Generic broadcast of location assistance data

Various techniques are provided for Location Services (LCS) Assistance Data broadcast, for example for implementation in LTE and LTE-A systems. The embodiments described herein may use the LPP/LPPe positioning protocol, by making use of existing unsolicited Provide Assistance Data (PAD) messages. Embodiments avoid the need to define and implement a separate broadcast Assistance Data protocol. Additional exemplary embodiments for scheduling and verifying of the broadcast Assistance Data messages are described herein.

BACKGROUND

Location Services (LCS) provided by or in association with wireless networks can be useful or essential to many applications—for example to locate a user engaged in an emergency call, to obtain navigation (e.g. driving directions), to locate nearby friends or facilities and to track valuable objects and assets.

The Long Term Evolution (LTE) wireless access interface is a standard in the mobile phone network technology tree, developed by the 3rd Generation Partnership Project (3GPP), that also produced the Global System for Mobile Communications (GSM), Enhanced Data rates for GSM Evolution (EDGE), Universal Mobile Telecommunications System (UMTS) and High Speed Packet Access (HSPA) network technologies. The LTE Positioning Protocol (LPP) is the protocol defined by 3GPP to support LCS in a wireless network based on LTE with capabilities to locate a User Equipment (UE). LPP extensions (LPPe) is a positioning protocol developed by the Open Mobile Alliance (OMA) that extends LPP to support location for access types in addition to LTE as well as adding further position methods applicable to both LTE and other wireless access types such as GSM, UMTS and WiFi. LPP may be used by itself in an LTE network or may be combined with LPPe to support LCS in LTE and/or other networks. In the latter case, the combined protocol may be referred to as LPP/LPPe.

Current 3GPP defined technology uses point-to-point positioning protocols such as LPP and LPP/LPPe to support LCS. The use of point-to-point protocols may result in significant signaling and processing requirements on both the network and UEs and difficulty in providing adequate location support for all UEs accessing a network. Furthermore, while delivery of LCS Assistance Data via broadcast has been standardized for GSM and UMTS access, it has not been deployed. One reason for this is additional implementation impact—e.g. to network base stations, Location Servers and UEs. A second reason is that the broadcast Assistance Data standards are based on an old 3GPP Release (Release 98 completed in 1999) and do not contain any Assistance Data enhancements defined since then. A third reason is that some broadcast systems, such as those already defined to support GSM and UMTS broadcast location Assistance Data, have limited bandwidth and cannot broadcast large amounts of Assistance Data (e.g. GNSS (Global Navigation Satellite System) ephemeris data) with a low latency. However, broadcast location Assistance Data remains potentially useful to avoid the overhead and delay in obtaining assistance data by point to point means (e.g. using LPP or LPP/LPPe). The problem is to define it in a manner that would be suitable for implementation and with adequate performance for receiving devices.

SUMMARY

Various techniques are provided for LCS Assistance Data broadcast, for example for implementation in LTE and LTE Advanced (LTE-A) systems. The embodiments described herein, use the LPP/LPPe combined positioning protocol, by making use of existing unsolicited Provide Assistance Data (PAD) messages. The embodiments of the invention avoid the need to define and implement a separate broadcast Assistance Data protocol. Enabling broadcasting for LCS Assistance Data has the potential of enabling: faster and more accurate location; use of target based position methods such as GNSS; offloading of Location Servers; an ability to charge for some/all broadcast assistance if ciphering is used; and an ability to support roamers as well as home subscribers in the serving network. Broadcast of Assistance Data is also potentially applicable to both control plane location solutions developed by 3GPP and 3GPP2 and the SUPL (Secure User Plan Location) location solutions developed by OMA.

An exemplary method for broadcasting data may include sending information associated with broadcast messaging from a Location Server point to point to a device using a positioning protocol, and broadcasting one or more Assistance Data (AD) messages from the Location Server to the device based on the information associated with the broadcast messaging. In one embodiment, the positioning protocol may be an LTE Positioning Protocol (LPP) protocol combined with an LPP extensions (LPPe) protocol The information associated with the broadcast messaging may include at least one of deciphering keys, deciphering key IDs, AD Types, AD Type IDs, scheduling of one or more AD messages, broadcast systems, broadcast areas and authentication information. The sending of the information associated with the broadcast messaging point to point may be in response to a request from the device sent point to point to the Location Server using the positioning protocol.

In some embodiments, one or more AD messages may use, ciphering described in the information associated with the broadcast messaging sent point to point, or scheduling described in the information associated with the broadcast messaging sent point to point. Additionally, the information associated with the broadcast messaging may be used to identify where and how the one or more AD messages are being broadcast, wherein the information identifying where and how the one or more AD messages are being broadcast comprises one or more of a geographic area within which the one or more AD messages are being broadcast, a set of cell sites within which the one or more AD messages being broadcast, a period of time for a transmission of the one or more AD messages, a validity period for the one or more AD messages or a system broadcasting the one or more AD messages, or information identifying a type of the AD being broadcast described in the information associated with the broadcast messaging sent point to point.

In some implementations of the method, at least a portion of the one or more AD messages may be ciphered, wherein the one or more AD messages are encapsulated for ciphering and wherein the one or more AD messages are ciphered using information associated with broadcast messaging sent point to point.

In some embodiments, broadcasting the AD from the Location Server to the device comprises transmitting the one or more AD messages to a Broadcast Subsystem for broadcast to the device. Broadcasting the AD may further comprise exchanging information with the Location Server including one or more of exchanging broadcast capabilities, receiving a request for a specific AD from the Broadcast Subsystem at the Location Server, receiving an indication from the Broadcast Subsystem at the Location Server on a current or future available broadcast capacity, or receiving an acknowledgement for the one or more AD messages successfully transferred to the Broadcast Subsystem from the Location server.

Moreover, in some embodiments, the method performed by the Location Server may associate each of the one or more AD messages with a unique message ID, wherein no more than one AD message is associated with the same unique message ID within a message validity period. The method may assign a label to each of a plurality of broadcast AD types in an AD message from the Location Server to the device. The method may also obtain location AD associated with an access node or Global Navigation Satellite Systems (GNSS). In one implementation, the AD may be obtained using Operations and Maintenance (O&M) signaling. The method may also include updating the one or more AD messages at the Location Server when a plurality of contents of the one or more AD messages need to be changed.

In some implementations, the contents or/and scheduling of the one or more AD messages may be adapted based on a type and a number of point to point AD requests from a plurality of devices and/or a type of access network available in a local area. The content for the one or more AD messages may be adapted based on a level of device support detected for the device. The content for one or more AD messages may comprise the AD for Assisted-Global Navigation Satellite System (A-GNSS) and the level of device support comprises the device supporting A-GNSS, and a frequency of the one or more AD messages is increased in response to detecting a large number of attached devices that support device based A-GNSS.

In some aspects, the broadcasting frequency of the AD may be increased in response to one or more of determining that an increased number of devices are requesting information associated with the broadcast messaging point to point, determining that an increased number of location requests from a plurality of devices is high, determining that a current time is similar to a time of day associated with statistically high activity, determining that a density of attached devices for a geographic area is high, and determining that the Location Server is congested by point to point location service requests or by scarcity of resources.

In an exemplary method for receiving Assistance Data (AD), the method may include receiving information associated with broadcast messaging from a Location Server point to point using a positioning protocol, and receiving one or more AD messages broadcasted from the Location Server according to the information associated with the broadcast messaging. The information associated with the broadcast messaging may comprise at least one of deciphering keys, deciphering key IDs, AD Types, AD Type IDs, scheduling of one or more AD messages, broadcast systems, broadcast areas and authentication information. In some implementations, the positioning protocol may be an LTE Positioning Protocol (LPP) protocol combined with an LPP extensions (LPPe) protocol. Moreover, the information associated with the broadcast messaging comprises information identifying where and how one or more AD messages are being broadcast, wherein the information identifying where and how the one or more AD messages are being broadcast comprises one or more of a geographic area within which the one or more AD messages being broadcast, a set of cell sites within which the one or more AD message are being broadcast, a period of time for a transmission of the one or more AD messages, a validity period for the one or more AD messages, a system broadcasting the one or more AD messages or a type of the AD being broadcast. In some implementations, the one or more AD messages are received through a Broadcast Subsystem.

An exemplary server for broadcasting data may include a transceiver configured to send information associated with broadcast messaging from a server point to point to a device using a positioning protocol, and broadcast Assistance Data (AD) messages from the server to the device according to the information associated with the broadcast messaging, sent point to point; and a processor configured to determine the information associated with the broadcast messaging, wherein the information associated with the broadcast messaging may comprise at least one of deciphering keys, deciphering key IDs, AD Types, AD Type IDs, scheduling of AD, broadcast systems, broadcast areas and authentication information. The sending of the information associated with the broadcast messaging point to point may be in response to a request from the device sent point to point to the Location Server using the positioning protocol.

In some embodiments, the processor may cipher the one or more AD messages using the information associated with the broadcast messaging sent point to point, or scheduling described in the information associated with the broadcast messaging sent point to point. Additionally, the information associated with the broadcast messaging may be used, by the processor, to identify where and how the one or more AD messages are being broadcast, wherein the information identifying where and how the one or more AD messages are being broadcast comprises one or more of a geographic area within which the one or more AD messages are being broadcast, a set of cell sites within which the one or more AD messages being broadcast, a period of time for a transmission of the one or more AD messages, a validity period for the one or more AD messages or a system broadcasting the one or more AD messages, or information identifying a type of the AD being broadcast described in the information associated with the broadcast messaging sent point to point.

In some aspects of the server, at least a portion of the one or more AD messages may be ciphered, by the processor, wherein the one or more AD messages are encapsulated for ciphering and wherein the one or more AD messages are ciphered using information associated with broadcast messaging sent point to point.

In some embodiments, broadcasting the AD from the Location Server to the device comprises transmitting the one or more AD messages to a Broadcast Subsystem for broadcast to the device, using the transceiver. Broadcasting the AD may further comprise exchanging information with the Location Server including one or more of exchanging broadcast capabilities, receiving a request for a specific AD from the Broadcast Subsystem at the Location Server, receiving an indication from the Broadcast Subsystem at the Location Server on a current or future available broadcast capacity, or receiving an acknowledgement for the one or more AD messages successfully transferred to the Broadcast Subsystem from the Location server.

Moreover, in some embodiments, the processor associated with the Location Server may associate each of the one or more AD messages with a unique message ID, wherein no more than one AD message is associated with the same unique message ID within a message validity period. The processor may assign a label to each of a plurality of broadcast AD types in an AD message from the Location Server to the device. The server may also obtain location AD associated with an access node or Global Navigation Satellite Systems (GNSS). In one implementation, the AD may be obtained using Operations and Maintenance (O&M) signaling. The method may also include updating the one or more AD messages at the Location Server when a plurality of contents of the one or more AD messages need to be changed.

In some implementations, the contents or/and scheduling of the one or more AD messages may be adapted based on a type and a number of point to point AD requests from a plurality of devices and/or a type of access network available in a local area. The content for the one or more AD messages may be adapted based on a level of device support detected for the device. The content for one or more AD messages may comprise the AD for Assisted-Global Navigation Satellite System (A-GNSS) and the level of device support comprises the device supporting A-GNSS, and a frequency of the one or more AD messages is increased in response to detecting a large number of attached devices that support device based A-GNSS.

In some implementations the broadcasting frequency of the AD may be increased, by the processor and the transceiver, in response to one or more of determining that an increased number of devices are requesting information associated with the broadcast messaging point to point, determining that an increased number of location requests from a plurality of devices is high, determining that a current time is similar to a time of day associated with statistically high activity, determining that a density of attached devices for a geographic area is high, and determining that the Location Server is congested by point to point location service requests or by scarcity of resources.

An exemplary device for receiving Assistance Data (AD) may include a transceiver for receiving information associated with broadcast messaging from a Location Server point to point using a positioning protocol, and receiving one or more AD messages broadcasted from the Location Server according to the information associated with the broadcast messaging. The information associated with the broadcast messaging may be determined by a processor to include one or more of at least one of deciphering keys, deciphering key IDs, AD Types, AD Type IDs, scheduling of one or more AD messages, broadcast systems, broadcast areas and authentication information. In some implementations, the positioning protocol may be an LTE Positioning Protocol (LPP) protocol combined with an LPP extensions (LPPe) protocol. Moreover, the information associated with the broadcast messaging may comprise information identifying where and how one or more AD messages are being broadcast, wherein the information identifying where and how the one or more AD messages are being broadcast comprises one or more of a geographic area within which the one or more AD messages being broadcast, a set of cell sites within which the one or more AD message are being broadcast, a period of time for a transmission of the one or more AD messages, a validity period for the one or more AD messages, a system broadcasting the one or more AD messages or a type of the AD being broadcast. In some implementations, the one or more AD messages are received through a Broadcast Subsystem.

An exemplary non-transitory computer readable storage medium coupled to a processor, wherein the non-transitory computer readable storage medium may comprise instructions executable by the processor, the instructions comprising instructions to send information associated with broadcast messaging from a Location Server point to point to a device using a positioning protocol, wherein the information associated with the broadcast messaging comprises at least one of deciphering keys, deciphering key IDs, AD Types, AD Type IDs, scheduling of one or more AD messages, broadcast systems, broadcast areas and authentication information, and broadcast Assistance Data (AD) messages from the Location Server to the device according to the information associated with the broadcast messaging, sent point to point.

Another exemplary non-transitory computer readable storage medium coupled to another processor, wherein the non-transitory computer readable storage medium may include instructions executable by the processor, the instructions comprising instructions to receive information associated with broadcast messaging from a Location Server point to point using a positioning protocol, wherein the information associated with the broadcast messaging comprises at least one of deciphering keys, deciphering key IDs, AD Types, AD Type IDs, scheduling of one or more AD messages, broadcast systems, broadcast areas and authentication information; and to receive one or more AD messages broadcasted from the Location Server according to the information associated with the broadcast messaging.

An exemplary apparatus may include means for sending information associated with broadcast messaging from a server point to point to a device using a positioning protocol, wherein the information associated with the broadcast messaging comprises at least one of deciphering keys, deciphering key IDs, AD Types, AD Type IDs, scheduling of one or more AD messages, broadcast systems, broadcast areas and authentication information, and means for broadcasting Assistance Data (AD) messages from the server to the device according to the information associated with the broadcast messaging, sent point to point. An exemplary device may include means for receiving information associated with broadcast messaging from a Location Server point to point using a positioning protocol, wherein the information associated with the broadcast messaging comprises at least one of deciphering keys, deciphering key IDs, AD Types, AD Type IDs, scheduling of one or more AD messages, broadcast systems, broadcast areas and authentication information, and means for receiving one or more AD messages broadcasted from the Location Server according to the information associated with the broadcast messaging.

