JP2007088586A - Handoff system and method in multimedia mobile network of internet protocol base - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for performing handoff of connection of a mobile apparatus from a first access point to a second access point. <P>SOLUTION: The method includes a step 304 of scanning a network with regard to a plurality of available access points, a step 310 of comparing connection strength each of the plurality of available access points for a mobile apparatus with a predetermined margin, a step 320 of authenticating an access point determined that the connection strength exceeds a predetermined margin, a step 322 of adding an authenticated access point to a relevant table, a step 328 of comparing the connection strength for the first access point with a predetermined margin, a step 330 of selecting the authenticated access point as a second access point when the connection strength for the first access point exceeds the predetermined margin, and a step 336 of deleting the first access point from the relevant table. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates generally to mobile communication systems, and more particularly, to systems and methods for handoff in Internet Protocol (IP) based multimedia mobile networks.

  In a mobile communication system, such as an IP-based multimedia mobile network, service continuity as mobile end users move between service areas associated with the system's access points (APs). And it is important that quality is maintained. This is especially true for real-time applications such as VoIP, video over IP, video conferencing, and instant messaging. It is generally recognized that connection latency between mobile devices should not exceed 50 milliseconds. Current technology requires hundreds of milliseconds to switch from one access point to another.

  The conventional system and method for providing handoff management utilizes the concept of anchors as disclosed in “Mobility Management for a Multimedia Mobile Network” in US Pat. System to be included. An anchor is a network node assigned to a mobile user station that functions until a packet is deleted or changed as a permanent node that is sent intermediately. The anchor sends the packet to the mobile station regardless of where it moved in the system. Thus, the packet is directed to the anchor from which the packet is directed to the mobile station. If the mobile station is sufficiently far from its anchor, the system makes the decision to change the mobile station's anchor to a closer network node so that packet routing is optimized.

Another handoff management system is disclosed in Patent Document 2 “Mobility Management Techniques for Use in an Internet Protocol-Based Multimedia Mobile Network”. It is disclosed. Each network node comprises a handoff module that is responsible for collecting relevant information from neighboring nodes. Mobiles communicating with network nodes assist in handoff decisions by providing signal strength information from neighboring nodes. Based on the information in the process, the handoff manager determines when and to which node the mobile should be handed off.
US Pat. No. 6,160,804 US Pat. No. 6,735,202

  While prior art systems and methods provide handoff management, there remains a need for systems and methods for handoff in IP-based multimedia mobile networks that further reduce connection latency.

  The system and method of the present invention includes creating a plurality of virtual related clients in a mobile device. A virtual association client establishes an association between a mobile device and multiple access points without establishing a connection between them.

  According to one aspect of the invention, a method for handing off a mobile device connection from a first access point to a second access point in a multimedia mobile network comprises: Scanning, comparing the connection strength of each of the plurality of available access points to the mobile device with a predetermined margin, and authenticating an access point determined to have a connection strength exceeding the predetermined margin Adding the authenticated access point to the association table; comparing the connection strength for the first access point with a predetermined margin; and the connection strength for the first access point with a predetermined margin. Authenticated access if below Including selecting a point as a second access point, and a step of deleting from the associated table the first access point.

  According to another aspect of the invention, a system for handing off a mobile device connection from a first access point to a second access point in a multimedia mobile network is connected to the first access point. A mobile device that scans the network for available access points, compares the connection strength with each of the available access points against a predetermined margin, and Authenticates an access point that is determined to exceed a predetermined margin, adds the authenticated access point to the association table, compares the connection strength for the first access point with the predetermined margin, Authenticated if the connection strength to the access point is below the specified margin Select an access point as a second access point is operable to first access point to delete from the associated table.

  According to yet another aspect of the present invention, a method for handing off a mobile device connection from a first access point to a second access point in a multimedia mobile network includes a plurality of available access points. Scanning the network for, comparing the connection strength of each of the plurality of available access points to the mobile device with a predetermined margin, and determining the access point that the connection strength is determined to exceed the predetermined margin. Authenticating, adding the authenticated access point to the association table, comparing the connection strength for the first access point with a predetermined margin, and the connection strength for the first access point is predetermined. Authenticated if below the margin of Including selecting the access point as a second access point, and connecting the mobile device to the second access point, and a step of deleting from the associated table the first access point.

The foregoing and other features, aspects, and advantages of the present invention will be better understood with reference to the drawings, detailed description, and claims.
The following detailed description is the best mode for carrying out the invention. Since the scope of the present invention is defined by the appended claims, this description should not be construed as limiting, but as provided for the purpose of illustrating the general principles of the invention. It is.

  The present invention generally provides a system and method for handoff in an IP-based multimedia mobile network that includes creating a plurality of virtual associated clients on a mobile device. A virtual association client establishes an association between a mobile device and multiple access points without establishing a connection between them.

