GeoLENs™ LTE System Features

e-SMLC (e-Serving Mobile  Location Center):

The eSMLC will provide the centralized serving location calculation platform for the evolved UTRAN in LTE. Andrew is actively participating in the 3GPP working groups defining the interfaces, protocols, and functionality for the eSMLC with initial product release slated for 2010.

• 3GPP compliant SLs interface support
• Supporting enhanced cell, time-of-arrival, and UE-based and UE-assisted AGPS location determination technologies as standards emerge.
• It will be supportable as a software upgrade on existing Gen4 MLC deployments
• The eSMLC can co-reside on the MLC with SAS, SMLC, and GMLC functionality

 GMLC (Gateway Mobile Location Center)

• Controls and authenticates requests for a subscriber’s location from applications
• Coordinates transformation of position    information into latitude and longitude that is handed off to an application or PSAP
• Interfaces to MSC and HLR to query for Cell ID positioning, allowing for cost-effective low  accuracy solution
• Interfaces to Public Safety Answering Points (PSAPs) or other Emergency/Public Safety Authorities for E911, E112, etc.
• Supports standards-based interfaces

                - 3GPP/GSM Le interface

                - Mobile Location Protocol (MLP) for location services and European E112 emergency                   interface

                - J-STD-036 for E911 Phase 2 in the U.S.

• Can be combined with SMLC, SAS, SLP, etc. on single equipment platform

GeoLENs™ LTE Locating Methods:

A-GPS based positioning

Hybrid A-GPS Positioning

Assisted-GPS (A-GPS) is a handset-based mobile locating method fundamentally based on GPS locating technology but functionally distributed between the mobile and a centralized server. Mobiles must be specially equipped to receive GPS signals from multiple GPS satellites in order to make measurements of the signals from GPS satellites and relay this information or their calculated position through the mobile network to the SMLC/SAS/SLP software (iSAS: Control Plane, SUPL: User Plane implementations). In cases where the mobile does not compute its own location from GPS data, the SMLC/SAS/SLP uses GPS data relayed from the target mobile to compute the mobile's position. Once determined, the position can be sent to a gateway mobile location center (GMLC) or SUPL Location Platform (SLP) for distribution to the application that originated the location request. A-GPS is a supplemental form of GPS whereby GPS satellite position data is sent from the SMLC/SAS/SLP through the mobile network to the mobile to assist the mobile in determining which GPS satellites it should attempt to acquire. This supplemental data is intended to:

• Speed the mobile's satellite signal acquisition process.
• Increase the mobile's ability to receive signals from the target GPS satellites.

A-GPS is intended to reduce latency and improve other location performance when a mobile's view of GPS satellites is obscured. That can occur when the caller is in a building, in a vehicle, or in an "urban canyon." Although A-GPS does improve overall locating performance, accuracy, latency, and yield performance can be subject to degradation if a mobile's view of GPS satellites is obscured.

Cell ID Positioning

Allows basic location services to be deployed using existing handsets and network capabilities and kick start market interest and revenues.

• Cell sector location coordinates passed to the application
• Can be accomplished using a standalone Gateway Mobile Location Center (GMLC) that connects to MSC and HLR using ATI
• SMLC based when deployed
• Can be configured to provide mid point of the cell if desired

TA/NMR Positioning

• Timing Advance (TA) is an existing parameter conceived to avoid overlapping of bursts transmitted by several Mobile Stations (MSs) in the same cell
• For positioning purposes the TA is an estimate of the absolute distance between MS and serving BTS
• Statistical TA information can be used to adapt to different environments
• By combining TA with the coordinates of the serving BTS and eventually with orientation and angular width of the serving sector, the MS position can be estimated

Uplink Time Difference of Arrival – U-TDOA

UTDOA takes timing measurements of standard handset RF procedures (uplink).  It calculates the difference in the time of arrival of the RF signal between multiple pairs of Location Measurement Units (LMUs) .  The differences in arrival time determine hyperbolic curves between receivers of where the mobile could be.  The location is then estimated by the best intersection of the multiple hyperbolic curves..

 LMUs may also be equipped with antennae capable of providing angle of arrival measurements (AoA) which can augment timing measurements where coverage or DOP is poor.

O-TDOA Location Solutions

• Mobile makes timing measurements on the downlink
• Measurements reported to location server
• Timing measurements may be augmented with other types of measurements such as Round Trip Delays
• Location Server computes fix with a knowledge of timing measurements and base station locations.

User Plane Location (SUPL) Solutions

For User Plane (SUPL) location in GSM networks, please refer to Andrew’s SUPL Location Platform (SLP).