WO2010127597A1

WO2010127597A1 - Handoff method, device and system

Info

Publication number: WO2010127597A1
Application number: PCT/CN2010/072242
Authority: WO
Inventors: 树贵明; 丁志明; 杨永利
Original assignee: 华为技术有限公司
Priority date: 2009-05-07
Filing date: 2010-04-27
Publication date: 2010-11-11
Also published as: CN101883312A

Abstract

Embodiments of the present invention discloses a handoff method, device and system belonging to the communication field, which can guarantee the continuity of the service in the process of handing off a dual-mode terminal from a Worldwide Interoperability for Microwave Access (WiMAX) network to a Wireless Fidelity (WiFi) network under the operation mode of a single radio frequency. The technical solution provided by the embodiments of the present invention is as follows. The handoff method includes: receiving a first request message transmitted by the terminal through a WiMAX access network; acquiring information of WiFi network access points (APs) near the terminal from an AP information server according to the terminal position information carried in the said first request message; determining a target AP and providing said target AP information to the terminal through a first response message; starting and completing the pre-authentication process from the terminal to the WiFi network. The technical solution provided by the embodiments of the present invention applies to the wireless communication system.

Description

The present invention claims the priority of the Chinese Patent Application entitled "Switching Method, Equipment and System", filed on May 7, 2009, the Chinese Patent Office, Application No. 200910136555. This is incorporated herein by reference. The present invention relates to the field of communications, and in particular, to a handover method, device, and system. Background technique

WiFi (Wireless Fidelity) is a wireless LAN technology defined by the IEEE standards organization for wireless broadband access. At present, many network operators around the world have deployed a large number of WiFi hotspots to provide wireless Internet access. WiMAX (Worldwide Interoperabiity for Microwave Access) is also a wireless broadband access technology defined by the IEEE standards organization. It is also one of the third international standards for wireless communication technology. There are many operators around the world. Use WiMAX technology to build a wireless broadband access network. Both WiFi and WiMAX are important wireless broadband access technologies, but each has its own advantages and disadvantages. WiFi has a fast deployment speed, low cost, high bandwidth, no need for authorization to use the spectrum, but a small coverage. WiMAX has a large coverage range, but there will be more users in a large coverage area, so that the average user bandwidth will decrease.

WiFi can be used as a supplement to WiMAX. When the indoor WiMAX signal is not strong or the densely populated location uses the WiFi access point, the multimode terminal accesses the WiMAX core network through the WiFi network. In other cases, the multimode terminal directly connects. Into the WiMAX network. In this way, multimode terminals must ensure continuity of service when switching between WiMAX and WiFi access networks. The so-called service continuity is that when switching access points (such as between different WiMAX base stations, or between WiMAX base stations and WiFi access points), the connection between the multimode terminal and the service network before and after the handover is not interrupted, and the network Switching is transparent to business processes.

The dual-mode terminal has two RF circuits, which use WiMAX radio when connected to the WiMAX access network, and use WiFi radio when connecting to the WiFi access network. WiFi and WiMAX use different operating frequencies. The dual-mode terminal can have two working modes when switching between two access technologies, one is a dual-radio working mode, and the other is a single-radio working mode. The dual-mode terminal preferentially uses the single-frequency operation mode. The single-frequency operation mode means that only one radio is working at any time. When the dual-mode terminal switches from the WiMAX access network to the WiFi access network, the WiMAX radio needs to be turned off first, and the WiFi is turned on. The radio frequency, select a WiFi access point, and then associate with the access point to complete the authentication to the WiFi network, so as to complete the handover from WiMAX to WiFi. In this case, since the WiFi network access point is selected And the authentication process of the dual-mode terminal to the WiFi network takes a long time, so the continuity of the service cannot be guaranteed in the process of switching the dual-mode terminal from the WiMAX network to the WiFi network. Summary of the invention

The embodiments of the present invention provide a handover method, device, and system, which can ensure continuity of services in a process of switching from a WiMAX to a WiFi network in a single radio frequency operation mode.

In order to achieve the above object, the embodiment of the present invention adopts the following technical solutions:

A switching method includes:

Receiving, by the WiMAX access network, a first request message sent by the terminal, where the first request message includes terminal location information;

Obtaining, according to the terminal location information carried in the first request message, the WiFi network access point information around the terminal from the access point information server, determining the target access point, and passing the target access point information through the first response. The message is provided to the terminal;

The pre-authentication process of the terminal to the WiFi network is initiated and completed.

A switching method includes:

Using the authentication server in the WiMAX core network to complete the pre-authentication process to the access point in the surrounding WiFi network;

Switch from WiMAX access network to WiFi network.

A switching service function entity, including:

a first receiving module, configured to receive, by using a WiMAX access network, a first request message sent by the terminal, where the first request message includes terminal location information;

An acquiring module, configured to obtain, according to the terminal location information carried in the first request message, information about WiFi network access points around the terminal from the access point information server, determine a target access point, and obtain the target access point Information is provided to the terminal through the first response message;

The first pre-authentication module is configured to initiate and complete a pre-authentication process of the terminal to the WiFi network.

A terminal, comprising:

a second pre-authentication module, configured to perform an pre-authentication process to an access point in the surrounding WiFi network by using an authentication server in the WiMAX core network;

A switching module for switching from a WiMAX access network to a WiFi network.

A switching system comprising: a handover service function entity, configured to receive, by using a WiMAX access network, a first request message sent by the terminal, where the first request message includes terminal location information, and the slave terminal location information carried in the first request message is accessed from the terminal The point information server obtains the WiFi network access point information around the terminal, determines the target access point, and provides the target access point information to the terminal through the first response message, and initiates and completes the pre-authentication of the terminal to the WiFi network. process;

The terminal is configured to perform a pre-authentication process to an access point in the surrounding WiFi network by using an authentication server in the WiMAX core network, and switch from the WiMAX access network to the WiFi network.

