WO2001030095A1

WO2001030095A1 - System, method, and apparatus for supporting thin client data communications using r-data messages on cellular digital circuit switched bearer

Info

Publication number: WO2001030095A1
Application number: PCT/SE2000/001907
Authority: WO
Inventors: Donald Joong
Original assignee: Telefonaktiebolaget Lm Ericsson (Publ)
Priority date: 1999-10-20
Filing date: 2000-10-03
Publication date: 2001-04-26
Also published as: AU1181301A

Abstract

Upon receiving a data communication at a WAP gateway (140), a home location register ('HLR' (126)) is queried to determine a mobile switching center ('MSC' (120)) currently serving a wireless client (105) to whom the data communication is addressed. The data communication is then sent (330) in one or more ANSI-41/SS7 messages (312) to the serving MSC along with a unique teleservice identifier that identifies the data communications for delivery to the wireless client over a traffic channel instead of a control channel. Responsive thereto, the serving MSC directs the base station serving (125) the wireless client to especially allocate (348) a traffic channel connection to the wireless client in the absence of a concurrently being handled voice call. The serving MSC then constructs (343) one or more R-Data messages containing the data communication for transmission to the addressee wireless client over the circuit switched call comprising the especially allocated traffic channel.

Description

SYSTEM, METHOD, AND APPARATUS FOR SUPPORTING THIN

CLIENT DATA COMMUNICATIONS USING R-DATA MESSAGES ON

CELLULAR DIGITAL CIRCUIT SWITCHED BEARER

BACKGROUND OF THE INVENTION

Technical Field of the Invention

The present invention relates to telecommunications, and more particularly, to wireless data communications.

Description of Related Art

Advances in microelectronic technology have provided numerous portable computer-like devices. Portable computer-like devices include, for example, Personal Digital Assistants ("PDA"), Handheld Personal Computers ("HPC"), and smart phones.

A PDA is a handheld device which acts like an electronic organizer or diary. Among the functions performed by a PDA include small scale database applications, word processing, and appointment scheduling. A handheld personal computer, often referred to as a "palm top" provides personal computing in a handheld device. A smart phone is a microprocessor-controlled electronic telephone with a touch sensitive screen that interactively allows a user to place a call, send E-mail, and perform certain financial transactions.

Each of the foregoing devices provide a user with computer-like functions. However, in contrast to desktop computers, the foregoing devices are portable, thereby permitting a user to be mobile. Additionally, with advances in cellular telecommunications, the functions of the foregoing devices are expanded to client/server applications as well.

Computer systems are often connected to another computer system, typically a server, to form a computer network. When networked together, communication between the separate computer systems is possible. A server is a class of shared computers that are used to handle service common to all connected computers, known as clients. A common use of the server also includes handling and maintaining databases, and controlling access to voice mail, E-mail, or facsimile. Performing the foregoing functions at a server is advantageous because the same functions can be accessed from any of the clients which can be located about a large geographic area. Additionally, the functions can be simultaneously accessed by more than one client.

Clients often access servers using a wireline connection, such as through the public switched telephone network or a coaxial cable. However, advances in cellular telecommunications technology now allow clients to access servers using the mobile air interface. Because a wireline connection is no longer required, handheld computer-like devices can access server functions without restricting the user's mobility. A computer, or computer-like device accessing a server using the air interface is known as a wireless client.

When a client/server connection is established, any information to be transmitted must be formatted in a manner suitable for transmission. Additionally, information regarding various transmission parameters, such as the speed, ready to send signals, and ready to receive signals, must also be formatted and transmitted. Furthermore, the format of the information, as well as the convention for communicating the transmission parameters, must be known to the client or server receiving the transmission. The foregoing is accomplished using what is known in the art as a protocol. A protocol is a specific set of rules, procedures or conventions relating to the format and timing of data transmission. By establishing a common protocol between the client and server, information can be transmitted in a reliable manner understandable to both the client and the server.

The Wireless Application Protocol (WAP) was created to optimize data communication with wireless clients. Ideally, the WAP based service should be used on top of a packet switched transport such as Cellular Digital Packet Data (CDPD) or General Packet Radio Service (GPRS). However, due to standardization delays and the prohibitive cost of deploying a new packet radio service, wireless operators are looking at other transports to offer WAP based service. Another transport that has been considered is known as R-Data. R-Data messages provide very efficient two-way messaging capability to and from wireless clients and are the transport used by Cellular Messaging Teleservice (CMT) to provide Short Messaging Service (SMS). However, the amount of data that can be carried in an R-Data message is limited to between 160-239 octets (1280 - 1912 bits). Furthermore, R-Data messages are conventionally sent on a digital control channel (DCCH). A WAP session would accordingly require numerous R-Data messages to and from the wireless client over the DCCH and this would easily exhaust the DCCH ' s bandwidth capacity.

