BRPI0817070B1 - DELAYED RADIO RESOURCE SIGNALING IN A MOBILE RADIO NETWORK - Google Patents

Abstract

delayed radio resource signaling in a mobile radio network. an implementation of a system, device and method for communicating location data from a mobile station, enhancing location data, optimally communicating assistance data, and/or reducing rebids of position measurement request messages in a network wireless.

Description

Cross reference to related requests

[001] The present application claims priority under 35 U.S.C. §119(e) to: provisional US patent application 60/971,453 entitled “GSM Control Plane positioning preemption RRLP Implementation for MS and SMLC”, filed September 11, 2007 (prosecutor dossier number 072346P1); and provisional US patent application 61/012,039, entitled “GSM Control plane positioning preemption RRLP Implementation for MS and SMLC”, filed December 6, 2007 (attorney dossier number 072346P2), the disclosures of which are expressly incorporated by reference here in full.

FUNDAMENTALS Field of invention

[002] The present invention relates generally to communication systems, and more particularly to intensifying position location using a global navigation satellite system.

[003] Fundamentals of the invention

[004] It is often desirable, and sometimes necessary, to know the location of a mobile station (e.g., a cell phone). The terms “location” and “position” are synonymous and are used interchangeably here. For example, a user may use a mobile station (MS) to navigate through a website and may click on location-sensitive content. The location of the mobile station can then be determined and used to provide appropriate content to the user. There are many other scenarios in which knowledge of the mobile station location is useful or necessary. For example, the FCC 911 order requires carriers to provide augmented 911 services including geolocating a mobile station that makes a call to 911 emergency services. The mobile station may be provisioned such that it can obtain location services from a network domestic and also while roaming on a visited network. The mobile station can communicate with various network entities in the home network to determine the mobile station location whenever necessary.

[005] There are many different types of technologies employed to calculate the location of mobile stations in wireless networks with varying levels of success and accuracy. Network-based methods include angle of arrival (AOA) using at least two towers, time difference of arrival (TDOA) using multilateration, and location signature using RF fingerprinting to match RF patterns that mobile stations display at known locations. Several mobile station-based methods incorporate GPS, Advanced Direct Link Trilateration (A-FLT), Network Measurement Report/Timing Advance (TA/NMR), and/or Enhanced Observed Time Difference (E-OTD).

[006] Another mobile station-based method is GPS-assisted (A-GPS), in which a server provides Assistance Data to the mobile station so that it has a low Time to First Fix (TTFF), to allow acquisition of weak signal, and optimize mobile station battery usage. A-GPS is used as a location technology in isolation or hybridized with other positioning technologies that provide range-like measurements. An A-GPS server provides data to a wireless mobile station that is specific to the approximate location of a mobile station. Assist Data helps the mobile station lock onto satellites quickly, and potentially allows the telephone set to lock onto weak signals. The mobile station then performs the position calculation or optionally returns the measured code phases to the server to perform the calculation. The A-GPS server may make use of additional information such as round-trip timing measurements from a cellular base station to the mobile station to calculate a location where it may not otherwise be possible; for example when there are not enough visible GPS satellites.

[007] Advances in satellite-based global positioning system (GPS) position correction technologies, timing advance (TA), and terrestrial-based augmented observed time difference (E-OTD) enable accurate determination of geographic position (e.g. latitude and longitude) of a mobile station. As geographic location services are used in wireless communications networks, such position information may be stored in network elements and delivered to nodes on the network using signaling messages. Such information may be stored in a Service Mobile Location Center (SMLC), a stand-alone SMLC (SAS), a Position Determine Entity (PDE), a Secure User Plane Location Platform (SLP), and security databases. special purpose mobile subscriber location.

[008] An example of a special purpose mobile subscriber location database is the SMLC proposed by the 3rd Generation Society Project (3GPP). In particular, 3GPP has defined a signaling protocol to communicate mobile subscriber position information to and from an SMLC. This signaling protocol is referred to as Radio Resource Location Services (LCS) protocol, denoted RRLP, and defines signaling messages communicated between a mobile station and an SMLC related to the location of a mobile subscriber. A detailed description of the RRLP protocol is found in 3GPP TS 44.031 v7.9.0 (2008-06) 3rd Generation partnership project; Technical specification group GSM Edge radio access network; Location services (LCS); Mobile station (MS)-serving mobile location center (SMLC) radio resource LCS protocol (RRLP) (Release 7).

[009] In addition to the North American Global Positioning System (GPS), other Satellite Positioning Systems (SPS), such as the Russian GLONASS system or the proposed European Galileo System can also be used to locate the position of a mobile station. However, each of the systems operates according to different specifications.

[0010] A weakness of a satellite-based position location system is the time it takes to acquire an accurate position correction. Typically, position accuracy is traded off for acquisition speed and vice versa. That is, a more accurate correction takes longer. Therefore, there is a need for a communications system, including a global navigation satellite system (GNSS), that can determine a position location for a mobile station based on satellite signals sent from two or more satellites to provide efficiencies and Additional advantages for position location including increased accuracy. There is a need to increase accuracy whilst not detrimentally impacting the acquisition speed or final acquisition time of acquiring a position correction from a mobile station, for example during an emergency services (ES) call or service sessions. value added (VAS).

SUMMARY

[0011] Some embodiments of the present invention provide a method of reducing rebids of Position Measuring Request messages between a network and a mobile station in a wireless network, the method comprising: transmitting an RRLP assistance data message; receive an RRLP assistance data Ack message; wait until a predetermined time, where the predetermined time based on time location data is required; transmit, at the predetermined time, the RRLP Position Measurement Request message comprising a network response time and a network accuracy, wherein the network response time comprises a value representing a shortened response time not greater than 4 seconds, where the network accuracy comprises a value representing low accuracy of no less than 100 meters, and where the RRLP Position Measurement Request message does not comprise Assistance Data; and receiving, at a time before the location data is required, an RRLP Position Measurement Response message comprising the location data.

[0012] Some embodiments of the present invention provide a network for reducing rebids of Position Measurement Request messages between the network and a mobile station in a wireless network, the method comprising: a timer to wait until a predetermined time, wherein the predetermined time is based on a time location data is required; a transmitter for transmitting, at the predetermined time, a Position Measurement Request message comprising a network response time and a network accuracy; and a receiver for receiving, at a time before the location data is needed, a position Measurement Response message comprising the location data. The network wherein the network response time comprises a value representing a short response time of no more than 4 seconds. The network in which the network accuracy comprises a value representing low accuracy of not less than 100 meters. The network in which the Measurement Request position does not comprise Assistance Data. The network in which the Position Measurement Request message comprises an RRLP Position Measurement Request message. The network in which the Position Measurement Response message comprises an RRLP Position Measurement Response message.

[0013] Some embodiments of the present invention provide a computer-readable product comprising a computer-readable medium comprising: code for causing at least one computer to wait until a predetermined time, wherein the predetermined time is based on a location data of time that is needed; code for causing at least one computer to transmit, at the predetermined time, a Position Measurement Request message comprising a network response time and a network accuracy; and code for causing the at least one computer to receive, at a time before the location data is required, a Position Measurement Response message comprising the location data. The computer-readable product wherein the network response time comprises a value representing a shortened response time of no more than 4 seconds. The computer-readable product in which the network accuracy comprises a value representing low accuracy of not less than 100 meters. The machine-readable product in which the Position Measurement Request does not comprise Assistance data. The computer-readable product wherein the computer-readable medium further comprises: code for causing at least one computer to transmit a Support Data message; and code for causing at least one computer to receive an Ack assistance data message. The computer-readable product wherein the Position Measurement Request message comprises an RRLP Position Measurement Request message. The computer-readable product wherein the Position Measurement Response message comprises an RRLP Position Measurement Response message.

[0014] Some embodiments of the present invention provide a method, in a network, for minimizing rebids between the network and a mobile station in a wireless network, the method comprising: sending a Request message thereby opening a session at the mobile station; determining, while the session is open, that an RR message is ready to be sent at the mobile station; avoid aborting the session with the RR message; and receive a Reply message thus closing the session. The method in which the act of avoiding aborting the session comprises: waiting to send the RR message; and send the RR message after the session is closed. The method of avoiding aborting the session comprises abandoning the RR message. The method wherein the Request message comprises an RRLP Position Measurement Request message. The method wherein the Request message comprises an RRLP Assistance Data message.

[0015] Some embodiments of the present invention provide a network for minimizing rebids between the network and a mobile station in a wireless network, the network comprising: means for sending a Request message thereby opening a session at the mobile station; means for determining, while the session is open, that an RR message is ready to be sent to the mobile station; means to avoid aborting the session with the R message; and means to receive a Reply message thus closing the session. The method in which the means to avoid aborting the session comprises: means to wait to send the RR message; and means to send the RR message after the session is closed. The method of avoiding aborting the session comprises abandoning the RR message. The method wherein the Request message comprises an RRLP Position Measurement Request message. The method wherein the Request message comprises an RRLP Assistance Data message.