The embodiment of the invention provides a handover method, device and system. When a terminal switches from a WiMAX access network to a WiFi network, the terminal first uses the authentication server in the WiMAX core network to complete the pre-authentication process to the surrounding WiFi network access point. Then, turn off the WiMAX radio, turn on the WiFi radio, and switch from WiMAX to WiFi. Through the pre-authentication process to the surrounding WiFi network access point, the authentication process of the terminal selecting the WiFi network access point and the terminal to the WiFi network can be greatly reduced. The time required to ensure continuity of the business. 1 is a schematic diagram of a network architecture of a WiMAX network interacting with a WiFi network according to an embodiment of the present invention; FIG. 2 is a flowchart of a handover method according to an embodiment of the present invention;

FIG. 3 is a flowchart of a handover method according to an embodiment of the present invention;

4 is a flowchart of a handover method according to an embodiment of the present invention;

FIG. 5 is a flowchart of a handover method according to an embodiment of the present invention;

6 is a block diagram of a handover service function entity device according to an embodiment of the present invention;

FIG. 7 is a block diagram of a terminal device according to an embodiment of the present invention;

FIG. 8 is a block diagram of a handover system according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The switching method, device and system provided by the embodiments of the present invention are described in detail below with reference to the accompanying drawings.

Figure 1 shows the network architecture of the WiMAX network interacting with the WiFi network. These include WiMAX Access Network (WiMAX ASN), WiMAX Core Network (WiMAX CSN), and WiFi Access Network (WiFi ASN).

The WiMAX access network includes functional entities such as a WiMAX base station (BS), an access network gateway (ASN_GW), an external proxy, a DHCP (Dynamic Host Configuration Protocol) proxy (or relay), and an authenticator. DHCP proxy (or relay) address allocation server (DHCP service) in the terminal and WiMAX core network Forward an IP (Internet Protocol) address assignment message between the AAA server or the AAA server. When the terminal is connected to the WiMAX network, the authenticator cooperates with the AAA server in the core network to authenticate the terminal. The external proxy is configured to receive the packet sent by the home agent in the WiMAX core network when the terminal roams, and forward the packet to the roaming terminal.

The WiMAX core network includes a home agent (HA, also known as a home agent), an access point information server (IS), an authentication server (AAA, Authent ication Authorization Account), and address allocation. Server, etc. When the home agent roams the terminal, it receives the message sent by the communication partner to the terminal, forwards it to the external agent in the access network where the roaming terminal is currently located, and then forwards it to the terminal by the external agent, or directly to the terminal. The AAA server records and manages the user's account information, authenticates the terminal when the terminal initially enters the network or switches, and authorizes the terminal that passes the authentication. In the case of roaming, when the terminal is attached to the access network, the core network of the visited place may provide the function of the AAA proxy for the authentication of the terminal, and forward the relevant AAA message between the roaming terminal and the AAA server at the home of the terminal. The network access point information server is connected to a database that stores network topology information, including access point information in the WiMAX network and the WiFi network, such as location, power, operator, protocol version number, and associated external Network, etc. In order to assign an IP address to a terminal, the WiMAX core network usually also includes an address allocation server, which may be a DHCP server or a logical entity having a mobile IP address allocation function on the AAA server.

The WiFi access network is a Wireless Local Area Network (WLAN). When the terminal accesses the WiMAX core network through the WiFi access network, the terminal first connects to the access point of the WiFi access network using the WiFi protocol (Access Point). , AP), then connect to the WiMAX core network through the WiFi access network, and then reconnect to the Internet or other service network through the WiMAX network.

As shown in FIG. 1, the dotted line is the data path when the terminal UE connects from the WiFi access network to the WiMAX core network, and the solid line indicates the data path of the terminal from the WiMAX access network to the WiMAX core network.

Embodiment 1:

An embodiment of the present invention provides a handover method. As shown in FIG. 2, the method includes:

201. The first request message sent by the terminal is received by the WiMAX access network, where the first request message includes terminal location information.

When the terminal decides to switch from the WiMAX network to the WiFi network, the terminal sends a first request message to the handover service function entity in the WiMAX core network through the currently connected WiMAX access network, where the first request message includes at least terminal location information. The terminal location information includes current location information of the terminal; or location information of the terminal at least one time point, or a time interval at which the terminal obtains the two previous location information; or the current motion rate and direction of the terminal, and the radius of the current motion curve of the terminal. The specific sending process is that the first request message is first sent to the current terminal. The connected WiMAX base station is forwarded by the base station to the handover service function entity. The handover service function entity in the WiMAX network receives the first request message sent by the terminal and includes the terminal location information. In the embodiment of the present invention, the handover service function entity is located in the WiMAX CSN. In actual applications, the handover service function entity may also be located at a location other than the WiMAX CSN, such as in a WiAMX ASN, or in a WiFi ASN, or a WiMAX ASN and a WiFi ASN. between.

202. Obtain, according to the terminal location information carried in the first request message, the WiFi network access point information around the terminal from the access point information server, determine the target access point, and pass the target access point information to the first response. The message is provided to the terminal;

After receiving the first request message, the handover service function entity sends an access point information request message to the access point information server in the WiMAX network according to the terminal location information in the first request message, where the access point information request message includes The terminal location information requests the access point information of the WiFi network around the terminal. After receiving the access point information request message, the access point information server determines the WiFi network access point information around the location where the current terminal is located according to the terminal location information, or determines the neighboring WiFi network that the terminal is about to reach according to the motion trend of the terminal. Access points, and return these access point information to the handover service function entity through the access point information response message. The switching service function entity receives the access point information response message returned by the access point information server, determines the target access point in the target WiFi network, and sends a first response message to the terminal, indicating that the handover request of the terminal is accepted, A response message includes target access point information in the terminal target WiFi network.

The above method for obtaining a WiFi network access point around the terminal may have the following implementation manners:

(1) The access point information request message of the handover service function entity to the access point information server includes the current location and historical location or motion trend information of the terminal, and the access point information server returns the information of the access point that meets the requirement.

(2) The switching service function entity calculates the possible location of the terminal according to the current location and historical location or the motion trend information of the terminal, and sends the two location information to the access point information server, and the access point information server returns Access point information that covers both the current location of the terminal and the future location of the terminal.

(3) The switching service function entity calculates the possible location of the terminal according to the current location and historical location or the motion trend information of the terminal, and queries the access point information server to cover the specified location by using the current location and the future location respectively. Access point information, then find the intersection.

It should be noted that the steps calculated in the foregoing process may be completed by the handover service function entity or by the access point information server. In addition, the corresponding calculation step may also be performed by the terminal, and then directly carrying the information required for the access point information server to determine the peripheral access point of the terminal in the first request message.

