METHOD AND SYSTEM FOR ROAMING OF A MOBILE COMMUNICATIONS UNIT
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Accused Products
Abstract
Method when roaming by a mobile communication device (40) including a SIM card (41) identifying itself using an IMSI roams between a home network (10) and one or several visited networks (20,26,30,36), which networks are interconnected by a PSTN (1). The method includes the steps of:
- a) storing on the SIM card (41) a first IMSI associated with a first collaborating network (20);
- b) initiating a location update procedure using the first IMSI;
- c) triggered by the location update procedure and based on the first IMSI, causing an STP (Signal Transfer Point) (25) of the first collaborating network (20) to send a location update message to an ITP (Internet Transfer Point) (29); and
- d) causing the first ITP (29) to forward the message to an STP (16) of the home network (10) via a wide area network (6) and not using the PSTN (1).
45 Citations
33 Claims
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1-18. -18. (canceled)
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19. Method for use when a mobile communication device (40) roams between a mobile communication home network (10) in a home country (3) and one or several mobile communication networks (20,26,30,36) in one or several visited countries (4,5), which home network (10) and networks (20,26,30,36) in said visited countries are interconnected by a PSTN (Public Switched Telephone Network) (1) operated by one or several PSTN operators (7,8,9), via which PSTN (1) telephone signaling can be performed during roaming using a telephony signaling protocol, which mobile communication device comprises a Subscriber Identity Module (SIM) card (41) identifying itself to each network using an International Mobile Subscriber Identity (IMSI), wherein the method comprises the steps of
a) storing on the SIM card (41) a first visited country IMSI which is associated with a first collaborating mobile communication network (20) in the first visited country (4), and using it for network identification of the SIM card (41); -
b) when the mobile device (40) is located within the coverage area of the first collaborating network (20), causing the mobile device (40) to initiate a location update procedure using the first visited country IMSI; wherein the method further comprises the subsequent steps of c) triggered by the said location update procedure and based on the first visited country IMSI used therein, causing the first collaborating network (20) to investigate the contents of the said first IMSI, and, depending on the contents of said first IMSI, causing a first STP (Signal Transfer Point) (25) of the first collaborating network (20) to send a location update message to a first ITP (Internet Transfer Point) (29) without using the PSTN (1); d) in case the location update message was sent to the first ITP (29), causing the first ITP (29) to simply forward the location update message to a home ITP (17) via the internet (6) and not using the PSTN (1), and in turn causing the home ITP (17) to forward the location update message to a home STP (16) of the home network (10); and e) causing a subsequent signaling message addressed to the mobile device (40) and using the first visited country IMSI to be sent by the home STP (16) to the home ITP (17), which uses the first visited country IMSI to identify the first ITP (29) and then forwards the subsequent message to the first ITP (29), over the internet and without using the PSTN (1), whereupon the first IPT (29) forwards the subsequent message to the first STP (25) for distribution to the mobile device (40). - View Dependent Claims (20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30)
a2) triggered by the location update message, sending an instruction message over the air to the mobile device (40) to change, to the first visited country IMSI, the IMSI used for network identification of the SIM card (41); and a3) causing the mobile device (40) to store the first visited country IMSI on the SIM card (41) and to use it for network identification of the SIM card (41).
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21. Method according to claim 19, wherein the method comprises the additional steps of
e) causing the mobile device (40) to store an APN (Access Point Name) identifying a GGSN (Gateway GPRS Support Node) (13) in the home network (10); - and
f) upon a data connection attempt by the mobile device (40) using the APN, setting up an Internet data connection to the mobile device (40) via the GGSN (13) and an SGSN (Serving GPRS Support Node) (23) in the first collaborating network (20).
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22. Method according to claim 19, wherein, upon roaming from the coverage area of the first collaborating network (20) to the coverage area of a second visited network (36) in a second visited country (5) after step d) has been performed, the method comprises the additional steps
g) causing the mobile device (40) to change the IMSI used for network identification of the SIM card (41) back to the home IMSI and then to perform a device network refresh; -
h) triggered by a location update message resulting from the change of IMSI used for network identification and received by the home network (10), sending an instruction message over the air to the mobile device (40) to change, to a second visited country IMSI which is associated with a second collaborating mobile communication network (30) in the second visited country (5), the IMSI used for network identification of the SIM card (41); and i) resuming the method from step b), but with the second visited country (5), second collaborating network (30), second visited country IMSI and a second ITP (39) instead of first visited country (4), first collaborating network (20), first visited country IMSI and first ITP (29), respectively.