Embodiments of the invention create the possibility for a device to use LPP/LPPe point-to-point as a means of obtaining critical information related to LPP/LPPe broadcast. This avoids relying on network based control plane protocols to obtain broadcast related information at a device (such as deciphering keys for use when broadcast Assistance Data is ciphered), which is not suitable when SUPL rather than a control plane is used as a location solution in many implementations. In addition, a method of categorizing and advertising broadcast location Assistance Data is defined and a method of adapting existing LTE System Information Blocks (SIBs) is defined to support LPP/LPPe assistance data broadcast. Segmentation of LPP/LPPe broadcast messages is also enabled. Applicability to any broadcast system is enabled by treating PAD messages as blocks of data from the perspective of the broadcast system that may carry labeling information on content, use of ciphering, change of data content and segmentation inside the PAD messages and invisibly to the broadcast system. This will enable PAD messages to be broadcast (like any other data) by any broadcast system. Embodiments of the invention additionally describe techniques for labeling Assistance Data, for example to refer to assistance data parameters inside the messages in a concise manner or to indicate supported broadcast Assistance Data. Other embodiments enable broadcast Assistance Data to be authenticated by any receiving UE to overcome possible falsified broadcast from malicious sources.

DETAILED DESCRIPTION

LCS support by or in association with a wireless network typically employs a Location Server in or associated with the network that enables the location of a mobile terminal to be obtained by the Location Server and/or by the terminal. The location may be needed (e.g. requested) by some client application which may be inside or associated with the mobile terminal (e.g. an application or the mobile terminal user) or may be external to the network and not directly associated with the mobile terminal. In some standards and implementations, the mobile terminal may make measurements of radio transmission from network base stations, access points (e.g. WiFi access points (APs)) and/or satellites (e.g. the Global Positioning System (GPS)) and may transfer these measurements (e.g. on request) to the Location Server for computation of the mobile terminal location by the Location Server. In other standards and implementations, a mobile terminal may make the radio measurements and in addition then compute its position—and possibly then transfer the position to the Location Server if requested. To enable a mobile terminal to make radio measurements more reliably, accurately and faster and optionally enable a terminal to compute its position from the radio measurements, a Location Server may transfer Assistance Data to the mobile terminal (e.g. on request) such as Assistance Data containing orbital data for GPS satellites or satellites for other Global Navigation Satellite System (GNSS) systems such as GLONASS and Galileo. Assistance data may also contain location coordinates of base stations and access points nearby to the terminal, timing information and signal power for base station radio transmission and other data to assist location measurements and location computation. Examples of positioning methods that may make use of Assistance Data include Assisted GPS (A-GPS), Assisted GNSS (A-GNSS), Observed Time Difference Of Arrival (OTDOA), Advanced Forward Link Trilateration (AFLT) and Enhanced Cell ID (E-CID). The 3GPP LPP definition in 3GPP Technical Specification (TS) 36.355 and the OMA definition of LPPe in LPPe Extensions Specification version 1.0 contain definitions of A-GPS, A-GNSS, OTDOA and E-CID, while the 3rd Generation Partnership Project 2 (3GPP2) provides a definition of AFLT in 3GPP2 TS C.S0022.

To enable a Location Server to know the capabilities of a mobile terminal to support different types of Assistance Data, make different types of radio measurement and support different positioning methods, the capabilities of the terminal may be transferred (e.g. on request) by the terminal to the Location Server. A similar capability transfer in the reverse direction may be used to provide a mobile terminal with the capabilities of a Location Server to provide different types of Assistance Data and support different types of radio measurements. All of the interactions just mentioned between the Location Server and mobile terminal would typically be conducted using point to point signaling (e.g. via a radio access network and one of more core network entities such as routers or gateways) which may consume resources and increase delay.

The point to point interactions just described may be supported by positioning protocols such as LPP, LPP/LPPe and the protocol defined in 3GPP2 TS C.S0022. The interactions may be supported within a control plane solution such as one of the solutions defined in 3GPP TSs 23.271, 49.059, 25.305 and 36.305 and in 3GPP2 TS X.S0002. The interactions may also be supported within a user plane solution such as one of the OMA Secure User Plane Location (SUPL) version 1.0, version 2.0, version 2.1 and version 3.0 solutions defined by OMA in Enablers OMA-ERP-SUPL-V1—0, OMA-ERP-SUPL-V2—0, OMA-ERP-SUPL-V2—1 and OMA-ERP-SUPL-V3—0, respectively. In a control plane location solution, existing network interfaces and protocols are enhanced and used for most signaling (e.g. to support UE to Location Server point to point interaction) whereas with a user plane solution such as SUPL, the SUPL Secure Location Platform (SLP) Location Server interacts with a UE, known in SUPL as a SUPL Enabled Terminal (SET), via a data (e.g. TCP/IP) connection that is mostly transparent to other network entities.

FIG. 1(PRIOR ART) shows a sample positioning session using the LPP (point-to-point) positioning protocol for Location services (LCS) for LTE. This is an example of point to point interaction between a Location Server and a mobile terminal. Transaction T1fromFIG. 1, is for capability exchange between the Location Server and the UE (LPP Request/Provide Capabilities). In transaction T1, the Location Server sends a request to the UE for some or all of the UE's positioning capabilities with respect to the LPP protocol and the UE then returns these capabilities. A UE could be a mobile phone, wireless PDA, PC, or any other device that can connect to an LTE wireless network. A UE may also be interchangeably referred to as a target, a mobile terminal, a mobile device, a SET or a device throughout the specification. The location information subsequently obtained by the Location Server may be made available to support Location Based Services (LBS) for value-added applications or clients which are accessible to mobile subscribers or to other third parties. Wireless network and wireless devices are in an advantageous position to support LCS due to the inherent geo-location capability of radio signals as well as the user mobility tracking of the system. The information exchange in transaction T1inFIG. 1makes the server aware of the UE positioning capabilities (e.g. A-GNSS support, supported cellular network measurements for OTDOA and E-CID, etc.). Based on this information, the server can make a decision on the positioning method to be used, based on both the UE capabilities and the requested quality-of-position (response time, accuracy).

As shown inFIG. 1, the actual location information request is carried out during the T2transaction which starts with the server sending an LPP Request Location Information message to the UE containing the position methods being requested, details on the measurements needed (e.g. which GNSS systems, GNSS signals and network base stations need to be measured and whether the UE or the Location Server will compute the location). The message may also carry other reporting instructions such as periodicity for multiple locations and required response time.

Having received the LPP Request Location Information message, the UE begins its positioning activities. In some scenarios, this activity may trigger a request for some Assistance Data—e.g. if the UE does not already have sufficient Assistance Data from previous requests to obtain all the requested measurements and, if asked, compute a location. For instance, if the server requests UE based A-GNSS location in which the UE both obtains GNSS measurements and computes its own location, and the UE does not have the latest ephemeris data for the requested GNSS systems, the UE may request these with the LPP Request/Provide Assistance Data mechanism (Transaction T3). Other Assistance Data, such as an approximate reference location for the UE (e.g. based on the current UE serving cell or serving AP), a reference time, a GNSS ionosphere model, base station and WiFi AP locations to name just a few may also be provided to the UE as part of transaction T3. As part of transaction T3, the UE sends its request for specific Assistance Data to the server and the server returns as much of this Assistance Data as it can to the UE. Having received the requested Assistance Data, the UE makes measurements (e.g. of GNSS systems, base stations, WiFi APs) and then, if also asked by the server, computes its location, and reports the location information (for example, measurements or a computed location) back to the Location Server in an LPP Provide Location Information message which terminates transaction T2.

As described above, the current 3GPP based technology uses point-to-point protocols such as LPP and LPP/LPPe to support LCS. The same applies to support of LCS in networks defined by 3GPP2 such as Code Division Multiple Access 2000 (CDMA2000) and High Rate Packet Data (HRPD) networks which also employ point to point positioning protocols between a server and mobile terminal such as the protocol defined in 3GPP2 TS C.S0022. The use of point-to-point protocols results in significant signaling and processing requirements on both the network and UEs and difficulty in providing location support for all UEs accessing a network. Furthermore, while LCS Assistance Data via broadcast has been standardized for GSM and UMTS access, it has not been deployed. One reason is the additional implementation impact to network base stations, Location Servers and UEs. Another reason is that the broadcast Assistance Data standards are based on 3GPP Release 98 (defined in 1999) and do not contain any Assistance Data enhancements defined since then. A third reason is that some broadcast capabilities, such as those already defined to support broadcast location Assistance Data for GSM and UMTS, have limited bandwidth and cannot broadcast large amounts of Assistance Data (e.g. GNSS ephemeris data) with a low latency. However, broadcast location Assistance Data remains potentially very useful. The problem is to define it in a manner that would be suitable for implementation and with adequate performance for receiving devices. Embodiments of the invention, described below, solve these and other problems.

I. Broadcast Support Using Point to Point

FIG. 2is a signaling flow diagram illustrating an exemplary embodiment of the invention for a broadcast protocol for Location Service (LCS) for LTE. The signaling in process200is performed by processing logic that comprises hardware (circuitry, dedicated logic, etc.), software (such as is run on a general purpose computing system or a dedicated machine), firmware (embedded software), or any combination thereof. In one embodiment, the process200is performed by one or more computer systems2300as described inFIG. 23. In one embodiment, the receiving and transmitting steps described below may be facilitated utilizing the transceiver2350described inFIG. 23.

InFIG. 2, the Location Server215may correspond to Location Server504described later with reference toFIG. 5Aand UE220may correspond to UE/SET502inFIG. 5A. The Location Server215inFIG. 2communicates point to point with the UE220for exchanging some Assistance Data, location estimates, capabilities and providing the schedule and/or other information regarding Assistance Data that is being broadcast. In some implementations, an intermediary system or plurality of subsystems, such as a Broadcast Subsystem506described inFIG. 5A,FIG. 5BandFIG. 6, may facilitate exchange of information and also assume some or all of the broadcasting responsibilities.

During the T1transaction inFIG. 2, using the LPP/LPPe Request Assistance Data message, at step201, which is sent by UE220to Location Server215, the UE220may provide its current serving cell (or current access point or current access network) along with other access networks visible to UE220and/or other optional related information to the Location Server215and may request information about Provide Assistance Data messages being broadcast by the Location Server215. The UE220may request the Assistance Data at some initial time, for example when the UE attaches to the network or in instances when the Assistance Data is changing.

Exemplary enhancements to the LPP/LPPe Request Assistance Data message, as in step201, are illustrated inFIG. 20. In response to UE220's LPP/LPPe Request Assistance Data message, the Location Server215may respond with an LPP/LPPe Provide Assistance Data message, as illustrated at step202, with information about Provide Assistance Data messages that are being broadcast. Exemplary enhancements to the LPP/LPPe Provide Assistance Data message for supporting broadcasting, as in step202, are illustrated inFIGS. 21A and 21B.

Briefly discussingFIG. 3, the figure shows exemplary information that may also be included in the response from the Location Server215to the UE220in the LPP/LPPe Provide Assistance Data message, as in step202, as part of the response to the LPP/LPPe Request Assistance Data message, as in step201, in transaction T1ofFIG. 2. At block302, the various types of PAD messages being broadcast in UE220's local area may be included. GNSS ephemeris Assistance Data, GNSS almanac Assistance Data, WiFi related data, and E-CID related data are each examples of different PAD types. So, for example, GNSS ephemeris data for GLONASS may be one PAD type and may be broadcast in PAD messages separate to those for other PAD types such as GNSS almanac data or WiFi related data. At block304, associated type IDs (also included in broadcast PAD messages) may also be included if the association between PAD types and Type IDs is not standardized. For example, a Type ID could contain several value fields—e.g. a primary field indicating a specific positioning method (e.g., A-GNSS, LTE OTDOA, UMTS OTDOA) and one or more secondary fields qualifying the Assistance Data for this position method (e.g. in the case of A-GNSS, one field indicating whether Assistance Data is ephemeris, almanac or ionospheric correction etc. and a further field indicating a specific GNSS constellation (e.g. GPS L1 C/A, modernized GPS, GLONASS etc.). Note that Type IDs may merely be labels for PAD types—e.g. short alphanumeric character strings or numeric values. When type IDs are standardized (i.e. when the type ID for any type of Assistance Data is defined in some publicly available standard), block304may be omitted and block302may carry the standardized types being supported for broadcast. When type IDs are not standardized, block304may carry some reference to different types of Assistance Data (e.g. using conventions already defined for point to point signaling) and a corresponding type ID which the Location Server may also include in the broadcast PAD messages to enable recipient UEs to quickly determine broadcast PAD message content. At block306, the broadcasting schedule of the different PAD types may be included for the broadcasting phase. At block308, deciphering key values and associated deciphering key IDs may be included if the broadcast of some or all PAD messages are ciphered. Deciphering key IDs are labels (e.g. numeric values or short alphanumeric character strings) for the actual deciphering key values. At block310, the applicable duration of deciphering keys and optionally additional deciphering keys to be used after the duration of current deciphering keys expires may also be included. At block312, the message may also include authentication information that allows the UE to determine if broadcast PAD messages that are later received actually come from server215versus some other untrusted source. In addition to the parameters discussed inFIG. 3, other parameters as discussed inFIGS. 21A and 21B, such as broadcastSystem, accessNetworks, coverageArea and serverID, may also be included as parameters for the LPP/LPPe Provide Assistance Data message for supporting broadcasting. Parameters additional to or distinct in some way from these may also be included such as identification of one or more broadcast systems that support broadcast of location Assistance Data, a geographic area or set of geographic areas or set of cell sites within which Assistance Data is broadcast.

The content of the information block inFIG. 3may be specific to the UE's current location or current serving cell. For instance, if the user moves to some new serving cell or new location (nearby to or far from an earlier serving cell or earlier location), the UE220and the Location Server215may need to proceed through the provisioning steps201and202inFIG. 2again in order to provide different data for the new serving cell or new location.

