KR20100004833A - Method of transmitting information for inter radio access technology hand over - Google Patents

Abstract

PURPOSE: A method of transmitting information for handover between heterogeneous networks is provided to use a super frame structure, thereby efficiently obtaining heterogeneous network information. CONSTITUTION: A base station transmits a super frame header to a terminal(S1101). A query response message is received to obtain heterogeneous network information(S1102). The base station arbitrarily transmits the heterogeneous network information to the terminal(S1103). The base station is unable to transmit a heterogeneous network information response message to the terminal in a corresponding super frame. The base station broadcasts the heterogeneous information to the terminal using a next super frame header(S1104).

Description

Method of transmitting information for Inter Radio Access Technology Hand Over}

The present invention relates to a method for transmitting and receiving heterogeneous network information between a terminal and a base station to perform a heterogeneous network handover in a wireless access system. The present invention also relates to a new header structure and a data transmission / reception method for supporting heterogeneous network handover.

Embodiments of the present invention relate to handover between different types of networks, i.e., handover between heterogeneous networks. Hereinafter, a brief description will be given of a general handover and a MIH HO.

The handover refers to a function of maintaining a call when a mobile terminal moves out of a communication zone such as a mobile communication cell and enters another base station area out of a base station during a call.

The handover occurs when the state of the radio channel in the base station to which the subscriber station belongs is bad, when the subscriber station moves from the current sector to another sector in the base station and when moving from the current base station area to another base station area.

In addition, the handover may be classified into softer handover, soft handover, and hard handover according to how the channel is switched.

Softer handover is a handover that occurs inside a cell. Softer handover refers to the UE changing to a good channel or the like among channels being used within cell coverage. Soft handover is a method in which a terminal simultaneously operates two adjacent channels, and eventually terminates one channel at the end. In the CDMA method, since the same frequency band is used, it can be easily implemented. Hard handover is a method in which the terminal disconnects a channel currently in a call and immediately connects to another channel.

Handover can be classified into Network Controlled Handoff (NCHO), Mobile Assisted Handoff (MAHO) and Mobile Controlled Handoff (MCHO) according to the subject performing the handover. Can be.

Intra-RAT (Intra Radio Access Technology) handover method refers to a method for supporting handover between homogeneous networks. I-RAT handover is a method of seamless handover and service when the UE moves out of the area of the base station (eg, serving base station) that controls the terminal within the homogeneous network to an area managed by another target base station. Provides service continuity. This is to improve the convenience of the terminal user.

Inter-RAT (Inter Radio Access Technology) handover method refers to a method for supporting handover between heterogeneous networks using different radio access technologies. For example, inter-RAT handover refers to a terminal performing handover to a target base station in another heterogeneous network out of a cell area of a serving base station in a homogeneous network. Hereinafter, the inter-RAT handover will be referred to as inter-network handover or heterogeneous network-independent handover.

The Institute of Electrical and Electronic Engineers (IEEE) 802.21, which is currently undergoing international standardization of Media Independent Handover (MIH), provides seamless handover and service continuity between heterogeneous networks. Continuity) to improve user convenience of a mobile terminal.

The IEEE 802.21 standard aims to improve user experience by supporting handover between different radio access networks, and supports cooperative use of information available in mobile terminals and networks. To this end, an access point of a network such as a mobile station and a base station must provide multi-modal, which supports a plurality of wireless standards and simultaneously connects one or more radio interfaces. It means you can allow.

In this specification, the mobile terminal is a multi-mode node that supports one or more interface types, and the interface may be in various forms. For example, a wire-line type such as IEEE 802.3-based Ethernet, a wireless interface based on the IEEE 802.XX series including IEEE 802.11, IEEE 802.15 or IEEE 802.14, and cellular such as 3GPP and 3GPP2. (Cellular) interface defined by the standardization organization is possible.

A multi-mode mobile terminal has a physical layer and a media access control layer (MAC) in each mode, and a MIH layer is located below the IP layer. In addition, the MIHF (MIHF) of the mobile terminal is a logical entity and can be freely positioned while interfacing through each layer and a service access point (SAP) in the protocol stack.

Medium Independent Handover (MIH) is preferably defined between the IEEE 802 series interface or between the IEEE 802 series interface and the non-IEEE 802 series interface (3GPP, 3GPP2) mentioned above. In addition, the MIH preferably supports higher layer mobility support protocols such as Mobile IP and Session Initiation Protocol (SIP) in order to provide a seamless service for the user.

