KR20030047455A - Packet data service method for wireless telecommunication system - Google Patents

Abstract

PURPOSE: A packet data service method of a radio communication system is provided to allow plural terminal equipments connected to one mobile node in a network model to receive an IP address. CONSTITUTION: A mobile node sets a PPP(Point-to-Point Protocol) link to a packet data service node(S100). A DHCP client of a terminal equipment transfers DHCPDISCOVERY message for receiving an IP address(S110). A BOOTP relay agent of the mobile node transfers the DHCPDISCOVERY message to a DHCP server of a packet data service node(S120). The packet data service node selects one IP address from an internal IP pool and transfers DHCPOFFER message including the selected IP address to the mobile node(S130). The mobile node transfers the DHCPOFFER message to the terminal equipment by using a hardware address included in the DHCPOFFER message(S140). The terminal equipment transfers DHCPREQUEST message in a unicast form to the packet data service node through the mobile node to check whether the IP address is used by a different host(S150,S160). The packet data service node judges whether the IP address is effective in response to the DHCPREQUEST message, and transfers DHCPACK message to the terminal equipment through the mobile node if the IP address is effective(S170,S180). The terminal equipment uses a packet data service with the IP address(S190).

Description

Packet data service method of wireless communication system {PACKET DATA SERVICE METHOD FOR WIRELESS TELECOMMUNICATION SYSTEM}

The present invention relates to a packet data service method, and more particularly, to a method for wirelessly using a packet data service through a mobile node operating as a router.

IMT-2000 (International Mobile Telecommunications-2000) is a next-generation wireless communication system that integrates the specifications of various mobile phone systems currently operated by each country, and enables communication service anywhere in the world with one terminal. . The IMT-2000 can access various services through one terminal. For example, users can also conduct video conferencing while simultaneously connecting to the Internet / Intranet for graphical access, multimedia mail exchange, and sending large amounts of data files. It also offers global roaming, wireless video services, video teleconferencing and two-way entertainment.

One of the communication technologies for providing various services as described above is the Code Division Multiple Access (CDMA) 2000 system. In a CDMA 2000 system, a voice or data received from a wireless communication network is delivered to a packet-based IP network by carrying a packet (IP packet) according to the Internet Protocol (IP), thereby enabling the mobile node to have a final IP address. Mobile terminal or mobile host). The packet data service refers to all kinds of call services in which voice or data is carried in the form of packets on the whole or part of the path from the transmitting end to the receiving end.

In a wireless communication system supporting packet communication, a mobile node needs a unique address for identifying a mobile node in a packet network in order to receive a packet data service. In an IP network, this becomes an IP address. Preferably, every mobile node must have a unique IP address, but because the number of available IP addresses is limited across the packet network, in practice, the IP address is temporarily assigned only when the user uses the service, that is, dynamic allocation. The method is mainly used.

The CDMA2000 1x wireless communication system supports two services, namely, Simple IP service and Mobile IP service, for dynamically assigning IP addresses to mobile nodes. The IP address assigned by the Simple IP service is deleted when the connection is terminated, but the IP address assigned by the Mobile IP service is used as long as the mobile node does not move to another address allocation service area.

On the other hand, in IS-707, a standard document on which CDMA services are based, a type of mobile terminal (MT) capable of receiving packet data services is divided into a relay model and a network model. Doing. This model is divided according to whether the mobile node has a TCP (Transmit Control Protocol) / IP (Internet Protocol) stack.

That is, in the relay model, a TCP / IP stack is provided in a terminal equipment connected to a mobile node, and the mobile node provides a function of a modem to the user terminal and provides a point-to-point packet service for packet service. Point Protocol) The establishment of the link or the actual execution of the packet service application is performed at the user terminal. On the other hand, in the network model, the mobile node is provided with a TCP / IP stack, the PPP link is terminated at the mobile node, and the mobile node and the user terminal are interconnected via Ethernet. At this time, the mobile node operates as a kind of router and has a function of forwarding packets between the network and the user terminal.

However, the currently used standard for code division multiple access (CDMA) mobile communication service, for example, TSG-P IS-835, does not consider the mobile node of the network model at all. have. In particular, in the network model, a plurality of user terminals may be connected to one mobile node in the model configuration. According to the currently used standard, one mobile node may establish only one PPP link. That is, while the PPP link is established, the mobile node has only one IP address assigned to it. However, as mentioned earlier, in the network model, several user terminals can be connected to one mobile node, and each user terminal must have a different IP address for packet communication. Accordingly, in the network model, a plurality of user terminals connected to one mobile node need an IP address and a method for using a packet data service.

