GeoLENs LTE Locating Methods:

Assisted GPS (A-GPS)

A-GPS Hybrid 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).

GeoLENs GSM Location Methods:
A-GPS based positioning

A-GPS Hybrid 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.

 TA/NMR Positioning

• Timing Advance (TA) is an existing GSM 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

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

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.

Multiple Range Estimation Locator - MREL

MREL (Multiple Range Estimation Location) is the next generation of location technology used with Andrew’s Location Measurement Units (LMUs). MREL and U-TDOA use different techniques to determine the location of a mobile.  MREL exploits features in the newer digital signaling protocols to produce location results in areas U-TDOA cannot.  For example, MREL requires only two sensor sites instead of U-TDOA’s three, which is particularly important in rural or highway corridors where only two sensor sites might be available.

MREL makes innovative use of the feedback loop that exists between a mobile and a base station to determine the actual time that the mobile transmits a signal of interest.  MREL then uses the transmission time and the time of arrival of the signal at a sensor site to determine a circular range ring, where the mobile could be located, around each sensor site.  The location is then estimated by the best intersection of the multiple range-rings.  

Conversely, U-TDOA calculates the difference in the time of arrival of the mobile signal between multiple pairs of receivers.  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.

Unlike U-TDOA, MREL is not dependent on time differences of arrival of a signal at multiple sensor sites.  MREL uses absolute times of transmission and arrival.  Because MREL does not rely on differences, it is able to generate a range ring for each sensor site and has the ability to generate accurate location information with just two sensor sites.  U-TDOA cannot generate accurate location information with anything less than three sensor sites.

Testing shows that in a comprehensive set of environments, MREL offers a high accuracy location capability in areas where A-GPS and U-TDOA may fail.  MREL coupled with the other location technologies available in GeoLENs provides the most comprehensive and competitive location solution on the market today, both for LBS and E911 applications.

User Plane Location (SUPL) Solutions

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

GeoLENs UMTS/WCDMA Locating Methods:

UMTS Assisted GPS (A-GPS)

WCDMA A-GPS Hybrid Location

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.

Round Trip Timing Positioning

RTT Positioning

Round Trip Time (RTT) is a control plane mechanism whereby the node-B measures the signal propagation distance between the mobile and the base station.  It accomplishes this by utilizing a known downlink message transmit time from the node-B, measuring the corresponding uplink acknowledgement from the mobile, and subtracting off the message receive/transmit delay within the mobile.  This produces the round trip (two-way) signal delay, half of which can be used to compute the distance the signal travels between the mobile and the base station.  This RTT distance results in a circular ring around the base station representing  mobile location possibilities.  If the mobile is in a region where multiple base stations can communicate with the mobile, multiple RTT measurements can be computed and the intersection of multiple rings represents the mobile location.

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

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.

User Plane Location (SUPL) Solutions

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

GeoLENs Secure bUser Plane—SUPL Location Methods

A-GPS based 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

 GeoLENs IP Location System Features—Location Information Server (LIS):

• Location of a device connected to an IP network
• Multiple Access Technologies
• Wired Broadband – DSL, Cable, Ethernet
• Wireless Broadband – 3G and 4G Access Technologies, Wi-Fi
• Enterprise and Government – IP networks
• Location Information Server
• Part of the access network
• Support for NENA i2 and IMS architectures
• Enables true IP service deployment – service accessible from any type of access network

In cases where an infrastructure provider makes static location information directly available to the ISP, the Internet provider can store these records directly in the GeoLENs ISP LIS. The GeoLENs ISP LIS supports a large number of static identifier to location mapping records that can be quickly loaded and changed as required.

In some environments there is a dynamic binding between the statically provisioned identifier, that maps to location, and the IP address of the device. In these configurations the GeoLENs ISP LIS resolves the dynamic binding by using AAA or DHCP data prior to determining the corresponding location of the device.

Location Information Server (LIS) – Internet location services model:

 Location by value:

• Device obtains location from the location server in the access network
• Device conveys location* to the service in the applicable application protocol

* Location values are  encoded as a PIDF-LO per RFC4119

Location by reference:

• Device obtains reference from the location server in the access network
• Device conveys reference to the service in the applicable application protocol.
• Service queries location server directly for location value one or more times

The protocol used for 1 & 3 is HELD (HTTP Enabled Location Delivery). Step 2, location conveyance, is application protocol dependent (e.g. SIP supports location conveyance)

GeoLENs WiMAX 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

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.

Multi-lateration:

• Uses mobile scanning reports
• Mobile makes Observed Time Different (OTD) timing measurement on the downlink signal from the base station to the handset
• Multiple measurements of signal from different base stations are made by the handset
• Radio  network computes Round Trip Delay (RTD)
• OTD and RTP measurements passed to the Location Server
• Location Server computes location fix.