[0016] Some embodiments of the present invention provide a network for minimizing rebids between the network and a mobile station in a wireless network, the network comprising: a transmitter for sending a Request message thereby opening a session at the mobile station; logic for determining, while the session is open, that an RR message is ready to be sent to the mobile station; logic to avoid aborting the session with the RR message; and a receiver to receive a Reply message thereby closing the session. The network in which the logic to avoid aborting the session comprises: a timer to wait to send the RR message; wherein the transmitter is additionally to send the RR message after the session is terminated. The network in which the logic to avoid aborting the session comprises logic to abandon the RR message. The method wherein the Request message comprises an RRLP Position Measurement Request message. The method wherein the Request message comprises an RRLP Assistance Data message.

[0017] Some embodiments of the present invention provide a computer-readable product comprising a computer-readable medium comprising: code for causing at least one computer to send a Request message thereby opening a session at the mobile station; code for causing the at least one computer to determine, while the session is open, that an RR message is ready to be sent to the mobile station; code to cause at least one computer to avoid aborting the session with the RR message; and code to cause at least one computer to receive a Reply message thereby closing the session. The method wherein the code for causing the at least one computer to avoid aborting the session comprises: code for causing the at least one computer to wait to send the RR message; and code to cause at least one computer to send the RR message after closing the session. The method wherein the code for causing the at least one computer to avoid aborting the session comprises code for causing the at least one computer to abandon the RR message. The method wherein the Request message comprises an RRLP Position Measurement Request message. The method wherein the Request message comprises an RRLP Assistance Data message.

[0018] These and other aspects, characteristics and advantages of the invention will be evident from reference to the embodiments described below.

BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Embodiments of the invention will be described, by way of example only, with reference to the drawings:

[0020] Figures 1A, 1B and 1C show various components and interfaces in a wireless network.

[0021] Figure 2 shows a message flowchart of a typical position location process using RRLP sessions.

[0022] Figure 3 shows pseudo segmentation of assistance data.

[0023] Figures 4 and 5 illustrate determination of stop position based on an MS that receives an extra RR message.

[0024] Figures 6 and 7 show events that start and stop a GPS engine, in accordance with embodiments of the present invention.

[0025] Figure 8 shows a message flowchart that highlights premature location determination, in accordance with embodiments of the present invention.

[0026] Figures 9 and 10 illustrate a method of continuing position determination after an extra RR message is received, in accordance with embodiments of the present invention.

[0027] Figures 11 and 12 illustrate a method of optimally ordering downloaded Assistance Data, in accordance with Embodiments of the present invention.

[0028] Figures 13 and 14 show a method of sending position requests in time, according to embodiments of the present invention.

[0029] Figures 15 and 16 show a method of delaying (or abandoning) new RR messages to avoid aborted sessions, in accordance with embodiments of the present invention.

[0030] Figures 17, 18, 19, 20 and 21 illustrate a method of varying an accuracy parameter to balance response time and accuracy in an emergency services (ES) call, in accordance with embodiments of the present invention.

[0031] Figure 22 shows a message flowchart for a value added service (VAS), in accordance with embodiments of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

[0032] In the following description, reference is made to the attached drawings, which illustrate various embodiments of the present invention. It is understood that other modalities may be utilized and mechanical, compositional, structural, electrical and operational changes may be made without departing from the spirit and scope of the present disclosure. The following detailed description should not be taken in a limiting sense. In addition, some portions of the detailed description that follow are presented in terms of procedures, steps, logic blocks, processing, and other symbolic representations of operations on data bits that may be performed in electronic circuitry or in computer memory.

[0033] A procedure, computer-executed step, block of logic, process, etc., is intended here to be a self-consistent sequence of steps or instructions that lead to a desired result. Steps are those that use physical manipulations of physical quantities. These quantities may be in the form of electrical, magnetic or radio signals capable of being stored, transferred, combined, compared, and otherwise manipulated in electronic circuitry or in a computer system. These signals can sometimes be referred to as bits, values, elements, symbols, characters, terms, numbers or similar. Each step can be performed by hardware, software, firmware, or a combination thereof. In a hardware implementation, for example, a processing unit may be implemented in one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPs), logic devices programmable gate arrays (FPGAs), processors, controllers, microcontrollers, microprocessors, electronic devices, other device units designed to perform the functions described herein, and/or combinations thereof.

[0034] Throughout this specification, reference may be made to "an example", "a characteristic", "an example", or "a characteristic" means that a specific characteristic, structure or aspect described with respect to the characteristic and /or example is included in at least one feature and/or example of claimed subject matter. Thus, the appearances of the phrases “in an example”, “an example”, “in a characteristic” or “a characteristic” in various places throughout this specification are not necessarily all referring to the same characteristic and/or example. Furthermore, specific characteristics, structures or aspects may be combined into one or more examples and/or aspects.

[0035] “Instructions” as mentioned herein refer to expressions that represent one or more logical operations. For example, instructions may be “machine-readable” in that they are interpretable by a machine to perform one or more operations on one or more data objects. However, this is merely an example of instructions and the claimed subject matter is not limited in this respect. In another example, instructions as mentioned herein may refer to coded commands that are executable by a processing circuit having a command set that includes the coded commands. Such an instruction may be encoded in the form of a machine language understood by the processing circuit. Again, these are merely examples of an instruction and claimed subject matter is not limited in this respect.

[0036] “Storage medium”, as mentioned here, refers to physical media capable of maintaining expressions that are perceivable by one or more machines. For example, a storage medium may comprise one or more storage devices for storing machine-readable instructions and/or information. Such storage devices may comprise any one or several types of media including, for example, magnetic, optical or semiconductor storage media. Such storage devices may also comprise any type of long-term, short-term, volatile or non-volatile memory devices. However, these are merely examples of a storage medium, and the claimed subject matter is not limited in these respects. The term “storage medium” does not apply to vacuum.

[0037] Unless otherwise specifically mentioned, as is evident from the following discussion, it is recognized that throughout this specification, discussions using terms such as “process”, “compute”, “calculate”, “select”, “ form”, “enable”, “inhibit”, “locate”, “terminate”, “identify”, “start”, “detect”, “obtain”, “host”, “maintain”, “represent”, “estimate” , “receive”, “transmit”, “determine” and/or similar refer to the actions and/or processes that can be performed by a computing platform, such as a computer or similar electronic computing device, that manipulates and/or transforms data represented as physical electronic and/or magnetic quantities and/or other physical quantities comprised in the computing platform's processors, memories, records and/or other information storage, transmission, reception and/or display devices. Such actions and/or processes may be performed by a computing platform under the control of machine-readable instructions stored on a storage medium, for example. Such machine-readable instructions may comprise, for example, software or firmware stored on a storage medium included as part of a computing platform (e.g., included as part of a processing circuit or external to such a processing circuit). Furthermore, unless specifically mentioned otherwise, processes described herein, with reference to flowcharts or otherwise, may also be performed and/or controlled, in whole or in part, by such a computing platform.

[0038] Wireless communication techniques described herein may be in connection with various wireless communication networks such as a wireless remote area network (WWAN), a wireless local area network (WLAN), a wireless personal area network wire (WPAN) and so on. The term “network” and “system” can be used interchangeably here. A WWAN can be a Code Division Multiple Access (CDMA) network, a Time Division Multiple Access (TDMA) network, a Frequency Division Multiple Access (FDMA) network, a Time Division Multiple Access (FDMA) network frequency division multiple access network (OFDMA), a single carrier frequency division multiple access network (SC-FDMA), and so on. A CDMA network can implement one or more radio access technologies (RATs) such as cdma2000 or Wideband-CDMA (W-CDMA), to name just a few radio technologies. Here, cdma2000 may include technologies implemented according to IS-95, IS-2000, and IS-856 standards. A TDMA network may implement Global System for Mobile Communications (GSM), Digital Advanced Mobile Telephone System (D-AMPS), or some other RAT. GSM and W-CDMA are described in documents from a consortium called “3rd Generation Partnership project” (3GPP). Cdma2000 is described in documents from a consortium called “3rd Generation Partnership Project 2” (3GPP2). 3GPP and 3GPP2 documents are publicly available. A WLAN can comprise an IEEE 802.11x network, and a WPAN can comprise a Bluetooth network, an IEEE 82.15x, for example. Wireless communication implementations described here can also be used with respect to any combination of WWAN, WLAN and/or WPAN.

[0039] A device and/or system may estimate the location of a device based, at least in part, on signals received from satellites. In particular, such a device and/or system may obtain “pseudo-range” measurements comprising approximations of distances between associated satellites and a navigation satellite receiver. In a specific example, such pseudo-range may be determined on a receiver that is capable of processing signals from one or more satellites as part of a Satellite Positioning System (SPS). Such an SPS may comprise, for example, a Global Positioning System (GPS), Galileo, Glonass, to name a few, or any SPS developed in the future. To determine its position, a satellite navigation receiver can obtain pseudo-range measurements for three or more satellites as well as their positions at the time of transmission. By knowing the satellite's orbital parameters, these positions can be calculated for any point in time. A pseudorange measurement can then be determined based, at least in part, on the time a signal travels from a satellite to the receiver, multiplied by the speed of light. Although techniques described herein may be provided as implementations of location determination in a GPS and/or Galileo types of SPS as specific illustrations, it should be understood that these techniques may also apply to other types of SPS, and that the claimed subject matter does not is limited in this respect.

