(51) Int Cl.: H04W 4/02 ( )

Transcription

1 (19) TEPZZ_6 9B_T (11) EP B1 (12) EUROPEAN PATENT SPECIFICATION (4) Date of publication and mention of the grant of the patent: Bulletin 1/2 (21) Application number: (22) Date of filing: (1) Int Cl.: H04W 4/02 (09.01) (86) International application number: PCT/US04/ (87) International publication number: WO 0/0111 ( Gazette 0/0) (4) WIRELESS NETWORK LOCATION-BASED REFERENCE INFORMATION AUF EINEM DRAHTLOSEN NETZWERKORT BASIERENDE REFERENZINFORMATIONEN INFORMATIONS DE REFERENCE BASEES SUR L EMPLACEMENT DANS UN RESEAU HERTZIEN (84) Designated Contracting States: AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IT LI LU MC NL PL PT RO SE SI SK TR Designated Extension States: AL HR LT LV MK () Priority: US (43) Date of publication of application: Bulletin 06/18 (73) Proprietor: TeleCommunication Systems, Inc. Annapolis, MD 211 (US) (72) Inventors: POHUTSKY, Joseph Annapolis, MD 213 (US) GROAN, Joel Shoreline, WA (US) HELME, Steve Seattle, WA (US) (74) Representative: Walker, Neville Daniel Alan Ipconsult 21A Commercial Road Swanage, Dorset BH19 1DF (GB) (6) References cited: EP-A WO-A1-97/4164 WO-A2-98/21913 WO-A2-03/0683 US-A US-A US-A US-A US-A US-B US-B US-B US-B EP B1 Note: Within nine months of the publication of the mention of the grant of the European patent in the European Patent Bulletin, any person may give notice to the European Patent Office of opposition to that patent, in accordance with the Implementing Regulations. Notice of opposition shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention). Printed by Jouve, 7001 PARIS (FR)

2 1 EP B1 2 Description BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] This invention relates generally to the field of wireless telecommunications. More particularly, it relates to a system and method for implementing a location-related information service in a wireless phone network, particularly with respect to short messaging systems (SMS), IS-41C, and location-enabled content pulls. [0002] In todays world, wireless devices such as wireless telephones play an important role. Much information is but a phone call away. [0003] One service that a wireless device can provide is information relating to a particular area. For instance, if one were traveling or otherwise in an unfamiliar area and wanted to locate a nice restaurant, perhaps a friendly inquisition of a gas station attendant might be helpful. Or, advertising signs might be the basis for selection of a good meal. A phone book is also a conventional way to find a particular service. [0004] Wireless devices have provided the ability to determine the location of services in an area much more conveniently. For instance, one existing wireless device technology uses mobile originated short messaging system (SMS) techniques. In this conventional technique, a user drafts and sends a text message to a particular service to which they subscriber. The text message that the user writes must include the type of content desired, together with basic information regarding a broadly defined location of the user, e.g., zip code, city or state. [000] Unfortunately, conventional techniques require the user to know their geographic location at any particular time, and to enter that geographic location as well as the particular type information sought via their mobile originated short message system (SMS) service. This knowledge is often difficult if not impossible to obtain accurately, and the required inputs are cumbersome and extensive. [0006] There is a need for a mobile system that is capable of quick, accurate, and easily obtained locationbased information. [0007] U.S. Patent No. 6,60,46 and WO 03/0683 teach information that is provided to a a mobile handset without the use of directory assistance digits suffixed by at least one auxiliary digit associated with the requested location information. [0008] U.S. Patent No. 6,60,46 appears to disclose information that is provided to a communication device in response to a request for such service received from the communication device. The request may be in the form of a digits request trigger or short message service (SMS) origination message that is initiated from a wireless telephone. The digits request trigger or SMS origination message is sent frcm the communication device to a wireless web information services gateway. The gateway retrieves the requested information from one or more sources for forwarding to a user via an SMS message. [0009] WO 03/0683 appears to teach a handset that can send a request to a landmark location messaging server to obtain details of location landmarks in the form of an SMS. The request contains the phone number of a mobile station together with category data D1. D2 or D3. 2. Background of Related Art BRIEF DESCRIPTION OF THE DRAWINGS [00] Features and advantages of the present invention will become apparent to those skilled in the art from the following description with reference to the drawings, in which: Fig. 1 shows the four main components of an exemplary 411 xx system in accordance with the principles of the present invention. Fig. 3 shows an exemplary 411 xx application internal call flow for the exemplary 411 xx system shown in Fig. 1. DETAILED DESCRIPTION OF ILLUSTRATIVE EM- BODIMENTS [0011] The present invention provides a 411xx value added service to wireless users. The disclosed 411xx service allows a mobile user who may be unfamiliar with their current geographic location to nevertheless obtain desired information. [0012] In accordance with the principles of the present invention, a mobile user is provided with quick, accurate, and current information relating to the geographic area, e.g., different services in their current location, stores, libraries, gas stations, etc., via a mobile terminated (MT) short message system (SMS) message. [0013] The present invention is a variant of the traditional directory assistance information service call In accordance with an embodiment of the present invention, in addition to the traditional dialed digits, a mobile user would also dial a number (or numbers) representing a feature code for a particular service. Example services might be nearby automated teller machines (ATMs), or local traffic information. [0014] The xx in the 411xx service name represents two digits by way of example only. More than 2 extra digits may be implemented within the principles of the present invention, as may only a single extra digit in extremely simple systems. [001] Upon receiving a 411xx call, the mobile switching center (MSC) generates an ORREQ/TCAP trigger based on a translation of the requested service represented by the extra xx digits. For a GSM system, this 2