203. Initiate and complete a pre-authentication process of the terminal to the target WiFi network.

After the handover service function entity determines the target access point, instructing the terminal to initiate the target WiFi network The pre-authentication process, at which point the terminal is still connected to the WiMAX network. The handover service function entity establishes a tunnel with the terminal through the WiMAX network and establishes a tunnel with the authentication server in the target WiFi network through the WiFi network. Before the terminal switches from the WiMAX access network access network to the WiFi network, the handover service function entity completes the target access in the terminal-to-target WiFi network by using the established tunnel between the terminal and the tunnel with the authentication server. Pre-certification of points.

When the terminal performs pre-authentication to the WiFi network through the WiMAX network, the terminal is still connected to the WiMAX access network, but when the terminal performs radio frequency switching after completing the pre-authentication to the WiFi network, the terminal will be in a period of time with WiMAX, WiFi. The two networks are not connected. In order to keep the existing services of the terminal uninterrupted, the handover service function entity needs to send a keep connection request to the home agent in the WiMAX network. After receiving the keep-alive request, the home agent performs related processing on the current terminal through the WiMAX network, including: marking that the connection is being switched, and also buffering the data for the connection, so that the cached data is completed after the handover is completed. Send to a new destination. The home agent returns a keep-alive response message to the handover service function entity, indicating acceptance of the connection request.

The embodiment of the invention further provides a switching method. As shown in FIG. 3, the method includes:

301. Using an authentication server in the WiMAX core network to complete a pre-authentication process to an access point in the surrounding WiFi network;

Before the pre-authentication process, the terminal further sends a first request message to the WiMAX access network, where the first request message includes terminal location information; and then the terminal receives the first response message returned by the WiMAX access network, where the first The response message includes target access point information in the terminal target WiFi network. The terminal may use the target access point included in the first response message as the target access point of the handover, and use the authentication server in the WiMAX core network to complete the pre-authentication process to the access point, or may select the access point by itself. Sending a second request message to the handover service function entity, where the second request message carries the target access point information selected by the terminal. .

302. Switching from the WiMAX access network to the WiFi network.

When the terminal is ready to switch from the WiMAX network to the WiFi network, the terminal turns off the WiMAX radio and turns on the WiFi radio to switch from the WiMAX access network to the WiFi network.

The embodiment of the present invention provides a handover method. When a terminal switches from a WiMAX access network to a WiFi network, the terminal first uses the authentication server in the WiMAX core network to complete the pre-authentication process to the surrounding WiFi network access point, and then closes. WiMAX radio, turn on the WiFi radio, switch from WiMAX to WiFi, and pass the pre-authentication process to the surrounding WiFi network access point, which can greatly reduce the time required for the terminal to select the WiFi network access point and the terminal to the WiFi network authentication process. To ensure continuity of business.

Embodiment 2: An embodiment of the present invention provides a handover method. As shown in FIG. 4, the method includes:

401. The first request message that is sent by the terminal and includes the location information of the terminal.

When the terminal decides to switch from the WiMAX network to the WiFi network, the terminal sends a first request message to the handover service function entity in the WiMAX core network through the currently connected WiMAX access network, where the first request message includes at least terminal location information. The terminal location information includes current location information of the terminal; or location information of the terminal at least one time point, or a time interval at which the terminal obtains two previous and second location information; or the current motion rate and direction of the terminal, and the current motion curve of the terminal The radius. The specific sending process is that the first request message is first sent to the WiMAX base station to which the terminal is currently connected, and is forwarded by the base station to the handover service function entity. The handover service function entity in the WiMAX network receives the first request message sent by the terminal and includes the current location information of the terminal. In the embodiment of the present invention, the handover service function entity is located in the WiMAX CSN. In actual applications, the handover service function entity may also be located at a location other than the WiMAX CSN, such as in a WiAMX ASN, or in a WiFi ASN, or a WiMAX ASN and a WiFi ASN. between.

402. Send, according to the location information, an access point information request message that includes current location information of the terminal to the access point information server, and request access point information of the WiFi network around the terminal.

The handover service function entity receives the first request message, according to the terminal location information in the first request message

The access point information server in the WiMAX network sends an access point information request message, where the access point information request message includes terminal location information, and requests access point information of the WiFi network around the terminal.

403. Receive an access point information response message returned by the access point information server.

After receiving the access point information request message, the access point information server determines the WiFi network access point information around the location where the current terminal is located according to the terminal location information, or determines the surrounding WiFi network that the terminal is about to reach according to the motion trend of the terminal. Access points, and return these access point information to the handover service function entity through the access point information response message. The handover service function entity receives the access point information response message returned by the access point information server.

(3) The switching service function entity calculates according to the current location and historical location or motion trend information of the terminal. The next possible location of the terminal is used to query the access point information server for the access point information covering the specified location with the current location and the future location, and then find the intersection.

404. Send a first response message that includes the target access point information in the terminal target WiFi network to the terminal, and instruct the terminal to initiate a pre-authentication process to the target WiFi network.

After receiving the access point information response message, the handover service function entity determines that the current terminal switches the target access point in the target WiFi network, and sends a first response message to the terminal, indicating that the handover request of the terminal is accepted, the first response The message includes target access point information in the terminal target WiFi network. The pre-authentication process is initiated to the peripheral target WiFi network, and the terminal is still connected to the WiMAX network.

It should be noted that, if the first request message sent by the terminal in step 401 is only used to query the WiFi access point information around the current location, and does not include the handover request indication to the WiFi network, the terminal needs to obtain the handover target. After the in-point handover, a second message needs to be sent to the handover function serving entity for requesting handover, and the second destination message for requesting handover carries the handover target access point information selected by the terminal, and the handover function service entity After making a decision on the handover request, sending a second response message to the terminal, and including an indication of whether to agree to the handover, if the handover service function entity initiates the pre-emption of the terminal to the target access point Certification process.

405. Establish a tunnel with the terminal through the WiMAX access network, and establish a tunnel with the authenticator in the target WiFi network through the WiFi network.

After determining the target access point information in the current terminal handover target WiFi network, the handover service function entity establishes a tunnel with the terminal through the WiMAX network, and establishes a tunnel with the authenticator in the target WiFi network through the WiFi network. .

406. Perform, by using the tunnel, pre-authentication of the target access point in the terminal to the target WiFi network; before the terminal switches from the WiMAX access network access network to the WiFi network, the handover service function entity utilizes the established The tunnel between the terminals and the tunnel with the authenticator completes the pre-authentication of the target access point in the terminal-to-target WiFi network.