[0040] Techniques described here can be used with any of several SPS, including the aforementioned SPS, for example. Furthermore, such techniques can be used with positioning determination systems that use pseudoliths or a combination of satellites and pseudoliths. Pseudolites may comprise ground-based transmitters that broadcast a Pseudo Random Noise (PRN) code or other range code (e.g., similar to a CDMA or GPS cellular signal) modulated onto an L-band carrier signal (or other frequency), which can be synchronized with GPS time. Such a transmitter may be assigned a unique PRN code to permit identification by a remote receiver. Pseudoliths can be useful in situations where SPS signals from an orbiting satellite might be unavailable, such as in tunnels, mines, buildings, urban canyons, or other enclosed areas. Another implementation of pseudoliths is known as radio beacons. The term “satellite” as used herein is intended to include pseudoliths, pseudolith equivalents, and possibly others. The term “SPS signals” as used herein is intended to include SPS-like signals from pseudoliths or pseudolith equivalents.

[0041] As used herein, a portable mobile device or mobile station (MS) refers to a device that may from time to time have a position or location that changes. Changes in position and/or location may include changes in direction, distance, orientation, etc., as some examples. In specific examples, a mobile station may comprise a cellular telephone, wireless communication device, user equipment, laptop computer, other personal communication system (PCS) device, and/or other portable communication device. A mobile station may also comprise a processor and/or computing platform adapted to perform functions controlled by machine-readable instructions.

[0042] This request is related to the following requests, each filed simultaneously with this application and each included in full here: “Optimized Ordering of assistance data in a mobile radio network” by Kirk Allan Burroughs (attorney dossier number 072346); “Improved GPS Yield for emergency calls in a mobile radio network” by Thomas Rowland (attorney dossier number 080114); and “Dynamic measure position request processing in a mobile radio network” by Thomas Rowland (attorney dossier number 080116).

[0043] Figures 1A, 1B and 1C show various components and interfaces in a wireless network. For simplicity, the description below uses general terminology used in wireless networks or specific terminology used in reference to a specific standard although the techniques described here may be applicable across several different wireless network standards. For example, such a wireless network includes Code Division Multiple Access (CDMA), which is a high-capacity digital wireless technology that was pioneered and commercially developed by QUALCOMM Incorporated. Another wireless network includes Global System for Mobile Communications (GSM), which used an alternative digital wireless technology. Yet another wireless network includes Universal Mobile Telephone Service (UMTS), which is a future generation high-capacity digital wireless technology.

[0044] Figure 1A includes a mobile station (MS 10), a base station subsystem (BSS 20) including a base transceiver station (BTS 22) and a base station controller (BSC 24), a mobile switching center (MSC 30), a public switched telephone network (PSTN) and a serving mobile location center (SMLC). The MS 10 is any mobile wireless communication device, such as a cellular telephone that has a baseband modem for communicating with one or more base stations. MSs referenced in this disclosure include a GPS receiver or equivalent receiver to provide position determination capabilities. The term GPS used below is used in a generic sense to mean a satellite or pseudo-satellite system. The MS 10 and the BTS 22 communicate wirelessly via an RF air interface referred to as interface One. One or more MSs 10 may communicate with the BTS 22 or BSS 20 at a time. Internally to the BSS 20, the BTS 22 can communicate with the BSC 24 via an Abis interface. A BSC 24 can support multiple BTSs 22 in a used network. Here, when referring to air One interface messages from the network (downlink) and from the MS 10 (uplink), these messages may be referred to as being communicated using a BTS 22 or equivalently using a BSS 20. An Lb interface couples one or more BSCs 24 and/or BSSs 20 can be coupled to the MSC 30 using an A interface. The MSC 30 connects a circuit switched PSTN 30 to the MS 10 to provide a voice call to the public network. Other network elements or network components may be connected to the BSS 20, MSC 30 and PSTN 40 to provide other services.

[0045] For example, the SMLC 50 may be coupled to the network to provide location services, and is shown connected to the BSC 24 via an Lb interface. The SMLC 50 can also be connected to the wireless network via the MSC 30 and an Ls interface. The SMLC 50 provides overall coordination to locate mobile stations and can also calculate the final estimated location and estimated accuracy obtained. SMLC 50 is used generically here to mean a positioning server, which are also referred to as Position Determination Entity (PDE) in CDMA networks, Service Mobile Location Center (SMLC) in GSM networks, and independent SMLC (A -GPS) (SAS) on WCDMA cellular networks.

[0046] A positioning server is a systems resource (e.g., a server) typically on the wireless network, working in combination with one or more GPS reference receivers, which is capable of exchanging GPS-related information with an MS. In an MS-Assisted GPS-A session, the positioning server sends GPS Assist Data to the MS to augment the signal acquisition process. The MS can return pseudo-range measurements back to the positioning server, which is then able to compute the position of the MS. Alternatively, in an MS-based GPS-A session, the MS sends back computed position results to the positioning server.

[0047] Figure 1B shows a layered model of the Um and Lb interfaces. The layers in the MS 10 (target MS) include a first layer referred to as the physical layer, layer one or L1, a second layer referred to as L2 (LAPDm), a third layer referred to as a radio resource (RR) layer modeled after according to the GSM 04.08 specification, and finally an application layer. In this case, the application layer is a radio Resource Location Protocol (RRLP) defined in the GSM 04.31 and GSM 04.35 recommendations. The BSS 20 (shown as BSC 24) has a corresponding layered model including L1, L2 (LAPD) and RR layers, with RRLP messages passing through the BSS 20. The BSS 20 relays the lower layers as required to the SMLC 50 through of the Lb interface. The layers include MTP, SCCP BSSLAP-LE and BSSLAP layers, which correspond to the MTP, SCCP BSSLAP-LE and BSSLAP layers in SMLC 50. For additional information about the BSSAP-LE and BSSLAP interfaces, see recommendations GSM 09.21 and GSM 08.71.

[0048] Messages passing from network element to network element may pass through multiple different interfaces and corresponding protocols. For example, a message passing from the SMLC positioning server 50 to the BSS 20 to the MS 10 will be communicated as a first message over the Lb interface, possibly another message over the Abis interface, and a final message over the Um interface. In the present disclosure, a message will be referred to by its application layer and air interface name for simplicity. For example, a request from the SMLC positioning server 50 destined for the MS 10 may be referred to by the RRLP Position Measurement Request air interface application layer name. Additionally, for clarity, the BSS 20 and the SMLC 50 may be referred to collectively as the network 70, which may include a BTS 22, a BSC 24 and an SMLC 50 or may include a BSS 20 and an SMLC 50.

[0049] Figure 1C shows a message flowchart of a normal RRLP session. At time a, the SMLC 50 sends a Request message 80 to the BSS 20 via the Lb interface. The BSS 20 repackages and forwards this request as an RRLP Request 85 transmitted over the air interface A downlink to the MS 10. Internally, the MS 10 begins an RRLP session and eventually responds via the air interface A uplink with a RRLP Response message 90. The BSS 20 repackages and forwards this response to the SMLC 50 in a response message 95 via the Lb interface, which the SMLC 50 receives as time b. Hereinafter, such request and responses to and from the SMLC 50 will be referred to as RRLP requests and RRLP responses.

[0050] The 3GPP RRLP application layer currently supports five messages. The first message is an RRLP Position Measurement Request message used in the downlink. Network 70 uses this message to request location measurements or a location estimate from MS 10. The message includes instructions for MS 10 and may also include Assistance Data for MS 10. Assistance Data is described in additional detail below. The second message is an RRLP Position Measurement Response message used in the uplink and complements the RRLP Position Measurement Request message. The MS 10 uses this message to respond to the network 70 with position estimation information and other position-related information. The RRLP Position Measurement Request message and the RRLP Position Measurement Response message operate together to start and end an RRLP session.

[0051] The third and fourth messages also operate together to start and end an RRLP session. The third message is another downlink message referred to as an RRLP Assistance Data message, which the network 70 uses to send Assistance Data to the MS 10. Assistance Data optionally includes Increased Observed Time Difference reference BTS information ( E-OTD) (e.g. BTS position and signaling information) and E-OTD measurement information for up to eight additional BTSs. The fourth message is an RRLP Assistance Data Acknowledgment (Ack) message used in the uplink. The RRLP Assistance Data Ack message is simply used by the MS 10 to acknowledge, to network 70, receipt of the RRLP Assistance Data message. The fifth message is an atypical message called an RRLP Protocol Error, which can be used in the downlink or uplink to report an error in the protocol.

[0052] Figure 2 shows a message flowchart of a typical position location process using RRLP sessions. The MS 10 and the network 70 can be viewed as a server-client model with the MS 10 acting as the client and the network 70 acting as the server. An RRLP session begins with a request from network 70 and typically ends with a response from MS 10. At time a, a position finding process begins with network 70 and MS 10 communicating an RRLP Assist Data message 110. That is, network 70 sends an RRLP Assistance Data message 110 to the MS 10 and the MS 10 begins a new RRLP session upon receipt of the RRLP Assistance Data message 110. Typically, shown at time b, a MS 10 completes the RRLP session with an acknowledgment response referred to as RRLP Assistance Data Ack message 112.