Returning back toFIG. 2, as illustrated by step203, using the transceiver2350and the processor2310, the UE220may begin monitoring for and receiving LPP/LPPe Broadcast Provide Assistance Data messages on broadcast systems that may have been indicated by the Location Server215in step202some time after exchanging information with the Location Server215during the T1transactions. At some later time, at steps204and205, during the T2transactions, the Location Server215may instigate the capabilities exchange protocol between the Location Server215and the UE220. For exchanging capabilities, in one embodiment, the LPP/LPPe protocol may be enhanced to allow the exchange of Assistance Data broadcast capabilities between the Location Server215and the UE220. In some embodiments, both the Location Server215and the UE220are broadcast Assistance Data capable. Moreover, Location Server215and UE220may each support transfer of certain types of Assistance Data using one or more broadcast systems. The capabilities exchange shown in steps204and205enable Location Server215to discover which types of assistance UE220is able to receive using broadcast over different broadcast systems such as evolved/enhanced Multimedia Broadcast Multicast Service (eMBMS) and LTE SIBs. Messages sent in opposite directions to those shown in step204and205(not shown inFIG. 2) may enable UE220to discover similar information regarding server215's capability to send Assistance Data via broadcast. Once the capabilities are exchanged, both the UE220and the Location Server215may be aware if they can begin or continue to participate in the broadcast Assistance Data protocol with one another. The capabilities information may additionally include, but is not limited to 1) the ability to send or receive broadcast Assistance Data, 2) types of broadcast system supported (e.g. LTE SIB, eMBMS, OMA BCAST), 3) ability to cipher/decipher broadcast Assistance Data, 4) ability to authenticate messages, 5) the Type IDs for the PADs supported and 6) ability to send assistance or receive assistance data point to point related to broadcast of PAD messages. In some embodiments, steps204and205may also or instead occur in the same direction and/or the reverse direction to that shown inFIG. 2prior to steps201and202—e.g. to enable UE220to determine whether Location Server215supports broadcast of assistance data and can provide the assistance data in step202that is requested in step201. In some embodiments, the assistance data sent in step202may be sent unsolicited by the server—e.g. based on knowing the UE220's capability to support this assistance data—without the need for the request in step201.

Transaction T2for exchanging capabilities may include LPP/LPPe Request Capabilities message, as in step204, from the Location Server215to the UE220and LPP/LPPe Provide Capabilities message, as in step205, from the UE220to the Location Server215. Exemplary enhancements to the LPPe Request Capabilities message for supporting broadcasting are further illustrated inFIG. 18. Similarly, exemplary enhancements to the LPPe Provide Capabilities message for supporting broadcasting are further illustrated inFIG. 19.

Embodiments of the invention may also select to implement a T3transaction instigated by the Location Server215for acquiring the location estimates from the UE220. At step206, the Location Server215may send an LPP/LPPe Request Location Information message for requesting location estimates from the UE220. In one embodiment, the UE220may use previously acquired Assistance Data in performing its location measurements and location computation, using the processor2310, if requested, such as Assistance Data received at step203via a broadcast LPP/LPPe Provide Assistance Data message. In another embodiment, at step207, the UE220may monitor for another, perhaps updated, broadcast LPP/LPPe Provide Assistance Data message for estimating location information. At step225, the UE220may perform positioning (e.g. location measurements and possibly location computation) using Assistance Data received from the Location Server215in step203and/or step207. In some embodiments, the processor2310of the UE uses Assistance Data previously stored in device storage2325or temporarily maintained in the Working memory2335. At step208, the UE220sends an LPP/LPPe Provide Location Information message with the location measurements or location estimate obtained in step225to the Location Server215.

As shown at step209, the Location Server215may continue to broadcast LPP/LPPe Provide Assistance Data messages with the Assistance Data to the UE220along with other UEs at scheduled intervals. The broadcast schedule may be communicated to the UE220point to point, for example may be provided in step202ofFIG. 2, and instead or in addition may be broadcast to the various UEs, such as via step203and/or step207and as described in further detail below. The UE220has the broadcast schedule and knows which types of Assistance Data are being broadcast and their schedule and can choose to receive Assistance Data rather than requesting the Assistance Data point to point from the Location Server each time. In some embodiments, the broadcast schedule is stored at the Storage Device2325or temporarily maintained in the working memory2335. For example, the UE220may receive information from the Location Server identifying a type or types of Assistance Data that are broadcast.

The UE220may continue to receive broadcast Provide Assistance Data messages, as shown at step209. In addition to responding to requests by the Location Server215for location estimates (e.g. as in steps206and208), the UE220may perform positioning (as shown at block230) autonomously without requesting additional information from the Location Server215. For instance, the UE220may perform positioning in response to an internal application request from the UE220itself and may make use of Assistance Data received via broadcast (e.g. in step209) to support such positioning.

In some embodiments, the UE220may receive information from the Location Server215(e.g. in step202and/or step203ofFIG. 2) regarding where and/or how Assistance Data is being broadcast. For example, the information may indicate a geographic area or set of geographic areas and/or a set of cell sites within which location Assistance Data is broadcast, and/or the information may identify a system (e.g. eMBMS, LTE SIBs) which is broadcasting the location Assistance Data.

Receiving Assistance Data via broadcast, as exemplified inFIG. 2, may be more efficient from both a Location Server215and UE220perspective than receiving the same Assistance Data point to point, as exemplified inFIG. 1. In particular, the Location Server can broadcast the same Assistance Data, once, in a particular cell, to many UEs rather than sending the Assistance Data separately to each UE220by point to point means. Further, the UE220does not need to request the Assistance Data but can instead receive it via broadcast and store the data for future location use. Assistance data which has a long life time of several hours or more (e.g. GNSS ephemeris, GNSS almanac, GNSS ionospheric data, base station and WiFi AP coordinates and map related data for cities, towns or individual buildings) can be usefully broadcast at infrequent intervals by a server and stored for the period of the data validity by recipient UEs.

In the above described embodiment ofFIG. 2, during transaction T1, the LPP/LPPe Provide Assistance Data response message, as in step202, from the Location Server215to the UE220is provided using point to point protocol. This also applies to the Assistance Data request and transfer in transaction T3inFIG. 1. When the request for Assistance Data by the UE in such a transaction includes a request for Assistance Data related to location support and/or a request for Assistance Data related to broadcast support, instead of using a point to point protocol, the Location Server215may broadcast the requested Assistance Data to one or more UEs (e.g. UEs2212ofFIG. 22). Broadcasting the requested Assistance Data allows for additional efficiencies if the Location Server215has a number of open requests from UEs2212for Assistance Data associated with broadcasting and/or Assistance Data related to location support. Referring back toFIG. 3, in one embodiment, the Location Server broadcasts the data associated with types of PAD (block302), associated type IDs (block304), and scheduling information (block306). In some embodiments, the deciphering keys (block308) and the duration associated with the deciphering keys (block310) are not broadcasted. Since UEs will have requested the Assistance Data initially point to point, the Location Server215may reply (e.g. in step202inFIG. 2) with an indication that some of the requested Assistance Data is available via broadcast. Alternatively, the Location Server215may not provide such an indication but may instead provide the UE with sufficient information related to the broadcast of Assistance Data to enable the UE to then look for the missing Assistance Data via broadcast. In some embodiments, Location Server215may provide all the Assistance Data that each UE explicitly requests by point to point means (e.g. as in transaction T1inFIG. 2) but may record the Assistance Data requests and the areas in which they were made and use this record to predict likely future requests from other UEs in the same or other areas. Based on such a prediction, Location Server215may broadcast the Assistance Data that it expects UEs will later request thereby enabling these UEs to obtain the Assistance Data via broadcast and no longer need to request point to point.

The Location Server215may adapt the scheduling of broadcast Assistance Data according to the types and number of point to point Assistance Data requests from UEs2212. A particular type of broadcast Provide Assistance Data message may be sent at a higher frequency when many UEs request the information contained in order to reduce the amount of point to point provisioning. The frequency of Provide Assistance Data broadcast may also be increased when 1) the location requests from UEs or from LCS clients are high (e.g. has increased), 2) the time of the day corresponds statistically to high location activity, 3) the density of attached UEs is high, or 4) the Location Server becomes congested by point to point location services. The content of the broadcast Assistance Data can also be adapted to the level of UE support. For instance, A-GNSS ephemeris, almanac, acquisition assistance and other types of A-GNSS Assistance Data can be sent more often when a large number of attached UEs2212support UE based A-GNSS and are able to receive A-GNSS Assistance Data via broadcast. Assistance Data content may also be adapted to the types of access networks available in a local area. For instance, broadcast of WiFi and Femto Assistance Data can occur in indoor locations where there are many WiFi access points and Femtos but not outside where there are usually only a few access points or Femto cells. In some embodiments, Assistance Data, for example as requested by a UE220, may provide information on where and/or how Assistance Data is being broadcast. For example, the message may indicate a geographic area or set of cell sites within which location Assistance Data is broadcast and/or identification of a system which is broadcasting the location Assistance Data. The Assistance Data may instead or in addition identify a type or types of Assistance Data that are broadcast.

The Assistance Data may be ciphered by the Location Server215, using one or more processors2310, to allow billing for the service and/or restriction to only certain sets of UEs (e.g., home subscribers but not roamers). Cipher keys may be the same or different over different local areas (e.g. same or different per cell or per group of cells) and may be changed at intervals. Additionally, the cipher keys may also be the same or different for different types of broadcast Provide Assistance Data messages. Different cipher keys allow different levels of service to different user groups overlapping the same service area and provide for a model for selective charging of users based on the service provided. As described inFIG. 3, at block308, the Location Server215can provide deciphering key values to UEs as part of other Assistance Data associated with support of broadcast Assistance Data. The deciphering key values may be associated with deciphering key IDs (which would be broadcast in the clear) so a UE220knows which deciphering key value to use. Furthermore, the deciphering keys may have temporal properties (disclosed at block310) and the deciphering keys may expire after a pre-determined duration, requiring the user to periodically refresh their keys. These temporal properties of the deciphering keys allow for better control over the keys and also enable pay-per-duration usage models. Further details of ciphering techniques and exemplary embodiments are discussed inFIGS. 12,13,14and15.

It should be appreciated that the specific steps illustrated inFIG. 2provide a particular method of switching between modes of operation, according to an embodiment of the present invention. Other sequences of steps may also be performed accordingly in alternative embodiments. For example, alternative embodiments of the present invention may perform the steps outlined above in a different order. To illustrate, a user may choose to change from the third mode of operation to the first mode of operation, the fourth mode to the second mode, or any combination there between. Moreover, the individual steps illustrated inFIG. 2may include multiple sub-steps that may be performed in various sequences as appropriate to the individual step. Furthermore, additional steps may be added or removed depending on the particular applications. One of ordinary skill in the art would recognize and appreciate many variations, modifications, and alternatives of the process200.

FIG. 4is a flow diagram, showing an embodiment of the invention performed by the Location Server. The process400is performed by processing logic that comprises hardware (circuitry, dedicated logic, etc.), software (such as is run on a general purpose computing system or a dedicated machine), firmware (embedded software), or any combination thereof. In one embodiment, the process400is performed by one or more computer systems2300as described inFIG. 23. In one embodiment, the receiving and transmitting steps described below may be facilitated by the various devices utilizing the transceiver2350described inFIG. 23.

In some embodiments, some of the responsibilities of broadcasting Assistance Data are facilitated by a Broadcast Subsystem506and location server504as discussed inFIG. 5A,FIG. 5BandFIG. 6. Referring toFIG. 4, in one embodiment, the Location Server, which may be the location server215ofFIG. 2, may be responsible for deciding, using one or more processors2310, what types of location Assistance Data are to be broadcast (block402), deciding broadcast scheduling (e.g. periodicity for each PAD type) (block404), deciding means of broadcast (e.g. LTE System Information Block (SIB), OMA BCAST (Mobile Broadcast Services Enabler Suite), eMBMS (evolved or enhanced Multimedia Broadcast and Multicast Service)) (block406). Some Provide Assistance Data broadcast messages may be restricted to carry only certain types of Assistance Data in some broadcast systems (e.g. LPPe vendor proprietary Assistance Data such as map data might be allowed for eMBMS but not for LTE SIBs). The Location Server215may be configured for broadcast using operation and maintenance (O&M) signaling. O&M signaling allows adapting, controlling and upgrading of the network nodes. At block408, the Location Server215obtains any Assistance Data associated with access nodes (such as network base stations and access points) including, but not limited to location coordinates and timing information from the nodes directly, through O&M signaling or through any other suitable means. The Location Server215may also obtain Assistance Data from other sources—e.g. GNSS reference receivers in the case of Assistance Data for A-GNSS. At block410, the processor2310of the server constructs Provide Assistance Data broadcast messages in working memory2335, based on available Assistance Data and in some cases specific to particular locations of the cell areas. For example, the server may include Assistance Data related to a certain set of neighboring base stations and access points in PAD messages to be broadcast in the general area served by these base stations and access points but not necessarily in PAD messages to be broadcast in other areas. The server also ciphers Provide Assistance Data messages, using one or more processors2310, if ciphering is used (block412). Details for ciphering a message are discussed in more detail inFIGS. 12,13,14and15. As part of block412, the server may also include authentication data in PAD messages to enable recipient UEs to verify that the PAD messages received via broadcast indeed come from the Location Server215and not some other non-trusted source. At block414, once the Provide Assistance Data messages are ready, the Location Server sends the Provide Assistance Data message to broadcast nodes (e.g. eNodeBs) or gateways (e.g. Mobility Management Entities (MMEs) or a Broadcast Multicast Service Center (BM-SC)), which may be part of the Broadcast Subsystem506of FIG.5A/5B. The Location Server may separately include in association with each PAD message one or more of a message ID, a type ID or set of type IDs, decipher key ID, version ID and scheduling and duration information. The message ID may identify the PAD message and any later updated versions of the PAD message. The type ID or set of type IDs may indicate the type or types of Assistance Data contained in the PAD message. In some embodiments, the type ID or set of types IDs may also identify the PAD message and any later updated versions of the PAD message (e.g. if each PAD message contains a unique type ID or unique set of type IDSs) which may make inclusion of a message ID unnecessary. The decipher key ID may indicate the deciphering key value needed to decipher the PAD message. The version ID may indicate whether the PAD message has been updated with new Assistance Data where, for example, the version ID starts at some initial value (e.g. zero or one) in the first PAD message and changes (e.g. by being incremented by one) each time the content of the PAD message has changed. The scheduling and duration information may indicate the preferred periodicity of broadcast or particular triggering conditions for broadcast (such as having a certain minimum number of broadcast capable UEs in a particular serving cell) and the required overall duration of broadcast. At block416, the Location Server215may update a Provide Assistance Data message when its content needs to change due to previous included Assistance Data no longer being valid and new Assistance Data being available and sends the new message possibly with an incremented version ID but same message ID to broadcast nodes to replace the previous Provide Assistance Data message of this type. In another implementation, some of the responsibilities described in reference toFIG. 4may be shared or delegated to a Broadcast System, as described in further detail below inFIG. 5A,FIG. 5BandFIG. 6.