Accordingly, an object of the present invention, which was created to solve the problems of the prior art operating as described above, is to provide a method in which a plurality of user terminals connected to one mobile node are assigned an IP address in a network model.

Another object of the present invention is to provide a method of using a packet data service by a plurality of user terminals connected to one mobile node in a network model.

In order to achieve the above object, an embodiment of the present invention provides a packet data service for a user terminal that does not have a unique IP (Internet Protocol) address that can be identified on a packet network. In the method for

Receiving, by the user terminal, a unique IP address from a packet data service node, which is a gateway between the wireless communication network and the packet network, using a mobile node connectable to the wireless communication network;

And using the packet data service by the user terminal using the assigned IP address.

1 is a network diagram of a CDMA 2000 system to which the present invention can be applied.

2 illustrates a detailed configuration for allocating an IP address to a user terminal through a mobile node according to the present invention.

3 is a message flow diagram illustrating an operation procedure for allocating an IP address to a user terminal through a mobile node according to the present invention.

Hereinafter, with reference to the accompanying drawings will be described in detail the operating principle of the preferred embodiment of the present invention. In the following description of the present invention, detailed descriptions of well-known functions or configurations will be omitted if it is determined that the detailed description of the present invention may unnecessarily obscure the subject matter of the present invention. Terms to be described later are terms defined in consideration of functions in the present invention, and may be changed according to intentions or customs of users or operators. Therefore, the definition should be made based on the contents throughout the specification.

In the packet data service according to an embodiment of the present invention to be described below, a plurality of user terminals connected to one mobile node in a network model receive IP addresses using Dynamic Host Configuration Protocol (DHCP), which is an Internet standard protocol. It is characterized by. DHCP, as known by the Internet standard protocol Request for Comments (RFC) 2131, defines a communication procedure for a host without an IP address to be assigned an IP address by exchanging messages with a DHCP server.

1 schematically illustrates a network configuration of a CDMA 2000 system to which the present invention can be applied. Hereinafter, the main components according to the present invention will be described mainly.

Referring to the configuration of FIG. 1, the mobile nodes 120a and 120b may be connected to one or more user terminals 110a, 110b and 110c. These mobile nodes 120a and 120b connect base stations 130a and 130b to radio channels according to the CDMA 2000 standard and receive call services. Typically, the base stations 130a and 130b include base transceiver stations (BTSs) and a base station controller (BSC). The Mobile Switching Center (MSC) 140 connects the base stations 130a and 130b to other subscriber systems such as a Public Switched Telephone Network (PSTN) via a path not shown, thereby providing mobile nodes 120a and 120b. It provides a circuit-based call service according to the conventional method. The base stations 130a, 130b and the mobile switching center 140 form a wireless communication network in accordance with the CDMA 2000 standard.

Meanwhile, the base stations 130a and 130b are connected to the data core network, that is, the IP network 160 through the packet data service node (PDSN) 150. Here, the packet data service node 150 is a gateway for interconnecting the IP network 160 with another network. In particular, the packet data service node 150 connected to the wireless communication network in an advanced network structure may include a mobile switching center 140.

Here, the IP network 160 is connected to another network 170 including a plurality of Internet service providers and nodes, and provides packet data services to the mobile nodes 120a and 120b. To this end, the IP network 160 includes a plurality of network elements, namely, Domain Name Server (DNS) 162, Authentication, Authorization and Accounting server (AAA server) 164, Home Agent (HA) 166, MG (Media Gateway) 168 and the like. Description of these operations will be omitted since it is outside the scope of the present invention.

In the network operating as described above, the packet data service node provides a packet service to the mobile node through a CDMA wireless communication network. When the packet data service node is a mobile node of the relay model, the packet data service node establishes a PPP link with the user terminal and assigns an IP address to the user terminal to enable internet access of the user terminal.

In the present invention, in the case of the Simple IP service in which the packet data service node assigns an IP to the mobile node, a DHCP server function is added to the packet data service node, and a relay agent function is added to the mobile node to transmit the user terminal. The message can be delivered to the packet data service node. In this case, the relay agent allows a DHCP client in a user terminal to access a DHCP server in a packet data service node existing on a remote network. As a result, a plurality of user terminals connected to one mobile node are assigned respective IP addresses.

