KR20130097355A - The method for processing a seamless handover using a multi packet transmission mode - Google Patents

Abstract

PURPOSE: A method for processing a seamless handover using a multi packet transmission mode is provided to activate two links at the same time for transmitting a packet concurrently. CONSTITUTION: A method of a seamless handover from a first link to a second link through a dual modem terminal comprises the steps of: determining whether a connection state of the second link satisfies a predetermined criterion; activating the second link if the connection state of the second link satisfies the predetermined criterion; starting dual streaming transmission and reception through both of the first link and the second link; terminating the dual streaming transmission and reception; and performing a call through the second link. [Reference numerals] (AA) Call is made via a mobile communication network; (BB) WiFi connection is detected; (CC) Is it possible to access an anchor via the WiFi connection ?; (DD) Is the WiFi connection's response ping value larger than a minimum critical level (R_p) ?; (EE) Is the WiFi connection's signal intensity larger than a minimum critical level (S_min) ?; (FF) Has the WiFi connection been maintained for a critical time (T) ?; (GG) Automatic hand over method ?; (HH) Dual streaming transmission/reception process gets launched; (II) Mobile communication network session ends / a call is made using the WiFi connection; (JJ) User is asked whether he/she is ready for the connection

Description

Seamless handover processing using multi-packet transmission method {THE METHOD FOR PROCESSING A SEAMLESS HANDOVER USING A MULTI PACKET TRANSMISSION MODE}

The present invention relates to a method for realizing seamless handover when a terminal roams between heterogeneous networks through a plurality of channels after securing each multiple communication path with a plurality of heterogeneous networks.

Fixed Mobile Convergence (FMC) network can use wired and wireless communication services in one terminal, and all heterogeneous networks can be linked to IP network such as IMS (IP Multimedia Service) regardless of communication network. It is a system that can provide.

In the second generation of mobile communication, wired / wireless convergence service using UMA (Unlicensed Mobile Alliance) based dual mode terminal supporting two modes of wireless LAN and GSM or CDMA mobile communication method uses mobile communication service in outdoor macro cell and indoor In the picocell, the mobile communication service was received through a WLAN access point. The dual mode terminal entering the indoor accesses the indoor wireless LAN AP and then connects to the devices (SGSN / GGSN and MSC) of the mobile carrier backbone through the high-speed network to receive voice and packet services.

However, the dual mode terminal operating in the initial FMC service environment of the UMA method is inconvenient in that handover between the macro cell network and the pico cell network is not supported and the system mode must be manually selected.

High frequency of mobile phone usage and traffic distribution in indoor environment, elimination of poor wireless quality indoor environment, network layout and design for high speed wireless packet service serviced in 4G system, development of MPS (Multiple Play Service) service era, various There is a strong demand for automatic roaming or seamless handover of FMC services in accordance with the emergence of smart phones requiring a wireless access method.

When IMS network technology is commercialized, WIFI-based FMC technology, 2G / 3G mobile communication, or femtocell services based on portable wireless Internet such as Wibro can be integrated into IP core network to support seamless handover between heterogeneous networks. FMC service is available.

A key important technology in FMC service is mobility management technology, which can freely handover when heterogeneous roaming, between two heterogeneous wireless networks to provide mobility or handover between pico or femtocell network environment such as home or office and outdoor macro cell. The technology for handling handover includes the VCC standard, and the MIH standard of IEEE 802.21 is a technology capable of processing handover between various networks at the data link layer regardless of a transmission medium. This technical standard is designed to be handed over by an exchange or IMS servers in the operator's network.

Specific handover implementation techniques in the FMC service network include Motorola's US Patent Publication No. 2009/0197594 A1 entitled "System and method for Fixed Mobile Convergence Using a Residential Gateway Apparatus," and "Method and Apparatus for Supporting SIP / IMS_based". Femtocells, US Patent Publication No. 2009/0067417 A1 of Tatara Systems entitled "Femtocells," which refers to a method for handover procedure in an environment in which an associated call processing server and a media gateway are disposed in an operator's network.

