DE20280091U1 - Device for forwarding short messages - Google Patents

Description

- 1 facility
for forwarding text messages

The invention relates to a device for forwarding short messages to a mobile terminal, for example a mobile telephone with a short message centre for transmitting the short message to the mobile terminal via a switching unit assigned to the subscriber number of the mobile terminal and with a register which contains the information about the switching unit assigned to the subscriber number of the mobile terminal, wherein a computer is provided which
Forwarding the text message to a virtual subscriber number of the mobile device, which converts the virtual subscriber number into the actual subscriber number of the mobile device
and the information determined via the register associated with the subscriber number of the mobile terminal about the switching unit associated with the mobile terminal and a
Subscriber assigned identifier to the short message center
transmitted.

A data service was created in GSM (Global Systems for Mobile Communication)-based mobile phone networks to transmit short messages, known as SMS (Short Messages System). This data service is used to send short messages, limited to 160 alphanumeric characters.
Character limited messages between mobile phones or
Terminals quickly and cheaply. In addition to sending
In addition to short text messages, multimedia objects such as ring tones or images can also be transmitted from one terminal to another. The term terminal or Short Message Entity (SME) can be understood as a mobile phone, a handheld computer, a personal computer or a similar device with which short messages can be sent and received. For the purpose of transmitting short messages, the user enters, for example,
of a mobile phone on the keyboard a short
text message and then sends it to the phone number
of the recipient. If the message is on the mobile phone
of the recipient, the recipient is notified via an audio or vibration signal, after which he can read the message on the display of his mobile phone.

Normally, when transmitting a text message from one mobile device to another, the

A short message is sent to a short message service center (SMSC - Short Message Service Center) of the respective mobile phone network operator and temporarily stored there. The short message service center attempts to forward the short message to the recipient by sending a request, the so-called Send Routing Information (SRI), to a register (Home Location Register HLR). The register (HLR) contains information about the subscribers. The recipient can be located in the so-called Home Location Register (HLR) using the recipient's subscriber number (MSISDN). The HLR register responds to the short message service center with information about a corresponding switching unit, the so-called Mobile Switching Center (MSC), via which the recipient can be reached, as well as the identifier assigned to the subscriber (IMSI - International Mobile Subscriber Identification). The corresponding switching unit searches for the subscriber or the corresponding base station in the cell in which the recipient's mobile device is currently located and sends the short message to this base station, from which it is finally transmitted to the mobile phone. The procedural steps within the mobile phone network usually follow the so-called SS7 (Signalling System No. 7) protocol, a standard defined in the GSM specification that concerns the transmission protocol for the transmission of short messages between mobile phones.

Mobile phone network operators offer so-called virtual numbers, which can be used to reach a mobile device, particularly a mobile phone, within a virtual network. For example, mobile phones on a private branch exchange can be reached using direct dial numbers with fewer digits than the actual mobile phone numbers. The use of such virtual subscriber numbers is indicated, for example, by a digit reserved for this purpose at a specific position on the mobile phone number. This means that when a virtual subscriber number is dialed, the sender's phone number automatically recognizes that it is such a virtual subscriber number, and the appropriate steps are taken when connecting the calls.

However, a problem with such virtual subscriber numbers occurs when sending text messages. While for every real subscriber number within the mobile network

network, which contains the necessary information about the corresponding switching unit (MSC) of the subscriber, no such register exists for virtual subscriber numbers. As a result, short messages cannot be sent to virtual subscriber numbers.

A similar problem occurs when sending text messages from external networks to a recipient in the mobile device's home network.

US 5 768 509 A, for example, describes a method for sending short messages via telecommunications networks and a corresponding short message center. The method filters out short messages and only transmits a short message if it is determined that it may be delivered. Otherwise, the short messages temporarily stored in the short message center are deleted. For this purpose, the short message center does not maintain its own subscriber administration or subscriber database, but obtains the subscriber data from the Home Location Register.

A method of the type in question is described, for example, in WO 99/29125 A2, in which the virtual subscriber numbers are assigned to the actual subscriber numbers in accordance with the signaling system No. 7 (SS7 Signaling System No. 7) commonly used in telecommunications. The disadvantage here is that the SS7 protocol is not yet widely used in data networks outside of telecommunications and thus access to databases outside of the SS7 network is not possible.