407. Send a keep connection request to a home agent in the WiMAX core network.

When the terminal performs pre-authentication to the WiFi network through the WiMAX network, the terminal is still connected to the WiMAX network access network, but when the terminal performs radio frequency switching after completing the pre-authentication to the WiFi network, the terminal will have a period of time. In the state of being disconnected from both WiMAX and WiFi networks, in order to keep the existing services of the terminal uninterrupted, the handover service function entity needs to send a keep connection request to the home agent in the WiMAX network.

408. Receive a keep-alive response message indicating that the connection request is received by the home agent. After receiving the keep-alive request, the home agent performs related processing on the service performed by the current terminal through the WiMAX network, including: marking the connection. Switching, you can also cache data for this connection to send the cached data to the new destination after the switch is complete. The home agent returns a keep-alive response message to the handover service function entity, indicating acceptance of the connection request.

409. Receive a handover end message sent by the terminal.

After the terminal switches from the WiMAX network to the WiFi network, the terminal sends a handover end message to the handover service function entity through the WiFi network, indicating that the handover of the terminal from the WiMAX network to the WiFi network is completed. After the handover service function entity receives the handover end message, the terminal may The WiMAX access network connected before the terminal handover sends a resource release message to release the resources related to the terminal. This process has been involved in the prior art and will not be described here.

An embodiment of the present invention provides a handover method. As shown in FIG. 5, the method includes:

501. Send a first request message to the WiMAX access network, where the first request message includes terminal location information; the terminal location information includes current location information of the terminal; or location information of the terminal at least one time point. Or the time interval at which the terminal obtains the two pieces of position information before or after; or the current movement rate and direction of the terminal, and the radius of the current motion curve of the terminal. The specific sending process is that the first request message is first sent to the WiMAX base station to which the terminal is currently connected, and is forwarded by the base station to the handover service function entity. The handover service function entity in the WiMAX network receives the first request message sent by the terminal and includes the current location information of the terminal.

502. Receive a first response message returned by the WiMAX access network, where the first response message includes target access point information in the terminal target WiFi network.

The switching service function entity receives the first request message, and sends an access point information request message including terminal location information to the access point information server in the WiMAX network according to the terminal location information in the first request message, requesting to obtain the terminal periphery. Access point information for WiFi networks. The access point information server determines the WiFi network access point information around the location where the current terminal is located according to the terminal location information, or determines the access point of the surrounding WiFi network that the terminal is about to reach according to the motion trend of the terminal, and connects these access points. The point information is returned to the handover service function entity through the access point information response message. After receiving the access point information response message, the handover service function entity determines that the current terminal switches the target access point in the target WiFi network, and sends a first response message to the terminal, indicating that the handover request of the terminal is accepted, the first response The message includes the target access point in the terminal target WiFi network. Information.

503. Perform an pre-authentication process to an access point in the surrounding WiFi network by using an authentication server in the WiMAX core network;

The terminal may use the target access point in the first response message as the target access point of the handover, or may select another access point, send a second request message to the handover service function entity, and carry the terminal information in the second request message. Selected target access point information. The handover service function entity then initiates a pre-authentication process to the target access point. The pre-authentication process to the target access point is completed using the authentication server in the WiMAX core network.

504. Turn off the WiMAX radio and turn on the WiFi radio.

After the terminal completes the pre-authentication process to the access point in the surrounding WiFi network through the current WiMAX network, the terminal turns off the WiMAX radio unit and turns on the WiFi radio unit. If technically allowed, the terminal can turn on the WiFi radio in advance to receive only without transmitting, so that the access point of the WiFi network can be discovered in advance without disturbing the communication on the WiMAX radio, thereby speeding up the handover process.

505. Scan a surrounding WiFi network access point, and select an access point that can support the current service of the terminal from the WiFi network access points that may be scanned by using the access point information obtained from the access point information server;

After the terminal turns on the WiFi radio, the terminal can passively scan the WiFi access point. The so-called passive scanning means that the terminal does not send a message to the outside, but passively receives the beacon frame periodically sent by the WiFi access point, and can receive the beacon. The frame indicates that there is a WiFi access point nearby, and can obtain some necessary information from the beacon frame, such as service network information that can be accessed through the access point. If the terminal turns off the WiMAX radio and turns off the WiMAX radio, the terminal can also use the active scanning method to find the WiFi access point. The so-called active scanning means that the terminal actively sends the probe request frame and carries the relevant information in the probe request frame. After receiving the probe request frame, the WiFi access point sends a probe response frame to the terminal if it determines that it meets the filter condition in the probe request frame. The terminal determines the presence of the WiFi access point by receiving the probe response frame, and obtains the capability of the WiFi access point, the information of the accessible service network, and the like from the probe response frame. The terminal combines the access point information obtained from the handover response message, and selects an access point from the scanned WiFi access point that can access the currently used WiMAX core network for subsequent connection work. The specific process of the terminal scanning the access point and selecting the access point is described in the IEEE 802.11 basic protocol and the 802.llu supplementary protocol, which are not described in detail herein.

506. Associate with the selected WiFi network access point.

After selecting the determined AP, the terminal associates with the AP, and initiates the authentication process to the WiFi network after the association is completed. The authentication process is specified in the 802. lx protocol and is referenced in the 802.11 protocol.

507. Receive an authentication request message sent by an authenticator in a WiFi network, where the authentication request message includes a request. The terminal provides information of its identity;

The authenticator in the WiFi network sends an authentication request message to the terminal requesting the identification information of the terminal.

508. The identifier information of the terminal is returned to the authenticator, and the identifier information is forwarded by the authenticator to an authentication server in a global microwave interconnection access core network.

The terminal returns the identification information of the terminal to the authenticator. After receiving the identification information, the authenticator forwards the identification information to the authentication server in the WiMAX core network, that is, the AAA server. The AAA server checks whether the identity information already exists, that is, whether the terminal has been registered. Because the terminal is connected to the WiMAX core network through the WiMAX access network, the AAA server already has the identification information of the terminal, and then the AAA server verifies the authenticity of the terminal according to the 802. lx protocol, and the authenticator is in the AAA server and the terminal. The authentication message is forwarded until the authentication is completed.

