo,Intro- duction of Android handset,First commercial WLAN fingerprinting systems,Emergence of RFID,First GPS capable iPhone,LBS features and supporti

11、ng services,Introduction of 3G networks,Introduction of finder LBSs Restaurants Filling stations ATMs ,Google launches GoogleMaps,First Child tracking services,First location-based Mobile gaming,GPS works indoors,Integration of location data into social network services,Location-based dating,First c

12、ommercial Proactive LBSs,Emergence of common middleware for proactive, cross-referencing, and multi-target LBSs,Application-oriented LBSs,New middleware features for spam avoidance and privacy preservation,Merging of outdoor and indoor LBS applications,LBS Evolution,LBS Evolution,Mobile Service Disc

13、overy,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 acr

14、oss 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,Service Discovery Protocols,Se

15、rvice 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+03HDV+03 Wide-area Service Discovery Wide-area extension to SLP (WASRV) Berkeley Secure Service

16、Discovery Service (SSDS),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 RS

17、erPool (Reliable Server Pooling) Client-side approach SmartClient,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,Conceptual Model of the Three-tier Discovery Architectu

18、re,Different selection criteria Guided selection User transparency Scalability (Performance),Domain Discovery Sub-system,On-campus registry hierarchy example,Global Service Discovery,service,BA,Client,GSR,Domain hierarchy GSR-capable registry BA-capable registry,BA,GSR,BA,BA,Domain-1,Domain-2,Domain

19、-3,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

20、 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,Java for Mobile Serv

21、ices,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 Archite

22、cture for resource-poor devices Jini requires J2ME CDC/RMI Profile as the minimal runtime environment,Jini Proxy Architecture,Mobile Clients,Jini Proxy (VTC Service Delivery),Context-aware Jini Lookup Service,Jini Protocol,Service Providers,Enhanced Jini Protocol,Context-Aware Service Discovery,VTC-Based Service Delivery,Standard Jini Protocol,Jini Proxy Architecture,Jini Proxy functions as a proxy to a Jini ne