The aim of the present invention is to create a device which, even when virtual subscriber numbers are assigned, enables text messages to be forwarded to a mobile terminal and allows access to databases in various data networks to convert the virtual subscriber numbers into real subscriber numbers. In addition, the device should be easy to implement so that greater acceptance and a broader application of so-called virtual networks can be achieved.

The object of the invention is achieved by providing a module for connection to data networks such as the Internet or Local Area Networks (LAN). The corresponding process steps run on the computer, preferably in the form of a corresponding computer program. The transmission

the table values for converting the virtual subscriber number into the actual subscriber number (MSISDN) in the TCP/IP (Transmission Control Protocol/Internet Protocol)-based protocol. This also enables text messages to be sent to mobile devices with virtual subscriber numbers, with the virtual subscriber number being assigned to the real subscriber number using TCP/IP-based protocols. These protocols represent a standard within computer networks, particularly the Internet. This makes it possible to access databases located in standard data networks such as the Internet for the purpose of assigning virtual subscriber numbers to real subscriber numbers. The database can, for example, be an SQL (System Query Language) database or databases that allow queries using the HTTP (Hyper Text Transfer Protocol) protocol or the HTTPS (Hyper Text Transfer Protocol Secured Socket Layer) protocol. The data format can be based on HTML (Hyper Text Mark Up Language) or XML (Extensible Mark Up Language). In particular, the LDAP (Lightweight Directory Access Protocol) protocol can be used to access the data. This makes it possible for the desired data for assigning the virtual subscriber numbers to the real subscriber numbers to be accessible via standard protocols and access mechanisms that are common in data networks. After the virtual subscriber number has been converted into the actual subscriber number, a query is sent in a known manner to the associated home location register of the actual subscriber number, to which this responds with appropriate information about the switching unit and the identifier assigned to the subscriber (IMSI), via which the mobile device can be reached. The text message is then sent via the text message center to the appropriate switching unit and then to the recipient's mobile device. A home location register is simulated for the virtual subscriber number. This is therefore also referred to as a virtual home location register (vHLR), which converts the virtual subscriber number into the actual subscriber number. As a result, the virtual Home Location Register simulates a short message center, which sends a request (Send Routing Information - SRI) to the real Home Location Register of the real subscriber number

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sends, whereupon the real home location register responds with corresponding information to the virtual home location register, which forwards this response to the short message center. The short message center then sends the temporarily stored short message in the known manner to the corresponding switching unit and then to the recipient's mobile device. The computer naturally has corresponding connections to receiving and transmitting devices in the relevant mobile network, so that sent short messages or queries can be directed to the computer to determine the switching center of the receiving mobile device. The module for connecting to data networks thus enables access to databases for converting virtual subscriber numbers into real subscriber numbers via TCP/IP protocols. The virtual subscriber number of the mobile device can be converted into the actual subscriber number using a mathematical calculation rule. When using a corresponding formula, no database or similar is required to store all possible subscriber numbers. Furthermore, the virtual subscriber number of the mobile device can be converted into the actual subscriber number using a code or coding process.

To detect the presence of a virtual subscriber number of the mobile device, at least one position of the actual subscriber number can be assigned a predetermined number. This allows the system to automatically recognize that it is a special subscriber number. By coding or assigning additional positions to the actual subscriber number, additional information about virtual subscriber numbers and the virtual network can be determined.

Advantageously, the query regarding the switching unit assigned to the subscriber is sent to the register and the information about the switching unit is transmitted to the short message center using the SS7 (Signalling System No.7) protocol. This protocol is an established standard within mobile telephony.

According to a further feature of the invention, a database is provided which is connected to the computer and contains the virtual subscriber numbers and the associated actual subscriber numbers. Advantageously, the database

integrated into the computer.

Furthermore, a test module, preferably integrated in the computer, can be provided to verify the subscriber number of the mobile terminal. This test module checks whether the actual subscriber number of the mobile terminal also exists and, if a non-existent subscriber number is present, initiates appropriate process steps, such as sending a corresponding error message to the sending mobile terminal. An unknown subscriber number can occur, for example, when converting an incorrect, unassigned virtual subscriber number using the method according to the invention.