It should be appreciated that the specific steps illustrated inFIG. 4provide a particular method of switching between modes of operation, according to an embodiment of the present invention. Other sequences of steps may also be performed accordingly in alternative embodiments. For example, alternative embodiments of the present invention may perform the steps outlined above in a different order. To illustrate, a user may choose to change from the third mode of operation to the first mode of operation, the fourth mode to the second mode, or any combination there between. Moreover, the individual steps illustrated inFIG. 4may include multiple sub-steps that may be performed in various sequences as appropriate to the individual step. Furthermore, additional steps may be added or removed depending on the particular applications. One of ordinary skill in the art would recognize and appreciate many variations, modifications, and alternatives of the process400.

FIG. 5Ais a simplified architecture diagram illustrating embodiments of the invention for a broadcast protocol for Location Services (LCS) for using a Broadcast Subsystem. The interactions512between UE502and the Location Server504, represent point to point interactions for exchanging information between the UE502and Location Server504(shown as interactions512ofFIG. 5A) and may be conducted via one or more wireless and/or wireline networks such as GSM, UMTS, LTE, CDMA2000, HRPD, WiFi, packet cable networks (not shown inFIG. 5A). Interactions512may correspond to steps201,202,204and205inFIG. 2. The exchange of information may include information associated with broadcasting Assistance Data from the Location Server504to the UE502via the Broadcast System506. The Location Server504may be implemented as a SUPL SLP, a Serving Mobile Location Center (SMLC) for GSM, a Standalone SMLC (SAS) for UMTS, an Evolved SMLC (E-SMLC) for LTE or a Position Determining Entity (PDE) for CDMA2000. The UE502may comprise a mobile phone, wireless PDA, PC, or any other device that can connect to a wireless or wireline IP capable network. The Location Server504communicates with a Broadcast Subsystem506. In one embodiment, the Broadcast Subsystem506is responsible for receiving information associated with broadcasting Assistance Data from the Location Server504and broadcasting the Assistance Data to one or more UEs502. The Broadcast Subsystem may exchange information with the Location Server504, including one or more exchange of broadcast capabilities between the Broadcast Subsystem506and the Location Server504, a request for specific AD from the Broadcast Subsystem506to the Location Server504, an indication from the Broadcast Subsystem506to the Location Server504on the current or future available broadcast capacity, or an acknowledgement for AD data successfully transferred to the Broadcast Subsystem506from the Location Server504.

In one embodiment, the Broadcast Subsystem506comprises a Gateway510and a RAN508. In some embodiments, the Gateway510may be an MME or BM-SC the RAN508can be a system configured to operate within a GSM, UMTS, LTE, WiFi, CDMA2000, or HRPD network. The Location Server504broadcasts the Assistance Data via the Gateway510and the RAN508to the UE502. In one embodiment, the message from the RAN508to the UE502is a Provide Assistance Data message, however, the interactions and data transmission between the Location Server504and the Gateway510, and the Gateway510and the RAN508may comprise information associated with broadcasting Assistance Data rather than the final message that is broadcast out to the UEs. In one embodiment, Location Server504may perform the functions of Gateway510in which case Gateway510may not be present. Broadcasting assistance data from RAN508to UE/SET502may make use of a wireless network such a GSM, UMTS, LTE, CDMA2000, HRPD or WiFi network or access point (not shown inFIG. 5A). Broadcasting of assistance data, as exemplified by interactions514,516and518inFIG. 5A, may correspond to steps203,207and209inFIG. 2.

FIG. 5Bis a block diagram describing an exemplary embodiment of the invention for a broadcast protocol for Location Service (LCS) using a Broadcast Subsystem. The embodiment may be applicable to LTE networks as well as to other networks such as GSM, UMTS, CDMA2000 and HRPD networks. Elements502,504,506,508and510inFIG. 5Bmay correspond to the same numbered elements inFIG. 5A. As can be seen inFIG. 5B, a UE502(or SUPL Enabled Terminal (SET)) may use a point to point communication to obtain information on broadcast Assistance Data availability in some embodiments. The point to point communication may comprise an LPP/LPPe point to point communication over SUPL, for example. In some other embodiments, a UE502may communicate over a control plane to obtain the information. The UE502may additionally or instead obtain any decipher keys. The information and/or decipher keys may be obtained from a Location Server504, for example. A UE502(implemented as a SET) may comprise a device that can communicate with a SUPL server (SLP). Communication with the SLP may be handled by SUPL supporting software running on the device. For example in the case of SUPL, a UE (or SET) may comprise a mobile phone, wireless PDA, PC, or any other device that can connect to a wireless or wireline IP capable network. In some embodiments, the UE502described above and/or with respect toFIG. 22comprises a SET, and the two may be used interchangeably herein.

At step521, the UE502may send a LPP/LPPe Request Assistance Data message to the Location Server504. An example of the additional parameters for the LPP/LPPe Request Assistance Data message may be partially represented byFIG. 20. In response to the LPP/LPPe Request Assistance Data message, at step522, the Location Server, in one embodiment, sends a LPP/LPPe Provide Assistance Data message with deciphering keys, geographic information, broadcast availability, etc. to the UE502.

After and possibly before the UE502obtains the information and/or deciphering keys, at step523, the Location Server504may send Assistance Data to one or more nodes for broadcast, such as a Broadcast Subsystem506. For example, the Location Server504may package location Assistance Data into LPP/LPPe Provide Assistance Data messages (e.g. as described with respect toFIG. 4) and then send the packaged Assistance Data to a Broadcast Subsystem506. In one embodiment, the Broadcast Subsystem506comprises a gateway510and a RAN508(radio access network). The Provide Assistance Data messages may arrive at the gateway510—for example, an eMBMS BM-SC (Broadcast Multicast Service Center)—or other node, such as an MME for LTE SIB broadcast. At step524, the gateway510or other node may transfer, forward, or otherwise transmit the Assistance Data to the RAN508for broadcast to the UE502(step525), for example from network base stations. In some embodiments, Location Server504may transfer the Assistance Data messages to be broadcast directly to RAN508and may in this case emulate the functions of gateway510.

In one embodiment, the communications illustrated inFIG. 5Band discussed above may be segmented into provisioning and broadcasting phases. In another embodiment, the communications illustrated inFIG. 5Bmay be segmented into preparation, rendering and termination phases as discussed below with respect toFIG. 6. For example, the preparation phase may comprise steps521and522, when a UE502uses LPP/LPPe point to point over SUPL (or possibly control plane) to obtain information on broadcast Assistance Data availability and any decipher keys. As a further example, the rendering phase may comprise, steps523,524and525, when the Location Server504packages location Assistance Data into LPP/LPPe Provide Assistance Data messages which are sent to a gateway510(e.g. eMBMS BM-SC) or other node (e.g. MME for LTE SIB broadcast) for onward transfer to the RAN508for broadcast from network base stations. In some embodiments, steps521and522inFIG. 5Bmay correspond to steps201and202, respectively, inFIG. 2and steps523,524and525inFIG. 5Bmay correspond collectively to each of steps203,207and209inFIG. 2.

FIG. 6is a signaling flow diagram illustrating an exemplary method performed by an embodiment of the invention for broadcasting location Assistance Data to one or more UEs. The signaling in process600is performed by processing logic that comprises hardware (circuitry, dedicated logic, etc.), software (such as is run on a general purpose computing system or a dedicated machine), firmware (embedded software), or any combination thereof. In one embodiment, the process600is performed by one or more computer systems2300as described inFIG. 23. In one embodiment, the receiving and transmitting steps described below may be facilitated utilizing the transceiver2350described inFIG. 23.

Referring toFIG. 6, the Broadcast Subsystem, Server/Location Server and Target/UE may denote, respectively, Broadcast Subsystem506, Location Server504and UE/SET502inFIG. 5Aand are then referred to as these in the description below. Thus, the Broadcast Subsystem may comprise a gateway510, as shown inFIG. 5AandFIG. 5B. In another embodiment, the broadcast system may be interchangeably used with a gateway. In one embodiment, the Broadcast Subsystem506ofFIG. 5AandFIG. 5Band the gateway discussed above are functionally similar.

Referring toFIG. 6, in one embodiment, the method for broadcasting the location Assistance Data to one or more UEs (e.g. UEs2212fromFIG. 22) may be segmented into a preparation phase, a rendering phase and a termination phase. During the preparation phase, LPP/LPPe Assistance Data is transferred from the Location Server504to the Broadcast Subsystem506. Depending on the Broadcast Subsystem506, the preparation phase may include additional steps not shown in FIG.6—e.g. exchange of broadcast capabilities between the Broadcast Subsystem506and the Location Server504, a request for specific Assistance Data from the Broadcast Subsystem506to the Location Server504, an indication from the Broadcast Subsystem506to the Location Server504on the current or future available broadcast capacity, an acknowledgment from the Broadcast Subsystem506for Assistance Data successfully transferred to the Broadcast Subsystem506from the Location Server504.

At Step601, the Location Server504may package the Assistance Data to be broadcast into one or more LPP/LPPe Provide Assistance Data messages, using one or more processors2310and working memory2335. Each LPP/LPPe Provide Assistance Data message may be well formed (i.e. can be decoded by a UE502independently of other messages). The content of each message may be location and/or time specific—e.g. may be applicable to a specific geographic area and/or to a specific period of time. Each message may include an end of transaction indication. Different messages may or may not carry different transaction IDs. In some instances, messages may not include an LPP sequence number or LPP acknowledgment request. The Location Server504may include in each message a unique message ID and the validity time and/or the validity area for the included Assistance Data. The Location Server may optionally cipher some or all messages.

At step602, the Location Server504transports an LPP/LPPe Provide Assistance Data message to the Broadcast Subsystem506. The Location Server504may include additional information such as broadcast triggering conditions (e.g. periodicity), priority, applicable geographic area and time period.

At step603, the Location Server504may repeat step602to transport one or more additional LPP/LPPe Provide Assistance Data messages to the Broadcast Subsystem506. Depending on the interface to the Broadcast Subsystem506, some or all of the messages in steps602and603may be sent together as a single package.

During the rendering phase, LPP/LPPe Assistance Data is broadcast to the plurality of UEs. Depending on the Broadcast Subsystem506, the rendering phase may include additional steps not shown in FIG.6—e.g. advance notification by the Broadcast Subsystem506to the UE502of the type or types of Assistance Data to be later broadcast together with scheduling information, requests by interested UEs to the Broadcast Subsystem506for information to enable subsequent broadcast reception.

At step604, the Broadcast Subsystem506may broadcast the LPP/LPPe Provide Assistance Data message received in step602without modification. The broadcast may occur from multiple nodes (e.g. from multiple base stations) and may be accompanied by additional information identifying, for example, the type of Assistance Data and use of ciphering. The broadcasting may also employ segmentation of a large broadcast message by the broadcast subsystem506into a number of smaller segments with reassembly of these segments into the original broadcast message at the UE502. A UE502that is both able to and chooses to receive the broadcast, using the transceiver2350, may decipher the message, using the processor2310, if ciphering was employed and decode the message contents. If the message includes a message ID, the target UE502may discard the message if a broadcast message with the same message ID was received and stored within a period less than the validity time if a validity time was included in the message or less than a pre-determined time (e.g., 24 hours) otherwise. Otherwise, the UE502may store the Assistance Data from the message, overwriting any previous Assistance Data of the same type, if needed. The UE502may use the Assistance Data to support positioning until such time as the validity time (if included in the message) has expired or the UE502recognizes it is no longer in the validity area (if included in the message).

In one implementation, the Location Server504is responsible for ensuring that any message ID included in a previous broadcast message is not reused for a new broadcast message before the message validity time, if included in the previous message, or a default value, such as 24 hours, have expired since the final broadcast of the previous message. This action may help prevent confusion of the new message with the previous message by recipient UEs. In some implementations, message duplication may be recognized in other ways (e.g. via a Cyclic Redundancy Check (CRC) on the message contents). In the event that message duplication is not recognized, the same Assistance Data will be re-stored, in working memory2335or storage2325, which may be inefficient, but may not harm UE502operation.

At step605, the Broadcast Subsystem506broadcasts the one or more additional LPP/LPPe Provide Assistance Data messages received in step603in a similar manner to step604. At step606, broadcast of each message in steps604and605may be repeated and the periodicity or other triggering conditions for broadcasting each message may be the same or different.

During the termination phase, LPP/LPPe Assistance Data that no longer needs to be broadcast may be removed from the Broadcast Subsystem506. Depending on the Broadcast Subsystem506, the termination phase may include additional steps not shown in FIG.6—e.g. notification by the Broadcast Subsystem506to the Location Server504concerning the actual number of broadcasts for each LPP/LPPe Provide Assistance Data message, the areas in which and/or nodes from which the broadcasts occurred and, if known, the size of the UE audience. At step607, the Broadcast Subsystem506ceases broadcasting any message received at step602or603and deletes it when instructed by the Location Server504or when dictated by scheduling information originally received at step602or step603, for example.

It should be appreciated that the specific steps illustrated inFIG. 6provide a particular method of switching between modes of operation, according to an embodiment of the present invention. Other sequences of steps may also be performed accordingly in alternative embodiments. For example, alternative embodiments of the present invention may perform the steps outlined above in a different order. To illustrate, a user may choose to change from the third mode of operation to the first mode of operation, the fourth mode to the second mode, or any combination there between. Moreover, the individual steps illustrated inFIG. 6may include multiple sub-steps that may be performed in various sequences as appropriate to the individual step. Furthermore, additional steps may be added or removed depending on the particular applications. One of ordinary skill in the art would recognize and appreciate many variations, modifications, and alternatives of the process600.

FIG. 7is a flow diagram, showing an embodiment of the invention performed by the Broadcast Subsystem. The process700is performed by processing logic that comprises hardware (circuitry, dedicated logic, etc.), software (such as is run on a general purpose computing system or a dedicated machine), firmware (embedded software), or any combination thereof. In one embodiment, the process700is performed by one or more computer systems2300as described inFIG. 23. In one embodiment, the receiving and transmitting steps described below may be facilitated utilizing the transceiver2350described inFIG. 23.

