PROVISIONING OF GPS ASSISTANCE DATA IN A WCDMA NETWORK

Abstract: A method of provisioning differential GPS (DGPS) assistance data (58, 59) over a WCDMA wireless communication network (10) to facilitate positioning of mobile communication devices (12, 20). The method comprises providing differential GPS assistance data over a dedicated physical data channel (DPDCH) and/or a dedicated physical control channel (DPCCH). The mobile communication terminal has an integrated GPS receiver and can comprise of cellular or PCS telephony handsets, a mobile computer, PDAs, etc. The present invention facilitates a mechanism for providing the DGPS assistance data to achieve positioning of the mobile communication device accuracy down to about 5 meters.

Description: PROVISIONING OF GPS ASSISTANCE DATA IN A WCDMA NETWORK FIELD OF THE INVENTION The present invention is generally related to wireless communication networks, and more particularly to a wideband code division multiple access (WCDMA) third generation (3G) network for mobile positioning. BACKGROUND OF THE INVENTION Wireless communication networks including fixed wireless and cellular-type mobile communications networks continue to evolve. There are several available technologies for providing wireless communications including CDMA, TDMA, GSM, AMPS and D-AMPS. These networks continue to be deployed throughout the world. Many equipment suppliers throughout the world currently manufacture these various systems and typically work through standards groups to ensure commonality and interoperability of the various networks. As wireless communications networks move into the next century, a new type of wireless network is evolving currently known as wideband code division multiple access (WCDMA) based third generation (3G) networks. These third generation wireless systems are slowly becoming a reality for FPLMNs. There is a desire to provide positioning of a mobile subscriber within a wireless network. Current implementations are based on time difference of arrival (TDOA) techniques, which give an accuracy of position down to about 18 meters. While this accuracy is adequate for several features and can be implemented in today's networks, there is required more accurate positioning of a mobile subscriber. An improved mobile-based positioning solution will also reduce the need for extra capacity in the network required and used for positioning. Development is still currently underway with techniques being deliberated by standards committees to determine how best achieve improved resolution of positioning of a mobile station, especially in WCDMA based 3G networks. SUMMARY OF THE INVENTION The present invention achieves technical advantages as a method of provisioning differential GPS assistance data in a WCDMA network over the dedicated physical data channel (DPDCH), and/ or the dedicated physical control channel (DPCCH). By providing differential GPS assistance data over these channels, mobile stations having a GPS receiver within a WCDMA based 3G network can accurately determine position of the mobile station to an accuracy of about 5 meters. The mobile user terminal may comprise of a mobile cellular-type mobile station, such as a PCS or cellular phone, but may also include a computer, or a PDA. The mobile communication terminal according to the present invention includes mechanisms for exchanging wireless communications with a serving wireless communication network, and in addition, means to receive differential GPS assistance data over a dedicated physical channel, such as the DPDCH or DPCCH. The mobile communication terminal further has circuitry and software in a GPS receiver to determine a position of the mobile communication terminal as a function of this GPS assistance data with improved resolution. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a block diagram of a wireless communication network including a WCDMA wireless network for third generation systems; Figure 2 is a flow diagram of a method of the present invention providing differential GPS (DGPS) assistance data over the DPDCH or DPCCH on a WCDMA carrier to support differential GPS positioning of a mobile station in the network; Figure 3 is a block diagram of one format for providing differential GPS assistance data over the DPCCH; and Figure 4 is a block diagram of an alternative embodiment of the present invention providing differential GPS assistance data over the DPDCH. DESCRIPTION OF THE PREFERRED EMBODIMENT Figure 1 illustrates a block diagram of a communication network 10 according to the preferred embodiment of the present invention. Communication network 10 preferably comprises a wireless telephony network seen to include an originating mobile station 12 coupled by an RF communication link to a servicing WCDMA originating network 14. The originating mobile station 12 is preferably a wireless communication device comprising a wireless mobile station. The originating WCDMA network 14 is seen to be coupled to a transit network or communication link 16, which may comprise a public switched telephone network (PSTN), but could also comprise of other networks including an optical network if desired. The transit network 16 interfaces and communicates electrical signals including digitized voice calls between originating network 14 and a terminating network 18. Terminating network 18 may be the same as, or different than, the originating network 14, and may comprise of AMPS, D-AMPS, TDMA, GSM and IS-95 networks. For purposes of illustration, terminating network 18 is depicted as a WCDMA network. Terminating network 18 is coupled to and services via an RF link a terminating mobile station 20, which may comprise of a fixed or mobile station such as a wireless cellular or PCS subscriber. The wireless stations and networks may have codecs to provide encoding and decoding of digital signals communicated over the transit network 16. The originating WCDMA