  Referring to FIG. 1, mobile communication system 100 includes a plurality of mobile devices 102 connected to a plurality of access points 120 via links 110. The plurality of access points 120 are connected via a link 130. Mobile device 102 may include a wireless telephone and other multimedia communication devices. Access point 120 may include fixed or mobile routers, network nodes, and gateways. Links 110 and 130 are preferably wireless links. Although only two mobile devices 102 and two access points 120 are shown, those skilled in the art will appreciate that the system and method of the present invention can accommodate many such mobile devices 102 and access points 120. Will be understood.

  As shown in FIG. 2, the mobile device 102 and access point 120 include a processor 200 that is connected to a memory 210 and a transceiver 220. An antenna 230 may be connected to the transceiver 220. The processor 200 is operable to perform the steps of the handoff method according to an aspect of the present invention. Memory 210 is operable to store program instructions for performing the steps of the methods described herein and storing association tables.

  A method 300 for handoff in an IP-based multimedia mobile network from a first access point to which a mobile device 102 is connected to a second access point to which the mobile device 102 is not yet connected includes: It is shown in FIG. In step 304, a plurality of second access points 120 available to the mobile device 102 are scanned. The availability of the second access point 120 is determined by factors including signal strength and signal quality. In step 308, a determination is made whether there is a second access point 120 available. If there are no available second access points 120, return to step 304 and if there is any, the connection strength is evaluated for each of the available second access points 120 in step 310. The

  If the connection strength does not exceed the predetermined margin for all the second access points 120, the process returns to step 304. If any one of the connection points exceeds 120, the association table 400 (FIG. 4) is looped in step 314. . The second access point 120 whose connection strength is below the predetermined margin is deleted from the association table 400 at step 318. A second access point 120 whose connection strength exceeds a predetermined margin is authenticated in step 320. Authentication includes establishing a virtual connection between the mobile device 102 and its second access point 120. In step 322, each authenticated second access point 120 is added to the association table 400 and the virtual association client sent to the mobile device 102.

  In step 324, the connection strength of the mobile device 102 with the first access point 120 is ascertained. The connection strength with the first access point 120 is compared with a predetermined margin in step 328. If the connection strength exceeds the predetermined margin, the process returns to step 304. If not, in step 330, the second access point 120 with the best signal strength and signal quality is selected as the optimal associated access point 120, and the mobile device 102 connects to the optimal associated access point 120. Is done. In step 332, the first access point 120 is deleted from the association table 400. In step 334, the first access point 120 is unauthenticated and deleted from the association table 400 in step 336. The method then returns to step 304.

  A system for providing handoff in an IP-based multimedia mobile network includes program instructions that are stored in memory 210 for processor 200 to perform method 300.

  Of course, it will be understood that the foregoing description relates to preferred embodiments of the invention and that changes may be made without departing from the spirit and scope of the invention.

1 is a schematic diagram of a mobile communication system according to the present invention. 1 is a schematic diagram of a mobile device and access point according to the present invention. 3 is a flow chart of a handoff method according to the present invention. The related table by this invention.

Explanation of symbols

102: Mobile device, 120: Access point

Claims (3)

A method of handing off a mobile device connection from a first access point to a second access point in a multimedia mobile network comprising:
Scanning the network for multiple available access points;
Comparing the connection strength of each of the available access points to the mobile device against a predetermined margin;
Authenticating an access point whose connection strength is determined to exceed the predetermined margin;
Adding the authenticated access point to an association table;
Comparing the connection strength for the first access point with the predetermined margin;
Selecting the authenticated access point as the second access point if the connection strength to the first access point is below the predetermined margin;
Deleting the first access point from the association table;
A method comprising: A system for handing off a mobile device connection from a first access point to a second access point in a multimedia mobile network comprising:
A mobile device connected to the first access point, the mobile device comprising:
Scan the network for multiple available access points,
Comparing the connection strength with each of the plurality of available access points to a predetermined margin;
Authenticate an access point whose connection strength is determined to exceed the predetermined margin,
Add the authenticated access point to the association table;
Comparing the connection strength for the first access point with the predetermined margin;
If the connection strength for the first access point is below the predetermined margin, select the authenticated access point as the second access point;
A system operable to delete the first access point from the association table. A method of handing off a mobile device connection from a first access point to a second access point in a multimedia mobile network comprising:
Scanning the network for multiple available access points;
Comparing the connection strength of each of the plurality of available access points to the mobile device with a predetermined margin;
Authenticating an access point whose connection strength is determined to exceed the predetermined margin;
Adding the authenticated access point to an association table;
Comparing the connection strength for the first access point with the predetermined margin;
Selecting the authenticated access point as the second access point if the connection strength to the first access point is below the predetermined margin;
Connecting the mobile device to the second access point;
Deleting the first access point from the association table;
A method comprising:

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