As shown inFIG. 7, the broadcast system is responsible for broadcasting Provide Assistance Data messages received from a Location Server504, such as Location Server504inFIG. 5AandFIG. 5B, according to the scheduling and for the duration (block702), while possibly also broadcasting control parameters in association with each broadcast PAD message comprising one or more of a message ID, a type ID or set of type IDs, a version ID and optionally a decipher key ID, authentication information and other parameters (block704). The control parameters may have been received from the Location Server504along with the broadcast message—e.g. may have been transferred in step523ofFIG. 5Bor step602or603ofFIG. 6. The message ID may enable a recipient UE502to determine whether a particular message was already received or not. The version ID may tell a recipient UE502whether a particular message has been updated with new Assistance Data. The type ID or set of types IDs may tell a recipient UE502what type or types of Assistance Data are contained in the message and enable the UE502to decide if the broadcast message should be received or ignored. In some embodiments, the type ID or set of types IDs may also identify the PAD message and any later updated versions of the PAD message (e.g. if each PAD message contains a unique type ID or unique set of type IDs) which may make inclusion of a message ID unnecessary. The decipher key ID may identify a decipher key value received earlier by the UE502(e.g. by point to point means from the Location Server) that is needed to decipher the broadcast message. The authentication information may enable a recipient UE502to verify that the broadcast message was originated from the particular trusted Location Server504. In some embodiments, one or more of the control parameters may be embedded inside the broadcast message by the Location Server504and not be visible to or require explicit transfer from the broadcast subsystem506. The Broadcast Subsystem506may also replace a previous Provide Assistance Data message with any updated Provide Assistance Data message received from the Location Server504(block706). At block708, the Broadcast Subsystem506may possibly also construct and then broadcast an un-ciphered broadcast message containing the types IDs for PAD messages being broadcast and their associated scheduling information to enable UEs to promptly determine what is being broadcast and when. Furthermore, at block710, the Broadcast Subsystem506may also be responsible for performing any segmentation of individual Provide Assistance Data messages wherein each segment may contain one or more of the message ID, the type ID, a segment number and possibly the total number of segments.

It should be appreciated that the specific blocks/steps illustrated inFIG. 7provide a particular method of switching between modes of operation, according to an embodiment of the present invention. Other sequences of steps may also be performed accordingly in alternative embodiments. For example, alternative embodiments of the present invention may perform the steps outlined above in a different order. To illustrate, a user may choose to change from the third mode of operation to the first mode of operation, the fourth mode to the second mode, or any combination there between. Moreover, the individual steps illustrated inFIG. 7may include multiple sub-steps that may be performed in various sequences as appropriate to the individual step. Furthermore, additional steps may be added or removed depending on the particular applications. One of ordinary skill in the art would recognize and appreciate many variations, modifications, and alternatives of the process700.

FIG. 8is a signaling flow diagram illustrating an exemplary embodiment for a Periodic/Triggered Assistance Data Transfer, initiated and terminated for transfer of Assistance Data via broadcast. The signaling in process800is performed by processing logic that comprises hardware (circuitry, dedicated logic, etc.), software (such as is run on a general purpose computing system or a dedicated machine), firmware (embedded software), or any combination thereof. In one embodiment, the process800is performed by one or more computer systems2300as described inFIG. 23. In one embodiment, the receiving and transmitting steps described below may be facilitated utilizing the transceiver2350described inFIG. 23.

Embodiments of the invention, as described inFIG. 8may enable the same Assistance Data that would normally be transferred using the point to point “Periodic/Triggered Assistance Data Transfer with Update” procedure defined for OMA LPPe version 1.0 (in OMA TS OMA-TS-LPPe-V1—0) to be transferred instead using broadcast. In the point to point “Periodic/Triggered Assistance Data Transfer with Update” procedure defined for LPPe version 1.0, a target UE and Location Server initially agree, using a control LPP/LPPe transaction, specific types of Assistance Data that the Location Server will subsequently periodically send to the target using a separate data transaction. During the data transaction, the target UE or Location Server can request a change to the type or types of Assistance Data being transferred using another control transaction after which the initial data transaction continues but with the newly requested Assistance Data now being transferred. In the case of Assistance Data transferred via broadcast to many target UEs, it may not be possible for the Location Server to initially agree the types of Assistance Data to be transferred with each target UE by point to point means as, for example, the Location Server may not know which target UEs may wish to receive this Assistance Data. This may create a problem for certain types of Assistance Data defined in LPPe version 1.0 that can only be sent using the “Periodic/Triggered Assistance Data Transfer with Update” procedure because it may not then be possible to broadcast such Assistance Data—e.g. using the procedure exemplified here inFIG. 6.

To circumvent the above problem, the procedure exemplified inFIG. 8may be employed for Assistance Data defined to be sent point to point using the “Periodic/Triggered Assistance Data Transfer with Update” procedure. In one embodiment, the Location Server504broadcasts an LPP/LPPe Provide Assistance Data message in step801using the procedure described inFIG. 7and/orFIG. 6. The message may use an arbitrary transaction ID T1and indicate the end of this transaction. The message may contain a periodic/triggered session ID S chosen by the Location Server504, an indication that this is a response to an initial request (for compatibility with LPPe version 1.0), LPPe control parameters identifying the type or types of Assistance Data to be transferred in later steps, the triggering or periodicity conditions for sending this data and a duration or other specific conditions for ending the Assistance Data transfer. The Location Server504may ensure that the session ID S is not used for any other periodic/triggered Assistance Data transfer in any geographic area at the same time as the procedure ofFIG. 8is ongoing and for a pre-determined period (e.g., 24 hours) after the procedure inFIG. 8terminates. In one embodiment, the session ID S may be defined as an integer between 1 and 256. In another implementation, the session ID S may include the provider ID, server ID and a 4 octet local session ID. The message in step801may be identical or almost identical to the message sent by a server point to point to a target UE to agree an initial UE request for transfer of Assistance Data point to point according to the “Periodic/Triggered Assistance Data Transfer with Update” procedure in LPPe version 1.0.

The Location Server504may periodically re-broadcast the message in step801to reach additional targets. A UE502that receives the message in step801via broadcast may identify the message as belonging to the “Periodic/Triggered Assistance Data Transfer with Update” procedure from inclusion of the session ID S and the indication that this is a response to an initial request for periodic/triggered Assistance Data transfer. If a UE502receives a subsequent message via broadcast that is identified as belonging to step801and carries the same session ID S as that for an ongoing procedure of this type and if the message may not be identified as a duplicate of the message that initiated this procedure (e.g. from use of the same broadcast message ID), then the UE502may abort reception for the ongoing procedure and may instigate reception for a new procedure based on the control parameters included in the subsequent message.

When the first triggering or periodicity condition occurs, the Location Server504sends via broadcast (e.g. using the procedure inFIG. 7and/or the procedure inFIG. 6) an unsolicited LPP/LPPe Provide Assistance Data message containing the periodic/triggered session ID S assigned in step801, an indication that this is a periodic/triggered Assistance Data delivery, and LPPe data parameters containing the Assistance Data indicated by the LPPe control parameters transferred in step801. The message may carry an arbitrary transaction ID T2and indicate the end of a transaction. In one implementation, no other Assistance Data may be included other than that indicated in step801.

The Location Server504or Broadcast Subsystem506may continue to broadcast further LPP/LPPe Provide Assistance Data messages containing new Assistance Data conforming to what was indicated in step801when each additional triggering or periodicity condition occurs. Each subsequent message may carry the session ID S, an arbitrary transaction ID T3and an end of transaction indication. Messages broadcast in steps802and803may also be resent by the broadcast subsystem in order to reach more target UEs. UEs that already received these messages may determine that the additional transmissions are duplicates from inclusion of the same message IDs. The session may be terminated by the Location server504at any time, after which the session ID S may not be used again for a period of 24 hours in one implementation. A UE that is receiving the messages in steps801,802and803may assume the procedure has terminated if step802or a repetition of step803are not observed for a period of time, such as an hour.

When the session is terminated, a Location Server504may optionally broadcast an LPP/LPPe Provide Assistance Data message to indicate that the session is terminated. The message may contain an arbitrary transaction ID T4, an indication that this is the end of a transaction, the periodic/triggered session ID S and an indication that this is a server update for a Periodic/Triggered Assistance Data transfer. The message may also contain LPPe control parameters indicating a zero or minimal duration (depending on what is defined for the associated Assistance Data) and a zero or minimal applicable geographic region. The message may be periodically re-broadcast to reach more UEs. Recipient UEs may then replace the old control parameters with the new ones and thereby end or soon end the session.

It should be appreciated that the specific steps illustrated inFIG. 8provide a particular method of switching between modes of operation, according to an embodiment of the present invention. Other sequences of steps may also be performed accordingly in alternative embodiments. For example, alternative embodiments of the present invention may perform the steps outlined above in a different order. To illustrate, a user may choose to change from the third mode of operation to the first mode of operation, the fourth mode to the second mode, or any combination there between. Moreover, the individual steps illustrated inFIG. 8may include multiple sub-steps that may be performed in various sequences as appropriate to the individual step. Furthermore, additional steps may be added or removed depending on the particular applications. One of ordinary skill in the art would recognize and appreciate many variations, modifications, and alternatives of the process800.

III. Scheduling Using System Information Blocks (SIBs)

In one embodiment, where distinct broadcast channels are supported, Assistance Data information may be conveyed by particular broadcast channels. A broadcast channel may be some logical or physical portion of the overall broadcast capability supported by a particular broadcast subsystem. As an example, each distinct System Information Block (SIB) broadcast by LTE eNodeBs may be considered to be a separate broadcast channel. Distinct channels may be used either specifically or generically. With specific use, each broadcast channel may be assigned to carry just one type of broadcast PAD. The assignment of the broadcast PAD type may be fixed and standardized. Also, the assignment could be dynamic with each channel (or a master channel like SIB1 for LTE) defining the Assistance Data type ID conveyed by the particular channel. The dynamic information for each channel may be transmitted using a specific pre-designated channel, such as SIB1 or some other SIB in the case of LTE. SIB1 may also contain parameters needed to determine if a cell is suitable for cell selection, as well as information about the time domain scheduling of the other SIBs.

For generic use of broadcast channels, one channel may carry multiple types of broadcast PAD. The supported PAD type IDs and their associated scheduling for a particular broadcast channel may then be defined by a scheduling message with its own PAD type ID that is also broadcast on the same channel. In an alternate embodiment, as discussed before, the types of broadcast PADs transmitted on a particular broadcast channel and their scheduling could be provided by the server to each UE using a point to point connection with LPP/LPPe (e.g. as in steps201and202inFIG. 2). In the cases described above, a long Provide Assistance Data message may be segmented into separate segments by the broadcast subsystem (e.g. eNodeB) and sent as separate messages on a broadcast channel.

SIBs for LTE carry network related information to all UEs and may be broadcast in each cell by the eNodeB. Each SIB has a unique definition (e.g. in 3GPP TS 36.331) associated with specific data that it transports. One or more SIBs may be carried within a SIB message, which is broadcast with a defined periodicity, such as 8 to 512 radio frames (e.g. 1 radio frame may occupy 10 msecs). One or more SIB messages may be broadcast each containing a distinct set of SIBs.

FIG. 9is a block diagram of an exemplary data structure showing the additional information that may be included in a SIB, when there is a one-to-one correspondence between the SIB and a particular type of Provide Assistance Data message carried by the SIB. In one embodiment, the SIBs are used in one-to-one correspondence with the PADs. One new SIB would be used for each PAD type ID that is supported, such as GNSS almanac, GNSS acquisition assistance, GNSS ephemeris, or WiFi data. The Assistance Data content for a particular SIB could be defined by 3GPP as part of the SIB definition or some other organization (e.g. OMA) could define the PAD content as part of LPPe, which may define how the Provide Assistance Data message will be conveyed by the assigned SIB. An exemplary set of additional data in the SIB is shown inFIG. 9. In one embodiment, the SIB could include 1) a PAD type ID (902) for the PAD message being conveyed which may be included when a SIB is allowed to carry more than one type of PAD message, 2) a segment number or a last/not last segment flag (904) if the PAD message is segmented such that a SIB only carries one message segment at a time, 3) a version ID (906) indicating whether a PAD message has or has not been updated, 4) a decipher Key ID (908) indicating a decipher key value to be used to decipher the message, and 5) the PAD message content (910) (e.g. carried as an octet string). In addition, the SIB may also include authentication information (not shown). Only some of the data fields may need to be repeated in the SIB for further segments after the first segment has been transferred in the SIB when segmentation is used. In addition, the PAD type may not need to be conveyed if the association of the PAD type with a particular SIB is fixed (e.g. defined in 3GPP TS 36.331), but may be conveyed when the association is dynamic in some embodiments.

FIG. 10is another block diagram of an exemplary data structure showing the additional information that may be included in a SIB, when multiple PAD types may be conveyed by one SIB. In one embodiment, multiple PAD types may be conveyed by one SIB, where one or a few new SIBs are defined to each carry multiple PAD types. Each new SIB could be carried in its own SIB message or could share a common SIB message with other SIBs. Each new SIB may transport one Provide Assistance Data message or one Provide Assistance Data segment each time it is sent. The content of each new SIB may be 1) a PAD type ID (block1002), 2) a version ID (e.g. included for the first segment only when a message is segmented) (block1004), 3) a decipher key ID (block1006), 4) a segment Number or last/not last segment flag (included if a message is segmented) (block1008), 5) the total number of segments (e.g. included for the first segment only if a message is segmented) (block1010), and 6) the PAD message content (e.g., carried as an octet string with a fixed maximum size) (block1012). When segmentation is used, segments of each message may be broadcast serially but consecutive segments from one message could be interleaved with segments from another message in consecutive transmissions of the same SIB.

In another embodiment, when multiple PAD types can be conveyed within one SIB, the server may provide a master schedule for the SIB to each eNodeB using the 3GPP LPPa protocol defined in 3GPP TS 36.455. Alternatively, each eNodeB could create its own master schedule based on less detailed scheduling instructions from the server. The master schedule determines the scheduling of Provide Assistance Data messages within the SIB and may itself be broadcast. The schedule for broadcasting the master schedule itself may be referred to in the SIB and, in one embodiment, may be further referred to in the master schedule as well. In one embodiment, the PAD type used to refer to the master schedule uses a reserved PAD type (e.g. of zero). The master schedule defines the order of Provide Assistance Data messages or Provide Assistance Data segments when segmentation is used that are broadcast within the SIB and may include the schedule for an integral number of transmissions for each PAD message in order that when the sequence of PAD transmissions defined within the master schedule are complete there will be no outstanding un-transmitted segments for any PAD message. In addition, Provide Assistance Data message content may not change for any PAD message during one master scheduling cycle (in order that recipient UEs only need to receive one transmission of each message during the master scheduling cycle, for example), but may change in a new cycle.