[0053] At time c, network 70 sends an RRLP Measurement Position Request message 120, which includes a position instruction and optionally assistance data. The network position instruction 70 includes a maximum response time (NW Response) defined by the network (NW) and minimum accuracy (NW Accuracy), also defined by the network (NW). In response to receiving the RRLP 120 Position Measurement Request message, a known mobile station starts its GPS engine. GPS is used generically to refer to a positioning system using satellite vehicles (SVs) and/or pseudo-satellites. The engine is also used generically as hardware and/or firmware and/or software that operates to process data. The MS 10 then determines one or more position corrections with each having an estimated uncertainty.

[0054] When the estimated uncertainty is less than or equal to the minimum network accuracy (NW Precision) signaled by network 70, or after MS 10 is computing a correction as long as allowed by the network response time parameter (NW Response), the location processing for. As shown at time d, the MS 10 reports the computed correction in an RRLP Position Measurement Response message 122 and also to the GPS engine. The difference in time between time references c and d can be substantial (e.g., 45 seconds to several minutes). An objective in position determination is to minimize this acquisition time. Another objective is to reduce the uncertainty of a given correction.

[0055] Figure 3 shows pseudo segmentation of assistance data. Assist data may include position data on one or more satellite vehicles (SVs). Because Assist Data typically contains information on 8 to 12 or more satellites, Assist Data is separated into multiple pseudo-segmented Assist Data message blocks, with each block containing information on one, two, three, or four satellites. In the example shown, Assistance Data is segmented into three pseudo segments. The first two blocks can contain information on three or four satellites and the final block can contain information on one, two, or three satellites for a total of seven to eleven satellites for the example shown.

[0056] The first block of Assistance Data is communicated from network 70 to MS 10 at time a in a first RRLP Assistance Data message 140. Upon receipt, a first RRLP session begins but quickly ends when MS 10 sends a RRLP Assistance Data Ack message 142 to network 70 at time b.

[0057] The second block of Assistance Data is communicated from network 70 to MS 10 at time c in a second RRLP Assistance Data message 144. Upon receipt, a second RRLP session begins. In this example at time d, the MS 10 does not have time to transmit an acknowledgment message before receiving a second RR message (referred to here as an extra RR message 130), which terminates the RRLP session created by message 144. The extra RR message can be any of several different RR messages. For example, a higher priority RR message such as a handover message may have been transmitted to MS 10.

[0058] A session is called acquired by preemption if the MS 10 receives a part of the downlink RRLP message or none of the downlink RRLP message. Preemption occurs when a message is placed on a network output queue for transmission. In some cases, before the downlink RRLP message can be fully transmitted, the remainder of the untransmitted message is still purged from the queue for the higher priority message. In these cases, the MS 10 may have received some but not all of the downlink RRLP message. In other cases, the downlink RRLP message is purged before the first bit of the message is even transmitted over the air interface. In these cases, the session is also considered acquired by preemption, however, MS 10 is not aware of the existence of the session. Often a preemption occurs when a downlink RRLP message is long, or when longer messages are in front of it (that is, other messages scheduled for an earlier transmission time) in the same downlink queue.

[0059] On the other hand, a session is said to be aborted if the MS 10 receives the entire downlink RRLP message but has not yet fully sent a response, such as an RRLP assistance data Ack message. An abort typically occurs when the MS 10 takes a relatively long period of time to respond to a downlink RRLP message.

[0060] In cases of both preemption and abortion, the existing session on MS 10 and/or network 70 ends. One objective is for the MS 10 to quickly respond to downlink RRLP messages, thereby minimizing aborted sessions. Another objective is for the network to send shorter downlink RRLP messages thereby keeping the queue less full and minimizing sessions acquired by preemption. Pseudo segmentation targets the second objective of having shorter downlink RRLP messages thereby reducing the chance of a session being preempted but does not address the first objective of quickly responding to downlink messages, as further described below, with associated message processing. RRLP Position Measurement Request.

[0061] Hereinafter, the terms abort, abort or aborted will be used in reference to the termination of a session caused by an abort session due to a receipt of an extra RR message or a preemption in the downlink queue by a higher priority downlink message .

[0062] To recover from an aborted session, network 70 transmits a rebid message. A rebid message is a subsequent transmission of a message previously placed on a downlink queue. In the example shown at time e, the second block of Assistance Data is included in an RRLP Assistance Data rebid message 148, which begins a third RRLP session at MS 10. The MS 10 acknowledges receipt with another Assistance Data Ack message. assistance RRLP 150 for network 70 in time f.

[0063] The final block of Assistance Data is transmitted from network 70 to MS 10 at time g in an RRLP Position Measurement Request message 120, which is received by MS 10 and begins a fourth session in this example. The MS 10 is now instructed to begin location determination, which may take 10s of seconds to several minutes. During the period of receiving the instruction to transmit a response, the session is vulnerable to session aborts by an extra RR message. In this example, the final session is not aborted but instead the MS 10 responds with an RRLP Position Measurement Response message 122 at time h.

[0064] Figures 4 and 5 illustrate determination of stop position based on an MS 10 that receives an extra RR message. In Figure 4 at time a, network 70 sends MS 10 an RRLP Assistance Data 110 message, then at time b, MS 10 responds with an RRLP Assistance Data Ack message 112. Network 70 and MS 10 may repeat this message exchange several times to then provide all assistance data to the MS 10 before starting the GPS engine. At time c, network 70 sends MS 10 an RRLP Position Measurement Request message 120 with the final block of Assistance Data. At this point, the MS 10 starts its GPS engine and begins position tracking.

[0065] At time d, network 70 sends MS 10 an extra RR message 130 (i.e., a message that MS 10 was not expecting to receive because it is in an ongoing session). This extra RR message 130, which occurred before the MS 10 was able to transmit a response message, causes the MS 10 to abort the current session initiated by the RRLP Position Measurement Request message 120. As part of aborting the session , the MS 10 for the GPS engine, finishes the position location process, responds to the extra RR message 130 and waits for the next request from the network 70. After a short delay of Δt in time e (where Δt = e - d), network 70 transmits a rebid of the RRLP 120A Position Measurement Request message, which causes the MS 10 to restart its GPS engine and begin position finding again. This process of sending message rebids 120A followed by an interruption by an extra RR message 130 may occur several times before the MS 10 is able to determine its position in the network response time and accuracy parameters provided. At time f, the MS 10 reports a determined position to the network 70 in an RRPL Position Measurement Response message 122.

[0066] Figure 5 shows this message exchange in the form of a state diagram. When the MS 10 receives an RRLP 120 Position Measurement Request message, the MS 10 enters state 200, which starts the GPS engine and begins position determination. In normal uninterrupted operation, the MS determines a position 220 and reports the position to the network by entering state 230, which sends an RRPL Position Measurement Response message 122. When a correction cannot be determined in the network response time predicted (e.g., when a response timeout occurs), the MS 10 may exit state 200 and enter state 230 where the MS 10 responds with the RRPL Position Measurement Responses message 122 containing a correction with worse accuracy than requested by the network.

[0067] The state diagram shows other situations that may occur. For example, the MS 10 will exit state 200 and enter state 210 when it receives an extra RR message 130. In state 210, the MS 10 stops the GPS engine and position determination. The MS 10 exits state 210 and re-enters state 200 when it receives an RRLP Position Measurement Request message 120A. Eventually, the MS 10 commonly determines a position or dwell time 220 and enters state 230 to respond with the RRPL Position Measurement Response message 122.

[0068] In the position location process described above, an MS 10 waits until an RRLP Position Measurement Request message 120 before starting its GPS engine and stops its GPS engine when it receives an extra RR message 130, thereby minimizing the length of time the GPS engine is in operation. By starting the GPS engine in response to receiving the RRLP Position Measurement Request message 120, the MS knows that the network 70 requires a position correction. In any other case, there is no guarantee that the network 70 will request a position correction from the MS 10. Therefore, by not starting before this time, the MS 10 saves battery power. The MS 10 also saves battery power by stopping the GPS engine after the RRLP session ends (for example, as a result of an abort or position correction report).

[0069] In accordance with some embodiments of the present invention, advantages may be realized by not following this knowledge procedure and instead starting the GPS engine in anticipation of receiving an RRLP 120 Position Measurement Request message. can be accomplished by not stopping the GPS engine after the RRLP session ends. At the cost of battery power, the GPS engine can be started early (i.e., before receipt of an RRLP Position Measurement Request message 120) and can continue the position determination process even if the RRLP session ends.

[0070] Figures 6 and 7 show events that start and stop a GPS engine, in accordance with embodiments of the present invention. The state diagram in figure 6 shows two states: state 800 where the GPS engine is not running and state 810 where the GPS engine has started and the position determination process has begun. Various network-side and user-side trigger events can occur that initiate a premature start of the GPS engine in anticipation of future receipt of an RRLP 120 Position Measurement Request message. of execution time. That is, a trigger event is not simply turning on the mobile station, which puts the mobile station into runtime operation. Some devices always run a GPS engine so no trigger event exists to start a GPS engine. A trigger event is not a user operation to specifically turn on a GPS location function of the mobile station. A trigger event is an event that typically does not turn on a GPS engine. Also, the trigger event occurs before receiving an RRLP Position Measurement Request message, which is a message that typically turns on a GPS engine.