In the present invention, using the dual modem in the handover area between the two links between the indoor network and the outdoor network, the FMC terminal equipped with a dual modem multiplexes two channels (Two Legs) of the macro cell link and the micro (pico) cell link. The present invention provides a method for seamless handover without disconnection of an existing call channel by transmitting and receiving to a system by channel bonding.

The present invention provides a seamless hand using anchor systems for handover processing a backbone such as a private PBX or VoIP in an office regardless of a call processing related system such as an operator's switchboard or a large-scale IMS server supporting SIP or IMS protocol. We want to provide a way to enable over.

In one aspect of the present invention, there is provided a seamless inter-link seamless handover method through a dual modem terminal capable of simultaneously activating two links. In the method, the handover from the first link to the second link includes detecting a connection of the second link, determining whether a connection state of the second link meets a predetermined criterion, and as the determination result, If the connection state of the second link satisfies a predetermined criterion, activating the second link, starting dual streaming transmission and reception through both the first link and the second link, and ending dual streaming transmission and reception; Making a call over the second link. Further, in the method, the handover from the second link to the first link determines whether the connection state of the second link satisfies the predetermined criterion, and as a result of the determination, the connection state of the second link. Does not meet the predetermined criteria, starting dual streaming transmission and reception through both the first link and the second link, ending dual streaming transmission and reception and starting a call over the first link, and Disconnecting the second link. At this time, the first link remains active during all the handover phases.

Advantageously, the handover from the second link to the first link comprises: judging whether the connection state of the second link satisfies a predetermined criterion after starting the dual streaming transmission and reception; And ending dual streaming and continuing a call over the second link if the connection state of the second link meets the predetermined criterion as a result of the trial, wherein the dual streaming transmission and reception is performed. Terminating and starting a call over the first link may terminate dual streaming and start a call over the first link if the connection status of the second link does not meet the predetermined criteria as a result of the trial. It includes a step.

Preferably, the predetermined criterion may be selected from the group consisting of a maximum ping response value of the second link, a minimum signal strength, a minimum connection holding time, an automatic handover method, and a user confirmation.

Advantageously, said first link may comprise a microcell link and said second link may comprise a microcell, picocell, or femtocell link.

As another aspect of the present invention, there is provided a seamless hand-over between heterogeneous terminals through a home FMC gateway having a multi-packet transmission function and a service proxy function. The method includes requesting, by the second terminal, the home FMC gateway for a handover from a first terminal in a call to a second terminal; Initiating dual streaming to simultaneously send and receive packets to and from a first terminal and a second terminal through the home FMC gateway; Transmitting a call termination message of a first terminal to the home FMC gateway; And after the home FMC gateway receives the call end message, ending the dual streaming and starting a call through the second terminal.

In still another aspect of the present invention, there is provided a seamless handover method between heterogeneous terminals through a terminal having a multi-packet transmission function and a service proxy function. The method may be performed by a first user using a first terminal and a second user using a second terminal having a multi-transmission function and a service proxy function through another third terminal of the first user. Transmitting an outgoing signal to a second terminal of the second user; When the second terminal of the second user receives the originating signal, the second terminal starts dual streaming to simultaneously transmit and receive packets to and from the first terminal and the third terminal using the multi-packet transmission function. step; Transmitting a call termination message of the first terminal to the second terminal; And when the second terminal receives the call end message, the second terminal ends the dual streaming and starts a call with the third terminal.

The present invention provides a seamless handover method between heterogeneous networks and heterogeneous terminals. In the seamless handover method of the present invention, there is no interruption in the handover process by simultaneously activating two links and transmitting packets at the same time, and a diversity effect can be obtained by combining packets transmitted simultaneously through two links to obtain a diversity effect. Can be improved.

In addition, since the method according to the present invention is directly handed over via a terminal having a dual modem, a home FMC gateway having a multi-packet transmission function and a service proxy function, a call exchange such as an operator's exchange or an IMS server is performed. Handover can be made independently of the device.