FIG. 11is block diagram of an exemplary data structure showing the information that may be included in the master schedule for scheduling PAD transmission according to the embodiment just described, when multiple PAD types are scheduled within one SIB. As shown inFIG. 11, the master schedule message content may contain 1) a PAD type ID to identify the master schedule message (block1102), 2) a version ID of the master schedule (which may be incremented whenever master schedule changes) (block1104), and 3) PAD Type IDs (T1, T2, T3, . . . . Tm) for each PAD message being scheduled, the corresponding number of segments or messages associated with each PAD Type (N1, N2, N3, . . . . Nm), and an end message flag for each PAD message (blocks1106,1108and1110). Each of the PAD Type ID entries refers to consecutive transmission of segments or complete messages for the given PAD type. Thus, the schedule implies that either N1segments or N1complete messages for PAD type T1will be initially broadcast using the SIB after any new master scheduling cycle has started followed by either N2segments or N2complete messages for PAD type T2followed by either N3segments or N3complete messages for PAD type T3and so until the scheduling cycle ends after either Nm segments or Nm complete messages have been transmitted for PAD type Tm. Each PAD type entry may further indicate whether complete messages or only message segments will be broadcast (e.g. whether N1segments or N1complete messages will be broadcast for PAD Type T1). In the case that message segments are to be broadcast, the end message flag may indicate whether the last message segment sent ends a complete message. It may be assumed (e.g. defined as part of the master schedule) that when message segments are broadcast, all segments will belong to the same PAD message. As an example, the following entry could be included in the master schedule: “PAD Type ID Ti, Ni segments, end message=Yes”. This would indicate transmission of Ni segments for the PAD type with Type ID Ti at this point in the master schedule and would further indicate that the last segment transmitted in this sequence terminated a complete PAD message. If the Location Server creates the schedule, it may be beneficial to know details about SIB content and maximum size and the periodicity of SIB transmission. In one embodiment, the Location Server may be configured using O&M.

FIGS. 9,10and11describe embodiments in which information related to broadcast of PAD messages on a SIB, such as information on broadcast content (e.g. PAD type ID) and/or information on broadcast scheduling (e.g. a master schedule), is provided by a SIB to target UEs in an LTE wireless network. In other embodiments, this information may be provided to target UEs using a SIB different to the SIB on which broadcast of PAD messages occur or may be provided to UEs by point to point means—e.g. as in step2inFIG. 2. In yet other embodiments, which may apply to LTE wireless networks or to other networks, broadcast of PAD messages may occur on a broadcast channel (e.g. a WiFi channel) or using a broadcast system (e.g. eMBMS) different to an LTE SIB and information related to this (e.g. information on broadcast content and/or broadcast scheduling) may be the same as or similar to that described inFIGS. 9,10and11and may further be provided using the same broadcast channel or the same broadcast system as that on which PAD messages are broadcast or may be provided using a different broadcast channel or different broadcast system or may be provided by point to point means.

Encapsulated and Unencapsulated Broadcast Assistant Data Message:

A broadcast Assistance Data message (e.g. as broadcast according toFIG. 6orFIG. 8) may comprise, a) an unencapsulated and unciphered LPP Provide Assistance Data message, b) an unencapsulated and unciphered LPP/LPPe Provide Assistance Data message, c) an encapsulated LPP Provide Assistance Data message that may optionally be ciphered and/or digitally signed, or d) an encapsulated LPP/LPPe Provide Assistance message that may optionally be ciphered and/or digitally signed. An unencapsulated message may consist of an LPP Provide Assistance Data message without an LPPe extension as defined for example in 3GPP TS 36.355 in case (a) or an LPP Provide Assistance Data message with an LPPe extension in case (b) as defined for example in OMA LPPe version 1.0.

Broadcast capable UEs may be informed of the variant being used by a server by point to point means—e.g. whether the server uses variant (a), (b), (c) or (d) above. Target UEs that have minimal broadcast capability (e.g. that do not support reception of Assistance Data point to point related to broadcast support and do not support variants (c) and (d) above) may assume the unencapsulated variant (a) or (b) and may then encounter decoding errors if the encapsulated variant (c) or (d) is used. Such UEs may then cease employing a particular broadcast system for receiving broadcast messages once a certain number of consecutive decoding errors are encountered.

FIG. 12illustrates an exemplary embodiment of an encapsulated broadcast message transmitted by a server for case (c) and case (d). In one embodiment, the server is a Location Server. In another embodiment, the server is a node belonging to a Broadcast Subsystem506. An encapsulated broadcast message comprises a plurality of broadcast control parameters (block1202) and a Provide Assistance Data message (block1206). The Provide Assistance Data message (block1206) may be an LPP Provide Assistance Data message defined for example as in 3GPP TS 36.355 for case (c) or an LPP/LPPe Provide Assistance Data message defined as in the OMA LPPe specification for case (d). The Location Server may or may not select ciphering and/or digitally signing the encapsulated broadcast message. Additional message portions may be included in the encapsulated broadcast message, if the Location Server ciphers or digitally signs the encapsulated broadcast message.

The broadcast control parameters enable detection of an already received broadcast message and may contain information on the geographic and time applicability of the message and the types of Assistance Data included. The cipher key ID and counter value (block1204) are included when ciphering is used and enable a recipient UE to determine the key value to be used for deciphering. The message portion (block1206) contains an LPP or LPP/LPPe Provide Assistance Data message and may be ciphered. A digital signature (block1208) may be appended, as shown inFIG. 12, and, if so, may be computed over portions of the message or the entire preceding message content. InFIG. 12, inclusion of an “(O)” indication for a block indicates that the block may be optional whereas inclusion of an “(M)” indication for a block or lack of an “O” indication indicates inclusion of the block may be mandatory in some embodiments. In other embodiments, the optional or mandatory elements may differ. InFIG. 12, a block A shown to the left of another block B indicates block A is transmitted before block B. In some embodiments, the blocks are transmitted in a different order than illustrated.

FIG. 13illustrates another exemplary embodiment of an encapsulated broadcast message transmitted by a server and uses the same conventions “(O)” and “(M)” as inFIG. 12and the same conventions on block transmission order in some embodiments. In one embodiment, the server is a Location Server504. In another embodiment, the server is a node belonging to a Broadcast Subsystem506. The Location Server504may or may not select ciphering and/or digitally signing the broadcast message. Additional message portions may be included in the broadcast message, if the Location Server ciphers or digitally signs the broadcast message.

The broadcast control parameters (block1302) enable detection of an already received broadcast message and may contain information on the geographic and time applicability of the message and the types of Assistance Data included. The cipher key ID and counter value (block1304) are included when ciphering is used. The message portion (block1306) contains an LPP or LPP/LPPe Provide Assistance Data message and may be ciphered. A digital signature (block1308) may be prepended, as shown inFIG. 13, and, if so, may be computed over portions of the message or the entire preceding message content.

As shown inFIG. 13, the digital signature portion (block1308) contains the associated public key identifier and may appear at the beginning of the message so that a target can determine as soon as reception begins whether it has the correct public key and, if so, can begin the authentication process while message reception is in progress.

In one embodiment, the Location Server may digitally sign the broadcast message. In one implementation, the Location Server may use asymmetric cryptography, such as RSA or elliptical cryptography or any other suitable means for digitally signing the broadcast message. In some aspects, a hash of the broadcast message may be signed. The Location Server may sign portions of the message or the entire encapsulated broadcast message. Authentication options enable a server to protect target UEs against spoofing of broadcast data by an attacker. The server may, for example, instruct all UEs via point to point means (e.g. as in steps201and202ofFIG. 2) that all broadcast PAD messages received using a particular broadcast subsystem and/or in a particular area are to be authenticated. If a target UE receives a broadcast PAD message using such a subsystem and in the particular area if included that does not contain a digital signature or that contains a digital signature that fails verification or refers to a key that the target UE does not possess, the target UE may discard the message. The target UE may then only accept messages that contain a verifiable digital signature. This convention may ensure that fraudulent broadcast of false location Assistance Data cannot be used to dupe target UEs into computing false locations or making false measurements and may serve to ensure integrity and reliability of location services.

Ciphering the Broadcast Assistant Data Message:

The Location Server may cipher the broadcast message. As shown inFIG. 12andFIG. 13, in one implementation, the Provide Assistance Data message may be ciphered. The Location Server may use symmetric cryptography, such as the Advanced Encryption Standard (AES) defined in Federal Information Processing Standards Publication 197, “Specification for the ADVANCED ENCRYPTION STANDARD (AES)”, published in November 2001, or any other suitable means for ciphering the Assistance Data message. In one implementation, a 128-bit key value may be used for AES and counter mode may be used as defined in the National Institute of Standards and Technology (NIST) Special Publication 800-38A, “Recommendation for Block Cipher Modes of Operation Methods and Techniques”, published in 2001. An example of such as implementation is further discussed inFIG. 15. An initial counter C1may be used to cipher a LPP/LPPe message provided to the UE by a server. Counter C1may be provided to the UE in two portions. The first portion, denoted C0, may be provided using point-to-point mode along with a ciphering key value (example, 128-bits). Additionally, an identifier (cipher key ID) for the first portion of the counter and the ciphering key value may be provided to the UE using point-to-point mode—e.g. according to steps201and202ofFIG. 2. The cipher key ID may be included in the encapsulated broadcast message (e.g. in block1204ofFIG. 12and block1304ofFIG. 13) to identify the ciphering key value for deciphering the message by the device. The second portion, denoted D0, may be provided in unciphered form as part of the overall encapsulated message—e.g. as part of block1204inFIG. 12and block1304inFIG. 13. A UE may then obtain C1as:
C1=(C0+D0)mod 2**128  (Equation 1),
where all values are treated as non-negative integers. In equation 1 and in other equations here, the double asterisk notation (**) denotes exponentiation. The value for D0may be different for different broadcast messages and may help ensure that the counters derived from C1for each message are different to the counters derived for any other message. To obtain any subsequent counter Ci from the previous counter Ci−1 for any message (as needed for counter mode AES deciphering of the message blocks contained within a message), the following operation may be used:
Ci=(Ci−1+1)mod 2**128  (Equation 2).
Authenticating the Broadcast Assistance Data Message:

The broadcasted Provide Assistance Data messages may be optionally digitally signed by the server to protect target UEs against spoofing of broadcast data by an attacker. The server may be the Location Server or a node part of the Broadcast Subsystem. Assistance data may be optionally digitally signed using techniques such as asymmetric cryptography. In one implementation, the RSASSA-PSS variant of the PKCS#1 v.2.1 RSA method defined in “PKCS#1 v2.1: RSA Cryptography Standard”, RSA Laboratories, published in June 2002 and in Internet Engineering Task Force (IETF) Request For Comments (RFC) 3447 where IETF RFC 3447 may take precedence for conflicts. These references define a set of fixed procedures and some optional procedures. An exemplary method for LPP/LPPe may use the following procedures and options for authentication, as shown in Table 1 below:

In Table 1, NIST 180-4 refers to NIST Federal Information Processing Standard (FIPS) Publication 180-4, “Secure Hash Standards (SHS)”, published in March 2012. In one embodiment, the authentication procedure may be performed at the UE using asymmetric cryptography. Asymmetric cryptography uses a key pair, comprising of a private and public key. A message containing a digital signature created using the private key may be verified using the public key. In one implementation, the server has access to the private key and the UEs have access to the public key. For example, the public key may be transferred by a server to a UE by point to point means as in steps201and202ofFIG. 2. Upon receiving the broadcasted message, the UE may verify the signature part of the received message (e.g. block1208or block1308) using the public key and verify that the message originated from the server.

At the server, a digital signature may be computed over the entire broadcast message (that has already been ciphered if ciphering is used) by first hashing and masking the message to yield a message representation of fixed length, such as 2047 bits. The message representation may then be signed using the RSA private key generating a signature of length 2048 bits. At the UE, the digital signature may be retrieved from the broadcast message and may be converted back to an expected message representation using the RSA public key. The expected message representation may then be compared against the actual message representation derived from the received message and if they are equal, the broadcast message is verified and authenticated.

The public key and a salt length for the authentication may be provided to a UE by a server and may be assigned a unique ID by the server. The transfer of the public key and the salt length to the UE may occur using point to point LPP/LPPe before the UE begins to receive broadcast Assistance Data—e.g. as described for step201and202inFIG. 2. The server identifies the public key and salt length to be used to authenticate any received broadcast LPP or LPP/LPPe message by including, as part of the broadcast message (e.g. as part of block1208inFIG. 12or block1308inFIG. 13), the unique identifier for the public key and salt length pair that was sent earlier point to point.

A UE may authenticate any broadcast message received that contains a digital signature if the UE already has the identified public key and salt length. If a server has earlier indicated by point to point means that authentication shall be used for a particular broadcast system, a UE may ignore any broadcast message received that does not contain the digital signature. Broadcast messages that fail authentication may also be discarded and the UE may cease using the associated broadcast system for some implementation dependent time period.

In one embodiment, when receiving a new broadcast message, a target may perform verification and decoding using the following steps (described in more detail inFIG. 14) in any order suitable:

1) Verification from broadcast control parameters that the message is not a duplicate and has a valid time and geographic area applicability.

2) Verification from broadcast control parameters that the message contains (or may contain) types of Assistance Data of interest to the UE.

3) Verification that the UE has the correct key or keys to perform authentication and deciphering when either or both of these are required.

4) Verification of any digital signature if included.

5) Deciphering of message content if ciphering was used.

6) Decoding of message content.

FIG. 14illustrates a flow diagram for an exemplary embodiment for verifying a broadcast message already received or being received at a target UE device. The process1400is performed by processing logic that comprises hardware (circuitry, dedicated logic, etc.), software (such as is run on a general purpose computing system or a dedicated machine), firmware (embedded software), or any combination thereof. In one embodiment, the process1400is performed by one or more computer systems2300as described in FIG.23. In one embodiment, the receiving and transmitting steps described below may be facilitated utilizing the transceiver2350described inFIG. 23.

In one embodiment, a server generates the broadcast message and is a Location Server504. In another embodiment, the broadcast message is broadcast using a server belonging to a node, such as a Broadcast Subsystem506. The device discussed below may represent a UE502/2212and perform embodiments of the invention. One or more processors may be used to decipher and authenticate messages. In some instances, a co-processor such as a crypto-processor may be used for certain functions.

As shown ifFIGS. 12 and 13, the broadcast message may comprise a plurality of broadcast control parameters and a Provide Assistance Data message. An encapsulated broadcast message may be an LPP or LPP/LPPe message. The Location Server504may or may not select ciphering and/or digitally signing the encapsulated broadcast message. Additional message portions may be included in the encapsulated broadcast message, if the Location Server ciphers or digitally signs the encapsulated broadcast message.