[0071] Firstly at 820, if the MS 10 detects the trigger event that an Emergency Services (ES) Call has been initiated, the MS 10 may transition from state 800 to state 810. Another transition initiated on the user side may occur if the MS 10 received a message from a mobile station application (MS App) indicating that a position correction is necessary. Network side events may also initiate transition from state 800 to state 810. For example at 840, if MS 10 receives the trigger event of a new RRLP Assistance Data message, MS 10 may transition from state 800 to state 810. At 850, if MS 10 receives the trigger event of a value added services (VAS) message, MS 10 may transition from state 800 to state 810. In conclusion, at 860, The known process of transitioning states is shown by receiving an RRLP Position Measurement Request message 120.

[0072] In addition to starting early as described with reference to figure 6, stopping the GPS engine can be advantageously delayed as shown in figure 7, which also includes two states. In state 900, the GPS engine is operating (for example, due to one of the events described above). In state 910, the GPS engine is stopped. Various events can trigger the transition from state 900 to state 910 to stop the GPS engine. For example, a position may be derived or a timeout may occur. At 920, the transition occurs as a result of recently sending an RRPL 122 position measurement response message when there is no other significant need for the engine to continue functioning as an MS APP expecting better position correction. The transition may also occur when a position correction has just been reported to an MS APP and the MS 10 is not anticipating an RRLP Position Measurement Request message 120 and not waiting to send an RRPL Position Measurement Response message 122 .

[0073] Abnormal cases can also cause the transition. For example, at 940, if the MS 10 is anticipating an RRLP Position Measurement Request message 120 (e.g., due to events 820 or 840 described above) but has not received the message within a predetermined period of time (e.g., 45, 60 or 90 seconds or a value selected from a time range of 30-60, 30-90, 30-120, 30-180, 30-240, 60-90, 60-120, 60-180, 60- 240, 90120, 90-180, 90-240, 120-180, 120-240, or similar as would be understood by one skilled in the art), the MS 10 may stop its GPS engine. Similarly in 940, if the GPS engine has been operating for a long time (e.g. 120 or 180 seconds), the MS 10 may wait and stop the GPS engine to save battery power.

[0074] Figure 8 shows a message flowchart that highlights premature location determination, in accordance with embodiments of the present invention. One objective is to start the GPS engine as soon as the MS 10 expects or anticipates a future RRLP Position Measurement Request message 120 from a network 70. At time a, the MS 10 recognizes dialed digits for an emergency services call (e.g. example, “911” in the USA, “112” in Europe or “119” in Japan). After the call is recognized as an emergency services call, the MS 10 may initiate position location by starting its GSP engine in anticipation of the need for a location correction from the MS 10.

[0075] At time b, network 70 sends an RRLP Assistance Data message 110 to MS 10. In response, at time c, MS 10 responds with an RRLP Assistance Data Ack message 112. This process of sending messages 110 and 112 may repeat until network 70 has transmitted sufficient assistance data. Finally, at time d, network 70 sends an RRLP Position Measurement Request message 120 to MS 10. MS 10 continues to determine its location. Next at time e, the MS 10 responds to the network 70 with an RRLP Position Measurement Response message 122 containing its determined position.

[0076] Figures 9 and 10 illustrate a method of continuing position determination after an extra RR message 130 is received, in accordance with embodiments of the present invention. Another objective is to continue operating the GPS engine through secondary abnormal events. In Figure 9, an extra RR message 130 aborts a current measurement session but the MS 10 continues position location processing and does not interrupt its GPS engine. At time a, the MS 10 receives an RRLP Assistance Data 110 message from network 70. In response at time b, the MS 10 responds with an RRLP Assistance Data Ack message 112. Again, this process of sending messages 110 and 112 may repeat until network 70 has transmitted sufficient assistance data.

[0077] At time c, network 70 sends an RRLP Position Measurement Request message 120 to MS 10. At this point the GPS engine is already running; based on MS 10 that recognizes an emergency call or other trigger event. At time d, before network 70 receives a response, network 70 stops the RRLP session started at time c. Known mobile stations terminate the RRLP session and also stop the GPS engine. Here, the MS 10 leaves the GPS engine uninterrupted to allow the position finding process to continue.

[0078] Finally at time e, network 70 again sends an RRLP Position Measurement Request message 120A to MS 10 in a rebid process. Again, the MS 10 does not restart the GPS engine but instead continues the localization process. As mentioned above, the abort and rebidding processes can repeat themselves. Next, at time f, the MS 10 responds to the network 70 with an RRLP Position Measurement Response message 122 containing its determined position.

[0079] Figure 10 shows a state diagram. The MS 10 enters state 300 when a trigger event occurs. Trigger events include receiving an RRLP Position Measurement Request message 120, receiving an RRLP Assistance Data message 110, acknowledging initiation of an emergency services call, and the like. In state 300, the MS 10 continues position determination if already in operation or begins position determination by starting the GPS engine if not already started.

[0080] Typically, MS 10 exits state 300 when the position is determined or when a dwell time occurs (shown as transition 310) and enters state 320. The dwell time, for example, may occur when MS 10 determines that the network 70 is waiting for a measurement in a small predetermined amount of time. In some cases, the MS 10 exits state 300 and enters state 330 when the MS 10 receives an extra RR message 130, which aborts the current RRLP session before the MS 10 can send its response.

[0081] In state 330, MS 10 aborts the current RRLP session but continues position determination. Upon receipt of an RRLP 120A Position Measurement Request message, the MS 10 enters state 340 but again continues the position determination process. After the MS 10 determines that the position or hold time occurs (shown as transition 340), the MS 10 exits state 340 and enters state 320. In state 320, the MS 10 sends its RRLP Position Measurement Response message 320 to network 70.

[0082] Figures 11 and 12 illustrate a method of optimally ordering downloaded assistance data, in accordance with embodiments of the present invention. Assistance data may be transmitted in one or more RRLP Assistance Data (pseudo-segmented) messages 110 and/or in an RRLP Position Measurement Request message 120. The optimal ordering of communication of Assistance Data from the network 70 to the MS 10 allows the MS 10 to advantageously begin the position determination process early and actively utilize segments of the Assist Data prior to instruction to do so by the RRLP Position Measurement Request message 120.

[0083] Figure 11 shows an optimal ordering of segmented Assistance Data 400. The first segment includes reference information 410 including a satellite time and a coarse location of MS 420. The first and remaining segments include vehicle position information of satellite (including almanac and ephemeris data) 430. Satellite vehicle position information 430 is ordered from most optimal 440, to the next most optimal 450, and continues to least optimal 460. Not all available satellites need to be placed in this list of optimally ordered Assistance Data.

[0084] The optimal ordering of satellites may take into account one or more factors to provide MS 10 with a set of satellites most likely to be viewable and useful to MS 10 to quickly determine its location. For example, coarse MS location knowledge can be used to query satellite positions shown empirically to be visible to mobile stations with similar coarse MS locations. The network 70 may search for satellites being in a region of space shown by observation or experimentation to be available to a mobile station having the same or similar coarse MS location.

[0085] Furthermore, knowledge of the coarse location of MS can be used to determine a general characteristic of the environment. This environmental characteristic can be used to identify the best satellites to allow MS 10 to determine its location. The rough location of MS may identify MS 10 as being situated, for example, in a rural landscape (e.g. in a flat rural setting), in a mountainous landscape (e.g. in a north-south oriented valley, or along of the western face of a mountain), or in an urban landscape (for example, in a dense city center with tall buildings). If the coarse location of MS indicates that MS 10 most likely has an unobstructed view of the sky, a network 70 may first provide satellite position information for a set of orthonormal or pseudo-orthonormal satellites, e.g., three closest satellites. 45 degrees from the horizon separated by 120 degrees from each other. Any two of these three satellites would be oriented approximately orthogonally to the mobile station. That is, a first line between the first satellite to the mobile station and a second line between the second satellite to the mobile station form a right angle (orthonormal) or an angle between 60 and 120 degrees (approximately orthogonally oriented). If MS's coarse location suggests that MS 10 would not be able to see satellites located in a specific region of space (for example, if a mountain blocks the eastern sky), then position information for those satellites may be lower in optimal list of satellites (or even removed from the list entirely).

[0086] In addition to reference information 410, the first segment of Assistance Data may also include information about one or two satellites, as provided by the permissible length of the message. The first second includes satellite position information that is most optimal 440 for the MS 10. The second Assist Data segment includes satellite position information for the next two, three, or four most optimal satellites 450. Each subsequent segment of Assist data includes satellite position information for equal or increasingly less optimal satellites until the set of 460 less optimal satellites is reached.

[0087] Figure 12 shows a flowchart for ordering and sending Assistance Data segments. In step 500, network 70 sorts a list of satellites from most to least optimal for RS 10 to produce an ordered list, both lists of which may also be stored in memory in network 70. The order may be specific to each MS. 10. For example, the order may depend on the gross location of MS. In step 510, the network 70 sends the first segment RRLP Assistance Data message, 110, including the reference information (i.e., reference time & coarse MS location) and satellite position information for the most optimal satellites. .