network 14 is seen to include a base transceiver station (BTS) 30 serving via a radio frequency (RF) link the originating mobile or fixed station 12. Each BTS 30 services multiple stations 12, although only one is shown for purposes of illustration and clarity. Originating network 14 is further seen to include a radio network controller (RNC) 32 and a network switching system (NSS) 34. The BTS and RNC are sometimes collectively referred to as a base switching station (BSS). RNC 32 interfaces voice calls between multiple BTSs 30 and NSS 34, wherein RNC 32 typically serves multiple BTSs 30, although only one is shown for purposes of illustrating the present invention. Similarly, NSS 34 services multiple RNCs 32, although only one is shown for purposes of illustrating the present invention. NSS 34 includes a home location register (HLR), a mobile positioning node, and a visitor location register (VLR) which includes and stores various information of the stations 12 currently being served by the originating network 14. Terminating network 18 is seen to include a BTS 40 serving the terminating station 20, and typically serves multiple stations 20. Terminating network 18 is further seen to include a RNC 42 and NSS 44. Terminating network 18 may operate according to the same operating protocol as originating network 14, i.e., both are WCDMA networks, or, the terminating network 18 may be different from the originating network 14, i.e., the originating network is WCDMA and the terminating network may be based on AMPS, D-AMPS, GSM, TDMA or IS-95 protocols. NSS 44 includes a HLR, and a VLR for maintaining a register of information for all stations 20 currently being served by the terminating network 18. A reference GPS receiver 46 provides GPS assistance data positioning information to the respective network 14 and network 18, for use by originating mobile station 12 according to the present invention. Transit network 16 is preferably a PSTN. Originating NSS 34 and terminating NSS 44 exchange digitized voice data thereover, which are preferably encoded in pulse code modulation (PCM) format, and transmitted at about 64 kbps. Although PCM is a preferred encoding format, other encoding formats are available according to the present invention. Likewise, other transfer speeds other that 64 kbps are also contemplated by the present invention. Generally, the digitized voice data transferred over transit network 16 can be in any format which is compatible and supported by both the originating network 14 and the terminating network 18. Referring now to Figure 2, there is illustrated at 50 a message flow diagram for providing differential GPS (DGPS) assistance data from reference GPS receiver 46 via transit network 16 to the user terminal 12. As illustrated at 52, the DGPS assistance data is continuously provided by a node of the network 10, such as the BTS 32, over the air interface to the user terminal 12 over either the dedicated physical data channel (DPDCH) or the dedicated physical control channel (DPCCH). At 54, there is illustrated a Positioning Request message sent by the RNC/ Core network 34 to initiate positioning of user terminal 12. This message is responsively forwarded by the BTS/ node B 32 to the user terminal 12 as Positioning Request message 56. At 58, the user terminal 12 has an integrated GPS receiver that processes the DGPS assistance data provided by the network 10 to determine the position or aid in the positioning of user terminal 12 using GPS satellite information according to techniques that are well known throughout the industry. The differential GPS assistance data can be processed to speed the search of a priori information from the GPS satellites (not shown) to determine positioning of the user terminal 12 to a resolution of about 5 meters. The current position of the user terminal 12 is provided in Positioning Response message 58 by user terminal 12 to the BTS/ node B 32, which message is forwarded in the Positioning Response message 59 to the RNC/ Core network 34. The DGPS assistance data is then continued to be provided over the air interface on the DPDCH or DPCCH as desired for future use. The user terminal 12 can comprise of many mobile communications devices including PCS and cellular-type mobile phones, computers provided with suitable remote access circuitry, and PDAs. Thus, limitation to the particular type of mobile user terminal 12 is not to be inferred in the present invention. Rather, the present invention is directed to providing the particular type of differential GPS assistance data over either or both the DPDCH or DPCCH on a WCDMA carrier to provide positioning accuracy down to about 5 meters. The integrated differential GPS receiver at the WCDMA end user terminal can be integral to the equipment, such as embedded within the handset of the mobile station, or an attachment. In addition, an external PC or PDA can be provided with an integrated differential GPS receiver, and be used as a very accurate map tool, for fleet management etc. Referring now to Figure 3, there is shown a block diagram of one communication format providing DGPS assistance data over the dedicated physical control channel (DPCCH) to mobile user 12. As illustrated, one data packet 60 of the DPCCH is seen to comprise a slot having a time frame of about 0.625 milliseconds. This data packet 60 may comprise a header comprising an N number of bits comprising the Pilot, a Transport Frame Indicator (TFI), and a Transport Power Control (TPC). This data is typically used to control power of the mobile station 12 on the uplink. This data packet 60 is seen to comprise of one slot of several slots of a frame generally shown at 62, the slots together having a frame time of about 10 milliseconds. This frame 62 is seen to comprise of one of a plurality of frames together comprising a superframe having a time duration of about 720 milliseconds. Still referring to Figure 3, the