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23. Method according to claim 19, wherein, in steps c) and d), the first visited country IMSI is not modified.
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24. Method according to claim 19, wherein the first ITP (29) is located in the first visited country (4), and wherein the home ITP (17) is arranged in the home country (3).
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25. Method according to claim 19, wherein a server comprising a HLR (Home Location Registry) (18) is connected to, but arranged externally to, the home network (10), and wherein, in step d), the home network (10) forwards the location update message to the HLR (18) based upon the IMSI contained in the location update message.
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26. Method according to claim 19, wherein all of the said IMSI codes except possibly the home IMSI are caused to be associated with a setting in the respective HLR (12,22,32) with which the IMSI in question is associated making available data communication but not voice communication when roaming of the mobile device (40).
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27. Method according to claim 26, wherein the data communication to and from the mobile device (40) when being served by a collaborating network (20,30) is in the form of Internet access, and is passed on to the home network (10) using a roaming exchange (2) or an Internet tunnel.
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28. Method according to claim 19, wherein the first and/or second visited country IMSI codes are caused to belong to a respective plurality of IMSI codes, which plurality is associated with a respective visited country (4,5) and caused to contain less individual IMSI codes than the total number of users of the method, and wherein all IMSI codes in said plurality are caused to be associated with a HLR (22,32) of the respective collaborating network (20,30) in the respective visited country (4,5).
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29. Method according to claim 19, wherein the SIM card (41) is caused to be provided with a software application (42) arranged to monitor in which country the mobile device (40) is currently located, arranged to perform the said changes of the IMSI used for network identification and arranged to perform the said device network refresh performances.
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30. Method according to claim 29, wherein the software application (42) is caused to monitor in which country the mobile device (40) is currently located by reading the country codes present in available networks at the current location of the mobile device, and wherein a change of such country codes is interpreted as roaming of the mobile device (40).
- 31. System for providing mobile communication signaling connection to a mobile communication device (40) within the coverage area of a home network (10) in a home country (3) and one or several mobile communication networks (20,30) in one or several visited countries (4,5), between which networks (10,20,30) the mobile device (40) can roam and which networks (10,20,30) are interconnected by a PSTN (Public Switched Telephone Network) (1) operated by one or several PSTN operators (7,8,9), via which PSTN (1) telephone signaling can be performed during roaming using a telephony signaling protocol, which mobile communication device (40) comprises a Subscriber Identity Module (SIM) card (41) arranged to identify itself to a network using an International Mobile Subscriber Identity (IMSI), wherein the system comprises a first ITP (Internet Transfer Point) (29) as well as functionality in a first collaborating mobile communication network (20) in a first visited country (4), which functionality is arranged to investigate the contents in a first IMSI, which first IMSI is used in a location update procedure initiated by the mobile device (40) when it is present within the coverage area of the first collaborating network (20), and, based upon the said first IMSI which is used therein and depending on the contents in the said first IMSI, to cause an STP (Signal Transfer Point) (25) in the first collaborating network (20) to send a first location update message, comprising the first IMSI, to the first ITP (29), without using the PSTN (1), wherein the system further comprises a home ITP (17), wherein the first ITP (29) is arranged to receive the said first location update message from the STP (25), and wherein the first ITP (29) is further arranged to simply forward the first location update message, via the internet (6) and not using the PSTN (1), to the home ITP (17), and the home ITP (17) in turn being arranged to forward the location update message to a home STP (16) of the home network (10), wherein the home ITP (17) is arranged to receive a subsequent signaling message, addressed to the mobile device (40) and using the said first IMSI, from the home STP (16), and to use the said first IMSI to identify the first ITP (29) and then to forward the subsequent message to the first ITP (29), over the internet and without using the PSTN (1), whereupon the first IPT (29) is arranged to forward the subsequent message to the first STP (25) for distribution to the mobile device (40).
Specification