[0088] In step 520, the network 70, for example using a controller or controller logic in the network 70 determines whether it is time to send an RRLP Position Measurement Request message 120. The network 70 may determine that it is time to send an RRLP 120 Position Measurement Request message if sufficient assistance data has already been sent to the MS 10. If the MS 10 has satellite position information for at least a predetermined number of satellites (e.g., 4-14 satellites ), then the network 70 may determine that the MS 10 has a sufficient amount of assistance data. Alternatively, if the predetermined number of satellites is not reached but there is no more satellite information available to send in an Assist Data message, the network can transmit the RRLP Position Measurement Request message (with or without a final piece of Service Data) or you can set a timer such that the RRLP Position Measurement Request message is sent to receive an RRLP Position Measurement Response message in time. Alternatively, network 70 may determine that MS 10 has a sufficient amount of Assistance Data if the time remaining before position correction is required by network 70 is less than a predetermined amount of time. In this case, the network 70 will determine that it is time to send the RRLP Position Measurement Request message 120 if a timeout has occurred. Alternatively, the network 70 may determine that it is time to send the RRLP Position Measurement Request message 120 if all Assistance Data was previously sent.

[0089] If it is not time to send the RRLP Position Measurement Request message 120, the network 70 may proceed to step 530. If it is time to send the RRLP Position Measurement Request message 120, the network 70 may proceed to step 540. In step 530, network 70 sends the RRLP Assistance Data message in next segment 110 including position information for the group of next most optimal satellites then returns to step 520. This loop between steps 520 and 530 can continue multiple times. In step 540, network 70 sends an RRLP Position Measurement Request message 120. The RRLP Position Measurement Request message 120 may contain a final segment of Assistance Data. Alternatively, the RRLP Position Measurement Request message 120 may be empty of any Service Data as described in detail below.

[0090] Figures 13 and 14 show a method of sending position requests in time, according to embodiments of the present invention.

[0091] In Figure 13, at time a, network 70 begins an RRLP session by sending an RRLP message as an RRLP Position Measurement Request message 120. This scenario assumes that network 70 has successfully sent one or more position measurement messages. RRLP 110 Service Data to the MS 10 or that the MS 10 already has Service Data in its memory. In the example shown, network 70 requires a position correction from MS 10 in approximately 35 seconds. At time b, the RRLP session is aborted due to some other RR 131 message.

[0092] In some cases, the RRLP message 120 shown at time a may still be in an output queue of the network 70, so the MS 10 did not receive an RRLP message and did not initiate the RRLP session. In this case, the other RR message 131 preempts the RRLP message 120 by removing it from the queue before it can be successfully transmitted completely out of the queue. Because the MS 10 previously received a trigger event, such as a first RRLP Assist Data message (not shown), the GPS engine is already in operation. During each subsequent message, the GPS engine continues uninterrupted until the position determination process.

[0093] Network 70 at time c determines that only a minimum amount of time remains until a position correction is required (e.g., approximately 4 seconds remain). The network 70 sends an RRLP Position Measurement Request message 120B to the MS 10. This message 120B is sent at a time (time c) such that a response will be received within that time (at time d). In some embodiments, the RRLP 120B Position Measurement request message is sent with NW Response Time and NW Accuracy parameters but without Assistance Data. The RRLP Position Measurement Request message 120 may include a short delay time (e.g. NW Response Time represents 2 or 4 seconds) for which the MS 10 must return a position correction and may contain a low value for uncertainty (NW accuracy indicates high accuracy, e.g. approximately 10 meters). Alternatively, the RRLP Position Measurement Request message 120 may include a set of position accuracy parameters to allow for large position uncertainty (NW Accuracy indicates low accuracy, e.g., approximately 250 meters). At time d, network 70 receives an RRLP Position Measurement Response message 122 from MS 10 still in time when approximately 0 seconds or close to 0 seconds remains.

[0094] The still-in-time procedure may be invoked because a rebid was necessary due to a previous interrupted RRLP session. In some cases the interrupted RRLP session must be a session started by a previous RRLP Position Measurement Request message 120 (as shown). In some cases the interrupted RRLP session may be a session initiated by an RRLP Assistance Data message 110. In some cases the interrupted RRLP session may be a session initiated by a previous RRLP Position Measurement Request message 120 or a RRLP 110 assistance data.

[0095] Figure 14 shows a process in a network 70 for position requests and responses in time. In step 600, network 70 determines a future time that an RRLP Position Measurement Response message 122 is required. In step 610, network 70 sets a timer, program, or the like and waits until just before location data is needed (e.g., 4 seconds before). During this waiting time after the last RRLP message and before the RRLP Position Measurement Request message still at time 120, the network can send other RR messages and not interrupt the position determination process of the mobile station.

[0096] In step 620, network 70 sends an RRLP Position Measurement Request message 120. This message 120 is sent without Assistance Data at a time providing MS 10 sufficient time to respond. In step 630, network 70 receives an RRLP Position Measurement Responses message 122 just before the position is needed.

[0097] As mentioned above, this still-in-time process can be implemented for all RRLP Position Measurement Request messages 120 being transmitted over Network 70. Waiting to send an RRLP Position Measurement Request message 120 until shortly before If a position correction is necessary (for example, if you experience rebids) it helps reduce instances of aborted sessions and saves channel bandwidth. Alternatively, this process may be implemented if one or more aborts and/or preemptions have occurred in the present communication with that MS 10. Alternatively, this process may be implemented if one or more aborts or preemptions have occurred in communications with other mobile stations in that cell. , for example, for mobile stations having similar coarse MS locations.

[0098] Figures 15 and 16 show a method of delaying (or abandoning) new RR messages to avoid aborted sessions, in accordance with embodiments of the present invention.

[0099] Figure 15 shows a method of minimizing rebids between a network 70 and an MS 10 in a wireless network. At time a, network 10 sends an RRLP Request message 100 thereby opening a session. The RRLP Request message 100 may be an RRLP Assistance Data message 110 or an RRLP Position Measurement Request message 120. At time b, before network 10 has received a response from MS 10, network 70 determines , while the RRLP session is still open, a new RR message is ready to be sent from network 70 to MS 10. In known systems, network 70 immediately sends this new RR message thereby aborting the current RRLP session. In accordance with embodiments of the present invention, network 70 waits, if permissible, to send new RR messages to prevent a current RRLP session from being aborted. That is, to avoid aborting the RRLP session, the network 70 holds the new RR message until after receipt of an RRLP Acknowledge/Reply message 102 thereby causing the RRLP session to terminate normally. Based on the specific new RR message, the network 70 may wait to send the new RR message or abandon the new RR message entirely. At time c, network 70 receives and acknowledges the RRLP Confirmation/Reply message 102. Shortly thereafter, at time d, if the new RR message is not abandoned, network 70 sends the new RR message after the RRLP session is terminated. thus avoiding aborting the RRLP session.

[00100] In figure 16 in step 650, network 70 sends an RRLP request message. In step 660, prior to termination of the RRLP session, network 70 determines that it has a new RR message ready to be sent to MS 10. In step 670, network 70 determines whether it is permissible to delay (or abandon) sending the new message. RR message. If not permissible, network 70 sends the new RR message in step 690, thereby inevitably aborting the current RRLP session. At step 680, network 70 waits for and then receives the RRLP Acknowledgment/Reply message 102. If the new RR message is delayed, processing continues to step 690 before completing processing. If the new RR message has been abandoned, there is no new RR message left to be sent and processing is complete.

[00101] Figures 17, 18, 19, 20 and 21 illustrate a method of varying an accuracy parameter to balance response time and accuracy in an emergency services (ES) call, in accordance with embodiments of the present invention.

[00102] Figure 17 shows an example of call flow processing for an emergency services (ES) call to utilize increased accuracy when time is available. At time a(t=0), MS 10 identifies an ES call. In response to the ES call ID, the MS 10 starts the GPS engine. The MS 10 can set an activity timer to a large value (e.g. Act_timer = 40 seconds). One purpose for an uptime is to monitor the activity (or inactivity) of messages between the network 70 and the MS 10. If there is no activity for the duration of time, the activity timer will timeout and the GPS engine will be stopped. .

[00103] At time b, network 70 sends a first RRLP Assistance Data message 140. This first message 140 contains reference information 410 (satellite time and coarse location of MS 420 of Figure 11). It also contains satellite position information for the most optimal satellites for the MS 10. At time c, the MS 10 responds with an RRLP 142 Assistance Data Ack message. At time d and time e, the process of communicating Data messages assistance messages 144 and confirmation messages 146 may repeat one or more times to send additional assistance data (satellite position information) for the next most optimal satellites to the MS 10.

[00104] Next, the network 70 prepares an RRLP Position Measurement Request message 120. The RRLP Position Measurement Request message 120 may contain a value for a network response time parameter (NW Response Time). This NW Response Time parameter can be set to indicate an intermediate response time (for example, a value of 4 corresponds to 16 seconds). Message 120 may also contain a network precision parameter (NW Precision). This NW accuracy parameter can be set to indicate an uncertainty or intermediate accuracy (for example, a value of 19 corresponds to 51.2 meters). This parameter and other parameters or ranges of uncertainty or distance described here with specific values are provided as examples only. Other values can be used. A value of 51.2 meters or 245.5 meters, for example, can be values that vary from 40 to 60 meters, 30 to 70 meters, 40 to 100 meters, 40 to 400 meters, 100 to 150 meters, 100 to 250 meters, 100 to 300 meters, 100 to 400 meters and the like as a person skilled in the art understands.

