KR20200038224A - Method and apparatus for IP address preservation in heterogeneous wireless networks - Google Patents

Abstract

According to the present invention, an IP address allocation apparatus, in order to allocate an IP address to a terminal in a multi-radio network environment including a first network and a second network different from the first network, when an IP allocation request message from a terminal connected to the second network is received, confirms whether to allocate an IP address to the terminal by checking terminal information included in the message. If it is determined to allocate an IP address, the IP address allocation apparatus determines whether to allocate a new IP address or the same IP address used in the first network different from the second network and provides the allocated IP address to the terminal.

Description

Method and apparatus for management of multi-radio network IP address allocation {Method and apparatus for IP address preservation in heterogeneous wireless networks}

The present invention relates to a multi-radio network IP address allocation management method and apparatus.

In general, IP address allocation is dynamically allocated through an address allocation server disposed in one network when a request is made from a user terminal. DHCP (Dynamic Host Configuration Protocol) is a protocol used for dynamic IP address allocation, and a user terminal requests an address from a DHCP client module to a server to obtain an IP address from an address allocation server after accessing the network. The DHCP server informs the user terminal of an address available in the server's IP address pool in response to the request according to the address request, so that the terminal can use the address as an IP address to enable IP communication.

Various types of wireless networks are composed of different protocols and network equipment that operate independently. 3GPP is a method for interworking these various types of wireless networks, and provides an internetworking architecture to enable integrated operation of multiple wireless networks.

Since various types of wired / wireless communication networks are separately assigned and assigned independently to the managed IP addresses, different IP addresses are assigned when one user terminal accesses each communication network. When the IP address is changed, the upper protocol for managing the session of the service traffic is disconnected, resulting in a problem in which communication is interrupted.

To solve this problem, a mobile IP protocol for providing IP mobility has been proposed. The same IP address can be assigned even if the IP address is connected to a different network by using the home address (HoA), which is the representative address of the terminal, and the Care of Address (CoA) used locally according to the network type.

However, IP mobility technology requires two addressing schemes and IP-in-IP tunneling to assign the same IP address. In addition, additional performance is required for encapsulation / decapsulation processing for releasing tunneling in user equipment and network equipment, and there is a problem in that a signaling burden for processing traffic to be transmitted and received is increased.

Even in the integrated operation structure of the multi-wireless network, IP address allocation of the user terminal can be integrated and managed. However, in order to maintain the same IP address when switching the access network, the anchor node must fix the address that can be assigned to a single terminal, and it must be possible to process mapping to the same address when requesting access to the address according to the access network.

However, in the related art, since a unique IP address is dependent on one network, communication of the user terminal through the other path, that is, one access network, is possible at one time. Therefore, if one IP is used in one network, the IP communication stack used in the other network must be released, and when returning to another network, the IP communication stack and all lower protocol stacks must be re-established. have.

Accordingly, the present invention provides a multi-wireless network IP address allocation management method and apparatus for maintaining IP communication seamlessly even when the access network of a user terminal is changed in a multi-wireless network environment.

In a multi-wireless network environment including a first network and a second network different from the first network, which is one characteristic of the present invention for achieving the technical problem of the present invention, an apparatus for allocating an IP address to a terminal,

When a plurality of IP addresses that can be assigned to a terminal are stored in a multi-radio network, and an IP address allocation request message is received for the terminal, a new IP address or an already assigned terminal is allocated based on the terminal information included in the request message An IP address storage unit that allocates the same IP address as the existing IP address; Determine whether an IP address is allocated to the terminal by checking whether there is an IP address already allocated to the same access network or a different network from the access network for the terminal requesting the IP address allocation, and received from the IP address storage unit An IP address management unit mapping an IP address so that the same IP is allocated to the first network and the second network for the terminal; And an IP address processing unit that transmits an IP address allocation request message transmitted from the terminal to the IP address management unit and provides the IP address mapped by the IP address management unit to the terminal.

The IP address management unit may transmit the IP address allocation message including IP address information for the different networks to the IP address storage unit if only the IP addresses for networks different from the network accessed by the terminal are stored.