MIH Function (MIHF) is a logical MIH entity, and helps the mobile station (MS) to perform handover between heterogeneous networks. The mobile terminal and the network may include a MIHF. At this time, the MIHF allows the exchange of information on the setting or status of the access network around the mobile terminal.

The MIH entity is located below the upper layer including the IP layer, which defines handover between the IEEE 802 series interface and the interfaces defined by 3GPP / 3GPP2 as well as the handover between the IEEE 802 series interfaces. That is, the MIH entity obtains information about another network from the second layer, thereby facilitating handover between heterogeneous networks. Meanwhile, the MIH function may exchange MIH signaling using information from the third layer such as user policy or configuration.

In a wireless access system to which embodiments of the present invention can be applied, a terminal and a base station must acquire information about neighboring heterogeneous networks in order to perform inter-RAT HO. At this time, it is preferable to use MIHF technology.

However, in a wireless access system requiring multi-radio operation, information on neighboring heterogeneous networks is required for the UE to attempt Inter Radio Access Technology HandOver (Inter RAT HO).

In the general technology, since there is no method for the UE to acquire necessary information during inter RAT HO, handover to a radio access system using heterogeneous radio access technology is impossible.

The present invention has been made to solve the problems of the general technology as described above, an object of the present invention is to provide an efficient handover method.

Another object of the present invention is to provide a method for transferring heterogeneous network information for inter RAT handover.

Another object of the present invention is to provide a superframe structure for transmitting heterogeneous network information.

In order to solve the above technical problem, the present invention discloses a method for transmitting and receiving heterogeneous network information between the terminal and the base station to perform a heterogeneous network handover in a wireless access system. In addition, the present invention discloses a new header structure and data transmission / reception method for supporting heterogeneous network handover.

In one aspect of the present invention, a method for delivering heterogeneous network information for heterogeneous network handover includes: receiving, by a terminal, a predetermined header including an indicator indicating whether heterogeneous network information is transmitted in a superframe in which a predetermined header is transmitted; And obtaining, by the terminal, heterogeneous network information using the indicator. At this time, the predetermined header may be transmitted periodically. In addition, the predetermined header may include a broadcast channel, and the indicator may be assigned to the broadcast channel. In this case, the broadcast channel may include a main broadcast channel (PBCH) and a sub broadcast channel (SBCH), and the indicator may be included in one of the main broadcast channel and the sub broadcast channel.

If the indicator indicates that the heterogeneous network information is transmitted in the superframe, the broadcast channel may further include a start frame number field indicating a start number of a subframe to which the heterogeneous network information is allocated. In this case, the start frame number field may be included in one of the main broadcast channel and the sub broadcast channel.

If the indicator indicates that heterogeneous network information is transmitted in the superframe, the terminal may receive the heterogeneous network information in a predetermined frame indicated by the start frame number field.

In an aspect of the present invention, if the indicator indicates that the heterogeneous network information is transmitted in the superframe, the broadcast channel included in a predetermined header may further include heterogeneous network information. If the indicator indicates that the heterogeneous network information is not transmitted in the superframe, the method may further include transmitting, by the terminal, a request message for requesting the heterogeneous network information to the base station. The method may further include receiving, by the terminal, a response message including heterogeneous network information from the base station. In this case, the response message may be transmitted to one or more terminals in a broadcast form.

In an aspect of the present invention, the request message may include an emergency information field indicating whether obtaining heterogeneous network information is an urgent situation. If the base station does not have heterogeneous network information, the response message may further include information on an expected time point for transmitting the heterogeneous network information. In this case, when the base station does not have heterogeneous network information, the base station may obtain heterogeneous network information from the target network information server and transmit the heterogeneous network information to the terminal.

In one aspect of the present invention, the predetermined header may be one of a superframe header or a subframe header.

In another aspect of the present invention, a method for delivering heterogeneous network information for heterogeneous network handover includes: periodically transmitting, by a base station, a superframe header including an indicator indicating whether heterogeneous network information exists in a predetermined superframe; And requesting heterogeneous network information from the terminal, receiving a request message including an emergency information field indicating whether an emergency situation exists, and transmitting, by the base station, a first response message including heterogeneous network information to the terminal. have.

In this case, the super frame header may include a broadcast channel including a main broadcast channel and a sub broadcast channel, and the indicator may be included in one of the main broadcast channel and the sub broadcast channel.

If the base station does not know the heterogeneous network information, the base station may further include obtaining the heterogeneous network information from the information server.

In another aspect of the present invention, when the emergency information field is activated, the base station may immediately transmit a first response message to the terminal.