A test module, preferably also integrated in the computer, can also be provided to verify the information about the switching unit assigned to the mobile device and/or the identifier assigned to the subscriber (IMSI). If an error occurs when transmitting the relevant information via the switching unit, an error message can be sent to the sending short message center. If the recipient's mobile device cannot be reached, the short message to be sent can be temporarily stored together with any other information and a new attempt to send it can be made at a later time. In addition, an appropriate error message can be sent to the sender of the short message. After a certain number of send attempts have been made, the short message can be automatically deleted. If an error occurs when determining the information about the switching unit of the mobile device or the identifier assigned to the subscriber (IMSI), an error message can be sent to the sending short message center. The sender of the short message can also be informed that the short message could not be sent correctly to the recipient.

The invention is explained in more detail below using embodiments with reference to the drawings.

Shown here:

Fig. 1 is a schematic block diagram illustrating the transmission of short messages between two mobile

telephones according to the state of the art;

Fig. 2 is a schematic block diagram illustrating the forwarding of short messages to mobile phones with virtual subscriber numbers according to the present invention;

Fig. 3 is a schematic diagram illustrating the process steps involved in forwarding short messages;

Fig. 4 is a schematic block diagram of the system components of the method for forwarding short messages;

Fig. 5 is a flow chart of a method for forwarding short messages to mobile phones with virtual subscriber numbers; and

Fig. 6 is a schematic block diagram illustrating the connection of the SS7 network to a TCP/IP network.

Fig. 1 shows a schematic block diagram to illustrate the transmission of short messages SMS from a mobile terminal 1 to another mobile terminal 2 within a mobile network 3. The sending mobile terminal 1 generates a short message SMS and transmits it to the short message center (Short Messages Service Center SMSC) 4 of the mobile network 3. The short message center 4 sends a request, the so-called Send Routing Information (SRI), to a register 5, the Home Location Register (HLR), which determines the current location of the terminal 2 based on the real subscriber number of the mobile terminal 2 to which the short message SMS is to be sent and responds with corresponding information SRI-RR to the short message center 4. The information SRI-RR in register 5 contains data about the current location of the called mobile terminal 2, which makes it possible to determine to which switching unit (MSC Mobile Switching Center) the short message SMS is to be transmitted. The short message center 4 sends the temporarily stored short message SMS together with the information received from the register 5 to the associated switching unit 6, which finally forwards the short message to the mobile terminal 2. If a short message SMS is sent from a mobile terminal 1 to a mobile terminal 2 with a virtual subscriber number, no corresponding register exists for this mobile terminal 2, so that the transmission of the short message SMS cannot be carried out.

Fig. 2 now shows a schematic block diagram for the

Transmission of a short message SMS from a mobile device in a foreign mobile network 7 to a mobile device 2 in the mobile network 3 of the mobile device 2. The short message SMS is forwarded to the short message center 4 of the mobile network 7 and from there a request (Send Routing Information SRI) is sent to a specially set up register 8, the so-called virtual home location register. In this vHLR register 8, which is formed by a computer, the virtual subscriber number of the mobile device 2 is converted into the real subscriber number. For this purpose, a database 9 can be provided in which the virtual and actual subscriber numbers are stored in pairs and can be queried by the computer 8. According to the invention, communication between the register or computer 8 and the database 9 takes place in the TCP/IP (Transmission Control Protocol/Internet Protocol) based protocol. Once the real subscriber number of the mobile terminal 2 is known, the request (Send Routing Information) is transmitted to the associated register 5, which responds to the computer 8 with the corresponding information SRI-RR. This information is forwarded to the short message center 4 of the mobile network 7, whereupon the short message SMS is sent to the corresponding switching center 6 of the mobile network 3 of the mobile terminal 2 and finally to the mobile terminal 2. The computer 8 has the function of a virtual home location register with respect to the short message center 4 and the function of a short message center with respect to the home location register 5 of the real subscriber number of the mobile terminal 2. The database 9 can be integrated in the computer 8. Instead of assigning the virtual and real subscriber numbers in a database 9, a conversion can also be carried out using a mathematical calculation rule or a coding method.

