-> Explanation of various techniques for Localization like Triangulation and Proximity Based Techniques. (OTDOA/ AOA/ GSM Fingerprinting/Hybrid technologies, etc.) -> Working of GPS and its drawbacks. -> AGPS- working and advantages. -> E911 call processing in AGPS. ->Location Based Services in 4G

2. Mrinal Agrawal

3. Sapna D’Souza

4. Megha Sarang

6. What is the need for Location Positioning services?? Regulation, FCC E-911 Mandate, passed in 1996 911 caller’s cell phone location should be determined and reported to Public Service Answering Point (PSAP) to within 100 meters 67% by every wireless operator Difficulties with method of triangulation: Accuracy and Capital

7. LBS: Location Based Services Information and entertainment service Example of Telecommunications convergence Uses Multiple Technologies namely- Geographic information system Location technologies Internet Wireless communication Mobile devices LBS includes vehicle tracking and mobile commerce

9. Delay in time between the signal transmission and signal reception of the GPS signal gives distance

10. The signal travels at a known speed

11. The signals provide information about the satellite’s location

13. Location Based Services

14. Definition: A service provided to a subscriber based on the current geographic location of the MS. Convergence of technologies

16. Three principle techniques from physical localization point of view 1. Signal strength and Network parameters  CellID, Timing Advance (TA), Round Trip Time (RTT) 2. Triangulation/ Trilateration:  Distance based Trilateration: GPS  Angle or Direction based Trilateration: AOA, TOA, AFLT, EOTD. 3. Proximity  Relies on Reference Planes.

20. GPS

22. Priniciple used : time of arrival(TOA)

23. Kinds of information used:

24. 1) Pseudorandom code

25. 2) Almanac data

26. 3) Ephemeris data

27. Four steps in determining position:

28. Step I : Triangulation

29. Step II : Measuring distance

30. Step III : Perfect timing

32. Drawbacks of GPS Time to first fix : 30sec to 10 min Weak satellite signal strength indoors High power consumption

34. Principle used : time of arrival

35. Kinds of information used:

36. 1) pseudorandom code

37. 2) almanac data

38. 3) ephemeris data

39. Four steps in determining position:

40. Step I : triangulation

41. Step II : measuring distance

42. Step III : perfect timing

44. Assisted- Global Positioning System (A-GPS) Enhances the start-up performance of a GPS satellite based positioning system Used extensively with GPS capable cellular phones Highly useful in E911 technologies

45. Reasons for Introducing A-GPS Launching a 911 emergency call would take the receiver several minutes to establish a fix GPS would have poor performance indoors, under dense foliage, in (urban) canyons etc GPS receiver would drain too much power from the handset. Incorporating a GPS receiver in the handset would be far too expensive and too bulky

46. How does A-GPS solve these Problems? Two categories of Assistance: 1) More quickly acquires satellites 2) Calculations done remotely The Assistance server has good satellite signal and lots of computation power. The network can provide Accurate time assistance (Atomic Time) It can supply orbital data for the GPS satellites to the cell phone enabling the cell phones to lock the satellites faster Obtains handsets position from MSC + GPS satellite seen by the MS Collects measurements and communicates back to the MS A-GPS receiver passes pseudo random code to the server which helps in calculating MS co-ordinates and hence the distance

47. A-GPS Arichitecture

48. E-911 Call Processing E911 call initiated by a GPS capable handset is sent to a WARN via BSC and MSC E-911 call provides some information about the serving cell to the WARN WARN consists of a database of GPS satellites Handset inquires about its position parameters from the satellites and provides this information to the PDE Handsets response is processed by the PDE and the calculated position is sent to the PSAP. Parallel to this a dedicated voice channel is established between the caller and the PSAP

49. LBS IN 4G

50. GPS-exclusive wireless location solution does not provide the accuracy or reliability needed to drive 4G applications. Severely limited in dense urban and indoor environments. For the type of applications that 4G promises, the solutions need to be accurate to within tens of meters, and work seamlessly across urban, suburban, rural, indoor and outdoor environments Hybrid approach solves the problem as it provides the accuracy, latency, reliability and yield needed for 4G networks. Hybrid obtained using independent location technologies like Assisted GPS (A-GPS), Enhanced Cell-ID (ECID), Uplink Time Difference of Arrival (UTDOA) pools each technology's advantages while mitigating the other technologies' weaknesses.

51. LBS in WIMAX and LTE

53. Mobile WiMAX, on the other hand, got a head start in time to market and is being deployed by Clearwire in partnership with Sprint.

54. LBS in WiMAX is based on the basic network reference model (NRM) specified by the WiMAX Forum.

57. The MS receives location requests from the applications and takes necessary measurements, and determines its location and provides it to the other requesting applications through upper layer messaging.

58. The LBS-ADV message delivers the XYZ coordinates, the absolute and relative position of serving and neighboring BS .

60. Most vendors are prepared to support either standard or most likely both standards. Because both technologies are based on Orthogonal Frequency Division Multiplexing (OFDM) they should be able to theoretically co-exist and interoperate. The target is that LTE networks would be able to support handsets enabled with WiMAX, and WiMAX networks would be able to support LTE handsets.

61. The OMA is focusing on the user plane approach. User plane networks take the location intelligence out of the carrier's mobile network elements and allow handsets to connect directly to location servers through IP, where the servers can be inside or outside the wireless service provider's network. The wireless network is therefore transparent to location applications, eliminating the need for carriers to build location performance directly in 4G networks, instead relying on outside providers for application serving.

62. OMA has developed a standard for user plane location called Secure User Plane Location (SUPL), providing a blueprint for how wireless location technology should work on 4G networks. SUPL enabled handsets connect directly to SUPL servers through IP transport over packet data services, taking advantage of this more powerful, flexible protocol. The wireless data transport is transparent and generic, thus permitting LTE, WiMAX or any other data protocol including GPRS/EDGE, UMTS/HSPA, EVDOor WiFi.

63. Thank You!