In another aspect of the present invention, if the emergency information field is activated, the method may further include, by the base station, immediately transmitting a second response message indicating a frame to which the first response message is transmitted to the terminal.

According to embodiments of the present invention has the following effects.

First, by using the embodiments of the present invention, it is possible to perform handover efficiently.

Second, by using the embodiments of the present invention, it is possible to efficiently perform heterogeneous handover.

Third, heterogeneous network information can be efficiently obtained by using the superframe structure disclosed in the embodiments of the present invention.

The present invention relates to a wireless access system. In addition, the present invention discloses a method for transmitting and receiving heterogeneous network information between a terminal and a base station to perform a heterogeneous network handover in a wireless access system. In addition, the present invention discloses a new header structure and data transmission / reception method for supporting heterogeneous network handover.

The following embodiments combine the components and features of the present invention in a predetermined form. Each component or feature may be considered to be optional unless otherwise stated. Each component or feature may be embodied in a form that is not combined with other components or features. In addition, some components and / or features may be combined to form an embodiment of the present invention. The order of the operations described in the embodiments of the present invention may be changed. Some components or features of one embodiment may be included in another embodiment or may be replaced with corresponding components or features of another embodiment.

In the description of the drawings, procedures or steps, which may obscure the gist of the present invention, are not described, and procedures or steps that can be understood by those skilled in the art are not described.

In the present specification, embodiments of the present invention have been described based on data transmission / reception relations between a base station and a terminal. Here, the base station has a meaning as a terminal node of a network that directly communicates with the terminal. The specific operation described as performed by the base station in this document may be performed by an upper node of the base station in some cases.

That is, various operations performed for communication with a terminal in a network consisting of a plurality of network nodes including a base station may be performed by the base station or other network nodes other than the base station. At this time, the 'base station' may be replaced by terms such as a fixed station, a Node B, an eNode B (eNB), an access point, and the like. In addition, the term “mobile station (MS)” may be replaced with terms such as a user equipment (UE), a subscriber station (SS), a mobile subscriber station (MSS), or a mobile terminal.

In addition, the transmitting end refers to a node transmitting data or voice service, and the receiving end refers to a node receiving data or voice service. Therefore, in uplink, a terminal may be a transmitting end and a base station may be a receiving end. Similarly, in downlink, a terminal may be a receiving end and a base station may be a transmitting end.

On the other hand, the mobile terminal of the present invention PDA (Personal Digital Assistant), cellular phone, PCS (Personal Communication Service) phone, GSM (Global System for Mobile) phone, WCDMA (Wideband CDMA) phone, MBS (Mobile Broadband System) phone And the like can be used.

Embodiments of the invention may be implemented through various means. For example, embodiments of the present invention may be implemented by hardware, firmware, software, or a combination thereof.

In the case of a hardware implementation, the method according to embodiments of the present invention may include one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs). Field programmable gate arrays (FPGAs), processors, controllers, microcontrollers, microprocessors, and the like.

In the case of implementation by firmware or software, the method according to the embodiments of the present invention may be implemented in the form of a module, procedure, or function that performs the functions or operations described above. The software code may be stored in a memory unit and driven by a processor. The memory unit may be located inside or outside the processor, and may exchange data with the processor by various known means.

Embodiments of the present invention may be supported by standard documents disclosed in at least one of the wireless access systems IEEE 802 system, 3GPP system, 3GPP LTE system and 3GPP2 system. That is, steps or parts which are not described to clearly reveal the technical spirit of the present invention among the embodiments of the present invention may be supported by the above documents. In addition, all terms disclosed in the present document can be described by the above standard document. In particular, embodiments of the present invention may be supported by P802.16e-2005 or P802.16 Rev2 / D4 (April 2008), which is a standard document of the IEEE 802.16 system.

Specific terms used in the following description are provided to help the understanding of the present invention, and the use of the specific terms may be modified in other forms without departing from the technical spirit of the present invention.

1 is a diagram illustrating a method for delivering heterogeneous network information using a broadcast method.

Referring to FIG. 1, a base station (BS: 802.16 entity MIH PoA) may transmit MIH capability information to a terminal (MS) 802.16 entity (MS101) through downlink channel descriptor (DCD) system information (S101).

The terminal and the base station perform an initial ranging procedure (S102).

The terminal may transmit a Subscriber Basic Capability Request (SBC-REQ) message to the base station to request the MIH capability TLV field and the SIQ TLV field, etc. (S103).