509. Negotiate a pairwise temporary key for a session with the authenticator, or directly interact with the authentication server to generate a paired temporary key for the session;

When the authentication is completed, the authenticator negotiates a pairwise temporary key for the session with the terminal, or the terminal directly interacts with an authentication server in the WiMAX core network to generate a paired temporary key for the session. After the terminal switches to the WiFi network, the key can be used to protect the communication between the terminal and the access point. These procedures are described in detail in the IEEE 802.11 protocol and will not be repeated here.

510. Obtain a network address by using a WiFi network, where the network address includes a home address and a care-of address; after completing the authentication process to the WiFi network, the terminal needs to allocate a network address to the WiFi network, and the process can be completed by using a DHCP protocol. The WiFi access network has a DHCP proxy or DHCP relay (re 1 ay) function that forwards DHCP messages to an IP (Network Protocol) address allocation server in the WiMAX network. The DHCP relay function simply forwards DHCP messages between the terminal and the address assignment server. However, in the case of a DHCP proxy, the IP address allocation server in the WiMAX core network should use a DHCP server. The DHCP proxy can also terminate the DHCP message and use other address allocation protocols, such as the Mobile IP protocol, to request an IP address from the AAA server in the WiMAX network. The DHCP proxy is called a DHCP proxy. Through the above two methods, the terminal can obtain an IP address through the WiFi network using only the DHCP protocol. The terminal can also directly use the mobile IP protocol. At this time, the WiFi access network has an external proxy for receiving the message that the terminal requests the network address.

The network address actually assigned to the terminal during the above address allocation process includes the home address and the care-of address of the terminal. The home address is generally unchanged, and the care-of address is sent directly to the terminal when the terminal uses the mobile IP protocol, which is also the address used by the terminal. When the terminal uses the DHCP protocol, the care-of address is only recorded on the access network side, and is not directly sent. To the terminal, the terminal does not know the existence of this address. For the DHCP protocol and mobile IP protocol, please refer to WiMAX existing Specifications, not described in detail here.

When the terminal uses the DHCP protocol, the WiFi network can also assign an IP address to the terminal in other ways. For example, the WiFi network can assign a private network address to the terminal, and then obtain a public network address from the WiMAX core network or use only the external public network. The address is then NAT/NAPT (Network Address and Port Translation) conversion for messages from the terminal or to the terminal.

In the process of obtaining the IP address by the terminal, the address assignment entity in the WiFi access network, that is, the DHCP proxy or the mobile IP foreign proxy, after obtaining the new care-of address assigned to the terminal, passes the new care-of address through the address binding update message. Send to the home agent in the WiMAX core network. In this way, the home agent can tunnel the message that should be sent to the terminal to the new care-of address. If the mobile IP protocol is not used, the address binding update message may be sent by the DHCP proxy to the core router in the WiMAX core network. The address binding update message includes the terminal's new globally routable IP address, which should be addressed by the WiMAX core router. The message sent to the terminal is sent to the new IP address. In this case, the communication peer needs to know the new IP address of the terminal.

The process of sending an address binding update message to a home agent or WiMAX core router by a DHCP proxy or foreign agent in the WiFi access network may occur during the address assignment process or after the address assignment is completed.

In the last step of address allocation, if the terminal uses the DHCP protocol, the terminal will receive a DHCP response message, or when the terminal uses the mobile IP protocol, the terminal will receive a mobile IP response message, and the terminal receives the above message. After that, it indicates that the address allocation process ends.

511. Send a handover end message to the handover service function entity in the WiMAX core network, indicating that the WiMAX access network is switched to the WiFi network.

The terminal sends a handover end message to the handover service function entity in the WiMAX core network through the WiFi access network. At this point, the handover process of the terminal from the WiAMX network to the WiFi network is completed.

It should be noted that after the handover service function entity receives the handover end message, it may send a resource release message to the WiMAX access network to which the terminal is originally attached to release resources related to the terminal.

Through the above process, the terminal completes the process of switching from the WiMAX access network to the WiFi network, and the service is not interrupted during the handover process. In the exceptional case, if the terminal does not scan for an available WiFi network access point in step 503, or the authentication of the terminal and the AAA server fails in step 506, or the address assignment process fails in step 508, the terminal may switch back. To the WiMAX access network, because the resources related to the terminal in the WiMAX access network are still reserved and are not released, the terminal only needs to send a revocation switching message to the handover service function entity, indicating that the handover process is cancelled, and then The handover service function entity sends a resume connection message to the home agent or core router to restore the previous connection, and the terminal can continue to use the service through the WiMAX access network. The embodiment of the present invention provides a handover method. When a terminal switches from a WiMAX access network to a WiFi network, the terminal first uses the authentication server in the WiMAX core network to complete the pre-authentication process to the surrounding WiFi network access point, and then closes. WiMAX radio, turn on the WiFi radio, switch from WiMAX to WiFi, and pass the pre-authentication process to the surrounding WiFi network access point, which can greatly reduce the time required for the terminal to select the WiFi network access point and the terminal to the WiFi network authentication process. To ensure continuity of business.

Embodiment 3:

The embodiment of the present invention provides a handover service function entity. As shown in FIG. 6, the handover service function entity includes a first receiving module 601, an obtaining module 602, and a first pre-authentication module 603.

The first receiving module 601 is configured to receive, by using a WiMAX access network, a first request message sent by the terminal, where the first request message includes terminal location information, and the acquiring module 602 is configured to be used according to the first request message. The terminal location information, obtaining the WiFi network access point information of the terminal from the access point information server, determining the target access point, and providing the target access point information to the terminal by using the first response message; the first pre-authentication module 603 is used to initiate and complete a pre-authentication process of the terminal to a WiFi network.

The handover service function entity further includes an indication module 604 for transmitting a keep-alive request message to the home agent in the WiMAX core network, indicating that the current service of the terminal is maintained.

In the embodiment of the present invention, the handover service function entity is located in the WiMAX CSN. In actual applications, the handover service function entity may also be located at a location other than the WiMAX CSN, such as in a WiAMX ASN, or in a WiFi ASN, or a WiMAX ASN and a WiFi ASN. between.

The embodiment of the present invention provides a terminal. As shown in FIG. 7, the terminal includes a second pre-authentication module 701 and a handover module 702.