3 3 EP B1 4 could be an ISUP based trigger, or a GSM message such as initiaidp. [0016] The 411 xx call is terminated on the MSC after an audible whisper notice plays to the caller, e.g., "thank you for calling, your requested information will be sent momentarily". [0017] Auxiliary benefits arise from the present invention as well. For instance, by virtue of terminating a request for services call at the relevant MSC. long distance charges are likely avoided. Moreover, in many subscriber plans, no airtime charges to the subscriber would apply. [0018] Fig. 1 shows four main components of an exemplary 411 xx system in accordance with the principles of the present invention. [0019] In particular, as shown in Fig. 1, an exemplary 411xx system has four major components: an application handling mobile switching center (MSC) feature code translations 2, a location system 4, a Short Messaging System (SMS) system 6, and a content provider 8. [00] In operation, as shown in step 1 of Fig. 1, a subscriber 1 requests directed information by dialing 411xx on his or her wireless telephone. The 411xx dialed number comprises lead digits of 411 (traditionally a telephone number for phone number information), followed by two (or more) trailing digits (i.e., XX ). [0021] In step 2, the 411xx telephone call is passed in an ORREQ/TCAP message to the location system 4, and then on to the SMS system 6 as shown in step 3. [0022] In step 4, the SMS system 6 requests content from the relevant content provider 8. [0023] In step, the content provider 8 packages the requested content information into an SMS message back to the SMS system 6. [0024] In step 6, the SMS system 6 forwards the SMS message including the requested content information to the MSC 2 servicing the subscriber 1. [002] In step 7, the SMS message response is delivered to the subscriber 1 from the MSC 2. [0026] Step 8 depicts TDR messages being transmitted by the SMS system 6 to the billing mediation server 1. [0027] Fig. 1 also depicts a step 0, which relates to the use of a 411 xx service in conjunction with advertising. In this application, once a subscriber sees, hears or is otherwise informed of particular 411xx information via advertising, he or she becomes induced into dialing the relevant 411 xx telephone number. [0028] Fig. 2 is an exemplary 411xx call flow ladder diagram for the exemplary 411xx system shown in Fig. 1. This is an ANSI-only call, and is used for exemplary purposes only. The present invention relates equally to GSM call flow. [0029] In particular, as shown in step 221, a subscriber 1 makes a phone call with 411xx dialed digits, that is transmitted to the servicing MSC 2. [00] In step 222, an ORREQ INVOKE message is transmitted from the MSC 2 to a STP 2, with relevant parameters for an otherwise conventional ORREQ IN- VOKE message, including [BILLID, MIN, ESN, MSCID, DGTSDIAL, ORIGTRIG, and TRANSCAP] [0031] In step 223, the STP 2 passes the ORREQ INVOKE message to an SCP The SCP returns an ORREQ RETURN RESULTS message with relevant parameters [identifier, Length, AccessDeniedReason, and ActionCode] [0032] In step 22, the STP 2 passes the ORREQ RETURN RESULTS message with relevant parameters [AccessDeniedReason and ActionCode] to the MSC 2. [0033] In step 227, the SCP 4 sends a SUBMIT_SM message to the relevant SMPP server 6 including relevant parameters, e.g., [service_type, source_addr_ton, source_addr_npi, source_addr, destination_addr_ton, destination_addr_npi, destination_addr, esm_class, protocol_id, priority_flag, schedule_delivery_time, validity_period, registered_delivery, replace_if_ present_flag, data_coding, sm_default_mg-id, sm_length, short_message, user_message_reference, sar_msg_ref_num, sar_total_segments, sar_segment_ seqnum] [0034] In step 228, the SMPP server 6 returns a SUBMIT_SM-RESPONSE message, including relevant parameters [command_length, command_id, command_status, sequence_number, and message_id] [003] In step 229, the SMPP server 6 transmits the SMPP MIN, Short Message to the subscriber 1. [0036] In step 2, a SMPP Delivery Receipt is transmitted by the MSC 2 to the SMPP server 6. [0037] In step 231, a DELIVER_SM message is transmitted by the SMPP server 6 to the SCP 4, including relevant parameters [service_type, source_addr_ton, source_addr_npi, source_addr, dest_addr_ton, dest_addr_npi, destination_addr, esm_class, protocol_id, priority_flag, schedule_delivery_time, validity_period, registered_delivery, replace_if_ present_flag, data_coding, sm_defauit_mg_id, sm_length, short_message, user_message_reference, and message_state] [0038] In step 232, the SCP 4 returns a DELIVER_SM-RESPONSE message back to the SMPP server 6, including the relevant parameters [command_length, command_id, command_status, sequence_number, and message_id] [0039] Fig. 3 shows an exemplary 411 xx application internal call flow for the exemplary 411 xx system shown in Fig. 1. [00] In particular, as shown in step 321 of Fig. 3, an ORREQ INVOKE message is passed from the STP 1 to a 411 SCPapp 2, including relevant parameters [BILLID, MIN, ESN, MSCID, DGTSDIAL, ORIGTRIG, and TRANSCAP] [0041] In step 322, an ORREQ RETURN RESULTS message is passed by the 411 SCPapp 2 back to the STP 1, including relevant parameters [Identifier, Length, AccessDeniedReason, and ActionCode] 3