[00105] At time f, network 70 sends the RRLP Position Measurement Request message 120. In some cases, a last set of Assistance Data is included in this message 120. In other cases, the last set of Assistance Data is included in the previous message, which was the RRLP 144 Service Data message.

[00106] To increase precision, the MS 10 may use a precision value that represents little or no uncertainty. For example, an Act_Accuracy parameter can be set to a value of 0, which represents 0 meters of uncertainty (the highest value of accuracy). Alternatively, the Act_Accuracy parameter can be set to a value of 1, 2, 3, or 4 to represent an uncertainty of 1.0, 2.1, 3.3, or 4.6 meters, respectively. Other values representing no or little uncertainty can also be used.

[00107] In some cases, where the MS 10 triggers this increased accuracy process, the MS 10 advantageously sets the Act_Accuracy parameter independently of the NW Accuracy parameter sent by the network 70. In other cases, where the network 70 triggers the precision process increased, the network 70 advantageously temporarily overrides its standard network accuracy (e.g., 51.2 m) and sets the parameter it will later send in an RRLP Position Measurement Request message 120 to the accuracy value that represents little or no accuracy. uncertainty.

[00108] Also shown, after time f, the MS 10 resets its activity timer from the current countdown time (e.g., 20 seconds) to a value that matches the network response time (Act_timer = NW response), for example, if the time remaining in the current activity timer is less than the response time provided on the network. In this way, the MS 10 will not prematurely close the GPS engine before a position measurement correction is determined and communicated to the network 70. The MS 10 may similarly set a second countdown timer for the response time (Act_timer = Acting Time NW answer). This timer can be used by the MS 10 to define when the MS 10 sends a certain position.

[00109] At time g, the elapsed time in the example is 36 seconds. The MS 10 used the entire allocated network response time in determining a position correction. Thus, although position accuracy was not obtained, a position of increased accuracy was considered to potentially have greater accuracy (or similarly less uncertainty) than required by standard network accuracy (e.g., 51.2 m).

[00110] By decreasing this uncertainty parameter to 0, the MS 10 will use the entire allowable network response time in computing a position correction. By decreasing the uncertainty parameter to a low value (e.g., 1, 2, 3, or 4) the MS 10 will more likely utilize the full allowable network response time unless a position correction can be determined with low estimated uncertainty. . The additional time used by the GPS engine to attempt to obtain a position correction with the necessary uncertainty decreased allows the MS 10 the opportunity to produce a position correction of increased accuracy.

[00111] At time g, the MS 10 sends an RRLP Position Measurement Response message 122 with one of the following components: LocationInfo; GSP-MeasureInfo; or LotionError. Typically, the MS 10 will respond with the LocationInfo component when the MS 10 determines an acceptable position correction or enters timeout. Alternatively, the MS 10 will respond with the GSP-MeasureInfo component when the MS 10 is instructed to provide measurements to the network 70, which allow the network 70 to determine a position based on this raw data.

[00112] Figure 18 shows another embodiment of call flow processing for an emergency services (ES) call. In this scenario, a position request message is still communicated in time for the MS 10 to respond with a position response in time. The flow begins as described above with reference to figure 17. At time a(t=0), the MS 10 identifies the ES call then in response, starts the GPS engine. Again, an activity countdown timer is set (Act_timer = 40 seconds). At time b, network 70 sends a first RRLP Assistance Data message 140. At time c, MS 10 responds with an RRLP Assistance Data message 142. The process may continue to communicate multiple sets of messages 140/142.

[00113] At time d, this scenario moves away from the previously described scenario. At time d, network 70 has the information it needs to send a position request message (an RRLP Position Measurement Request message 120), however, network 70 waits to send the message until a predetermined time before network 70 require a position correction. A default network accuracy can be set to provide sufficient accuracy (NW Accuracy = 19, representing 51.2 meters), however, the network-defined response time is drastically shortened. For example, the NW Response Time can be set to 2 (representing 4 seconds) or 1 (representing 2 seconds) instead of giving the MS 10 seconds. This drastically shortened time normally does not allow a mobile station to determine a position correction. Commonly, a mobile station requires tens of seconds to a few minutes. Here, as MS 10 started its position determination process early (for example, at time a), it has already been working on it for tens of seconds.

[00114] Again network 70 prepares an RRLP Position Measurement Request message 120. Message 120 contains the drastically shortened network response time (e.g., NW Response Time = 4 seconds) and network accuracy (e.g. example, Accuracy NW = 51.2 meters). At time e, the elapsed time in the example is 32 seconds and the network 70 sends the RRLP Position Measurement Request message 120. In this case, the last set of Assistance Data is included in the previous message (i.e., the last message RRLP Assistance Data 140), therefore this message 120 is sent without Assistance Data.

[00115] In some cases, the precision used by MS 10 is set to a value that represents low precision or equivalently high uncertainty (e.g., a value of 34 represents 245.5 meters), which may be a predetermined value or a default configurable value. This precision value representing low precision can be set in one of two ways: by network 70; or via MS 10.

[00116] If the accuracy value is set by network 70, network 70 sends RRLP Position Measurement Request message 120 with the network accuracy set to represent this low accuracy value (NW Accuracy). For example, network 70 may temporarily override the default network precision with the low precision value for this MS 10.

[00117] On the other hand, if the accuracy is set by the MS 10, the network 70 may send an RRLP Position Measurement Request message 120 with the network accuracy set to represent a standard network accuracy. The MS 10 overwrites or ignores the received network precision and uses a value that represents low precision instead. The MS 10 uses the network response time (NW Response Time) for both its internal countdown timer and its response time timer (i.e., Act_timer = NW Response Time and Act_RT = NW Response Time, respectively ). At time f, after the response time timer is zero (elapsed time in the example is 36 seconds), the MS 10 prepares and sends an RRLP Position Measurement Response message 122.

[00118] This scenario has several advantages. Since the MS 10 started the GPS engine early (at time a) and used the maximum possible time duration in determining a position correction while minimizing loss of battery power, it produced an increased position correction. Since the RRLP Position Measurement Request message 120 is short (because it does not contain assistance data), the probability that the message 120 will be acquired by preemption is decreased. Since the network response time is low (e.g., 4 seconds), the chance of the final RRLP session being aborted with other RR messages is decreased. If a decreased accuracy value (e.g. Act_Accuracy = 245.5 meters) is replaced with the default network accuracy (e.g. NW Accuracy = 51.2 meters), the chance of the final RRLP session being aborted with further RR messages is reduced even further.

[00119] Figure 19 shows yet another call flow processing modality for an emergency services (ES) call. In this scenario, a first position request message 120 (with or without Assistance Data) is communicated shortly after the final RRLP Assistance Data message 142. If this RRLP session is interrupted, the network 70 delays sending a position request message 120. 120A rebid position request (a message without Assistance Data) until a predetermined time based on when the position is needed. Otherwise, the events and message flow from time a to time f are identical to those described above with reference to Figure 17 and a description will not be repeated.

[00120] The sequence diverges from figure 17, at time g, where an extra RR message causes the current RRLP session to be aborted. Equivalently, the RRLP Position Measurement Request message 120 may have been preempted internally in the network output queue (e.g., because the RRLP Position Measurement Request message 120 is long as it contains Service data). In any case, the MS 10 does not have an RRLP session currently open or an instruction to respond with a position.

[00121] Network 70 delays sending a rebid message 120A until a computer time to provide MS 10 just enough time to respond with a position correction such that the position correction is received still in time for the network 70 report the same. Based on whether a previous RRLP session was aborted or preempted, network 70 may determine to switch from a first mode to a second mode. In the first mode, the network 70 sends a rebid based on the prematurely stopped RRLP session and sends a rebid position request message immediately as known. That is, the network 70 bases the timing of the next position request message on a past event, namely completion of the extra RR message and the need to resend the position request message as quickly as possible.

[00122] In this second mode, network 70 does not send a rebid position request message immediately. Instead, the network 70 advantageously waits for a duration of time based on when the position response is needed. That is, instead of basing the timing of the rebid position request message on a past event, the transmission is based on a future event. For example, the timing of the next position request is based on when position correction is needed (for example, based on the Remaining NW Response Time).

[00123] The timing of when the RRLP Position Measurement Request message 120 is transmitted may be based on a predetermined time before the time that position correction is required on the network 70. In the example shown, a predetermined time is set within 8 seconds (response time NW = 3) before position information is required by the network 70. Other predetermined times may be used, for example, based on empirical data from several mobile stations other predetermined times may be used (e.g. , an NW Response Time can be set to 1, 2, 4, 8 or 16 seconds). The network 70 may set a timer or schedule the measurement request message so that the message is transmitted at this future time.

[00124] At time h (t=32), network 70 ends the delay and transmits the Rebid RRPL Position Measurement Request message 120A. As indicated, the message does not contain Service Data. Alternatively, the delay in sending the RRPL rebid Position Measurement Request message 120A could be slightly shortened, the response time (NW response time) could be slightly increased, and the message 120A could contain some Assistance Data. Furthermore, the accuracy parameter used by MS 10 can be set to a large uncertainty value (e.g., 245.5 meters) by MS 10 overwriting the default grid value or by grid 70 as a temporary uncertainty value. The MS 10 resets its activity timer to the response time provided by the network (Act_timer = NW Response Time).