1 is a network diagram showing a configuration diagram of a service network in which the embodiments of the present invention and techniques are used.
FIG. 2 is a flowchart illustrating a process of handover using an indoor PBX system as an anchor in a service network configuration according to the present invention.
3 is a flowchart illustrating a handover process using a call processing server and a media gateway (CSCF) system of a backbone VOIP network as an anchor in a service network configuration diagram of the present invention.
4 generally illustrates a signal coverage overlap between two cells.
5 shows the overlapping state of the indoor VIFI network and the external micro 3G / LTE network in the actual situation.
6 is a functional block diagram for performing a seamless handover between heterogeneous networks in a smartphone having two or more network interfaces.
7 is a functional block diagram for performing seamless handover between heterogeneous networks by forming a connection link to two or more networks.
8 is a flowchart illustrating an algorithm for processing handover by determining a connection speed and signal strength when a terminal normally connects to a WIFI network of a micro cell during a call through a mobile communication network of a macro cell.
FIG. 9 is a flowchart illustrating an algorithm for processing a handover for conducting a call through a macro cell mobile communication network when the signal strength or response speed of the micro cell is slowed down during a call through the WIFI network of the micro cell.
10 and 11 are diagrams illustrating a procedure for performing handover between heterogeneous terminals.

1 is an indoor FMC network 100 of a house or an office, an IMS method or a conventional VOIP service network 200 in an external IP infrastructure environment, and a mobile communication network that provides a service for an FMC terminal to operate in an external macrocell. Service network configuration diagram in which the technique of the present invention consisting of 300 and other network 400 is used.

The indoor FMC network 100 includes an IP-based home FMC gateway 120 and an FMC terminal 110 supporting FMC services. The home FMC gateway 120 includes a wireless access point for an internal wireless LAN (Wireless LAN). AP) function and is connected to external network through IPDS network through xDSL interface. Of course, in general, a separate gateway or AP which is only responsible for various network functions such as AP function, external network access function, dynamic host configuration protocol (DHCP) function, IP sharing function, and routing function is separately installed, and the home FMC gateway 120 is an FMC. Although it may be desirable to build the system separately so that it can only handle the voice call function, in the present embodiment, they are represented as a single system for convenience. That is, the home FMX gateway 120 of this embodiment includes all the functions of a conventional home gateway, home PBX, and home FMC gateway.

The pico or femtocell 100 may be configured between the indoor FMC terminal 100 and the AP of the home FMC gateway 120 by a wireless access method such as a wireless LAN (WIFI), Wibro, CDMA, WCDMA, GSM, or the like.

In this figure, the terminal 110 and the terminal 310 are the same terminal device of a single body, and the indoor FMC gateway 120 of the pico or femtocell 100 is connected to the FMC indoor phone 110 such as a wireless telephone in the room. In the outdoor, it should be equipped with a normal dual-mode wireless modem so that it can be connected to the mobile communication network 300 subscribed to and operate as an FMC outdoor phone 310 such as a general mobile phone. The FMC terminal 110 or 310 may have three numbers such as a telephone number of an external mobile telephone network, a telephone number of a backbone VOIP network, and an extension number of an premises network.

* A terminal equipped with such a dual-mode wireless modem can configure a link with an indoor network 100 of a WLAN-based picocell or femtocell and simultaneously form a link with a mobile communication network 300 of an external network. This enables diversity effects and seamless handover.

The home FMC gateway is an IP-based system that supports the IMS protocol or the SIP-based VOIP protocol. It works in conjunction with the subscribed IMS core network.

The home FMC gateway can provide internal calls and various additional services among subscribers in the premises network using the IMS protocol. It is possible to provide call service between subscribers, and furthermore, interworking with media gateway server and IMS application server enables call service linked to various external networks such as mobile communication, PSTN network and other VOIP.

Home FMC is provided by the telephone adapter (TA) function that connects the internal and external networks in the home FMC gateway device, the call processing server and the media gateway (CSCF) server function and the media gateway function that are responsible for call processing. Various communication services are available using the gateway as an anchor system.