The above configuration will be described in more detail with reference to the drawings.

2 is a diagram illustrating a detailed configuration for allocating an IP address to a user terminal through a mobile node according to the present invention.

Referring to FIG. 2, in order to receive IP addresses of the plurality of user terminals 110 connected to the mobile node 120 in the network model using DHCP, the DHCP process may be performed on the user terminal 110, the mobile node 120, and the packet data service node 150. Function blocks that can be implemented should be implemented. The user terminal 110 has a DHCP client 111. The DHCP client 111 starts the DHCP process and receives an IP address to be used in the user terminal 111 through a message exchange with the DHCP server 151 provided in the packet data service node 150. The packet data service node 150 has a DHCP server 151. The DHCP server 151 obtains information necessary for selecting an IP address from an IP pool 153 that stores an assignable range of the IP address, and allocates an IP address for the user terminal 110. The RP interface block 155 connects the packet data service node 150 to the base station 130, and the PPP block 157 is responsible for establishing a PPP link between the packet data service node 150 and the base station 130.

The mobile node 120 operates as a router according to a network model, and has a relay agent 121 for delivering a DHCP message from the packet data service node 150 having the DHCP server 151 to the DHCP client 111 of the user terminal 110. The relay agent 121 is an internet host or router that transfers DHCP messages between a DHCP client and a DHCP server defined in RFC 2131. Since the DHCP is designed to use the same relay agent operation as described in the Boot Strap Protocol (BOOTP) standard, the relay agent 121 may be a BOOTP relay agent. A description of the BOOTP is as follows.

As defined in RFC 951, BOOTP refers to a bootstrap protocol for acquiring network configuration information used in computer systems without a boot disk as a disk device that stores an operating system for booting the system. If another computer, i.e. a computer with a client, requests the server for the IP address and the information required for start-up, the server responds. BOOTP is commonly used in local area networks (LANs).

Since the BOOTP described above is a protocol based on DHCP, in the present invention, the relay agent 121 according to the BOOTP is provided on the mobile node 120 so that the relay agent 121 is connected to the DHCP client 111 and the packet data service node 150 of the user terminal 110. Relay DHCP messages exchanged between DHCP servers 151.

If the mobile node 120 sends a DHCP message Since the mobile node 120 does not yet have an IP address, the source address of the IP packet carrying the DHCP message will be '0'. A general router does not forward IP packets with a source address of '0' to the outside. However, according to the present invention, when the mobile node 120 including the relay agent 121 receives such a packet, the mobile node 120 forwards the packet to the DHCP server 151 as a new BOOTP message. As such, the relay agent 121 disposed in the mobile node 120 performs relaying on the BOOTP message instead of general forwarding.

The IP routing tables 113, 123, and 159 arranged in the user terminal 110, the mobile node 120, and the packet data service node 150, respectively, contain routing information for sending a packet to a destination in TCP / IP. Therefore, the IP routing tables 113, 123, and 159 of the mobile node 120, which forwards packets through IP routing between the user terminal 110, the packet data service node 150, and the user terminal 110 and the packet data service node 150, which are allocated and assigned IP through DHCP, Information should be exchanged with the relevant blocks 111, 121, 151 so that packets can be transmitted normally.

Hereinafter, a procedure of exchanging packets between the user terminal 110 and the packet data service node 150 will be briefly described. At this time, DHCP is not involved in the packet delivery itself but only in the process of assigning an IP address to the user terminal 110. However, the packet data service node 150 manages information such as a PPP link with the mobile node 120, a radio interface with the base station 130, and a DHCP initialization process to transmit the actual data packet.

First, after the mobile node 120 establishes a PPP link with the packet data service node 150 in the same manner as the relay model, the user terminal 110 performs an DHCP process with the packet data service node 150 and receives an IP address. In this case, the DHCP message transmitted from the user terminal 110 is transmitted to the mobile node 120 through Ethernet, and the mobile node 120 transmits the packet to the packet data service node 150 through the PPP link. The packet is delivered to the packet data service node 150 through an air interface (air I / F) which may be defined as the base station 130 and IS-95C, IS-2000, or 1X EV-DO (Evolution Data Only).