Although R-Data messages can be sent on a traffic channel, current specifications and proposals, such as the IS- 136 Air Interface Specification, only permit R-Data messages to be sent over the traffic channel when the wireless client/mobile phone is already engaged in a voice call. Accordingly, it would be advantageous if traffic channels could be specifically allocated to a wireless client/mobile phone for the sole purpose of sending R-Data messages.

SUMMARY OF THE INVENTION

The present invention is directed to a system, and method for transmitting a data communication to a wireless client, using R-Data messages transmitted over a wireless traffic channel especially set up for that purpose. Upon receiving the data communication at a node, the mobile switching center (MSC) serving the wireless client is determined by querying the home location register (HLR). The data communication is then forwarded to the serving MSC in the form of one or more ANSI-41/SS7 messages. In one embodiment, wherein a wireless application protocol (WAP) gateway and a short messaging service (SMS) message center functionality are integrated, the WAP gateway encapsulates the data communication into ANSI-41/SS7 messages and forwards those messages to the serving MSC. In another embodiment, wherein the WAP gateway and the SMS message center are separated, the WAP gateway forwards the data communication to the SMS message center which encapsulates the data communication into ANSI-41/SS7 messages and forwards those messages to the serving MSC.

Included in the transmission of the ANSI-41/SS7 messages to the serving MSC is a teleservice identifier which identifies those messages as being received pursuant to a WAP session. Upon receiving the ANSI-41/SS7 messages with the WAP session teleservice identifier, the serving MSC composes and formats one or more R-data messages to include the data communication and directs a serving base station to allocate a digital traffic channel especially and solely for the purpose of conveying the R-Data messages. The serving MSC then transmits the R-Data messages to the mobile station through the base station using the allocated digital traffic channel.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosed invention will be described with reference to the accompanying drawings, which show important sample embodiments of the invention and which are incorporated in the specification hereof by reference, wherein:

FIGURE 1 is a block diagram of a telecommunications system wherein the present invention can be practiced;

FIGURE 2 is a block diagram of a wireless application protocol (WAP) gateway configured in accordance with the present invention;

FIGURE 3 is a signal flow diagram describing the operation of the telecommunications system of FIGURE 1 where the SMS message center functionality is integrated with the WAP gateway; and

FIGURES 4 is a signal flow diagram describing the operation of the telecommunications system of FIGURE 1, where the SMS message center functionality is separated from the WAP gateway.

DETAILED DESCRIPTION OF THE PREFERRED EXEMPLARY EMBODIMENTS

Referring now to FIGURE 1 , there is illustrated a block diagram of an exemplary telecommunications system, referred to generally by the numeral 100, configured in accordance with the principles of the present invention. The telecommunications system includes a wireless client 105 which can establish a client/server connection with a server 110 and vice versa. Although servers 110 are accessible over a direct link, such as a local area network (LAN), servers 110 are also commonly accessed over the Internet 112 via an Internet connection 113. A server 110 with an Internet connection 113 can then be accessed by clients 105 with Internet 112 access anywhere in the world.

The wireless client 105 can include a computer, or computer like system, capable of establishing a communication link 115 over the air interface. The communication link 115 over the air interface is often supported by a cellular telephone network 116. The cellular telephone network 116 includes at least one area 117 served by a mobile switching center (MSC) 120. The MSC 120 is in communication with at least one Base Station 125. The base station 125 is the physical equipment that provides radio coverage to a particular geographical portion (known as a cell) of the area 117.

A cellular telecommunications network engages in radio communication with wireless clients and mobile phones using radio channels which include traffic channels and control channels (referred to as TCHs and DCCHs, respectively) in a digital telecommunications network. The control channel is used to communicate various control signals between the cellular telecommunications network and the wireless client/mobile phones such as an incoming call alert. The traffic channels are used during phone calls to broadcast voice quality signals to the wireless client/mobile phone.

The MSC 120 is associated with a HLR 126, which is a database for maintaining and storing subscriber information such as subscriber profiles, current location information, International Mobile Subscriber Identity (EMSI) numbers, and other administrative information. The subscriber services associated with the wireless client 105 are defined in a subscriber profile that is stored in the HLR 126. The subscriber profile identifies wireless clients 105 using Mobile Identification Numbers (MIN). The HLR 126 may be co-located with a given MSC 120, integrated with the MSC 120, or alternatively can service multiple MSCs 120.

The WAP was established to optimize data communications with wireless clients 105. However, a large portion of Internet 112 traffic is communicated pursuant to the hypertext transmission protocol (HTTP) using Internet Protocol (IP) addresses. In accordance with the WAP, the wireless client 105 accesses the Internet 112 via a WAP gateway 140. The WAP gateway 140 receives data communications over the Internet 112 in HTTP format, translates the data communications to WAP format, and forwards the translated data communications in WAP format to the wireless client 105 through the cellular network. Likewise, the WAP gateway 140 receives data communications from the wireless client 105 in WAP format, translates the data communications to HTTP format, and forwards the translated data communications to the Internet 112.