The second pre-authentication module 701 is configured to complete the pre-authentication process to the access point in the peripheral WiFi network by using the authentication server in the WiMAX core network; the handover module 702 is configured to switch from the WiMAX access network to the WiFi network.

The terminal further includes a first sending module 703 and a second receiving module 704.

The first sending module 703 is configured to send a first request message to the WiMAX access network, where the first request message includes terminal location information, and the second receiving module 704 is configured to receive the first response message returned by the WiMAX access network. And the first response message includes target access point information in the terminal target WiFi network. The second pre-authentication module 701 can use the target access point in the first response message as the target access point for handover, and complete the pre-authentication process to the target access point by using the authentication server in the WiMAX core network.

The handover template 702 includes an authentication submodule 705, an acquisition submodule 706, and a second transmission submodule 707. The authentication submodule 705 is configured to be associated with the WiFi network access point and authenticated; the obtaining submodule 706 For obtaining a network address by using a WiFi network, where the network address includes a home address and a care-of address; the second sending sub-module 707 is configured to send a handover end message to the handover service function entity in the WiMAX core network, indicating that the WiMAX is The access network switches to the WiFi network.

The authentication sub-module 705 includes an association unit 708, a receiving unit 709, and a sending unit 710.

The association unit 708 is configured to be associated with the selected WiFi network access point; the receiving unit 709 is configured to receive

An authentication request message sent by the authenticator in the WiFi network, the authentication request message requesting the identification information of the terminal; the sending unit 710 is configured to return the identifier information of the terminal to the authenticator, and the identifier is used by the authenticator The identification information is forwarded to an authentication server in the WiMAX core network, the authenticator negotiates a pairwise temporary key for the session with the terminal, or the terminal directly interacts with an authentication server in the WiMAX core network, and is generated for The paired temporary key for the session.

The embodiment of the invention provides a handover service function entity and a terminal. When the terminal switches from the WiMAX access network to the WiFi network, the terminal first uses the authentication server in the WiMAX core network to complete the pre-authentication process to the surrounding WiFi network access point. Then, turn off the WiMAX radio, turn on the WiFi radio, and switch from WiMAX to WiFi. Through the pre-authentication process to the surrounding WiFi network access point, the authentication process of the terminal selecting the WiFi network access point and the terminal to the WiFi network can be greatly reduced. The time required to ensure continuity of the business.

Embodiment 4:

The embodiment of the present invention provides a handover system. As shown in FIG. 8, the system includes a handover service function entity 81 and a terminal 82.

The switching service function entity 81 is located in the WiMAX core network, and is configured to receive, by using a WiMAX access network, a first request message sent by the terminal, where the first request message includes terminal location information, and is carried according to the first request message. The terminal location information, obtaining the WiFi network access point information around the terminal from the access point information server, determining the target access point, and providing the target access point information to the terminal by using the first response message, initiating and completing the The pre-authentication process of the terminal to the WiFi network; the terminal 82 is configured to complete the pre-authentication process to the access point in the surrounding WiFi network by using the authentication server in the WiMAX core network, turn off the WiMAX radio frequency, and turn on the WiFi network radio frequency, from the WiMAX The access network switches to the WiFi network.

The terminal is further configured to send a first request message to the WiMAX access network, and receive a first response message returned by the WiMAX access network. The system further includes an access point information server 83, and the access point information server 83 is located in the WiMAX core network, and is configured to receive an access point information request message that is sent by the handover service function entity and includes current location information of the terminal, according to the The location information determines a WiFi network access point around the terminal, and returns an access point information response message to the handover service function entity.

The system also includes a home agent 84 in the WiMAX core network for receiving a keep-alive request sent by the handover service function entity and returning to the handover service function entity a keep-alive response message indicating acceptance of the connection request.

The system further includes an authenticator 85 in the WiFi network, configured to send an authentication request message to the terminal, receive the identification information returned by the terminal, and forward the identification information to the authentication in the global microwave interconnection access core network. The server negotiates a paired temporary key for the session with the terminal.

The system also includes an authentication server 86 in the WiMAX core network for receiving identification information sent by the authenticator, interacting with the terminal, and generating a paired temporary key for the session.

The handover service function entity 81 is further configured to send a keep connection request to the home agent in the WiMAX core network, to indicate that the current connection of the terminal is maintained, and to receive a keep connection response message returned by the home agent indicating acceptance of the connection request.

As shown in Figure 8, the workflow of the system is introduced:

901. The terminal sends a first request message to the handover service function entity.

When the terminal decides to switch from the WiMAX network to the WiFi network, the terminal sends a first request message to the handover service function entity in the WiMAX core network through the currently connected WiMAX access network, where the first request message includes at least terminal location information. . The specific sending process is that the first request message is first sent to the WiMAX base station to which the terminal is currently connected, and is forwarded by the base station to the handover service function entity.

902. The handover service function entity sends an access point information request message to the access point information server. The handover service function entity receives the first request message, and sends the access point information in the WiMAX network according to the terminal location information in the first request message. The server sends an access point information request message, where the access point information request message includes terminal location information, and requests access point information of the WiFi network around the terminal.

903. The access point information server returns an access point information response message to the handover service function entity. After receiving the access point information request message, the access point information server determines, according to the terminal location information, a WiFi network connection around the current terminal location. Incoming point information, or determining the access point of the surrounding WiFi network that the terminal is about to reach according to the trend of the terminal, and returning the access point information to the switching service function entity through the access point information response message. 904. The handover service function entity sends a first response message that includes the target access point information in the WiFi network of the terminal destination to the terminal, and instructs the terminal to initiate a pre-authentication process to the target WiFi network.

It should be noted that, if the first request message sent by the terminal in step 901 is only used to query the WiFi access point information around the current location, and does not include the handover request indication to the WiFi network, the terminal needs to obtain the handover target. After the in-point handover, a second message needs to be sent to the handover function serving entity for requesting handover, and the second destination message for requesting handover carries the handover target access point information selected by the terminal, and the handover function service entity After making a decision on the handover request, sending a second response message to the terminal, and including an indication of whether to agree to the handover, if the handover service function entity initiates the pre-emption of the terminal to the target access point Certification process.

905. The terminal completes the pre-authentication process to the WiFi network through the WiMAX network.

After determining the target access point information in the current terminal handover target WiFi network, the handover service function entity establishes a tunnel with the terminal through the WiMAX network, and establishes a tunnel with the authenticator in the target WiFi network through the WiFi network. . The handover service function entity uses the established tunnel between the terminal and the tunnel with the authenticator to complete the pre-authentication of the terminal to the access point in the surrounding WiFi network.

