XMLC - Proxy Mobile Location Centre
LBS applications request the location of a mobile phone over the Mobile Location Protocol (MLP) implemented in the XMLC. MLP is specified by the Open Mobile Alliance (OMA). The OMA have also specified a middleware layer referred to as a Location Enabling Server (LES). The XMLC implements the functionality specified for the LES.
The XMLC will authenticate the LBS Client in order to confirm that the application is allowed to make location requests.
In the MLP request a LBS Client can request Quality of Service parameters such as accuracy and response time. The XMLC controls which location methods that are selected in order to comply with these requests.
The MLP interface also allows setting spatial triggers and requesting periodic location reporting. Spatial trigger may be set for when entering a certain geography or proximity of another mobile device. For standardized positioning methods the MLC supports a polling solution in which the location of a mobile device will be obtained for each time instant requested for the periodic location report. For spatial triggers smart polling will decrease the time between location polls as a mobile approaches a boundary for which a spatial trigger is set. Smart polling reduces network load.
The XMLC will also handle load control such that an application does not over-load the network with too many requests. The maximum number of MLP Location Request allowed are set per LBS Client per second, or per a configurable time interval.
Privacy handling offers white-, black- and grey-lists. White-listed LCS Clients are always allowed to locate the subscriber. Black-listed LCS Clients are always prohibited from locating the subscriber. In order for a grey-listed LCS Client to locate a subscriber the subscriber must explicitly approve the request to locate the subscriber for each location.
The XMLC message proxying function for SMS, MMS, USSD, and WAP/HTTP allows for the creation of anonymous mobile centric location based services. The XMLC will intercept message from mobile devices sent towards an application server in order to obtain a Location Based Service. These messages will be modified to include the location of the user and to simultaneously hide the user-identity (by modifying the MSISDN parameter). Messages from the application to the mobile device are returned through the XMLC, which resolves the identity ambiguity. Note that the XMLC message proxying function offers a privacy benefit to subscribers using operator-integrated services. Mobile centric location applications that interact directly with external servers will otherwise reveal the identity of the mobile, and the subscriber.
Given the existence of operator-to-operator roaming agreements, the OMA Roaming Location Protocol (RLP), see reference [10], implemented in the XMLC, allows the location of a subscriber who has roamed into another network (so called “IP Roaming”).
The XMLC interfaces the Provisioning System using the Mobile Arts Subscriber Data Management (SDM) interface. This interface enables the external Provisioning System to read and write XMLC subscriber data.
The XMLC outputs ASN.1 formatted Charging Data Records (CDRs) that are fetched by the Billing System (mediation) using the File Transfer Protocol (FTP). The XMLC can also interface a PrePaid System via Diameter for prepaid/real-time charging.
The XMLC interfaces the Network Management System using SNMP.
The XMLC interfaces the Remote Access Gateway using VPN (LAN-to-LAN). The remote Access Gateway is needed for remote software support.
Customer care personnel access a message log-search at an Admin PC. Logs of all location interactions are stored for a configurable time, typically 60 days. An Administration PC can interface the XMLC using a Command Line Interface (CLI), FTP, SCP and SFTP or a Graphical User Interface (GUI) accessed from a standard web-browser.
For support reasons the XMLC can be accessed over VPN/IP (LAN-to-LAN) by a Remote Access Gateway.
The XMLC connects to the GMLC using the OMA Mobile Location Protocol (MLP) over Erlang interface. This Mobile Arts proprietary protocol offers implementation efficiencies over the standard protocol. Mobile Arts utilize the open development platform Erlang for all implementations.
By integrating with all these systems the XMLC abstracts the complexities of a telecommunications network into the simple OMA defined HTTP MLP interface. As a result, the time needed to integrate Location Based Services, and the complexities to be handled by an application provider, are substantially reduced. In addition to reducing the time to market for new services the XMLC also reduces the cost of deploying Location Based Services.
The Mobile Arts XMLC takes on some aspects of an SDP in that it:
- Abstracts the complexities of integrating with all required telecom nodes by providing one easy to use HTTP interface towards applications and/or an SDP (the OMA recommendation compliant MLP interface) and acting as a proxy for messages to and from applications.
- Provides subscriber profile and privacy features
- Authenticates applications
- Issues billing information (CDRs) for billing service providers (who offer LBS by running applications)
- Throttles traffic from applications (load control)
The XMLC however focuses on Location Based Services alone and does not support iPhone app store style features. Some operators choose to have one common SDP for all types of services. The Mobile Arts XMLC is easily integrated with an SDP.