The order described with respect to the flow diagram is an exemplary order and may be reordered in any suitable manner without departing from the scope of the invention. In some implementations, various steps may be performed simultaneously. The method ofFIG. 14may be performed by components of the UE502, such as the device described inFIG. 23, using hardware, software or firmware.

At block1402, the device receives or begins to receive a broadcast message, using the transceiver2350. In one embodiment, the device begins processing the information, using the processor2310, comprised in the broadcast message while still receiving portions of the broadcast message. For instance, the device may start processing portions of the broadcast control parameters and/or header associated with the broadcast message before or while receiving other portions of the broadcast message.

In some implementations, it may be advantageous to process portions of the header and/or broadcast control parameters before processing the rest of the message. For instance, for a ciphered message, the broadcast control parameters may provide more information on the protocol and keys used in ciphering the message. Similarly, for a digitally signed message, the device may retrieve the appropriate public key, convert the digital signature and also start hashing portions (or blocks) of the digital message as it is received by the device. Also, various steps for authenticating a message, such as converting the digital signature and hashing the message, may also be performed simultaneously or in parallel to each other. It may be an advantage to begin processing the message, using the processor2310, while it is still being received in order to more quickly determine if the message is valid, of use to the UE and can be completely decoded. If one or more of these conditions is not fulfilled, the UE may cease receiving the message thereby saving radio resources and possibly permitting other activities to more quickly occur.

At block1404, the device determines that the broadcast message is or is not a duplicate message using broadcast control parameters, at the processor2310using stored information at the working memory2335or other buffers. In an exemplary implementation, this may be determined using a timestamp or a unique message ID embedded in the header of the message. In one exemplary embodiment, a timestamp may be included in the message data that is digitally signed for the broadcast message, thus preventing an attacker from resending a message with a valid digital signature at some later time that is inconsistent with the timestamp.

At block1406, the device determines, using the processor2310, whether the broadcast message is applicable to the device by checking the time and geographic applicability of the broadcast message. For instance, a broadcast message with an old timestamp, an old time duration or a time duration in the future that has yet to occur or a broadcast message that belongs to a different geographic area or different area of a network may be discarded by the device. In some embodiments, a device may choose to receive and store a broadcast message carrying a time duration applicable to some future time instead of discarding the message.

At block1408, the device determines, using the processor2310, if the broadcast message has the Assistance Data of interest to the device. The device may determine the interest based on the Assistance Data type parameters of the broadcast control parameters associated with the broadcast message.

At block1410, the device may determine, using the processor2310, if the one or more keys needed for the authentication or/and deciphering steps are present on the device. In some embodiments, prior to performing this step, the device may check if the device is configured to receive authenticated and ciphered messages. The keys may be partially or fully exchanged during the point-to-point communication between the server and the device (e.g. as in steps201and202inFIG. 2). In some embodiments, a new point-to-point communication between the device and the server may be established, in response to detecting that the appropriate keys are not present at the device, for retrieving the appropriate keys.

At block1412, the device may verify the digital signature of the message, using the processor2310, if one is included. As shown inFIGS. 12 and 13, the digital signature may be appended or prepended to the message. In addition to the message components shown inFIGS. 12 and 13, the digital signature may also be embedded in the message. A digital signature, if included, may be computed over the entire message content. The digital signature portion may contain the associated public key identifier and may appear at the beginning of the message so that a target device may determine as soon as reception begins whether it has the correct public key and, if so, may begin the authentication process while message reception is in progress.

In one embodiment, the digital signature is converted using a public key stored at the device. The digital signature for the broadcast message may be generated using an RSA algorithm. In one implementation, the RSASSA-PSS variant of the PKCS#1 v.2.1 RSA method is used as described herein above. Prior to generating the digital signature, the server may first hash the contents of the broadcast message using a one-way function as described herein in association with Table 1. In one implementation, a Secure Hash Algorithm 1 (SHA-1) algorithm is used for hashing the broadcast message contents as referred to herein in Table 1. Once the message is hashed and masked to a shorter string (e.g. containing 2047 bits), the string is digitally signed using RSA (e.g. to create a digital signature containing 2048 bits). If the broadcast message is to be ciphered, then the contents may be ciphered before digitally signing the message. This allows the device to digitally authenticate the message before deciphering the message.

Upon receiving the broadcast message, the device digitally authenticates the message if authentication is enabled. The server and the device may negotiate through point-to-point communication prior to the broadcasting if authentication may be used as part of the communication. If the device is configured to authenticate messages, and the device receives messages without the digital signature or if the digital signature fails verification, the device may discard the message. If repeated discarding of the broadcast messages is necessitated due to failed authentication, the device may cease to receive broadcast messages via a particular broadcast system and/or in a particular area, temporarily or permanently, or may switch to a different mechanism of receiving messages. For instance, the device may switch back to a point-to-point protocol with the server or obtain new keys from the server.

In one embodiment, if the device is configured to authenticate broadcast messages and if the messages have a prepended digital signature, similar toFIG. 13, the device may begin authenticating the message while receiving the message. The device may convert the digital signature using a public key stored on the device and associated with the private key used to sign the broadcast message. The device may also hash the contents of the broadcast message and compare the hashed value against the converted value. If the values match, authentication passes and the digital signature is considered verified.

At block1414, the message content may be deciphered if ciphering is enabled, using the processor2310. In one embodiment, the device may discover if ciphering is enabled by inspecting the broadcast control parameters. As shown inFIGS. 12 and 13, in one embodiment, the Assistance Data included in the broadcast message is deciphered using a deciphering key value stored on the device (which may be the same as the ciphering key value used by the server or may be a public key counterpart to a private key used by the server). Contents of the broadcast message may be encrypted by the server and decrypted by the device using symmetric cryptography such as AES. One implementation of the AES algorithm is further discussed inFIG. 15. At block1416, once the contents are authenticated and deciphered (where authentication and ciphering is enabled) the contents of the broadcast message may be decoded by the device according to the LPP/LPPe protocol definition for retrieving the location Assistance Data.

It should be appreciated that the specific blocks/steps illustrated inFIG. 14provide a particular method of switching between modes of operation, according to an embodiment of the present invention. Other sequences of steps may also be performed accordingly in alternative embodiments. For example, alternative embodiments of the present invention may perform the steps outlined above in a different order. To illustrate, a user may choose to change from the third mode of operation to the first mode of operation, the fourth mode to the second mode, or any combination there between. Moreover, the individual steps illustrated inFIG. 14may include multiple sub-steps that may be performed in various sequences as appropriate to the individual step. Furthermore, additional steps may be added or removed depending on the particular applications. One of ordinary skill in the art would recognize and appreciate many variations, modifications, and alternatives of the process1400.

FIG. 15describes one implementation of AES. The following implementation provides a description of the algorithm use to cipher and decipher LPPe 1.1 broadcast Assistance Data messages. The algorithm uses AES ciphering with counter mode. AES is a block mode cipher algorithm that ciphers blocks of 128 bits at a time. However, Counter mode enables usage for a bit string that is not an exact multiple of 128 bits. Further, Counter mode enables a target (or a server) to perform most of the deciphering (or ciphering) processing independently of receipt of the data to be deciphered (or ciphered) which may enable more efficient processing—e.g. by enabling deciphering (or ciphering) to occur almost immediately when portions of data are received via broadcast (or obtained at a server). Provided counters are chosen in a non-repeating manner by the server (which is a requirement for Counter mode in some embodiments), every block of data will be ciphered in a unique manner.

The algorithm makes user of a sequence of counters <C1, C2, C3, . . . > each containing 128 bits, where C1is specified by the server and each subsequent counter (C2, C3etc.) is obtained from the previous counter by adding one modulo 2**128. Each counter Ci is ciphered using the AES algorithm with a common 128 bit key to produce an output block Oi of 128 bits. To perform ciphering of a broadcast message, the LPP/LPPe message is divided into blocks B1, B2, . . . Bn of 128 bits each, except for the last block Bn which may contain fewer than 128 bits. The ciphered message is obtained as a sequence of n blocks containing 128 bits each (except possibly for the last block) given by (O1XOR B1), (O2XOR B2), . . . (On XOR Bn), where XOR denotes bitwise exclusive OR. In the case of the last block, if Bn contains m bits (m<128), then the m most significant bits of On would be used for the exclusive OR. Deciphering is performed in the same way except that the blocks B1, B2, . . . Bn are now obtained from the ciphered message and the result of the exclusive OR operations yields the original unciphered message.

Abstract Syntax Notation One (ASN.1) Tables:

FIGS. 16A,16B,16C,16D and16E apply to broadcast of LPP and LPP/LPPe Provide Assistance Data messages and define exemplary possible broadcast restrictions and labeling applicable to the content of broadcast Assistance Data and limitations on the areas within which certain types of Assistance Data may be broadcast.FIGS. 16A,16B,16C,16D and16E also provide a means of labeling different types of Assistance Data. The labels may be used both within LPPe and by a broadcast system to concisely advertise support for particular types of Assistance Data and/or to provide broadcast scheduling information.

FIG. 16AandFIG. 16Bshow the different types of Assistance Data for LPP that may be broadcast where each Assistance Data type is referred to using its ASN.1 parameter name in the OMA LPPe version 1.1 TS. For each Assistance Data type, a possible area limitation is shown if the Assistance Data is only valid within a restricted area. A server may broadcast Assistance Data outside the area limitation if it is preferred to provide target devices with Assistance Data for a wider geographic area although there is no guarantee that the data will always be usable in that case. Other possible restrictions for Assistance Data are also shown where these exist—e.g. any possible restrictions on content. Assistance data that is time sensitive (e.g. GNSS time, GNSS real time integrity, GNSS acquisition assistance) may be updated as needed by the server and stale data may also be removed. For Assistance Data that includes an explicit validity area, broadcast outside the validity area may be allowed and a target may then verify presence within the validity area before using the data.

FIG. 16AandFIG. 16Balso shows labels that may be used within LPPe and by a broadcast system to refer to particular types of Assistance Data—e.g. when indicating broadcast support for different types of Assistance Data within LPPe or when indicating which Assistance Data types are being broadcast by a broadcast system. A label is specified as a sequence of n (n=1 to 4) numerical elements separated by periods—e.g. 2, 2.1, 2.1.3, 2.1.3.5—where n is the nesting level of the labeled data item.

InFIGS. 16A and 16B, the nesting level of any Assistance Data type is indicated using a “>” symbol in the first column where the number of concatenated “>” symbols m shown for any data item and its associated label indicates that its nesting level is m+1 where m is in the range 0 to 3. The order of data items inFIGS. 16A and 16Bmay follow the ASN.1 definition in the LPPe version 1.1 TS which means that the parent data item for any nested data item at level n is the closest preceding data item in the table at level n−1. Labels are shown in column 1 and show only the final elements, since preceding elements can be inferred from the final elements for the parent data items. As an example, the Assistance Data type otdoa-ProvideAssistanceData inFIG. 16Ahas a nesting level of 1 and label of 2; the data type otdoa-NeighbourCellInfo (which is nested within and one level deeper than otdoa-ProvideAssistanceData inFIG. 16A) has a nesting level of 2 and a label of 2.2; and the Assistance Data type gnss-DataBitAssistance inFIG. 16Ahas a nesting level of 4 and a label of 3.2.N.5 where N (N=1 to 8) indicates the particular GNSS or SBAS system to which it applies.

FIGS. 16C,16D, and16E show the different types of Assistance Data for LPPe version 1.1 that may be broadcast, with associated area limitations and other restrictions, where each data type is referred to using its ASN.1 parameter name as defined in the LPPe version 1.1 TS. The conventions used to define nesting levels and labels are as described above in association withFIGS. 16A and 16B.

The possible restrictions and labeling shown inFIGS. 16A,16B,16C,16D and16E are examples for the LPP and LPP/LPPe positioning protocols and may be replaced by other restrictions or other means of labeling in other embodiments.

To support the novel encapsulation, data type labeling, point to point assistance, ciphering and authentication as applicable to the LPP/LPPe protocol, new LPP/LPPe extensions may be defined in some implantations.FIGS. 17A,17B,18,19A,19B,20A,20B,21A,21B,21C and21D are examples of a new LPPe broadcast message extensions to support point to point Assistance Data related to broadcast (e.g. as used in steps201and202ofFIG. 2) and broadcasting with encapsulation, ciphering and authentication (e.g. as described in association withFIG. 13). Each figure shows the parameter content of a particular message extension in the form of a table, where the parameter content refers to new parameters added to an LPPe message to support broadcast. In each table, each row below the initial header row describes one parameter in the message extension, with the parameter name shown in the first column, the corresponding LPPe ASN.1 data type name shown in the second column, an indication of whether the parameter is optional shown in the third column (with blank entries here for parameters that are mandatory) and a description of the parameter meaning and usage given in the fourth column. The nesting level of each parameter within the message extension is shown using greater than symbols (“>”) in the first column where the number of consecutive “>” symbols plus one gives the nesting level. Thus, for example, a parameter with name “>>>example” would have a nesting level of 4. Any nested parameter P in a table is contained within the parameter closest to it and higher up in the table that has a nesting level one lower than that of P. Parameters with the lowest nesting level (of one) are directly contained within the message extension only. Nested parameters may only be included in a message extension when the parameter within which they are contained is also present in the message. When this condition occurs, a mandatory nested parameter will be present whereas an optional nested parameter may or may not be present. The order of parameters in the figures may closely follow the ASN.1 definition for OMA LPPe version 1.1. In some embodiments, whether particular parameters are mandatory or optional may be different to that shown in these figures.

FIGS. 17A and 17Billustrates an exemplary Broadcast Container used in embodiments of the invention. The Information Element (IE) OMA-LPPe-ver1-1-BroadcastContainer, shown inFIGS. 17A and 17B, may be used to encapsulate ciphered or unciphered LPP and LPP/LPPe Provide Assistance Data messages for delivery via broadcast. The use of this container enables transfer of information needed for ciphering support (e.g. cipher key identifier), message authentication (e.g. public key identifier and digital signature) and information that a UE can use to quickly identify the types of information being broadcast, the applicable area and time period and whether the data duplicates data already received. A UE that identifies a duplicate broadcast message or Assistance Data that is not of interest, not applicable or not supported can cease reception without the need to receive, decipher, decode and possibly authenticate the encapsulated LPP or LPP/LPPe message. Except for the encapsulated LPP or LPP/LPPe message, the parameters (e.g. control parameters) in an OMA-LPPe-ver1-1-Broadcast-Container may not need to be ciphered.