Referring now to FIGURE 2, there is illustrated a block diagram of an exemplary WAP gateway 140 in accordance with the present invention. The WAP gateway 140 maintains a table 205 correlating the MIN 210 associated with each wireless client 105 to IP addresses 215 for the clients. Those skilled in the art will recognize that the Internet uses IP addressing to address the destination of a communication. The IP addresses can be assigned when a subscriber at a wireless client 105 initially registers for Internet access. The IP addresses assigned to subscribers during initial registration are known as IP addresses. A server 110 contacting a wireless client 105 sends a communication to the IP address corresponding to the wireless client 105. The communication is received over the Internet 112 by the WAP gateway 140. A processor 220 within the WAP gateway 140 looks up the IP address 215 in the table 205 and determine the MIN 210 number associated therewith.

With further reference to FIGURE 1, the WAP gateway 140 uses the MIN 210 associated with the IP address 215 to send R-Data messages over an especially allocated traffic channel to the wireless client 105. The WAP protocol can be used on top of a transport known as R-Data. R-Data messages are the transport used by Cellular Messaging Teleservice (CMT) to provide short messaging service (SMS) to cellular mobile stations. Information is transmitted between the WAP gateway 140 and the wireless client 105 via an SMS message center ("MC") 142. The SMS message center 142 sends the information as one or more ANSI-41/SS7 messages transmitted to a serving mobile switching center 120 that formats the data communication as one or more R-data messages for delivery over the air interface to the wireless client 105. Alternatively, the SMS message center 142 functionality can be integrated with the WAP gateway 140, wherein the WAP gateway 140 encapsulates the data communication as one or more ANSI-41/SS7 messages transmitted to a serving mobile switching center 120 that formats the data communication as one or more R-data messages for delivery over the air interface to the wireless client 105. Upon receiving the R-Data messages, the wireless client 105 may process and display the data on a WAP browser at the wireless client 105. R-Data messages are normally sent on the DCCH to a client 105 by the serving MSC 120. However, to permit R-Data messages to be sent to the wireless client 105 on the traffic channel, the present invention proposes the conclusion of a new teleservice at the MSC 120 which identifies WAP session messages and responsive thereto especially allocates a traffic channel to support delivery of the messages to the wireless client.

Referring now to FIGURE 3, there is illustrated a signal flow diagram describing the operation of the telecommunications system of FIGURE 1 , where the SMS message center 142 functionality is integrated with the WAP gateway 140. The server 110 contacts the wireless client 105 by addressing a data communication to the IP address corresponding with the MEN of the wireless client 105, and sending the data communication (signal 305) to the WAP Gateway 140 via the Internet 112. The WAP gateway 140 receives the data communication (signal 305) and determines the MEN corresponding the received static IP address (action 310) to identify the addressee wireless client. The WAP gateway 140 then encapsulates the data communication (now comprising bearer data) into one or more ANSI-41/SS7 messages (action 312) and uses the MIN to transmit an SMS Request message (signal 315) to the HLR 126 to determine the MSC 120 serving the wireless client 105. The HLR 126 determines an address of the serving MSC 120 (action 320), and forwards the address of the serving MSC 120 to the WAP gateway 140 (signal 325). The WAP gateway 140 then addresses to the wireless client and sends one or more SMS Point-to-Point Invoke messages (signal 330) which includes a teleservice identification number indicating that the contained data communication (bearer data) is being sent in connection with a WAP session to the serving MSC 120. The teleservice identification number is mapped onto a Higher Level Protocol Indicator (HLPI).

The serving MSC 120 determines, to some selected degree of granularity, the location of the wireless client 105 by paging (signal 335) the wireless client having the identified MEN. The wireless client 105 responds by transmitting a page acknowledgment to the MSC 120 (signal 340). The serving MSC 120 uses the acknowledgment (signal 340) to determine the location of the wireless client 105 and the serving base station 125. The MSC 120, responsive to the teleservice identifier, then composes and formats one or more R-data messages to include the data communication (action 343) and directs (signal 345) the serving base station 125 to especially allocate (action 348) a digital traffic channel for use in making communication correction to the addressee wireless client 105. A circuit switched call is thus established between the MSC 120 and the wireless client 105. After the digital traffic channel is allocated, the MSC 120 forwards the created one or more R-Data messages (signal 350) to the wireless client over the especially allocated traffic channel. It should be noted that there is no concurrent addressee wireless client voice call being carried by the especially allocated traffic channel that is supporting the circuit switched call.