4 EP B1 6 [0042] In step 323, a NQUEUE message is transmitted by the 411 SCPapp 2 to the 411 Queue 3, including relevant parameters [cellid, mobil_id, dialeddigits, mscid, billingid, and transtime] [0043] In step 324, the 411 SCPapp 2 transmits a NQUEUE message to a 411 internal queue 4, including relevant parameters [cellid, mobil_id, dialeddigits, mscid, billingid, transtime] [0044] In step 32, a DQUEUE message is transmitted by the 411 queue 3 to the 411 content application, including relevant parameters [cellid, mobil_id, dialed- Digits, mscid, billingid, and transtime] [004] In step 326, a DQUEUE message is transmitted by the 411 internal queue 4 to the 411 content application, including relevant parameters [cellid, mobil_id, dialeddigits, mscid, billingid, and transtime] [0046] In step 327, an Internet API over TCP/IP message is transmitted by the content provider 7 back to the 411 content application. [0047] In step 328, a DBSelect message is transmitted from a database 6 to the 411 content application, including relevant parameters cellid, mobil_id, dialeddigits, mscid, billingid, transtime, contentcont, msg, and deliverycode]. [0048] In step 329, an NQUEUE message is transmitted from the 411 content application to the SMPP queue 9, including relevant parameters [cellid, mobil_id, dialeddigits, mscid, billingid, transtime, contentcont, msg, and deliverycode] [0049] In step 3, a DQUEUE message is transmitted from the MSPP Queue 9 to the 411 back end 3, including relevant parameters cellid, mobil_id, dialeddigits, mscid, billingid, transtime, contentcont, msg, deliverycode, and SmppseqNum] [000] In step 331, a NQUEUE message is transmitted from the 411 back end 3 to the DB Queue 8, including relevant parameters cellid, mobil_id, dialeddigits, mscid, billingid, transtime, contentcont, msg, delivery- Code, and SmppseqNum] [001] In step 332, a DBinsert message is transmitted from the 411 back end 3 to the database 6, including relevant parameters [cellid, mobil_id, dialeddigits, mscid, billingid, transtime, contentcont, msg, delivery- Code, and SmppseqNum] [002] The present invention is applicable for any mobile device that supports mobile terminated SMS (MT SMS), or any wireless telephone capable of receiving short message system (SMS), EMS or MMS messages. It has applicability with, e.g., call center based concierge services, and text based services. [003] The inventive system is relatively easy and affordable for the mobile operator to implement. [004] In accordance with the principles of the present invention, the short messaging may be combined with audio passages based on the particular application. [00] While the invention has been described with reference to the exemplary embodiments thereof, those skilled in the art will be able to make various modifications to the described embodiments of the invention without departing from the scope of the invention. Claims 1. A method of providing location-based reference information in a wireless network, the method CHAR- ACTERIZED as: receiving a request for location information from a subscriber device (1), said request for location information comprising dialed directory assistance digits suffixed by at least one auxiliary digit associated with said requested location information; querying a location-based wireless service (4) in response to said request for location information to automatically obtain a current location of said subscriber device (1); retrieving said requested location information associated with said obtained current location and selected using said at least one auxiliary digit; and transmitting said requested location information to said subscriber device (1). 2. The method of providing location-based reference 1, wherein: at least two auxiliary digits are suffixed to said end of said dialed directory assistance digits. 3. The method of providing location-based reference 1, wherein: said information telephone call is initiated with said dialed directory assistance digits. 4. The method of providing location-based reference 1, wherein: said current location of said subscriber device (1) is obtained using wireless or cellular network signaling.. The method of providing location-based reference 2, wherein: said current location of said subscriber device (1) is determined using an angle of arrival of a wireless signal from said subscriber device (1). 4