The base station may transmit a Subscriber Basic Capability Response (SBC-RSP) message including the MIH capability TLV, NSP ID, etc. to the terminal (S104).

A network control and management system (NCMS), which is a higher layer of the terminal, may transmit a C-MIH-IND message instructing to receive a MIH message to receive heterogeneous network information (S105). .

The MS, which has acquired the MIH capability information, may transmit a PKM-REQ message including a MIH query frame to the base station in order to obtain information about the heterogeneous network. In this case, the PKM-REQ message may include a code indicating a MIH initial request, a type of a transmission method, and a field indicating a specific MIH frame (S106).

The base station may include a field indicating the approval, the identifier, the delivery method and the status, and the period for the MIH request in the PKM-RSP message and transmit the same to the terminal (S107).

In addition, the base station transmits a C-MIH-IND message requesting to transmit the MIH message to the NCMS, the upper layer of the base station (S108).

The NCMS, which is the upper layer of the base station, may request information on the heterogeneous network by transmitting a MIH-IS-Query Request message including the MIH frame to the MIH PoS Information Server (S109).

The information server transmits a MIH-IS-Query Response message including information on heterogeneous networks to the NCMS of the base station (S110).

NCMS of the base station transmits the C-MIH-IND message instructing the base station to transmit the MIH message to the terminal (S111), the base station includes a MIH frame indicating heterogeneous network information after a predetermined period informed to the terminal in step S107 The SII-ADV broadcast message may be transmitted to one or more terminals. The terminal may receive the SII-ADV broadcast message broadcast from the base station after a predetermined cycle time from step S107 (S112).

The UE may transmit a C-MIH-IND message to inform the upper layer (NCMS) of receiving the MIH frame (S113).

In embodiments of the present invention, the information on the heterogeneous network may include a channel information, an operator information, information for setting an IP address, and the like, including a handover policy.

2 is a diagram illustrating an example of a frame structure that may be used in embodiments of the present invention.

Referring to FIG. 2, one super frame may include one or more frames, and one frame may include one or more subframes. In addition, one subframe may include one or more OFDMA symbols.

The length and number of superframes, subframes, and symbols can be changed according to user requirements or system environment. In embodiments of the present invention, the term 'subframe' is used. In this case, the 'sub frame' means all lower frame structures generated by dividing one frame into a predetermined length.

The subframe structure used in the embodiments of the present invention may be configured by dividing a generally used frame into one or more subframes. In this case, the number of subframes included in one frame may be determined by the number of symbols constituting the subframe. For example, suppose that one frame is composed of 48 symbols. If one subframe consists of six symbols, one frame may consist of eight subframes. In addition, if one subframe consists of 12 symbols, one frame may consist of four subframes.

In FIG. 2, it is assumed that one super frame has a length of 20 ms and one frame has a length of 5 ms. That is, one super frame may be composed of four frames F0, F1, F2, and F3. In addition, one frame F3 may have a frame structure composed of eight subframes. In this case, one subframe may be configured as six OFDMA symbols having a size of 617us. Each subframe may be allocated for uplink (UL) or downlink (DL) transmission. 2 shows a case where DL: UL is allocated at a 5: 3 ratio.

3 shows an example of a superframe structure and a superframe header structure according to an embodiment of the present invention.

3 is a diagram illustrating FIG. 2 in more detail. As shown in FIG. 3, a super frame is configured in 20 ms units and may be divided into four frames. In addition, each frame may be divided into five DL subframes and three UL subframes.

A super frame header (SFH) may be allocated to the first downlink subframe of the super frame. In addition, the SFH may include a broadcast channel (BCH) and a downlink shared channel (DL-SCH).

In this case, the broadcast channel (BCH) may include a primary broadcast channel (PBCH) and a secondary broadcast channel (SBCH). The main broadcast channel (PBCH) may be allocated broadcast information commonly used in a network. In addition, the sub broadcast channel (SBCH) may be assigned cell specific broadcast information (Cell specific).

The base station may transmit a super frame header (SFH) to the terminal to support inter-RAT HO. Referring to FIG. 3, the SBCH may include network topology information (NTI), paging information (PI), and other information.

In this case, the network topology information may include a Network Topology Information Indicator (NTII) and a Start Frame Number of Topology Information (SFN) field indicating a frame in which the topology information is transmitted.

The network topology information indicator NTII may indicate whether topology information including heterogeneous network information is transmitted in the specific superframe. If the topology information indicator (NTII) indicates that heterogeneous network information is transmitted to the terminal within a specific superframe, the terminal checks a Start Frame Number (SFN) field and the heterogeneous network information in the frame indicated by the SFN. Can be obtained.