2 illustrates a handover method when moving from an indoor network 100 to an external macrocell 300 using a home FMC gateway as an anchor system. The indoor FMC terminal 110 and the outdoor terminal 310 are the same device equipped with multiple modems.

In process 1 of FIG. 2, the FMC terminal in the room is connected to the home FMC gateway 120 using the extension number, and the home FMC gateway 120 is sent to the terminal 410 in the external network using the representative phone number. Connect the call.

The call channel between the home FMC gateway and the FMC terminal 110 is designated as Leg1, and the call channel between the home FMC gateway and the external network terminal 410 is designated as Leg0.

There are two ways to make a signal. The first is that the home FMC gateway requests and configures the call processing server 210 of the backbone VOIP network 200, and a call path is made via the media gateway 220. The call path 0 of FIG. 2 indicates this, which is divided into the actual packet mode section between the home FMC gateway and the MGW and the line mode section between the MGW and the counterpart phone 410. Second, there is a method of configuring a call path 0 in a direct line mode between the counterpart phones 410 in the home FMC gateway by using a TA function or a media gateway function interworking with an external network installed in the home FMC gateway.

In process 3 of FIG. 2, when the FMC terminal is busy during the call, a handover request is made by the terminal or the home FMC gateway. At this time, the home FMC gateway makes a call call establishment request to the same terminal 310 using the number system of the mobile communication network. As shown in Step 3, the channel 2 (Leg2) configured as described above may be formed in the circuit mode or the packet mode. The home FMC gateway and the terminal should activate both communication channels during the handover.

When the call path 2 (Leg2) is configured in packet mode, the FMC terminal 310 should be configured by initiating an IP line connection to the home FMC gateway. However, when configuring the line mode, the FMC terminal 310 in the home FMC gateway is reversed. You can call to configure.

The FMC terminal transmits and receives data dually through the home FMC gateway and the two channels. When both channels (call path 1 and call path 2) operate in packet mode, both dual channels are available for VOIP communication. Packets received through both paths can be combined and used using appropriate channel bonding techniques. This combines with the diversity mechanism to further improve call quality and seamlessly handle handovers. If call path 2 operates in line mode, the terminal must perform hard handover processing.

In step 3 of FIG. 2, the home FMC gateway instructs the terminal to complete the handover, and the terminal discards the channel of the indoor cell after the handover process and moves to a new inter-macro cell channel, and the home FMC gateway transmits and receives information only through the new channel. This is how the entire handover process is completed.

3 is a case where an incoming call is made from the external counterpart phone 410 to the FMC terminal 110 in the room, and the scenario and processing procedure are the same as those of FIG. 2.

The external caller 410 makes an incoming call to the FMC terminal 110 indoors by calling the home FMC gateway representative phone and connecting to an extension number and the backbone VOIP network number of the FMC terminal 110. There is a way to log. In the second case, since the corresponding information is stored in the location information and the registration server of the backbone VOIP network, it is possible to check which home FMC gateway the terminal is connected to, and call processing may be configured through the call processing server 210. . As another method, the counterpart phone 410 may be connected to an extension number by dialing an external subscription phone for the T / A function of the home FMC gateway, and the procedure thereof is the same as that of FIG.

4 is a structure in which the coverage of the mobile communication network of the macrocell and the WIFI network of the microcell is not mutually exclusive, but the macrocell includes the microcell, and the WIFI cell is moving because the coverage radius is very narrow within 20 meters due to congestion. It is shown that handover cannot be carried out exclusively for the terminal, and depending on the situation, the handover should be handled in a redundant or macro cell priority manner.

5 shows that the coverage of the WIFI network of the microcell is not proportional to the distance and changes depending on the situation. This means that when the coverage of the micro cell is above a certain standard, the call using the micro cell should be treated in a preferential manner.

6 is a functional diagram for handover processing using a multi-frame transmission technique of a terminal having a dual network interface. Two NIC devices are required to retrieve IP, which allows each to receive the same stream to seamlessly handover.

7 is a functional diagram required for handover processing using a multi-frame transmission technique transmitted and received through two or more different networks.