906. The handover service function entity sends a keep connection request message to the home agent.

When the terminal performs pre-authentication to the WiFi network through the WiMAX network, the terminal is still connected to the WiMAX network access network, but when the terminal performs radio frequency switching after completing the pre-authentication to the WiFi network, the terminal will be in contact with WiMAX for a period of time. The two networks are not connected to each other. In order to keep the existing services of the terminal uninterrupted, the handover service function entity needs to send a keep connection request to the home agent in the WiMAX network.

907. The home agent returns a keep-alive response message to the handover service function entity.

After receiving the keep-alive request, the home agent performs related processing on the current terminal through the WiMAX network, including: marking that the connection is being switched, and also buffering the data for the connection, so that the cached data is completed after the handover is completed. Send to a new destination. The home agent returns a keep-alive response message to the handover service function entity, indicating acceptance of the connection request.

908. The terminal switches the radio frequency mode.

After the terminal completes the pre-authentication process to the access point in the surrounding WiFi network through the current WiMAX network, Turn off the WiMAX radio unit and turn on the WiFi radio unit. If technically allowed, the terminal can open the WiFi radio in advance for receiving only and not transmitting, so that the access point of the WiFi network can be discovered in advance without causing interference to the communication on the WiMAX radio, thereby speeding up the handover process.

909. The terminal scans the surrounding WiFi network access point, and selects an access point that can support the current service of the terminal from the possible access to the WiFi network access point, and associates with the access point information obtained from the access point information server. The selected WiFi network access point initiates the authentication process to the WiFi network;

After the terminal turns on the WiFi radio, the terminal can passively scan the WiFi access point. The so-called passive scanning means that the terminal does not send a message to the outside, but passively receives the beacon frame periodically sent by the WiFi access point, and can receive the beacon. The frame indicates that there is a WiFi access point nearby, and can obtain some necessary information from the beacon frame, such as service network information that can be accessed through the access point. If the terminal turns off the WiMAX radio and turns off the WiMAX radio, the terminal can also use the active scanning method to find the WiFi access point. The so-called active scanning means that the terminal actively sends the probe request frame and carries the relevant information in the probe request frame. After receiving the probe request frame, the WiFi access point sends a probe response frame to the terminal if it determines that it meets the filter condition in the probe request frame. The terminal determines the presence of the WiFi access point by receiving the probe response frame, and obtains the capability of the WiFi access point, the information of the accessible service network, and the like from the probe response frame. The terminal combines the access point information obtained from the handover response message, and selects an access point from the scanned WiFi access point that can access the currently used WiMAX core network for subsequent connection work. The specific process of the terminal scanning the access point and selecting the access point is described in the IEEE 802.11 basic protocol and the 802. l lu supplemental protocol, which are not described in detail herein.

After selecting the determined AP, the terminal associates with the AP, and initiates the authentication process to the WiFi network after the association is completed.

910. The terminal completes an authentication process to the WiFi network.

The authenticator in the WiFi network sends an authentication request message to the terminal requesting the identification information of the terminal. The terminal returns the identification information of the terminal to the authenticator. After receiving the identification information, the authenticator forwards the identification information to the authentication server in the WiMAX core network, that is, the AAA server. The AAA server checks whether the identity information already exists, that is, whether the terminal has been registered. Because the terminal is connected to the WiMAX core network through the WiMAX access network, the AAA server already has the identification information of the terminal, and then the AAA server verifies the authenticity of the terminal according to the 802. lx protocol, and the authenticator is in the AAA server and the terminal. The authentication message is forwarded until the authentication is completed. After the authentication is completed, the authenticator negotiates a pairwise temporary key for the session with the terminal, or the terminal directly interacts with an authentication server in the WiMAX core network to generate a paired temporary key for the session. In the future, the terminal can formally access the WiFi network and protect the terminal by using the session key derived from the master key between the paired devices. Communication with the access point. These procedures are described in detail in the IEEE 802.11 protocol and will not be repeated here. 911. The terminal obtains a network address through a WiFi network.

After completing the authentication process to the WiFi network, the terminal needs to assign a network address to the WiFi network. This process can be completed through the DHCP protocol. The WiFi access network has a DHCP proxy or DHCP relay (re 1 ay) function that forwards DHCP messages to an IP (Network Protocol) address allocation server in the WiMAX network. The DHCP relay function simply forwards DHCP messages between the terminal and the address assignment server. However, in the case of a DHCP proxy, the IP address allocation server in the WiMAX core network should use a DHCP server. The DHCP proxy can also terminate the DHCP message and use other address allocation protocols, such as the Mobile IP protocol, to request an IP address from the AAA server in the WiMAX network. The DHCP proxy is called a DHCP proxy. Through the above two methods, the terminal can obtain an IP address through the WiFi network using only the DHCP protocol. The terminal can also directly use the mobile IP protocol. At this time, the WiFi access network has an external proxy for receiving the message that the terminal requests the network address.

The address actually assigned to the terminal in the above address allocation process includes the home address (H0A) and the care-of address (C0A) of the terminal, and the home address is generally unchanged, and the care-of address is directly sent to the terminal when the terminal uses the mobile IP protocol, which is also the terminal. Address used; When the terminal uses the DHCP protocol, the care-of address is only recorded on the access network side, and is not directly sent to the terminal. The terminal does not know the existence of this address. For the DHCP protocol and the mobile IP protocol, refer to the existing WiMAX specifications, which will not be described in detail here.

The DHCP proxy or external proxy in the WiFi access network sends address bindings to the home agent or WiMAX core router. The process of updating the message can occur during the address assignment process or after the address assignment is completed.

In the final step of address allocation, if the terminal uses the DHCP protocol, the terminal will receive a DHCP response. Answer message, or when the terminal uses the mobile IP protocol, the terminal will receive a mobile IP response message, and after the terminal receives the above message, it indicates that the address allocation process ends.

912. The terminal sends a handover end message to the handover service function entity.

It should be noted that after the handover service function entity receives the handover end message, according to the resource management policy of the network, it may be necessary to send a resource release indication message to the original WiMAX access network used by the terminal to release resources related to the terminal.