With reference now to FIGURE 4, there is illustrated a signal flow diagram where the SMS message center 142 functionality is separated from the WAP gateway 140. The server 110 contacts the wireless client 105 by addressing a data communication to the IP address corresponding with MIN of the wireless client 105, and sending the data communication (signal 405) to the WAP Gateway 140 via the Internet 112. The WAP gateway 140 receives the data communication (signal 405), determines the MIN corresponding the received static P address (action 410) to identify the addressee wireless client 105, and forwards (signal 415) the data communication to the SMS message center 142. The SMS message center 142 encapsulates the data communication (now comprising bearer data) into one or more ANSI-41/SS7 messages (action 420) and uses the MIN to transmit an SMS Request message (signal 425) to the HLR 126 to determine the MSC 120 serving the wireless client 105. The HLR 126 determines an address of the serving MSC 120 (action 430), and forwards the address of the serving MSC 120 to the SMS message center 142 (signal 435). The SMS message center 142 then addresses to the wireless client and sends one or more SMS Point-to-Point Invoke messages (signal 440) which include a teleservice identification number indicating that the contained data communication (bearer data) is being sent in connection with a WAP session to the serving MSC 120. The teleservice identification number is mapped onto a HLPI.

The serving MSC 120 determines, to some selected degree of granularity, the location of the wireless client 105 by paging (signal 445) the wireless client having the identified MIN. The wireless client 105 responds by transmitting a page acknowledgment to the MSC 120 (signal 450). The serving MSC 120 uses the acknowledgment (signal 450) to determine the location of the wireless client 105 and the serving base station 125. The MSC 120, responsive to the teleservice identifier, then composes and formats one or more R-data messages to include the data communication (action 453) and directs (signal 455) the serving base station 125 to especially allocate (action 460) a digital traffic channel for use in making a communication connection to the addressee wireless client 105. A circuit switched call is thus established between the MSC 120 and the wireless client 105. After the digital traffic channel is allocated, the MSC 120 forwards the one or more R-Data messages (signal 465) to the wireless client over the especially allocated traffic channel. It should be noted that there is no concurrent addressee wireless client voice call being carried by the especially allocated traffic channel that is supporting the circuit switched call.

Although the invention has been described with a certain degree of particularity, it should be recognized that elements thereof may be altered by persons skilled in the art without departing from the spirit and scope of the invention. Therefore, the invention is limited only by the following claims and their equivalents.

Claims

WHAT IS CLAIMED IS:

1. A method of transmitting a data communication to a wireless client said method comprising the steps of: constructing at least one R-Data message containing the data communication; especially allocating a wireless traffic channel connection to the wireless client in the absence of a currently being handled voice call for that wireless client; and transmitting said at least one R-Data message to said wireless client over said allocated wireless traffic channel.

2. The method of claim 1 further comprising the step of: determining a mobile switching center (MSC) serving the wireless client.

3. The method of claim 2 wherein the determining step further comprises the step of: sending a request to a home location register to determine the serving MSC.

4. The method of claim 2 further comprising the step of: receiving said data communication at a wireless application protocol ("WAP") gateway.

5. The method of claim 4 further comprising the step of: forwarding said data communication as an ANSI-41/SS7 message from said

WAP gateway to said serving MSC wherein the R-data messages are constructed.

6. The method of claim 5 wherein said forwarding step further comprises the steps of: forwarding said data communication from said WAP gateway to a Short Messaging Service ("SMS") message center; and forwarding said data communication as an SMS delivery message from said SMS message center to said serving MSC.

7. The method of claim 5 wherein said step of forwarding further comprises the step of sending an SMS point to point invoke message to the serving MSC.

8. The method of claim 5, wherein said forwarding step further comprises the step of: sending a teleservice indicator to the serving MSC indicating the need construct the R-data messages and especially allocate the wireless traffic channel for delivery of those R-data messages; and wherein said allocating step further comprises the step of: directing a base station to allocate said wireless traffic channel in response to the received teleservice indicator.

9. A telecommunications system for transmitting a data communication to a wireless client said telecommunications system comprising: a base station for especially allocating a traffic channel to said wireless client in the absence of a currently being handled voice call for that wireless client; and a mobile switching center (MSC) connected to the base station for constructing at least one R-Data message containing the data communication and transmitting said at least one R-Data message to said wireless client through the base station and over said allocated traffic channel.

10. The telecommunications of claim 9 further comprising: an intermediate node handling the data communication; and a home location register for providing an address associated with said MSC to said intermediate node.

11. The telecommunications system of claim 9 further comprising: a signal link connecting said intermediate node to said home location register for transmitting a request from the intermediate node to the home location register.

12. The telecommunications system of claim 9 wherein said intermediate node comprises: a SMS message center and wherein said SMS message center forwards said data communication to the serving MSC.

13. The telecommunications system of claim 12 wherein the SMS message center sends an SMS point to point invoke message containing the data communication to the serving MSC.