8 is a flowchart illustrating an algorithm for processing handover by determining a connection speed and signal strength when a terminal normally connects to a micro cell's WIFI network while a call is in progress through a macro cell mobile communication network. In the present embodiment, when the terminal detects a connection to the WIFI network of the microcell during the mobile communication network call, it is determined whether the connection to the anchor is possible through the WIFI. If the connection is not possible, continue the call over the mobile network. If the connection is possible, it is determined whether the ping response value does not exceed the ping maximum response threshold (hereinafter R _P ), for example, in the last 10 seconds. If the ping response value exceeds R _P , continue the call over the mobile network. If the ping response value does not exceed R _P , it is determined, for example, whether it is greater than the minimum signal strength threshold value (above S _min ) within the last 10 seconds. If the minimum signal strength is not greater than S _min , the call continues through the mobile communication network. If the minimum signal strength is greater than S _min , it is determined whether the WIFI connection is maintained above the keep-alive threshold (above T). If the connection is not maintained for more than T, continue the call over the mobile network. If the connection is maintained over T, it is determined whether the automatic handover method is used. If not, the user is asked to start dual streaming. Automatic handover or, if the user confirms to start dual streaming, starts dual streaming. When the handover is over, the session of the mobile communication network is terminated.

9 is a flowchart illustrating an algorithm for processing a handover for conducting a call through a mobile communication network of a macro cell when the signal strength of the micro cell becomes weak or a response time is slow while a call is performed through the micro cell's WIFI network. . In this embodiment, the terminal starts a mobile network session and starts dual streaming if the WIFI ping response value exceeds R _P or the WIFI minimum signal strength is less than Smin during the WIFI call, for example, in the last 10 seconds. During dual streaming, for example, if the WIFI ping response value exceeds R _P or the WIFI minimum signal strength is less than S _min during the last 10 seconds, the dual streaming ends and the call is switched over the mobile communication network. During dual streaming, if the WIFI network is stabilized, that is, for example, if the WIFI ping response value does not exceed R _P or if the WIFI minimum signal strength is greater than S _min , the dual streaming ends and continues the call over WIFI.

The steps shown in FIGS. 8 and 9 are for illustration and description only, and each step may be performed simultaneously or in a different order.

10 and 11 illustrate a procedure for handover between heterogeneous terminals. In general, handover is a function that allows the same terminal to continuously make a call without disconnection of a call when moving from a current communication cell to another communication cell.

Here, a function of handing a handheld terminal with a heterogeneous terminal that moves a call service from one cell to another terminal to another terminal or moves another cell to continue a call to another terminal.

For example, a call is handed over to another second terminal while a multimedia call is made with an external counterpart terminal to an indoor first terminal. In this case, the home FMC gateway has a function of transmitting a multi-packet and a service proxy function. When a heterogeneous terminal handover service is requested for a registered terminal, if the first terminal requested is a second terminal, the terminal is performing the original service. The packet is multi-transmitted to both terminals through the notification and approval process. In this case, the voice and video processing of both terminals is mixed or the multimedia information of the first terminal is used first, and the second terminal is simply copied. You can send only.

The handover to the heterogeneous terminal may be performed by the first terminal received from the gateway that the second terminal is available for service. In this case, the home FMC gateway notifies this to the second terminal, obtains approval, and then copies and transmits multimedia information to both sides.

Finally, when the first terminal in the existing call transmits a message ending the call to the gateway, only the P2P call is made between the second terminal and the counterpart terminal, and when the copy mode is called, the second terminal and the counterpart terminal perform the main call. The multimedia message may be copied to the first terminal to continuously watch.

As described above, the present invention configures the dual link between the VOIP terminal and the home FMC gateway, and uses the mechanism of transmitting and receiving duplicated frame packets individually through these links to provide redundant coverage characteristics between the wide area mobile network and the small coverage network. The present invention provides a method for seamlessly processing a communication handover and a method for distinguishing between a terminal and an external terminal by seamlessly processing a handover of a heterogeneous terminal period.