Through the above process, the terminal completes the handover process from the WiMAX network to the WiFi network, and can maintain the continuity of the service during the switching process. The exception is if, in step 909, the terminal does not scan any available WiFi network access points, or in step 910, the authentication of the terminal with the AAA server fails, or in step 911, the address allocation process fails, the terminal can return again. To the WiMAX access network, the resources related to the terminal in the original WiMAX network are still reserved, and the terminal only needs to send the revocation handover message to the handover service function entity, indicating that the handover process is cancelled, and then the handover service function entity sends the handover to the home agent. By resuming the connection message to restore the previous connection, the terminal can continue to use the service over the WiMAX access network.

The embodiment of the present invention provides a handover system. When a terminal switches from a WiMAX access network to a WiFi network, the terminal first uses the authentication server in the WiMAX core network to complete the pre-authentication process to the surrounding WiFi network access point, and then closes. WiMAX radio, turn on the WiFi radio, switch from WiMAX to WiFi, and pass the pre-authentication process to the surrounding WiFi network access point, which can greatly reduce the time required for the terminal to select the WiFi network access point and the terminal to the WiFi network authentication process. To ensure continuity of business. The above is only the specific embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily think of changes or substitutions within the technical scope of the present invention. It should be covered by the scope of the present invention. Therefore, the scope of the invention should be determined by the scope of the claims.

Claims

Rights request

A switching method, comprising:

The handover method according to claim 1, wherein the terminal location information comprises: location information of the terminal; or location information of the terminal at least one time point, or time when the terminal obtains two location information before and after Interval; or the current motion rate and direction of the terminal, the radius of the current motion curve of the terminal.

The handover method according to claim 1, wherein before the initiating and completing the pre-authentication process of the terminal to the WiFi network, the method further includes:

And receiving, by the terminal, a second request message sent by the WiMAX access network, where the second request message carries the selected target access point information.

The handover method according to claim 1, wherein after the initiating and completing the pre-authentication process of the terminal to the wireless fidelity network, the method further includes:

A keep-alive request message is sent to the home agent in the WiMAX core network to indicate that the current connection to the terminal is maintained.

5. A switching method, comprising:

The pre-authentication process to the access point in the surrounding WiFi network is completed by using the authentication server in the WiMAX core network; the WiMAX access network is switched to the WiFi network.

The handover method according to claim 5, wherein before the pre-authentication process of the access point in the peripheral WiFi network is completed by using the authentication server in the WiMAX core network, the method further includes:

Sending a first request message to the WiMAX access network, where the first request message includes terminal location information; receiving a first response message returned by the WiMAX access network, where the first response message includes the terminal target WiFi network Target access point information.

The handover method according to claim 6, wherein the terminal location information comprises: location information of the terminal; or location information of the terminal at least one time point, or time when the terminal obtains two location information before and after Interval; or the current motion rate and direction of the terminal, the radius of the current motion curve of the terminal.

The handover method according to claim 5, wherein the switching from the WiMAX access network to the WiFi network comprises:

Associated with a WiFi network access point and authenticated;

Obtaining, by the WiFi network, a network address, where the network address includes a home address and a care-of address; sending a handover end message to the handover service function entity in the WiMAX core network, indicating that the WiFi is switched from the WiMAX access network to the WiFi The internet.

The handover method according to claim 8, wherein the associating to the WiFi network access point and performing the authentication comprises:

Scan the surrounding WiFi network access point and select an access point from the scanned one or more WiFi network access points to access the WiMAX access network.

Associated to the selected WiFi network access point;

Receiving an authentication request message sent by an authenticator in the WiFi network, where the authentication request message requests identification information of the terminal;

Returning the identification information of the terminal to the authenticator.

10. A handover service function entity, comprising:

The handover service function entity according to claim 10, further comprising: an indication module, configured to send a keep connection request message to the home agent in the WiMAX core network, to indicate that the current service of the terminal is maintained.

12. A terminal, comprising:

A switching module for switching from a WiMAX access network to a WiFi network.

The terminal according to claim 12, further comprising:

a first sending module, configured to send a first request message to the WiMAX access network, where the first request message includes Terminal location information;

And a second receiving module, configured to receive a first response message returned by the WiMAX access network, where the first response message includes target access point information that the second pre-authentication module is to perform a pre-authentication process.

The terminal according to claim 12, wherein the switching module comprises:

An authentication submodule, configured to associate to a WiFi network access point and perform authentication;

Obtaining a sub-module, configured to acquire a network address by using the WiFi network, where the network address includes a home address and a care-of address;

And a second sending submodule, configured to send a handover end message to the handover service function entity in the WiMAX core network, indicating that the WiMAX access network is handed over to the WiFi network.

The terminal according to claim 14, wherein the authentication submodule comprises: an association unit, configured to associate to a selected WiFi network access point;

a receiving unit, configured to receive an authentication request message sent by an authenticator in a WiFi network, where the authentication request message requests identification information of the terminal;

And a sending unit, configured to return, to the authenticator, identification information of the terminal.

16. A switching system, comprising:

a handover service function entity, configured to receive, by using a WiMAX access network, a first request message sent by the terminal, where the first request message includes terminal location information, and the slave terminal location information carried in the first request message is accessed from the terminal The point information server obtains the WiFi network access point information around the terminal, determines the target access point, and provides the target access point information to the terminal through the first response message, and initiates and completes the pre-authentication of the terminal to the WiFi network. Process

The switching system according to claim 16, wherein the terminal is further configured to send a first request message to the WiMAX access network, and receive a first response message returned by the WiMAX access network.

The switching system according to claim 16, further comprising:

The access point information server is configured to receive an access point information request message that is sent by the handover service function entity and includes the terminal location information, and determine, according to the location information, a WiFi network access point around the terminal, and The handover service function entity returns an access point information response message.

The switching system according to claim 16, further comprising:

a home agent, configured to receive a keep connection request message sent by the handover service function entity, and to the The service function entity returns a keep connection response message indicating acceptance of the connection request.

The switching system according to claim 16, further comprising:

An authenticator, configured to send an authentication request message to the terminal, receive the identifier information returned by the terminal, and forward the identifier information to an authentication server in the global microwave interconnection access core network, and negotiate with the terminal to use The paired temporary key for the session.

And an authentication server, configured to receive the identifier information sent by the authenticator, interact with the terminal, and generate a paired temporary key for the session.