In addition, the network topology information indicator may indicate that heterogeneous network information is not transmitted to the terminal in the specific superframe. In this case, the UE may obtain topology information for handover between heterogeneous networks by checking the SBCH transmitted in the next superframe. Of course, the terminal may request to transmit heterogeneous network information to the base station without waiting for the next superframe.

In FIG. 3, as another method of transmitting topology information necessary for inter RAT HO to the MS, the topology information may be directly included in the SBCH and transmitted to the UE.

In addition, in the embodiments of the present invention, the topology information may include both homogeneous network topology information and heterogeneous network topology information. Of course, the topology information may separately include homogeneous network topology information and heterogeneous network topology information.

In FIG. 3, the base station may continuously transmit topology information including heterogeneous network information to the terminal at predetermined intervals (for example, every 20 ms). In addition, the topology information including the heterogeneous network information may be included in a neighbor base station advertisement message (NBR-ADV message) so that the base station may broadcast to the terminal whenever necessary or periodically.

In FIG. 3, the network topology information indicator may be used as a topology information message indicator, and the topology information may be used in the same meaning as the topology information message.

4 is a diagram illustrating another example of a superframe header structure according to one embodiment of the present invention.

Referring to FIG. 4A, the superframe header SFH may include a broadcast channel (BCH) and a downlink shared channel (DL-SCH). In this case, the downlink shared channel may be omitted according to the capacity of the broadcast channel.

The broadcast channel may include a network topology information field (NTI), a paging information field (PI), and other fields. In this case, the NTI field may include a topology information message indicator field indicating whether heterogeneous network information is included in a predetermined superframe and a field SFN indicating a start position of a subframe to which the topology information message is allocated.

Referring to FIG. 4B, the superframe header SFH may include a main broadcast channel (PBCH), a sub broadcast channel (SBCH), and a downlink shared channel (DL-SCH). In this case, the downlink shared channel may be omitted according to the capacity of the broadcast channel.

4 (b) shows that, unlike FIG. 3, the main broadcasting channel includes a network topology information field (NTI), a paging information field (PI), and other fields. In this case, the NTI field may include a topology information message indicator field indicating whether heterogeneous network information is included in a predetermined superframe and a field SFN indicating a start position of a subframe to which the topology information message is allocated.

3 and 4, the base station may additionally transmit parameters for supporting heterogeneous network handover to the terminal. That is, the base station may transmit various parameters necessary for handover (eg, Intra RAT HO or Inter RAT HO) and scanning to the terminal through a broadcast channel (BCH). In addition, the base station may use a main broadcast channel or a sub-broadcast channel to transmit various parameters to the terminal to support handover between heterogeneous networks. However, embodiments of the present invention will be described by taking an example in which the base station transmits parameters using a sub-broadcast channel (SBCH).

The base station may include parameters for supporting heterogeneous network handover in the SBCH and transmit them to the terminal. Handover and scanning related parameters that may be included in the SBCH are shown in Table 1 below.

Name Length value Handover Trigger TLV - - Scanning Trigger TLV - - Pre-Registeration TLV - - Neighbor Advertisement Message indication - - Intra scanning & Handover Threshold - - Intra RAT Scanning threshold - - Inter RAT Pre registration threshold - - Handover threshold - - Supported HO type - -

Referring to Table 1, parameters supporting heterogeneous network handover include a handover trigger TLV field, a scanning trigger TLV field, a pre-registration trigger TLV field, Neighbor advertisement message indication field, Intra scanning & handover Threshold field, Inter RAT Scanning threshold field, Inter RAT registration threshold field (Inter RAT) There are Pre-registration threshold, Handover Threshold field, Indication field of Pre-registration capability of other RAT networks, and Supported HO Type fields. .

Table 2 below shows the functions and operations of the handover trigger TLV, scanning trigger TLV, and pre-register trigger TLV fields.