The packet data service node 150 connects the relationship between the IP address assigned to the user terminal 110 through the DHCP process, the session of the RP (Radio Port) interface, and the PPP link (the IP address of the mobile node) with the mobile node 120. Save it. That is, when a packet to be transmitted from the outside to the user terminal 110 arrives at the packet data service node 150, the packet data service node 150 searches the IP routing table 159 in the packet data service node 150 based on the destination address of the packet. . An example of the IP routing table 159 of the packet data service node 150 is shown in Table 1 below.

Destination address Next hop interface IP address of the user's terminal IP address of mobile node eth0 IP address of mobile node IP address of the PCF vha1

Here, the PCF is a functional block existing in the base station 130 and performs an RP interface with the packet data service node.

The packet data service node 150 may be forwarded to the mobile node 120 in order to transmit a packet to the user terminal 110 from the IP routing table 159 configured as shown in Table 1 above. In addition, it can be seen that forwarding a packet to the mobile node 120 requires transmission to the PCF. The IP routing information is reflected in the IP routing table 159 at the time of PPP establishment between the mobile node and the packet data service node and the DHCP process initialization between the user terminal and the packet data service node.

When a packet to the user terminal 110 is received from the outside, the packet data service node 150 first refers to the IP routing table 159 to indicate that the packet is forwarded through the mobile node 120 and that the packet is forwarded to the mobile node 120 through the PPP link. In this case, the GRP encapsulation of the packet is detected at the RP interface 155, and the packet is forwarded to the user terminal 110 with reference to the information.

3 is a message flow diagram illustrating an operation procedure for allocating an IP address to a user terminal through a mobile node according to the present invention.

Here, DHCP messages refer to messages used by a DHCP client to connect to a DHCP server, request an assignment of an IP address, and receive an assigned IP address, as defined in RFC 2131.

Referring to FIG. 3, first, the mobile node 120 establishes a PPP link with the packet data service node 150 in the same manner as in the case of the relay model to deliver a DHCP message sent from the user terminal 110 to the packet data service node 150. )

Since the user terminal 110 needs to have an IP address to use the packet data service, the DHCP client 111 of the user terminal 110 transmits a DHCPDISCOVERY message for obtaining an IP address. (S110) In this case, the user terminal 110 does not have an IP address. And does not know the IP address of the DHCP server, the DHCPDISCOVERY message is broadcast through the mobile node 120. That is, the source address of the DHCPDISCOVERY message is "0.0.0.0" and the IP destination address is "255.255.255.255". In addition, the DHCPDISCOVERY message may include a hardware address of the user terminal 110 (generally, an address of a network card installed in the user terminal), that is, a MAC (Media Access Control) address.

Upon receiving the DHCPDISCOVERY message, the BOOTP relay agent 121 of the mobile node 120 transmits the DHCP message to the DHCP server 151 of the packet data service node 150. (S120) In order to deliver the message to the packet data service node 150, packet data has already been received. Use the PPP link established through service node 150 and PPP configuration.

After receiving the DHCPDISCOVERY message through the PPP link, the packet data service node 150 selects one IP address from the internal IP pool 153 and transmits a DHCPOFFER message including the selected IP address to the mobile node 120. In this case, since the packet data service node 150 does not know the IP address of the DHCP client 111 that will receive the DHCPOFFER message, the packet data service node 150 stores the PPP link that receives the DHCPDISCOVERY message and stores the DHCPOFFER message through the same PPP link. Send it. In this case, the DHCPOFFER message includes the IP address assigned to the user terminal 110 as well as the address of the DHCP server 151, and also contains the hardware address of the user terminal copied from the DHCPDISCOVERY message sent by the user terminal 110. The mobile node 120 receiving the DHCPOFFER message delivers the DHCPOFFER message to the user terminal 110 using the hardware address of the user terminal 110 included in the DHCPOFFER message (S140).

Upon receiving the DHCPOFFER message, the user terminal 110 transmits a DHCPREQUEST message to the packet data service node 150 through the mobile node 120 in the form of unicast to confirm that the IP address is not being used by another host (S150, 160). At this time, the IP source address of the transmitted DHCPREQUEST message is the IP address included in the DHCPOFFER message.