The IP address storage unit is a net mask used in an IP address band for a different second network that is different from the first network and is already assigned to the terminal among IP addresses to be provided to the terminal from the currently connected first network. It is checked whether there is a free IP address corresponding to, and if there is a free IP address, the same IP address as the second network may be allocated to the terminal for use in the first network.

The IP address storage unit may allocate a new IP address to the terminal when the free IP address is not present or the terminal information is not stored.

In the IP address allocation request message, the terminal information may include identifier information for identifying the terminal and network information accessed by the terminal.

Upon receiving a request for maintaining a communication resource from the IP address processing unit, even when the terminal moves from the connected first network to the second network, communication resources for the first network can be maintained.

Another feature of the present invention for achieving the technical problem of the present invention is to allocate an IP address to a terminal in a multi-radio network environment in which a first network and a second network different from the first network are included. How to do,

Receiving an IP allocation request message from the terminal connected to the second network, checking terminal information included in the message to determine whether to allocate an IP address to the terminal; If it is determined that the IP address is allocated, determining whether to allocate a new IP address or the same address as the IP address used in the first network different from the second network; And providing the assigned IP address to the terminal.

The determining may include assigning the same address as the IP address used in the first network, when it is determined that the terminal information for the terminal is stored and the IP address used in the first network is stored. You can.

The step of allocating the same address may include: checking whether there is a residual IP address in the second network based on a net mask used in the IP address band used in the first network; And if there is a residual IP address, assigning an IP address to be used in the second network in the same manner as the IP address used in the first network.

In the determining step, if the terminal information for the terminal is not stored or there is no residual IP address, a new IP address may be assigned to the terminal.

After the step of providing the terminal, when the terminal moves from the first network to the second network, it may be controlled to maintain communication resources for the first network.

According to the present invention, changes or modifications to the network stack of the user terminal connected to the heterogeneous network can be minimized.

In addition, since the addresses managed by the network use different subnet masks, IP address management is facilitated by simultaneously assigning one or more IP addresses to a single terminal for each heterogeneous network.

In addition, the user terminal can continuously provide the service to the user even if one or more access networks are connected.

1 is a flowchart showing general IP allocation signaling and IP connection / release status.
2 is an exemplary diagram of a network configuration according to an embodiment of the present invention.
3 is a structural diagram of an apparatus for allocating a multi-radio network IP address according to an embodiment of the present invention.
4 is a flowchart illustrating an IP address allocation method according to an embodiment of the present invention.
5 is an exemplary view showing a length of an IP and a subnet mask according to an embodiment of the present invention.
6 is an exemplary diagram of address mapping management according to an embodiment of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art to which the present invention pertains may easily practice. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. In addition, in order to clearly describe the present invention in the drawings, parts irrelevant to the description are omitted, and like reference numerals are assigned to similar parts throughout the specification.

Throughout the specification, when a certain part “includes” a certain component, this does not exclude other components unless specifically stated otherwise. In other specification specifications, the terminal is a mobile station (Mobile Station, MS), Mobile Terminal (MT), Subscriber Station (SS), Portable Subscriber Station (PSS), User Equipment (UE), Access Terminal (AT), etc. It may refer to or may include all or part of functions such as a mobile terminal, a subscriber station, a mobile subscriber station, and a user device.

In this specification, the base station (Base Station, BS) is an access point (Access Point, AP), a radio access station (Radio Access Station, RAS), Node B (Node B), a base transceiver station (Base Transceiver Station, BTS), MMR ( Mobile Multihop Relay) -BS or the like, or may include all or part of functions such as an access point, a radio access station, a Node B, a transmitting and receiving base station, and an MMR-BS.

In the exemplary embodiment of the present invention, it serves as an anchor of two different networks and may be referred to as P-GW, PDN-GW, Packet data network gateway, etc., and each component is a gateway, anchor, etc. It can include all or part of the functionality.

Hereinafter, a method and apparatus for managing a multi-radio network IP address allocation according to an embodiment of the present invention will be described with reference to the drawings.

Prior to describing an embodiment of the present invention, general IP allocation signaling will be described first with reference to FIG. 1.

1 is a flowchart showing general IP allocation signaling and IP connection / release status.