5 7 EP B The method of providing location-based reference 32, wherein: said current location of said subscriber device (1) is determined using a network generated location based on a centroid of a cell site sector s radio frequency (RF) polygon. 7. The method of providing location-based reference 1, wherein: 11. The system to provide location-based reference information in a wireless network according to claim, wherein: at least two auxiliary digits are suffixed to said dialed directory assistance digits. 12. The system to provide location-based reference information in a wireless network according to claim, wherein: said information telephone call is initiated with said dialed directory assistance digits. said current location of said subscriber device (1) is determined using a time difference of arrival of wireless signals from said subscriber device (1). 8. The method of providing location-based reference 1, wherein: said current location of said subscriber device (1) is determined using time of arrival of a wireless signal from said subscriber device (1). 9. The method of providing location-based reference 1, wherein: said current location of said subscriber device (1) is determined using a known location of a cell/sector servicing said subscriber device (1).. A system to provide location-based reference information in a wireless network, the system CHARAC- TERIZED as comprising: a receiver to receive a request for location information from a subscriber device (1), said request for location information comprising dialed directory assistance digits suffixed by at least one auxiliary digit associated with said requested location information; a location-based wireless service (4) queried in response to said request for location information to automatically obtain a current location of said subscriber device (1); a retriever to retrieve said requested location information associated with said obtained current location and selected using said at least one auxiliary digit; and a transmitter to transmit said requested location information to said subscriber device (1) Patentansprüche 1. Verfahren zum Bereitstellen von ortsgestützten Referenzinformationen, wobei das Verfahren dadurch gekennzeichnet ist, dass es Folgendes beinhaltet: Empfangen einer Anforderung von Ortsinformationen von einem Teilnehmergerät (1), wobei die genannte Anforderung von Ortsinformationen Wahlverzeichnishilfsziffern beinhaltet, die als Suffix wenigstens eine mit den genannten angeforderten Ortsinformationen assoziierte Zusatzziffer haben; Abfragen eines ortsgestützten drahtlosen Dienstes (4) als Reaktion auf die genannte Anforderung von Ortsinformationen, um automatisch einen aktuellen Ort des genannten Teilnehmergeräts (1) zu erhalten; Abrufen der genannten angeforderten Ortsinformationen, die mit dem genannten erhaltenen aktuellen Ort assoziiert sind und mit der genannten wenigstens einen Zusatzziffer gewählt werden; und Senden der genannten angeforderten Ortsinformationen zu dem genannten Teilnehmergerät (1). 2. Verfahren zum Bereitstellen von ortsgestützten Referenzinformationen nach Anspruch 1, wobei: wenigstens zwei Zusatzziffern einen Suffix an dem genannten Ende der genannten Wahlverzeichnishilfsziffern haben. 3. Verfahren zum Bereitstellen von ortsgestützten Referenzinformationen nach Anspruch 1, wobei: der genannte Informationstelefonanruf mit den genannten Wahlverzeichnishilfsziffern eingeleitet wird.

