Cell id GVHD : Hà Duyên Trung Sv thực hiện :Lương Kim Doanh Trần Hoàng Điệp Nguyễn Trung Thành Ngô Quang Thìn

Positioning Techniques Cell ID E-OTD Assisted GPS (A-GPS)

Cell ID

Round Trip Time (RTT) Corresponds to the Timing Advance Parameter in GSM RTT = T RX – T TX T TX - Time of transmission of the beginning of a downlink DPCH frame to a UE T RX - Time of reception of the beginning (the first detected path, in time) of the corresponding uplink DPCCH frame from the UE Measurements are possible on Downlink DPCH transmitted from NodeB and Uplink DPDCH received in the same NodeB Measured in active mode only

Cell ID Based Method Simplest method MS position is estimated with the knowledge of serving NodeB Position can be indicated as: Cell Identity of the serving cell Service Area Identity Location co-ordinates the serving cell Accuracy of the estimation depends on the coverage area of the cells

Enhancements to Cell ID Wide range of enhancements for the Cell ID based method –Cell ID + RTT (Round Trip Time) –Cell ID + Reference Signal Power Budget –Cell ID + RSCP (Received Signal Code Power)

Cell ID + RTT (Round Trip Time) Identical to Cell ID+TA (Timing Advance) method in GSM Accuracy of RTT measurements in UMTS is significantly higher (36m) RTT is used to calculate the distance from the NodeB to MS using propagation models Performance can be enhanced by incorporating the RTT measurements from all Node Bs in the Active Set Accurate RTT measurements through Forced Hand Over (FHO)

Cell ID + RTT (Round Trip Time) Some simulation results for urban & suburban areas (by Jakub Borkowski & Jukka Lempiainen) TopologyUrbanSuburban 67%95%67%95% 6-sector / m200 m50 m150 m 6-sector / m220 m55m170 m

Cell ID + Reference Signal Power Budget (RSPB) Coverage area of a cell can be determined by using RSPB RSPB gives information about - Node B transmitted power - Isotropic path loss - Coverage threshold at coverage area border for a given location probability - Cell radius for indoor and outdoor coverage SRNC may compare the received power levels with the power budget to accurately position the UE

Cell ID + RSCP (Received Signal Code Power)

GSC-9, Seoul11 Enhanced Observed Time Difference (E-OTD) MS Round Trip Timing

E-OTD Overview Triangulation based technique Handset based solution Does not use GPS in handset Enhancement to handset software required

Mobiles must synchronize with each BTS. Base stations regularly emit a synchronization burst. Mobiles monitor synchronization bursts of serving and all neighbor cells.

Mobile listens to bursts sent from neighboring BTSs Mobile records burst arrival times Position is triangulated from: -Coordinates of BTSs -Arrival time of burst from each BTS -Timing differences between BTSs

E-OTD - Site Implementation LMU Must Measure the Transmission Time of the Burst

Assisted GPS (A-GPS)

GSC-9, Seoul18 The Global Positioning System Base station MS GPS Ground Station ephemeris, almanac, clock...

GSC-9, Seoul19 The GPS Problem Base station MS ephemeris, almanac, clock... GPS Ground Station

GSC-9, Seoul20 Assisted GPS (A-GPS) Base station MS GPS Reference Receiver ephemeris, almanac, clock... DGPS, timing, xyz GPS Ground Station

GSC-9, Seoul21 Assisted GPS (A-GPS) Base station MS GPS Reference Receiver ephemeris, almanac, clock... DGPS, timing, xyz GPS Ground Station