The packet data service node 150 determines whether the IP address is valid in response to the DHCPREQUEST message, and if the determination result is valid, transmits a DHCPACK message to the user terminal 110 through the mobile node 120 (S170, S180). If the result is not valid, the mobile node 120 transmits a DHCPNACK message to the user terminal 110. Thereafter, the user terminal uses the packet data service with the IP address assigned through the above procedure (S190).

Meanwhile, in the detailed description of the present invention, specific embodiments have been described, but various modifications are possible without departing from the scope of the present invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be defined not only by the scope of the following claims, but also by those equivalent to the scope of the claims.

In the present invention operating as described in detail above, the effects obtained by the representative ones of the disclosed inventions will be briefly described as follows.

According to the present invention, an IP address may be assigned to each user terminal by implementing a DHCP protocol in a mobile node and a packet data service node. DHCP used at this time is an Internet standard protocol, so it has the additional effect of maintaining compatibility between products.

Claims (8)

A method for using a packet data service through a wireless communication network by a user terminal that does not have a unique Internet Protocol (IP) address that can be identified on a packet network, Receiving, by the user terminal, a unique IP address from a packet data service node connected to the packet network network using a mobile node accessible to the wireless communication network; The user terminal using a packet data service using the assigned IP address. The method of claim 1, wherein the step of assigning the IP address comprises: Establishing, by the mobile node, a point-to-point protocol (PPP) link with the packet data service node; When the user terminal transmits a message requesting the assignment of the IP address to the mobile node, relaying the message requesting the assignment of the IP address to the packet data service node; Allocating, by the packet data service node, an IP address for the user terminal in response to a message requesting assignment of the IP address; And when the packet data service node transmits a message including the assigned IP address to the mobile node, the mobile node relays a message including the assigned IP address to the user terminal. Said method. The method of claim 2, When the user terminal transmits a message confirming whether the assigned IP address is valid to the mobile node in response to the message including the assigned IP address, the mobile node confirms whether the assigned IP address is valid. Relaying the packet data service node to the packet data service node; Checking, by the packet data service node, whether the assigned IP address is valid in response to a message confirming that the assigned IP address is valid; If the allocated IP address is valid, if the packet data service node transmits a message indicating that the allocated IP address is valid, the mobile node indicates that the assigned IP address is valid. Relaying an informing message to the user terminal. The method of claim 2 or 3, wherein the message requesting the assignment of the IP address includes a hardware address of a user terminal that requests the assignment of the IP address. A packet data service node connected to a packet network, a mobile node connected to the packet data service node via a wireless communication network and operating as a router, and at least one user using a packet data service of the packet network through the mobile node A system for using a packet data service by a packet data service node in a system including a terminal, wherein the user terminal does not have a unique Internet Protocol (IP) address that can be identified on the packet network. Providing a Dynamic Host Configuration Protocol (DHCP) client for requesting an assignment of an IP address to the user terminal; Providing a DHCP server in the packet data service node to allocate an IP address to each of the user terminals in response to a request of the DHCP client; Providing a relay agent at the mobile node to relay DHCP messages exchanged between the DHCP client and the DHCP server; Receiving, by the DHCP client provided in the user terminal, an IP address from the DHCP server through the relay agent; And the user terminal uses a packet data service by the packet data service node using the assigned IP address. The method of claim 5, wherein the step of assigning the IP address comprises: Establishing, by the mobile node, a point-to-point protocol (PPP) link with the packet data service node; When the DHCP client provided in the user terminal transmits a message requesting the assignment of the IP address to the relay agent, relaying the message requesting the assignment of the IP address to the DHCP server; Assigning, by the DHCP server, an IP address for the user terminal that has requested the assignment of the IP address in response to the message requesting the assignment of the IP address; And when the DHCP server transmits a message including the assigned IP address to the relay agent, relaying the message including the assigned IP address to the DHCP client. Way. The method of claim 6, When the DHCP client sends a message confirming that the assigned IP address is valid in response to the message including the assigned IP address, the relay agent confirms whether the assigned IP address is valid. Relaying the DHCP server; The DHCP server confirming whether the assigned IP address is valid in response to a message confirming that the assigned IP address is valid; If the assigned IP address is valid, the DHCP server sends a message indicating that the assigned IP address is valid to the relay agent, and the relay agent notifies that the assigned IP address is valid. Relaying the DHCP client to the DHCP client. 8. The method as claimed in claim 6 or 7, wherein the message requesting the assignment of the IP address includes a hardware address of a user terminal requesting the assignment of the IP address.