[00125] In this example, the mobile subscriber activity timer was set to expire in 4 seconds (Act_timer = 4 seconds) however this timer is reset based on the time received (change Act_timer = NW Response Time = 8 seconds). The MS 10 can set its response time to the response time provided by the network (Act_RT = Response Time NW = 8 seconds). At time i (t = 36), the MS 10 reports the determined position with an RRLP Position Measurement Response message 122 then to the GPS engine.

[00126] Figure 20 shows a scenario where the network 70 transmits a measurement request message still in time but a previous rebid of an Assistance Data message causes the MS 10 to use a network-provided accuracy. Events and messages at times a through d are identical to those in Figure 19. At time e, the session is aborted with an extra RR message 144. Similarly, a network could have preempted message transition 144. At times f and g, the Assistance data is sent as a RRLP Assistance Data rebid message 144A and is acknowledged with an RRLP assistance data ack message 146. The rebid message may be a rebid of the first Assistance Data message (not shown), the second Assistance Data message (as shown) or any other in a segmented sequence of Assistance Data messages (not shown).

[00127] At time h (t=20), network 70 sends an RRLP Position Measurement Request message 120 to receive a measurement report message as described above. The MS 10 can set its activity timer to the network-supplied response time (Act_timer = NW Response Time = 16 seconds), it can set its response timer to the network-supplied response time (Act_RT = NW Response Time = 16 seconds) and can set its accuracy to the network-provided accuracy (Act_Accuracy = NW Accuracy = 51.2 meters).

[00128] In the previous examples, MS 10 normally uses a precision value that is a temporary value. This temporary value is a different value that is greater or less than the default network precision. In this example, the default network precision is used as an exception to using the different value. Finally, at time i (t=36), the MS 10 reports the determined measurement in an RRLP Position Measurement Response message 122.

[00129] In some cases, network 70 may detect the occurrence of a rebid (due to an abort or preemption). In this case, the network 70 modifies the network-supplied precision from the temporary value to the default network precision. Alternatively, the MS 10 may detect the occurrence of a Rebid Assistance Data message (due to an abort) and based on that event, the MS modifies its precision from the value. Alternatively, the MS may determine that the received measurement request message is delayed based on a measured time duration of the previous RRLP message.

[00130] Figure 321 shows a flowchart relating to modifying an accuracy parameter from the default network accuracy as described with reference to the previous four figures. At 700, after the MS 10 has received an RRLP Position Measurement Request message 120, a determination is made whether the message 120 was sent and received in a timely manner. This determination may be made by the MS 10 or the network 70 based on time (e.g., some expected communication time), based on aborts, or based on preemptions as described above. If the RRLP Position Measurement Request message 120 is in time, processing continues at step 710.

[00131] In step 710, the MS 10 uses a higher than normal accuracy (e.g., 0 meter) for maximum accuracy or a small selected value lower than the default network accuracy (e.g., a value between 1 and 10 meters or a value between 0 meters and the default network accuracy value) for a more accurate response.

[00132] If the RRLP 120 Position Measurement Request message is delayed, the accuracy may be set to the default network accuracy (not shown). Alternatively, if the RRLP Position Measurement Request message 120 is delayed, processing continues at step 720. Another test may be performed at step 720 to determine whether the message 120 is slightly delayed or very delayed. For example, an RRLP Position Measurement request message 120 may be determined to be slightly delayed if a rebid of an Assistance Data message was made. The RRLP Position Measurement Request message 120 may be determined to be too delayed if a rebid of a previous RRLP Position Measurement Request message was made. Alternatively, an RRLP Position Measurement request message 120 may be determined to be slightly delayed if it is communicated later than a first predetermined time (e.g., 24 seconds) but before a second predetermined time (e.g., 36 seconds). ). The RRLP Position Measurement Request message 120 may be determined to be too delayed if communicated later than the second predetermined time. In step 730, the MS 10 uses a standard network precision (i.e., NW Precision). In step 740, the MS 10 uses a lower accuracy value (e.g., 100, 200, or 250 meters) to speed up its position response.

[00133] Figure 22 shows a message flowchart for a value added service (VAS), in accordance with embodiments of the present invention. For a VAS, the MS 10 does not need to use the full amount of NW Response Time.

[00134] At time a (t=0), network 70 determines that a VAS has been started. In response, it sends an RRLP Assistance Data 140 message. The MS 10 upon receipt of the RRLP Assistance Data 140 message, starts its GPS engine and sets its activity timer to a predetermined value (a value greater than that used in the case of an ES call, e.g. Act_timer = 45 seconds). Also in response to receiving the RRLP Assistance Data message 140, the MS 10 sends, at time b, an RRLP Assistance Data Ack message 142. At times c and d, additional segments of Assistance Data may be communicated and acknowledged with additional pairs of RRLP 144 Assistance Data messages and RRLP 146 RRLP 146 Assistance Data Ack messages.

[00135] At time e (t = 20, Act_timer = 25), network 70 prepares an RRLP Position Measurement Request message with a standard network time (e.g., NW Response Time = 16 seconds) and a value standard network accuracy (e.g. NW Accuracy = 51.2 meters). Network 70 sends and MS 10 receives the RRLP Position Measurement Request message 120. Unlike an ES call, MS 10 does not discard any network-supplied parameters. The MS 10 sets its activity timer, active response timer, and activity accuracy parameters to network-supplied values (i.e., Act_timer = NW Response Time, Act_RT = NW Response Time, and Act_Accuracy = NW Accuracy, respectively) .

[00136] At time f (t = 34, Act_timer = 2), the MS 10 sends its determined position in an RRLP Position Measurement Response message 122 to the network 70. In this case, the MS sent the determined correction before the termination of network response time due to position uncertainty being less than the required network accuracy. Finally, in response to the report of the determined fix, MS 10 stops the GPS engine.

[00137] It should be understood that the invention can be put into practice with modification and alteration in the spirit and scope of the attached claims. The description is not intended to be exhaustive or to limit the invention to the precise form disclosed. It should be understood that the invention can be put into practice with modification and alteration.

Claims (14)

1. Method for reducing rebids of Position Measurement Request messages between a network (70) and a mobile station (110) in a wireless network, the method characterized by the fact that it comprises: determining (600), by the network, a first time when the Position Measurement Request message is required; transmit (620), over the network, at a predetermined time before the first time, a Position Measurement Request message comprising a network response time and a network accuracy, wherein the network response time is equal to or less that a time interval between the predetermined time and the first time; and receiving (630), via the network, the Position Measurement Response message comprising the location data. 2. Method according to claim 1, characterized by the fact that the network response time comprises a value representing a shortened response time of no more than 4 seconds. 3. Method according to claim 1, characterized by the fact that the network precision comprises a value that represents low precision of not less than 100 meters. 4. Method, according to claim 1, characterized by the fact that the Position Measurement Request does not comprise Assistance Data. 5. Method according to claim 1, characterized by the fact that it further comprises: transmitting an Assistance Data message; and receive a Support Data Confirmation message. 6. The method of claim 1, wherein the Position Measurement Request message comprises an RRLP Position Measurement Request message, or an RRLP Position Measurement Response message. 7. Network (70) for reducing rebids of Position Measurement Request messages between the network (70) and a mobile station (10) in a wireless network, characterized by the fact that it comprises: a timer for determining, by the network , a first time when the Position Measurement Request message is required; a transmitter to transmit, at a predetermined time before the first time, the Position Measurement Request message comprising a network response time and a network accuracy, wherein the network response time is equal to or less than the range of time between the predetermined time and the first time; and a receiver for receiving the Position Measurement Response message comprising the location data. 8. Method, in a network (70), for minimizing rebids between the network and a mobile station (10) in a wireless network, the method characterized by the fact that it comprises: sending (650) a Request message to open a session between the network and the mobile station (10); obtaining (660), while the session is open, a radio resource message that is ready to be sent to the mobile station (10); inhibit transmission of the radio resource message to the mobile station to avoid aborting the session through transmission of the radio resource message; and receive (680) a Reply message to close the session. 9. Method, according to claim 8, characterized by the fact that the act of avoiding aborting the session comprises: waiting for the RR message to be sent; and send the RR message after closing the session. 10. Method, according to claim 8, characterized by the fact that the act of avoiding aborting the session comprises discarding the RR message. 11. The method of claim 8, wherein the Request message comprises an RRLP Position Measurement Request message; or an RRLP Service Data message. 12. Network (70) for minimizing rebids between the network (70) and a mobile station (10) in a wireless network, the network characterized by the fact that it comprises: mechanisms for sending a Request message to open a session at the station mobile (10); mechanisms for obtaining, while the session is open, a radio resource message that is ready to be sent to the mobile station (10); mechanisms for inhibiting transmission of radio resource messages to the mobile station to avoid aborting the session with the radio resource message; and mechanisms for receiving a Response message to close the session. 13. Network, according to claim 12, characterized by the fact that the mechanisms to avoid aborting the session comprise discarding the RR message. 14. Memory characterized by the fact that it comprises instructions stored therein, the instructions being executed by a computer to carry out the method as defined in any one of claims 1 to 6 and 8 to 11.