6 9 EP B1 4. Verfahren zum Bereitstellen von ortsgestützten Referenzinformationen nach Anspruch 1, wobei: der genannte aktuelle Ort des genannten Teilnehmergeräts (1) anhand von drahtloser oder zellulärer Netzwerksignalisierung erhalten wird.. Verfahren zum Bereitstellen von ortsgestützten Referenzinformationen nach Anspruch 2, wobei: der genannte aktuelle Ort des genannten Teilnehmergeräts (1) anhand eines Ankunftswinkels eines drahtlosen Signals von dem genannten Teilnehmergerät (1) ermittelt wird. 6. Verfahren zum Bereitstellen von ortsgestützten Referenzinformationen nach Anspruch 32, wobei: der genannte aktuelle Ort des genannten Teilnehmergeräts (1) anhand eines netzwerkerzeugten Orts auf der Basis eines Zentroids eines Polygons der Funkfrequenz (RF) eines Zellenstandortsektors ermittelt wird. 7. Verfahren zum Bereitstellen von ortsgestützten Referenzinformationen nach Anspruch 1, wobei: der genannte aktuelle Ort des genannten Teilnehmergeräts (1) anhand einer Ankunftszeitdifferenz von drahtlosen Signalen von dem genannten Teilnehmergeräts (1) ermittelt wird dass es Folgendes umfasst: einen Empfänger zum Empfangen einer Anforderung von Ortsinformationen von einem Teilnehmergerät (1), wobei die genannte Anforderung von Ortsinformationen Wahlverzeichnishilfsziffern beinhaltet, die als Suffix wenigstens eine Zusatzziffer haben, die mit den genannten angeforderten Ortsinformationen assoziiert ist; einen ortsgestützten drahtlosen Dienst (4), der als Reaktion auf die genannte Anforderung von Ortsinformationen abgefragt wird, um automatisch einen aktuellen Ort des genannten Teilnehmergeräts (1) zu erhalten; einen Retriever zum Abrufen der genannten angeforderten Ortsinformationen, die mit dem genannten erhaltenen aktuellen Ort assoziiert sind und über die genannte wenigstens eine Zusatzziffer gewählt werden; und einen Sender zum Senden der genannten angeforderten Ortsinformationen zu dem genannten Teilnehmergerät (1). 11. System zum Bereitstellen von ortsgestützten Referenzinformationen nach Anspruch, wobei: wenigstens zwei Zusatzziffern einen Suffix für die genannten Wahlverzeichnishilfsziffern bilden. 12. System zum Bereitstellen von ortsgestützten Referenzinformationen nach Anspruch, wobei: 8. Verfahren zum Bereitstellen von ortsgestützten Referenzinformationen nach Anspruch 1, wobei: der genannte aktuelle Ort des genannten Teilnehmergeräts (1) anhand der Ankunftszeit eines drahtlosen Signals von dem genannten Teilnehmergerät (1) ermittelt wird. 9. Verfahren zum Bereitstellen von ortsgestützten Referenzinformationen nach Anspruch 1, wobei: der genannte aktuelle Ort des genannten Teilnehmergeräts (1) anhand eines bekannten Ortes eines/einer Zelle/Sektors ermittelt wird, die/der das genannte Teilnehmergerät (1) bedient.. System zum Bereitstellen von ortsgestützten Referenzinformationen, wobei das System dadurch gekennzeichnet ist, 4 0 der genannte Informationstelefonanruf mit den genannten Wahlverzeichnishilfsziffern eingeleitet wird. Revendications 1. Un procédé pour fournir des informations de référence basées sur l emplacement dans un réseau sans fil, le procédé CARACTÉRISÉ par : la réception d une demande d informations sur l emplacement provenant d un dispositif d abonné (1), ladite demande d informations sur l emplacement comprenant des chiffres de l assistance annuaire suffixés par au moins un chiffre auxiliaire associé avec lesdites informations demandées sur l emplacement ; interroger un service sans fil basé sur l emplacement (4) en réponse à ladite demande d informations sur l emplacement pour obtenir automatiquement un emplacement actuel dudit dis- 6