DGPS assistance data typically comprise of about 5 slots 60 within the frame 62. However, as standards evolve, this number of slots required to provide the DGPS assistance data may increase or decrease, and limitation to the number or length of slots required to provide the DGPS assistance data is not to be inferred in the present invention. Referring now to Figure 4, there is shown an alternative embodiment of the present invention whereby the DGPS assistance data is provided over the dedicated physical control channel (DPDCH) 70. Each packet of information 70 is seen to comprise of one slot of several slots forming a frame 72. These slots together comprise one frame of several frames 72 comprising a superframe 74. In this embodiment, the DGPS assistance data is provided in approximately 4 or 5 slots 70, although limitation to the format of the information is not to be inferred. The present invention achieves technical advantages by providing differential GPS assistance data over the DPDCH and/ or DPCCH of a WCDMA 3G wireless communication network to a mobile user to aid in positioning the mobile user. The present invention provides a mechanism facilitating positioning of a mobile communication terminal 12 to about 5 meters. The user terminal 12 is provided with an integrated differential GPS receiver to facilitate communication of the mobile device 12 with the WCDMA network 10. In addition, the user terminal 12 is provided with both circuitry and software to facilitate positioning of the mobile terminal 12 using the DGPS assistance data. The present invention comprises a mechanism for provisioning the data to provide very accurate map tools, fleet management, etc. in 3G WCDMA systems. Though the invention has been described with respect to a specific preferred embodiment, many variations and modifications will become apparent to those skilled in the art upon reading the present application. It is therefore the intention that the appended claims be interpreted as broadly as possible in view of the prior art to include all such variations and modifications.

Claims: WE CLAIM 1. A method of provisioning GPS assistance data to a mobile user terminal in a wireless communication network, comprising the steps of: a) providing differential GPS assistance data from a system node of said wireless communication network to said mobile user terminal over a dedicated physical data channel (DPDCH); and b) said mobile user terminal receiving said differential GPS assistance data on said DPDCH to determine a position of said mobile user terminal. 2. The method as specified in Claim 1 wherein said wireless communication network comprises a wideband code division multiple access (WCDMA) network. 3. The method as specified in Claim 2 wherein said mobile user terminal comprises a wireless mobile telephone. 4. The method as specified in Claim 2 wherein said mobile user terminal comprises a computer. 5. The method as specified in Claim 2 wherein said mobile user terminal comprises a PDA. 6. A method of provisioning GPS assistance data to a mobile user terminal in a wireless communication network, comprising the steps of: a) providing differential GPS assistance data from a system node of said wireless communication network to said mobile user terminal over a dedicated physical control channel (DPCCH); and c) said mobile user terminal receiving said differential GPS assistance data on said DPCCH to determine a position of said mobile user terminal. 7. The method as specified in Claim 6 wherein said wireless communication network comprises a wideband code division multiple access (WCDMA) network. 8. The method as specified in Claim 7 wherein said mobile user terminal comprises a wireless mobile telephone. 9. The method as specified in Claim 7 wherein said mobile user terminal comprises a computer. 10. The method as specified in Claim 7 wherein said mobile user terminal comprises a PDA. 11. A mobile communication terminal, comprising; means to exchange communications with a serving wireless communication network, and means to receive differential GPS assistance data over a dedicated physical data channel (DPDCH) and determine a position of said mobile communication terminal as a function of said differential GPS assistance data. 12. The mobile communication terminal as specified in Claim 11 wherein said wireless communication network comprises a wideband code division multiple access (WCDMA) network, said exchange means being adapted to communicate with said WCDMA network. 13. The mobile communication terminal as specified in Claim 12 wherein said terminal comprises a wireless mobile telephone. 14. The mobile communication terminal as specified in Claim 12 wherein said terminal comprises a computer. 15. The mobile communication terminal as specified in Claim 12 wherein said terminal comprises a PDA. 16. A mobile communication terminal, comprising; means to exchange communications with a serving wireless communication network, and means to receive differential GPS assistance data over a dedicated physical control channel (DPCCH) to determine a position of said mobile communication terminal as a function of said differential GPS assistance data. 17. The mobile communication terminal as specified in Claim 16 wherein said wireless communication network comprises a wideband code division multiple access (WCDMA) network, said exchange means being adapted to communicate with said WCDMA network. 18. The mobile communication terminal as specified in Claim 17 wherein said terminal comprises a wireless mobile telephone. 19. The mobile communication terminal as specified in Claim 17 wherein said terminal comprises a computer. 20. The mobile communication terminal as specified in Claim 17 wherein said terminal comprises a PDA.

Inventors: KRANSMO JAN L, KRANSMO, JAN, L.
Applicants: ERICSSON INC, ERICSSON INC.
Application year: 1999
Main classification: G01S5
IPC codes: G01S5, H04J13, H04Q7