Although the present invention has been described herein with respect to specific embodiments, this is merely exemplary and the present invention is not limited to the illustrated or described configuration. The scope of the present invention includes all various modifications and variations that can be easily read by those skilled in the art.

100: Network in home or office environment
110: FMC terminal used for a network in a home or office environment and connected to an AP by WIFI or femtocell method
111: UA (User Agent) in charge of the call function in the smartphone or FMC terminal
112: Handover manager that recognizes handover situation and decides which stream to send to UA
113: A program that receives multi-frames and checks sync and error of frames
120: A home FMC gateway used in a home or office network and acting as an AP and PBX switch in WIFI or femtocell mode.
200: backbone VOIP network capable of providing IMS-based or IP-based equivalent functionality
210: Device or VOIP server for call processing in the backbone VOIP network
220: Media gateway for exchanging voice or packet with existing other networks
300: mobile communication network to which the FMC terminal is subscribed
310: FMC terminal used in mobile communication network and the same device as 110 device
320: base station and exchange system of mobile communication network to which FMC terminal is subscribed

Claims (6)

A seamless inter-link handover method through dual modem terminals capable of simultaneously activating two links,
The handover from the first link to the second link is
Detecting a connection of the second link;
Determining whether a connection state of the second link satisfies a predetermined criterion;
Activating the second link if the connection state of the second link meets a predetermined criterion as a result of the determination, and starting dual streaming transmission and reception through both the first link and the second link; And
Terminating dual streaming transmission and reception and making a call over the second link;
Handover from the second link to the first link,
Determining whether a connection state of the second link satisfies the predetermined criterion;
Starting dual streaming transmission and reception through both the first link and the second link if the connection state of the second link does not meet the predetermined criterion as a result of the determination;
Terminating dual streaming transmission and reception and initiating a call over the first link; And
Disconnecting the second link;
And wherein said first link is active during all of said steps. ≪ RTI ID = 0.0 > 2 < / RTI > The method of claim 1, wherein in a handover from the second link to the first link:
After starting the dual streaming transmission and reception,
Judging whether the connection state of the second link satisfies a predetermined criterion; And
If the connection state of the second link meets the predetermined criterion as a result of the trial, terminating dual streaming and continuing a call over the second link;
Ending the dual streaming transmission and reception and starting the call over the first link, if the connection state of the second link does not meet the predetermined criterion as a result of the trial, end the dual streaming and the first link A method for seamless hand-over-link between links through a dual modem terminal capable of simultaneously activating two links, characterized in that it comprises the step of initiating a call over. The method of claim 1, wherein the predetermined criterion is selected from the group consisting of a maximum ping response value of the second link, a minimum signal strength of the second link, a minimum connection holding time, whether an automatic handover is performed, and whether a user is confirmed. A seamless inter-link handover method through dual modem terminals capable of simultaneously activating two links. 2. The link of claim 1, wherein the first link is a microcell link and the second link is a microcell, picocell, or femtocell link. Liver seamless handover method. A seamless handover method between heterogeneous terminals through a home gateway having a multi-packet transmission function and a service proxy function,
Requesting the home gateway from the first terminal in a call to the second terminal for handover;
Initiating dual streaming to simultaneously send and receive packets to and from a first terminal and a second terminal through the home gateway;
Transmitting a call termination message of a first terminal to the home gateway; And
And after the home gateway receives the call termination message, ending dual streaming and starting a call through the second terminal. A seamless handover method between heterogeneous terminals through a terminal having a multi-packet transmission function and a service proxy function,
When the first user using the first terminal and the second user using the second terminal having the multi-transmission function and the service proxy function are in a call, the second user via the other third terminal of the first user is called. Transmitting an outgoing signal to a second terminal of a user;
When the second terminal of the second user receives the originating signal, the second terminal starts dual streaming to simultaneously transmit and receive packets to and from the first terminal and the third terminal using the multi-packet transmission function. step;
Transmitting a call termination message of the first terminal to the second terminal; And
When the second terminal receives the call termination message, the second terminal terminates the dual streaming and starts a call with the third terminal. A seamless handover method between heterogeneous terminals through an equipped terminal.

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