7 11 EP B1 12 positif d abonné (1) ; récupérer lesdites informations demandées sur l emplacement associées avec ledit emplacement actuel obtenu, et sélectionnées en utilisant ledit au moins un chiffre auxiliaire ; et transmettre lesdites informations demandées sur l emplacement audit dispositif de l abonné (1). 2. Le procédé pour fournir des informations de référence fil selon la revendication 1, dans lequel : au moins deux chiffres auxiliaires sont suffixés à ladite fin desdits chiffres de l assistance annuaire. 3. Le procédé pour fournir des informations de référence fil selon la revendication 1, dans lequel : 1 ledit emplacement actuel dudit dispositif d abonné (1) est déterminé en utilisant une différence de temps d arrivée des signaux sans fil provenant dudit dispositif d abonné (1). 8. Le procédé pour fournir des informations de référence fil selon la revendication 1, dans lequel : ledit emplacement actuel dudit dispositif d abonné (1) est déterminé en utilisant le temps d arrivée d un signal sans fil provenant dudit dispositif d abonné (1). 9. Le procédé pour fournir des informations de référence fil selon la revendication 1, dans lequel : ledit emplacement actuel dudit dispositif d abonné (1) est déterminé en utilisant un emplacement connu d une cellule / d un secteur desservant ledit dispositif d abonné (1). ledit appel téléphonique d informations est enclenché par lesdits chiffres de l assistance annuaire. 4. Le procédé pour fournir des informations de référence fil selon la revendication 1, dans lequel : ledit emplacement actuel dudit dispositif d abonné (1) est obtenu en utilisant la signalisation d un réseau sans fil ou cellulaire.. Le procédé pour fournir des informations de référence fil selon la revendication 2, dans lequel : ledit emplacement actuel dudit dispositif d abonné (1) est déterminé en utilisant un angle d arrivée d un signal sans fil provenant dudit dispositif d abonné (1). 6. Le procédé pour fournir des informations de référence fil selon la revendication 32, dans lequel : ledit emplacement actuel dudit dispositif d abonné (1) est déterminé en utilisant un emplacement généré par un réseau basé sur un centroïde d un polygone de radiofréquences (RF) d un secteur de site de cellule. 7. Le procédé pour fournir des informations de référence fil selon la revendication 1, dans lequel : Un système pour fournir des informations de référence basées sur l emplacement dans un réseau sans fil, le système CARACTÉRISÉ en ce qu il comprend : un récepteur pour recevoir une demande d informations sur l emplacement provenant d un dispositif d abonné (1), ladite demande d informations sur l emplacement comprenant des chiffres de l assistance annuaire suffixés par au moins un chiffre auxiliaire associé avec lesdites informations demandées sur l emplacement ; un service sans fil basé sur l emplacement (4) interrogé en réponse à ladite demande d informations sur l emplacement pour obtenir automatiquement un emplacement actuel dudit dispositif d abonné (1) ; un récupérateur pour récupérer lesdites informations demandées sur l emplacement associées avec ledit emplacement actuel obtenu, et sélectionnées en utilisant ledit au moins un chiffre auxiliaire ; et un émetteur pour transmettre lesdites informations demandées audit dispositif d abonné (1). 11. Le système pour fournir des informations de référence basées sur l emplacement dans un réseau sans fil selon la revendication, dans lequel : au moins deux chiffres auxiliaires sont suffixés auxdits chiffres de l assistance annuaire. 12. Le système pour fournir des informations de référence basées sur l emplacement dans un réseau sans fil selon la revendication, dans lequel : 7

8 13 EP B1 14 ledit appel téléphonique d informations est enclenché par lesdits chiffres de l assistance annuaire

9 EP B1 9

10 EP B1

11 EP B1 11

12 EP B1 12

13 EP B1 REFERENCES CITED IN THE DESCRIPTION This list of references cited by the applicant is for the reader s convenience only. It does not form part of the European patent document. Even though great care has been taken in compiling the references, errors or omissions cannot be excluded and the EPO disclaims all liability in this regard. Patent documents cited in the description US B [0007] [0008] WO 0683 A [0007] [0009] 13