FIG. 18illustrates exemplary enhancements in the form of additional parameters to the LPP/LPPe Request Capabilities message that enable this message to request capabilities related to support of broadcast of Assistance Data. Step204ofFIG. 2represents an exemplary Request Capabilities message from the Location Server215to the UE220. The message may also be sent (though not shown inFIG. 2) from the UE220to the Location Server215. Similarly,FIGS. 19A and 19Billustrates exemplary enhancements in the form of additional parameters to the LPP/LPPe Provide Capabilities message that enable this message to provide capabilities related to support of broadcast of Assistance Data. Step205ofFIG. 2represents an exemplary Provide Capabilities message from the UE220to the Location Server215. The message may also be sent (though not shown inFIG. 2) from the Location Server215to the UE220.FIGS. 20A and 20Billustrate exemplary enhancements in the form of additional parameters to the LPP/LPPe Request Assistance Data message that enable this message to request (in a point to point manner) Assistance Data related to support of broadcast of Assistance Data. Step201ofFIG. 2and step521ofFIG. 5Brepresent exemplary Request Assistance Data messages from the UE220/502to the Location Server215/504.FIGS. 21A,21B,21C and21D illustrate exemplary enhancements in the form of additional parameters to the LPP/LPPe Provide Assistance Data message that enable this message to provide (in a point to point manner) Assistance Data related to support of broadcast of Assistance Data. Step202ofFIG. 2and step522ofFIG. 5Brepresent exemplary Provide Assistance Data messages from the Location Server215/504to the UE220/502.

In other embodiments, message extensions partly or completely different to those exemplified inFIGS. 17A,17B,18,19A,19B,20A,20B,21A,21B,21C,21D may be used to support broadcasting of LPP and LPP/LPPe PAD messages

Referring toFIG. 22, a wireless communication system2200includes various devices, such as user equipment2212(UE), base transceiver stations (BTSs)2214disposed in cells2216, and a base station controller (BSC)2218. The system2200may support operation on multiple carriers (waveform signals of different frequencies). Multi-carrier transmitters can transmit modulated signals simultaneously on the multiple carriers. Each modulated signal may be a Code Division Multiple Access (CDMA) signal, a Time Division Multiple Access (TDMA) signal, an Orthogonal Frequency Division Multiple Access (OFDMA) signal, a Single-Carrier Frequency Division Multiple Access (SC-FDMA) signal, etc. Each modulated signal may be sent on a different carrier and may carry pilot, overhead information, data, etc.

The BTSs2214can wirelessly communicate with the UEs2212via antennas. Each of the BTSs2214may also be referred to as a base station, an access point, an access node (AN), a Node B, an evolved Node B (eNodeB), etc. The BTSs2214are configured to communicate with the UEs2212under the control of the BSC2218via multiple carriers. Each of the BTSs2214can provide communication coverage for a respective geographic area, here the respective cells2216. Each of the cells2216of the BTSs2214is partitioned into multiple sectors as a function of the base station antennas. In some embodiments, one or more of the BTSs2214are implemented in the RAN508illustrated inFIG. 5AandFIG. 5B. Further, elements ofFIGS. 2,6, and8and other elements ofFIG. 5AandFIG. 5Bdescribed above may be included in the system2210. Although the server and Location Server discussed above and illustrated inFIGS. 2,5A,5B,6, and8are not illustrated inFIG. 22, the Location Server may be in communication with the BTSs2214and/or the BSC2218. For example, a type of SMLC implemented as the Location Server may be in communication with the BSC2218, directly or via a gateway. In some embodiments, one or more networks separate at least two of the elements illustrated inFIG. 22, and/or separate elements illustrated inFIG. 22from elements discussed above and/or illustrated with respect toFIGS. 2,5A,5B,6, and8.

The system22may include only macro base stations2214or it can have base stations2214of different types, e.g., macro, pico, and/or femto base stations, etc. A macro base station may cover a relatively large geographic area (e.g., several kilometers in radius) and may allow unrestricted access by terminals with service subscription. A pico base station may cover a relatively small geographic area (e.g., a pico cell) and may allow unrestricted access by terminals with service subscription. A femto or home base station may cover a relatively small geographic area (e.g., a femto cell) and may allow restricted access by terminals having association with the femto cell (e.g., terminals for users in a home).

The UEs2212can be dispersed throughout the cells2216. The UEs2212may be referred to as terminals, mobile stations, mobile devices, user equipment (UE), subscriber units, etc. The UEs2212shown inFIG. 22include mobile telephones, personal digital assistants (PDAs) and vehicular navigation and/or communication systems, but can also include wireless routers, other handheld devices, netbooks, notebook computers, etc.

A computer system as illustrated inFIG. 23may be incorporated as part of the previously described entities shown and discussed in reference toFIGS. 2-22. For example, computer system2300may be capable or, adapted to and configured to represent some or all of the components of the UE (referenced as220inFIG. 2,502inFIG. 5A,5B, and as2212inFIG. 22), Location Server (referenced as215inFIG. 2,504inFIG. 5A,5B), one or more servers implemented as part of the Broadcast Subsystem506, such as the Gateway510and RAN508or any other computing devices fromFIG. 22, such as Base Station Controller2218or BTSs2214or any other computing devices utilized in enabling embodiments of the invention.FIG. 23provides a schematic illustration of one embodiment of a computer system2300that can perform the methods provided by various other embodiments, as described herein, and/or can function of the devices, such as the UE, Location Server and the servers implemented as the Broadcasting Subsystem. It should be noted thatFIG. 23is meant only to provide a generalized illustration of various components, any or all of which may be utilized as appropriate.FIG. 23, therefore, broadly illustrates how individual system elements may be implemented in a relatively separated or relatively more integrated manner.

The computer system2300is shown comprising hardware elements that can be electrically coupled via a bus2305(or may otherwise be in communication, as appropriate). The hardware elements may include one or more processors2310, including without limitation one or more general-purpose processors and/or one or more special-purpose processors (such as digital signal processing chips, graphics acceleration processors, and/or the like); one or more input devices2315, which can include without limitation a mouse, a keyboard and/or the like; and one or more output devices2320, which can include without limitation a display device, a printer and/or the like.

The computer system2300may also include a communications subsystem2330, which can include without limitation a modem, a network card (wireless or wired), an infrared communication device, a wireless communication device and/or chipset (such as a Bluetooth™ device, an 802.11 device, a WiFi device, a WiMax device, cellular communication facilities, etc.), and/or the like. The communications subsystem2330may permit data to be exchanged with a network (such as the network described below, to name one example), other computer systems, and/or any other devices described herein. In many embodiments, the computer system2300will further comprise a working memory2335, which can include a RAM or ROM device, as described above.

The computer system2300may also include a transceiver2350for transmitting and receiving messages. The transceiver2350may comprise components, such as a transmitter and a receiver which are combined and share common circuitry or a single housing or may be separate. The transceiver2350may be modified to communicate with one or more network configurations, such as GSM, a CDMA, a WCDMA, a CMDA2000 1xRTT, or a LTE network.

A set of these instructions and/or code might be stored on a computer-readable storage medium, such as the storage device(s)2325described above. In some cases, the storage medium might be incorporated within a computer system, such as the system2100. In other embodiments, the storage medium might be separate from a computer system (e.g., a removable medium, such as a compact disc), and/or provided in an installation package, such that the storage medium can be used to program, configure and/or adapt a general purpose computer with the instructions/code stored thereon. These instructions might take the form of executable code, which is executable by the computer system2300and/or might take the form of source and/or installable code, which, upon compilation and/or installation on the computer system2300(e.g., using any of a variety of generally available compilers, installation programs, compression/decompression utilities, etc.) then takes the form of executable code.

As mentioned above, in one aspect, some embodiments may employ a computer system (such as the computer system2300) to perform methods in accordance with various embodiments of the invention. According to a set of embodiments, some or all of the procedures of such methods are performed by the computer system2300in response to processor2310executing one or more sequences of one or more instructions (which might be incorporated into the operating system2340and/or other code, such as an application program2345) contained in the working memory2335. Such instructions may be read into the working memory2335from another computer-readable medium, such as one or more of the storage device(s)2325. Merely by way of example, execution of the sequences of instructions contained in the working memory2335might cause the processor(s)2310to perform one or more procedures of the methods described herein.

The terms “machine-readable medium” and “computer-readable medium,” as used herein, refer to any medium that participates in providing data that causes a machine to operate in a specific fashion. Computer readable storage medium does not refer to transitory propagating signals. In an embodiment implemented using the computer system2300, various computer-readable media might be involved in providing instructions/code to processor(s)2310for execution and/or might be used to store such instructions/code. In many implementations, a computer-readable medium is a physical and/or tangible storage medium. Such a medium may take the form of a non-volatile media or volatile media. Non-volatile media include, for example, optical and/or magnetic disks, such as the storage device(s)2325. Volatile media include, without limitation, dynamic memory, such as the working memory2335.

The description herein and attached figures describe a general method or protocol of broadcasting communications that can be applied to any number of networks and/or architectures. Thus, although the above description refers to LPP/LPPe, the above examples are not limited to the enumerated embodiments. Those of skill in the art will appreciate how to extend the concepts described herein to other systems or architectures. For example, user plane location-based services may be combined with any number of broadcast services according to the description herein. In some embodiments, a user and/or device may subscribe to any number of broadcast services or receive localized Assistance Data pursuant to the description herein. In this way, a user or device is not required to receive a generic set of data, but may in addition or instead receive regional data or other information that varies by region.

Further, the description herein and attached figures provide the ability to broadcast location Assistance Data in the form of LPP and LPP/LPPe messages. The description and figures further enable a common and extensible standard for location assistance broadcast that is aligned with point to point location support using LPP/LPPe and that can be used with any broadcast mechanism (e.g. BCAST, (e)MBMS, SIBs etc.). In some embodiments, charging for location assistance via broadcast is possible via ciphering. In some embodiments, support of positioning by user devices will be enhanced due to faster access to Assistance Data. In some embodiments, network loading can be reduced in comparison to point to point assistance.

One embodiment for accomplishing the benefits herein includes a UE or SET using LPP/LPPe point to point over SUPL (or possibly control plane with LTE access) to obtain information on broadcast Assistance Data availability and any decipher keys, for example form a Location Server. The embodiment may further include a Location Server packaging location Assistance Data into LPP or LPP/LPPe Provide Assistance Data messages, which are sent to a gateway (e.g. eMBMS BM-SC) or other node (e.g. MME for LTE SIB broadcast) for onward transfer to a RAN for broadcast from network base stations.

The description herein and/or attached figures may be implemented or described in a standard in some embodiments, for example to increase interoperability between devices. For example, OMA may create a new version of LPPe to enable Assistance Data to be broadcast in a standard manner and to provide a UE or SET with associated information (e.g. decipher keys). Use of LPPe to support broadcast Assistance Data may avoid additional impacts to encode Assistance Data in a different way. It may also enable broadcast using any system (e.g. not just SIBs). Further, LPPe may be used point to point (e.g. with SUPL) to provide pre-information to a UE or SET—e.g. deciphering keys and/or availability and types of broadcast Assistance Data in different areas.

In addition to the benefits above, for example supporting a wide range of access types, LPPe in combination with LPP can support a wide range of positioning methods including A-GNSS (both code phase and high accuracy carrier phase variants), OTDOA for LTE and WCDMA, Enhanced Observed Time Difference (E-OTD), enhanced cell ID (for each wireless access type including WiFi), short range node associated positioning and use of sensors. These methods may be used in terminal assisted and terminal based modes. The terminal based mode may be useful for supporting applications on the terminal and functions, for example when the terminal already has needed or desired Assistance Data or can rapidly acquire Assistance Data from a network server (e.g. SUPL SLP or LTE E-SMLC) via broadcast.

Implementations or embodiments of the description herein and/or the attached figures may enable (A) broadcast of Assistance Data within LPP/LPPe Provide Assistance Data messages, and/or (B) the ability for a terminal to obtain information from a Location Server relevant to broadcasting in (A). Such implementations or embodiments may include provision of deciphering keys to a terminal and information on broadcast availability (e.g. from which system(s) and in which areas).

Implementations or embodiments of the description herein and/or the attached figures may ensure LPP and LPP/LPPe Provide Assistance Data messages can be broadcast in an unsolicited manner and containing any data that may be associated with local base stations and WiFi APs (examples include coordinates and GNSS timing association). Implementations or embodiments of the description herein and/or the attached figures may also enable labeling of different types of Assistance Data by any broadcast system that will support LPP and/or LPP/LPPe Assistance Data broadcast. For example, labeling could be achieved by assigning numeric identifiers to different types or different combinations of types of Assistance Data (e.g. assign type 1 to A-GNSS ephemeris, type 2 to A-GNSS almanac, type 3 to WiFi assistance etc.). The labeling may enable a broadcast system to indicate to terminals the types of Assistance Data being broadcast so a terminal can decide which data to receive and decode.

Implementations or embodiments of the description herein and/or the attached figures may further enable a terminal to request Assistance Data from a Location Server (in a point to point manner) that is applicable to broadcast. Such Assistance Data may support ciphering of broadcast Assistance Data and may provide information on where and how Assistance Data is being broadcast (e.g. a geographic area or set of cell sites within which location Assistance Data is broadcast and identification of the broadcast system) as well as identifying the type or types of Assistance Data that are broadcast. In addition, implementations or embodiments of the description herein and/or the attached figures may define terminal and server capabilities associated with broadcast Assistance Data support; provide guidance for support of LPPe broadcast by specific broadcast systems such as LTE SIBs, BCAST, and eMBMS; and/or provide guidance on how servers can create LPP and LPP/LPPe broadcast messages, manage scheduling, and/or change broadcast content. By receiving location Assistance Data transferred via broadcast, terminals can accumulate Assistance Data in advance and avoid both delay and use of network signaling when a location service is needed or desired. This may be beneficial, for example, when a terminal loses network access and/or to alleviate server congestion.

Embodiments of the invention as described above may use various protocol messages. In one embodiment, parameters for messages pertaining to the LPPe standard are added to support embodiments of the invention for broadcasting location Assistance Data. The parameters may be added to the OMA LPPe standard, but are not limited to any particular standard. Thus, the messages described inFIGS. 2-21may use the LPP and LPP/LPPe messages as described above, or the messages described below may be implemented in broadcast data implemented independent of an LPPe message or standard.

Implementations or embodiments of the description herein and/or the attached figures may allow operators to deploy an improved location service that can be available to both home users and roamers. Charging for the service is possible using ciphering. The service can provide augmentation of other broadcast services from an operator.