It is assumed that the terminal is assigned an IP through a first DHCP located in the first network to provide a communication service in the first network, and then moves to the second network. Then, as shown in FIG. 1, the terminal entering the second network transmits a DHCP discover / request packet, which is a packet indicating that IP allocation is required (S10). When the DHCP server receives the DHCP discover / request packet, it requests a free IP that can be allocated to the terminal through NAT (S11).

The NAT, which receives the DHCP discover / request packet, selects one address among a plurality of assignable IPs (S12), and transmits a packet indicating that the IP has been assigned, including the selected IP to the DHCP server (S13). The DHCP server transmits a DHCP offer / response packet including the corresponding IP to the terminal so that the terminal can use the IP (S14). At the same time, the gateway releases the IP communication resource with the first network to which the terminal was previously connected (S15).

Each procedure is already known, and detailed description is omitted in the embodiments of the present invention. In addition, for convenience of description, a part indicated by a dotted line is described as a part where IP communication is released, and a part indicated by a solid line is a part capable of IP communication.

At this time, when the terminal in the second network returns to the first network again, since the communication resource released in step S15 must be re-established (reestablishment) again, a problem such as a temporary suspension of services provided to the terminal occurs. do.

Accordingly, in the embodiment of the present invention, a technique for allocating an IP address required for IP communication of a user terminal by a Packet Data Network Gateway (P-GW), which is an anchor node of traffic, in an integrated structure of a multi-radio network will be described. . In addition, the P-GW, which is the principal that processes the dynamic address allocation requested from the user terminal, can maintain and allocate the same IP address using the identification information of the user terminal regardless of the type of access wireless network of the user terminal. Explain.

2 is an exemplary diagram of a network configuration according to an embodiment of the present invention.

2, the multi-wireless network according to an embodiment of the present invention is a gateway 200 or a wireless access point 300 is connected to the P-GW 100 including the IP address allocation device 110 , The gateway 200 is connected to another wireless access point 300 '.

When the P-GW 100 is requested to allocate a dynamic IP address from the terminal 400, the multi-wireless network IP allocation device 110 is connected to the terminal 400 once regardless of the type of the network in which the terminal 400 is located. If there is an assigned IP address, the same IP address is assigned. In addition to this, the P-GW 100 performs the function of a P-GW that is generally performed in a communication network, and the detailed description is omitted in the embodiments of the present invention.

The wireless access point 300 'is connected to the P-GW 100 through the gateway 200, or is directly connected to the P-GW 100. The functions of the wireless access points 300 and 300 'are generally known, and detailed descriptions are omitted in the embodiments of the present invention.

The structure of the IP address allocation device 110 that is included in the P-GW 100 and allocates a wireless IP address to the terminal 400 will be described with reference to FIG. 3.

3 is a structural diagram of an apparatus for allocating a multi-radio network IP address according to an embodiment of the present invention.

3, the IP address allocation device 110 includes an IP address storage unit 111, an IP address management unit 112, an IP address processing unit 113, and a signaling processing unit 114.

The IP address storage unit 111 stores a plurality of IP addresses that can be assigned to a terminal in a multi-radio network. In the embodiment of the present invention, an example of storing an IP address that can be assigned to a terminal requesting an IP address because it is not currently assigned to any terminal is described as an example, but an already allocated IP address may be stored and managed together. It is not limited to the method.

In addition, the IP address storage unit 111 checks the access network type of the terminal 400 included in the terminal information when an IP address allocation request is made including the terminal information from the IP address management unit 112. In addition, the net mask used in the IP address band for the other network allocated to the corresponding terminal 400 is checked to confirm whether there is a residual IP address that can be provided to the corresponding band in the newly accessed network.

If there is a residual IP address, it is assigned to the corresponding terminal and transmitted to the IP address management unit 112. Here, the terminal information includes identifier information for identifying the terminal and network access information indicating to which network the terminal is connected. However, when the terminal 400 accesses a new network or there is no residual IP address, a new IP address is allocated.

When the IP address management unit 112 receives an IP address allocation request message including terminal information from the IP address processing unit 113, it checks whether the IP address allocated to the terminal corresponding to the terminal information is stored. If the IP address for the access network to which the terminal is connected is stored, the corresponding IP address is notified to the terminal 400. This case corresponds to a case where the terminal 400 re-connects after handover from the corresponding network to another network.