Fig. 3 shows a diagram to illustrate the process steps when forwarding a short message from a short message center 4 (SMSC) to the switching unit 6 of a mobile terminal 2 with a virtual subscriber number. The short message center 4 transmits a request 10, the Send Routing Information (SRI), to the computer 8, which then sends a request 11 GET MSISDN (Mobile Station International Subscriber/Service Data Number) to announce the MSISDN.

No. to the database 9, whereupon the MSISDN No. is sent back to the computer 8 as a response 12. In the next process step, an SRI request 13 (Send Routing Information) is sent to the register 5 assigned to the actual subscriber number, and the information about the actual location of the mobile terminal 2 is sent back as a response 14. This so-called IMSI identification (International Mobile Subscriber Identification) is transmitted together with the MSC/VLR-ID identification (Mobile Switching Center/Visitor Location Register Identification) in accordance with step 15 to the short message center 4, whereupon the latter transmits the short message SMS to the corresponding switching unit 6 via the send command 16 (FSM - Forward Short Message). After the short message SMS has been successfully forwarded to the mobile terminal 2, a confirmation 17 OK is sent from the switching unit 6 to the short message center 4. In the event of an error during transmission, a corresponding error message NOK is sent to the short message center 4 instead of a confirmation. The flow chart shown does not show further error routines, for example if the mobile device cannot be reached or similar.

Fig. 4 shows the system components of the present method. These consist of a so-called vHLR process 18 and a database process 19. A signaling interface 20, which is connected to the vHLR process 18, is used to receive the requests to the computer 8 and to send the answers to these requests. The processes between modules 18 and 20 run in the so-called SS7 (Signalling System No. 7) protocol, which is a common standard in GSM networks. The module 20, the so-called SS7 protocol stack, contains the layers MAP - Mobile Application Part, TCAP - Transaction Capabilities, SCCT - Signaling Connection Control Part, MTP-3 and MTP-2 MTP - Message Transfer Part. The database process 19 is used to convert the virtual subscriber numbers into the actual subscriber numbers according to the invention, with communication taking place with an Internet protocol module 21 in the TCP/IP (Transmission Control Protocol/Internet Protocol) based protocol. Module 21 provides a connection to data networks such as the Internet or Local Area Networks (LAN). Module 21, the so-called Internet Protocol Stack, consists of the parts TCP (Transmission Control Protocol),

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IP (Internet Protocol) and UDP (User Datagram Protocol), which is used for datagram services.

Fig. 5 shows a flow chart of a method for forwarding text messages to mobile phones with virtual subscriber numbers. In step 100, the process begins in the virtual home location register according to the invention or the corresponding computer. According to step 101, a request, the send routing information, is received from the mobile network. According to step 102, the virtual subscriber number is converted into a real subscriber number, whereby a database is queried according to step 103. As an alternative to querying a database, a conversion can also be carried out according to a formula or a coding method. In step 104 of the method, a query is made as to whether the conversion of the subscriber number was successful; if not, a response is sent to the sending text message center according to step 105 that the subscriber is unknown and the method is terminated according to step 106. If the conversion was correct, a request (send routing information) is sent to the real home location register according to the real subscriber number of the mobile terminal in step 107. According to step 108, the request (Send Routing Information) is received by the register (HLR) and a response is sent from the register to the virtual home location register. This response contains the corresponding information, the so-called IMSI (International Mobile Subscriber Identification), together with the MSC/VLR ID (Mobile Switching Center/Visitor Location Register Identification). The query according to step 109 asks whether an error has occurred, in which case an error code is sent to the sending short message center according to step 110 and the process is ended according to step 111. If no error has occurred, the corresponding information (IMSI and VLR/MSC) is sent to the short message center of the mobile device to be sent according to step 112 and finally the process running at the virtual home location register is ended according to step 113.

