General Operation of the Geometrix® MLC Solution

At the heart of every Geometrix MLC system is a Geometrix Serving Mobile Location Center (SMLC, or SAS for UMTS) and a Gateway Mobile Location Center (GMLC or SUPL) that performs the following:

• Administers and controls the location system
• Retrieves measurement data from the network, from mobiles, or from location measurement units (LMUs)
• Calculates mobile positions from the measurement data
• Manages communications between the Geometrix MLC system and external entities such as gateway mobile location centers (GMLCs) and network operations centers

The SMLC/SAS/SLP performs data retrieval and calculation tasks associated with the specific location technologies deployed in the Geometrix MLC system (for example, A-GPS, CID, E-CID, Matrix, U-TDOA). A Geometrix MLC Serving Mobile Location Center (SMLC, or SAS for UMTS) may provide any combination of A-GPS, Matrix, CID, E-CID, and U-TDOA location methods, depending on the wireless operator's selection. A-GPS, CID, Matrix, and E-CID location technologies use measurements and data collected from mobile units and/or the network and do not require Geometrix MLC equipment components other than the SMLC/SLP. U-TDOA technology requires LMUs to be installed at selected BTS sites to measure time of arrival and other features of radio signals from target mobiles. An external data link to the SMLC provides a gateway for the Geometrix MLC maintenance network. The maintenance network can provide 24-hour, 7-day total system monitoring, transparent software upgrades, system backup, configuration modification, and an interface for remote troubleshooting and repair. The maintenance interface can connect to existing operations, administration, and management (OA&M) systems.

Operation on Typical Locations

The overall operation of a Geometrix® MLC system is depicted in the following flow diagram. Note that in typical applications Geometrix MLC location activity is initiated by an application external to the Geometrix MLC system itself. A gateway mobile location center (GMLC), in response to an application's request for a location, screens the request and forwards it through the network to the Geometrix MLC SMLC. Similarly, at the end of the location process, the Geometrix MLC SMLC usually sends calculated mobile position information through a GMLC to an external entity, generally the application that initiated the location activity or, in the case of public safety locations, to the appropriate emergency service center/public safety answering point. The operation of the Geometrix MLC system is rapid, accurate, and reliable; locating a mobile usually requires only a few seconds. The entire process can be summarized in the following typical eight steps:

1. MSC or LBS application launches location request to Geometrix GMLC server. The GMLC server receives request, determines appropriate positioning technology, including selection between SUPL and CoPL.
2. Geometrix SMLC/SAS/SLP server receives request from GMLC server and begins location process.
3. SMLC/SAS/SLP server queries network (for E-CID), target mobile (for A-GPS, Matrix), or Andrew LMU (for U-TDOA) for measurements or other data.
4. Mobile captures GPS or E-OTD measurements, or Andrew LMU (for U-TDOA only) and measures target mobile signal.
5. Mobile (for A-GPS, Matrix) or Andrew LMU (U-TDOA) sends measurements to Geometrix SMLC/SAS/SLP server.
6. Geometrix SMLC/SAS/SLP server receives measurements and computes position.
7. Geometrix SMLC/SAS/SLP server sends position data to GMLC server (through BSC and MSC).
8. Geometrix GMLC server sends position data to LBS application.

Geometrix® MLC (SMLC, GMLC, SLP or SAS for UMTS)

The Geometrix MLC (SMLC, GMLC, SLP, or SAS for UMTS) is the central processor at the heart of a Geometrix MLC system. Using measurements from mobiles for A-GPS or E-OTD, signal measurements from location measurement units (LMUs) for U-TDOA, or network cell/sector, timing advance, and other network data for E-CID, the SMLC calculates the position of target mobiles. The SMLC sends the mobile's position latitude and longitude calculations through the base station controller (BSC) and mobile switching center (MSC) to gateway mobile location centers (GMLCs) for distribution to applications/servers for location-based mobile services. In addition to calculating mobile positions, the SMLC also manages, coordinates, and administers the Geometrix MLC system and provides interfaces to external entities such as network operations and administration centers/systems.

Control Plane and User Plane Technologies

Andrew Corporation recognizes that wireless and cellular operators and service providers all have unique requirements for network and service deployment and evolution. By providing both Control Plane and User Plane technologies, Andrew Corporation is best suited to address the varying needs of our customers. Our location technologies employ both the Control Plane and User Plane approaches, giving our customers full and unparalleled flexibility in developing and evolving their networks to allow for convenient value-added location services offerings. Andrew's Geometrix® mobile location center is fully standards-compliant, to provide the most cost- and time-efficient location services development and deployment.

In 2002, the Open Mobile Alliance and internationally recognized Standard's Consortia were created to help develop technologies aimed at encouraging or enabling mobile data services, e.g., mobile Internet. A basic premise of the OMA is to create technologies that are “access independent,” so that the services enablers and applications being standardized would not be tied to the “lower” protocol layers of a wireless network. Thus, the service provider/operator only requires an IP data connection between the mobile and the access network to generate value-added services for end-users/customers. This allows application and service development that can function equally well in any 2G/2.5G or 3G network, whether that network is a GSM network or CDMA network, etc. Andrew Corporation is an active full member and participant in the Open Mobile Alliance since the inception of SUPL. Andrew's continued involvement in the creation of location technologies through the OMA ensures our customers the latest location technologies that will support their present and future network needs.

By creating enabling technologies that separate the application from the access methods, the notion of the User Plane is born. Technologies that utilize the specifics of the Access methods are termed Control Plane approaches.

Andrew's Control Plane Technology Choice
In traditional 2G/2.5G/3G systems, the GMLC/SMLC/SAS location applications utilize protocols developed to make use of the Control Plane technologies.

The use of Control Plane location technology may be beneficial for some operator deployments, such as those wishing to leverage existing location technologies (e.g., E911) for additional value-added location-based services. There are other considerations that may make Control Plane location technologies beneficial and would be specific to the service provider's or operator's current and future network needs.

Andrew's Geometrix Mobile Location Center offers GMLC/SMLC/SAS product and product combinations that support Control Plane location determining technologies (e.g., A-GPS, etc.) and can be combined in optimal ways to meet operator requirements.

Andrew's User Plane Technology Choice
The User Plane technology of choice deployed by Andrew Corporation for location services is the OMA industry standard called SUPL. SUPL, which stands for Secure User Plane Location, enables end-to-end secure IP connectivity between the mobile/nomadic device and the network. Andrew Corporation is a pioneer and leading player in the deployment of location-based services through SUPL. Our extensive experience in location enabling technologies combined with the benefits of SUPL leads to flawless success for the operator or service provider.

Locating Technology Deployment Requirements Table

1. Mobile Location Center may be able to serve multiple MSCs
2. Sparsing of LMUs (equipping less than 100% of BTS sites) may be possible, depending on network configuration and performance objectives.