However, if the IP address for the access network to which the terminal is connected is not stored, or if information about the corresponding terminal is not stored at all, the IP address management unit 112 includes the terminal information as the IP address storage unit 111. The IP address allocation request message is transmitted. To this end, in order to prevent one terminal from accessing different access networks and assigning different addresses, an IP address assigned to any terminal transmitted from the IP address processing unit 113 to be described later is logically the same IP address. Manage IP addresses to map addresses.

And when receiving the IP address assigned to the terminal 400 from the IP address storage unit 111, the IP address bound to each wireless network interface held by the terminal 400 is managed to be physically assigned the same IP address. To this end, the IP address management unit 112 stores and manages information on the terminal 400, an IP address allocated to the terminal 400, and wireless network interface information held by the terminal 400.

The IP address processing unit 113 transmits an IP address allocation request message including the terminal information of the terminal 400 to the IP address management unit 112 when the dynamic IP address allocation request signal is transmitted from the terminal 400, and the corresponding terminal ( 400) is requested. When it is confirmed that the information of the terminal is stored from the IP address management unit 112, an IP address is allocated to the terminal 400 based on the information.

In addition, the IP address processing unit 113 provides the IP address to the terminal 400 and, at the same time, if the terminal 400 is previously connected to another wireless network to the signaling processing unit 114, does not release communication resources required for connection. Ask to keep. In addition, the IP address processing unit 113 also performs a DHCP server function that is commonly used in a wireless network, and the DHCP server function is generally known, and thus detailed description is omitted in the embodiment of the present invention.

The signaling processing unit 114 processes signaling in consideration of a multi-radio network. When processing signaling, it is processed by disparate interfaces or between heterogeneous interfaces. In addition, when a request is made to maintain communication resources from the IP address processing unit 113, a procedure for arranging lower protocols is omitted so that communication resources of two wireless networks to which arbitrary terminals are connected are maintained.

A method of allocating an IP address to a terminal accessing a multi-radio network through the IP address allocation device 110 described above will be described with reference to FIG. 4.

4 is a flowchart illustrating an IP address allocation method according to an embodiment of the present invention.

In an embodiment of the present invention, the terminal 400 requests the allocation of a dynamic IP address to the P-GW 100 based on a request message and identification information of the terminal included in the request message. 110) determines an address to be allocated to the terminal. And it handles terminal address allocation through dynamic IP address allocation response. In addition, by avoiding the IP recovery procedure of the previous network to which the terminal 400 is connected, the network connection state can be maintained.

As illustrated in FIG. 4, when a terminal connected to the first network moves to a second network to access or connects to the second network from the beginning, the terminal 400 uses an IP address for IP communication in the second network Request allocation. To this end, the terminal 400 transmits a packet requesting an IP address allocation to the IP address processing unit 113 performing a DHCP server function together in the IP address allocation device 110 through the gateway (S100, S110). .

Here, the packet requesting the IP address allocation includes terminal information and information of a network connected to the terminal. In addition, the terminal information includes an identifier for identifying the terminal. The identifier includes an APN (Access Point Name), an interface MAC address, an International Mobil Subscriber Identity (IMSI), an International MSequipment Identity (IMEI), and a Temporary MSIdentification (TMSI). It will be described as an example that any one of the information is used.

In the packet transmitted in step S100, terminal information is not included and FLAG information may be included. It is possible to determine whether the terminal 400 processes an address by using the FLAG information. For example, the IP address processing unit 113 determines whether the terminal is simultaneously connected to a heterogeneous network with parameter information such as DHCP option 50. can do.

When the IP address processing unit 113 checks the information of the terminal using the packets transmitted through steps S100 and S110 (S120), the IP address management unit 112 determines whether the terminal 400 first requests an address, that is, the terminal It is checked whether the information is already stored in the IP address management unit 112 (S130). If information on the terminal 400 is not stored in the IP address management unit 112 and is determined to request an IP address for the first time, the IP address management unit 112 transmits the IP address storage unit 111 to the terminal 400. Request the address to be assigned to.