Fig. 6 shows a schematic block diagram of the inventive connection of a mobile radio network 3 to a data network 22 for the purpose of converting virtual subscriber numbers into real subscriber numbers with the aid of databases 9,

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which are accessible via common TCP/IP protocols. Accordingly, when a short message (SMS) is sent from a mobile terminal 1 in a mobile network 3 via the computer 8, the connection is established between the mobile network 3 in the SS7 protocol and the data network 22 in the TCP/IP protocol. The databases 9 can thus be accessed using SQLNET, HTTP, HTML or XML, for example.

If a database 9 is available in the form of an SQL database, access to assign the virtual subscriber number to the real subscriber number can be carried out, for example, in the following form:

CONNECT MSISDNDATABASE

SELECT REALMSISDN FROM MSISDNDATA WHERE VIRTUALMSISDN="xxxx"

Where xxxx stands for the desired virtual subscriber number MSISDN and the real subscriber number MSISDN is supplied via the REALMSISDN command.

If there is a database that can be queried using the HTTP or HTTPS protocols, access to the subscriber data can be established, for example, via a TCP/IP connection to the HTTP port of the subscriber number database server and the request can be made in the following form:

GET http://conversionserver/convertmsisdn?msisdn=1234567 HTTP/1.1

Host: conversionserver

The subscriber number database server is called "conversion server" and the desired virtual subscriber number MSISDN is identified with "1234567". The server then supplies the desired real subscriber number MSISDN in its &EEacgr;&Tgr;&Tgr;&Rgr; response in the following form:

HTTP/1.1 200 OK

Server: Microsoft IIS/4.0

Date: Tue, 02 Apr 2002 20:45:29 GMT Content-Type: text/html

Accept ranges: bytes

Last Modified: Wed, 08 Nov 2000 20:21:47 GMT

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ETag:L "felef084cl49c01:9277" Content Length:

<html> <head> <meta http-equiv="Content-Type" content="text/html; charset=iso-8859-l"> <title>msisdn data</title> </head> <body> < msisdn>98765432</msisdn> </body> </html>

where "98765432" represents the real subscriber number. The HTML display format was used. The XML format can also be used.

When using an LDAP server to query the data, the search request to the LDAP server also includes the virtual subscriber number MSISDN as a search key and the result in the response from the LDAP server contains the real subscriber number MSISDN being sought.

The device according to the invention is therefore characterized in that the assignment of the virtual subscriber numbers to a corresponding real subscriber number can be read from a database which is accessed via TCP/IP protocols.

Claims (5)

1. Device for forwarding short messages (SMS) to a mobile terminal ( 2 ), for example a mobile phone, with a short message center ( 4 ) for transmitting the short message (SMS) to the mobile terminal ( 2 ) via a switching unit ( 6 ) assigned to the subscriber number (MSISDN) of the mobile terminal ( 2 ), and with a register ( 5 ) which contains the information about the switching unit ( 6 ) assigned to the subscriber number (MSISDN) of the mobile terminal ( 2 ), wherein a computer ( 8 ) is provided which, when forwarding the short message (SMS) to a virtual subscriber number of the mobile terminal ( 2 ), converts the virtual subscriber number into the actual subscriber number (MSISDN) of the mobile terminal ( 2 ) and uses the information about the mobile terminal ( 2 ) determined via the register ( 5 ) assigned to the subscriber number (MSISDN) of the mobile terminal ( 2 ) assigned switching unit ( 6 ) and an identifier assigned to the subscriber (IMSI) to the short message center ( 4 ), characterized in that a module ( 21 ) is provided for connection to data networks, such as the Internet or Local Area Networks (LAN). 2. Device according to claim 1, characterized in that a database ( 9 ) is connected to the computer ( 8 ), which database ( 9 ) contains the virtual subscriber numbers and the associated actual subscriber numbers (MSISDN) of the mobile terminal ( 2 ). 3. Device according to claim 2, characterized in that the database ( 9 ) is integrated in the computer ( 8 ). 4. Device according to one of claims 1 to 3, characterized in that a test module, preferably integrated in the computer ( 8 ), is provided for verifying the subscriber number of the mobile terminal ( 2 ). 5. Device according to one of claims 1 to 4, characterized in that a test module, preferably integrated in the computer ( 8 ), is provided for verifying the information about the switching unit ( 6 ) assigned to the mobile terminal ( 2 ) and/or the identifier (IMSI) assigned to the subscriber.