The IP address storage unit 111 allocates and assigns an IP address according to the network accessed by the terminal 400, and the IP address information assigned to the terminal 400 by the IP address processing unit 113 through the IP address management unit 112. Inform (S131). In this process, the IP address management unit 112 stores and manages the information of the terminal 400 and the IP address assigned to the terminal.

The IP address processing unit 113 generates a response message informing that the dynamic address is allocated using the IP address information received from the IP address management unit 112 in step S131, and transmits it to the terminal 400 (S140).

Meanwhile, as a result of the IP address management unit 112 confirming in step S130, when the information of the terminal 400 is stored in the IP address management unit 112, it is confirmed that the IP address is already assigned to the corresponding terminal 400 ( S130). Then, the IP address management unit 112 checks the type of the network accessed by the terminal 400 (S132). This is because the IP address may be an IP address allocated through the first network, or the terminal 400 may be an IP address that has been previously allocated to the second network.

Since the network to which the terminal 400 is currently connected is the second network, if the IP address assigned to the terminal 400 stored in the IP address management unit 112 is connected to the second network and there is an assigned IP address, the same IP The address is allocated (S134).

However, if the network connected to the terminal 400 is the second network and the IP address stored in the IP address management unit 112 is confirmed to have only the assigned IP address connected to the first network, the IP address storage unit 111 ) Checks whether there are residual IPs corresponding to the IP address band allocated to the terminal 400 in the first network among the assignable IPs for the second network (S133). If there is a residual IP for the second network, the terminal 400 is assigned the same IP address as the IP used in the first network (S134). However, if there is no residual IP, a new IP address is allocated to the terminal 400 (S131).

When allocating an IP address, the IP address of the first network currently allocated and the net mask used in the corresponding IP address band are checked through the IP address storage 111. The IP and subnet mask length for each network will be described first with reference to FIG. 5.

5 is an exemplary diagram showing the length of IP and subnet mask for each network according to an embodiment of the present invention.

5 (a) shows the IP and subnet mask length of the mobile network, and (b) shows the IP and subnet mask length of the wireless LAN network. As shown in FIG. 5, in the case of IPv4, since it has a 32-bit address system, the IP address of the first network is equal to "IP_nw1 = IP address / net mask length for nw1 = 10.0.0.1/24".

As described above, subnet masks of different lengths are designated for different heterogeneous networks, but IP addresses are assigned to a network having many users, that is, many subscribers using a short subnet mask.

For example, since the subnet mask length of the mobile network is longer than the subnet mask length of the wireless LAN network, the IP address (IP_nw2) of the second network is derived and used from the IP address of the first network. However, each network uses a subnet mask of a specified length. Therefore, when the IP address of the first network is allocated, but the IP is newly allocated by newly accessing the second network, the IP address that the terminal 400 will use in the second network is "IP_nw2 = IP_nw1's IP address / net mask length for nw2 = 10.0.0.1/26 ".

That is, assuming that the IP address 1.1.1.1 is allocated to the terminal 400, the IP address of the first network to which the 24-bit net mask identified in the P-GW 100 is allocated and the 26-bit net mask are allocated. IP address of the second network is different from each other. However, from the standpoint of the terminal 400, since the rest of the portion except for the net mask portion becomes an actual IP address, it is confirmed that the same IP address is allocated.

The IP address management unit 112 transmits the selected IP address and subnet mask information to the IP address processing unit 113 through the above procedure. The IP address processing unit 113 allocates the generated IP address to the terminal 400 in response to the DHCP server (S140, S150).

When the requested IP allocation is completed through the new network, the second network, one or more IP addresses for the same terminal may be used in one terminal. Generally, since only one IP address is used in one terminal, a procedure of recovering the dually used IP address is performed.

When the IP address is recovered, a procedure for organizing protocols other than the available IP is involved. In the embodiment of the present invention, since a terminal can use a plurality of IP addresses, the protocol organizing procedure is omitted. That is, in the related art, when the communication resource re-enters the released network, the terminal has a problem of retrying the connection to the network.

However, in the embodiment of the present invention, even if the signaling processing unit 114 determines whether the terminal 400 is handed over (S160), it determines that the communication resource is maintained without releasing it, and then notifies the gateway 200 ( S170, S180). Therefore, the terminal 400 can maintain the network connection state because it does not perform the procedure for retrieving the IP address that has already been connected, as well as the procedure for rearranging the lower protocol.

An example of storing and managing addresses allocated to a plurality of terminals through the above procedure will be described with reference to FIG. 6.

6 is an exemplary diagram of address mapping management according to an embodiment of the present invention.

As illustrated in FIG. 6, it is understood that any terminals marked UE0001 have different identifiers, types, and subnet mask lengths from the mobile network and the wireless LAN network, but the same IP address (10.0.0.1) is allocated. You can. Accordingly, the UE0001 terminal can use the communication service using the same IP address even if handover is performed between the mobile network and the wireless LAN network, and there is no IP address retrieval procedure in the handover process, so the terminal maintains the network connection service. Can be provided without interruption.

For example, if a service is provided to a terminal through only one network unconditionally, such as MMS, SMS, or the like, when a terminal enters a network other than the corresponding network, the existing network is newly assigned an IP address and then service Since the service must be used, the service may be disconnected at the time of entering the new network. However, in the embodiment of the present invention, even when entering a new network, since the terminal is assigned the same IP address as the IP address assigned in the previous network, the service can be continuously provided without a service disconnection.

Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concept of the present invention defined in the following claims are also provided. It belongs to the scope of rights.

Claims (10)

In a multi-radio network environment in which a first network and a second network different from the first network are included, as an IP address allocation device for allocating an IP address to a terminal,
An IP address processor configured to receive an IP address allocation request message including network information of the first network and terminal information of the terminal from the terminal connected to the first network,
IP address management unit to check whether the terminal is assigned an IP address in the second network based on the terminal information, and
If the terminal has a first IP address assigned with the subnet mask of the second network, it is determined whether the first IP address can be used in the subnet mask of the first network, and the first IP address is determined. Address storage unit to allocate to the terminal to continue to be used in the first network, or to allocate the new second IP address to the terminal to use in the first network
IP address allocation device comprising a. According to claim 1,
The IP address management unit,
If only the first IP address assigned to the terminal in the second network is stored, an IP address allocation device for transmitting the IP address allocation request message to the IP address storage unit including the first IP address information. According to claim 1,
IP address allocation device having a different subnet mask length of the first network and a subnet mask length of the second network. According to claim 1,
The IP address storage unit,
IP address allocation device for allocating the second IP address to the terminal if the terminal information is not stored or the first IP address cannot be used in the subnet mask of the first network. According to claim 1,
The IP address allocation request message,
IP address allocation device including identifier information for identifying the terminal and network information accessed by the terminal. According to claim 1,
When a communication resource maintenance request is received from the IP address processing unit, the signaling processing unit maintains communication resources of the first network with respect to the terminal even when handing over from the first network accessed by the terminal to the second network.
IP address allocation device further comprising a. A method for allocating an IP address to a terminal in a multi-radio network environment in which an IP address allocation device includes a first network and a second network different from the first network,
Receiving an IP address allocation message including network information and terminal information of the first network accessed by the terminal from the terminal,
Checking whether there is a first IP address mapped to the terminal information,
Determining whether the first IP address can be assigned to the terminal in the subnet mask of the first network, when the first IP address assigned with the subnet mask of the second network exists in the second network; And
According to the determination result, the first IP address is assigned to the terminal to continue to be used in the first network with a subnet mask length different from the subnet mask length of the second network, or a new second IP address is assigned to the first network. In the step of assigning to the terminal
Including, IP address allocation method. The method of claim 7,
The step of assigning the IP address,
Checking whether there is a residual IP address in the subnet mask of the first network in correspondence to the subnet mask assigned with the first IP address in the second network; And
If there is a residual IP address, allocating the first IP address for use in the first network
IP address allocation method comprising a. The method of claim 8,
The determining step,
IP address allocation method for allocating the second IP address to the terminal if the terminal information of the terminal is not stored or there is no residual IP address in the subnet mask of the first network. The method of claim 8,
After the step of providing to the terminal,
Controlling the terminal to maintain communication resources for the second network when the terminal moves from the second network to the first network
IP address allocation method comprising a.

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