Name Length Value Type - Function - Computation defining trigger condition: 0x0: Reserved 0x1: Metric of neighbor BS is greater than absolute value 0x2: Metric of neighbor BS is less than absolute value 0x3: Metric of neighbor BS is greater than serving BS metric by relative value 0x4: Metric of neighbor BS is less than serving BS metric by relative value 0x5: Metric of serving BS greater than absolute value 0x6: Metric of serving BS less than absolute value Action - Action performed upon reaching trigger condition: 0x0: Reserved 0x1: Respond on trigger with MOB_SCN-REP after the end of each scanning interval 0x2: Respond on trigger with MOB_MSHO-REQ 0x3: On trigger, MS starts neighbor BS scanning process by sending MOB_SCN- REQ, by initiating autonomous neighbor cell scanning or both. 0x4: On trigger, MS starts Inter RAT neighbor BS scanning process by sending MOB_SCN-REQ 0x5: On trigger, MS starts Inter RAT handover by sending MOB_MSHO-REQ 0x6: On trigger, MS starts Inter RAT Pre-registration process by sending MOB_SCN- REQ 0x7: Reserved

The base station may include the contents of Table 2 in the SBCH and transmit to the terminal. Therefore, when the terminal satisfies the trigger condition of Table 2, scanning, pre-registration or handover may be performed.

In Table 1, a neighbor advertisement message indication (NBR-ADV) field indicates whether an NBR-ADV message is transmitted to the UE in a period of 20 ms of the corresponding superframe. The Intra RAT scanning & handover Threshold field represents a reference value for determining whether the UE satisfies a scanning or handover trigger condition. The heterogeneous network scanning threshold field, the heterogeneous network pre-registration threshold field, and the handover threshold field indicate a reference value for determining whether the terminal satisfies the scanning, pre-registration, or handover trigger condition.

In addition, another heterogeneous network pre-registration capability indication field indicates whether or not the pre-registration capability is supported for different heterogeneous networks. When the terminal needs to pre-register to another heterogeneous network, the terminal may scan only a network supporting the pre-registration capability. This field may be included in a message including heterogeneous network information other than SBCH and transmitted to the terminal (for example, it may be broadcast through a predetermined DL subframe in the form of a message including other heterogeneous network information. In particular, similar to the MOB_NBR-ADV message). The base station may broadcast other heterogeneous network pre-registration capability indication fields in the form of messages. At this time, the base station may transmit the information of the neighboring base station and homogeneous network neighbor base station together. Also, the base station may separate base station neighboring base station information and heterogeneous neighboring base station information, respectively, and transmit them using different SBCHs.

In addition, the supported HO Type field indicates a field indicating a handover type supported by the base station.

Fields and contents of Tables 1 and 2 may be transmitted through the sub-broadcast channel (SBCH) of FIGS. 3 and 4. However, the base station may transmit the contents of Tables 1 and 2 to the terminal through the main broadcast channel (PBCH) according to user requirements or channel environment. In addition, neighbor base station advertisement messages of heterogeneous networks including the contents of Tables 1 and 2 may be transmitted to the terminal in advance through DL subframes designated as broadcast messages in order to transmit neighbor base station information.

5 is a diagram illustrating a method of broadcasting SFH according to another embodiment of the present invention.

FIG. 5 discloses a method for transmitting a superframe header (SFH) including heterogeneous network information by a base station (BS) to support inter RAT HO. Referring to FIG. 5, the base station BS may periodically broadcast SFH to one or more terminals MS 1, MS 2,..., And MS n (S501, S502, and S503).

In this case, the base station may broadcast the SFH transmitted in steps S501 to S503 to one or more terminals using the SFH structure described with reference to FIGS. 3 and 4. That is, in FIG. 5, the base station may activate an indicator (eg, NTII) indicating whether heterogeneous network information is transmitted in the current superframe and transmit the same to the terminals through the BCH. In addition, when the NTII is activated, the base station may broadcast actual heterogeneous network information directly to one or more terminals, or inform the terminal of information on a frame in which the heterogeneous network information is transmitted.

6 illustrates another method of transmitting heterogeneous network information according to another embodiment of the present invention.

6 illustrates a method in which a terminal requests different heterogeneous network information from a base station, and the base station delivers heterogeneous network information owned to the terminal. In this case, it is assumed that the base station already knows heterogeneous network network information. In addition, when performing a network entry to the current base station (network entry), the terminal may negotiate a mutual capability (capability) as to whether to obtain inter-RAT network information (inter RAT network information) supported by the base station. .

Referring to FIG. 6 (a), the base station may transmit a superframe header (SFH) to the terminal at predetermined intervals. SFH may be transmitted in a specific superframe. In addition, depending on the channel environment, SFH may be transmitted for each superframe. In another embodiment of the present invention, the predetermined period during which the SFH is broadcasted is preferably a time corresponding to a superframe. Therefore, in the embodiments of the present invention, when using the superframe structure of FIGS. 2 and 3, the base station may transmit the SFH to the terminal in a period of 20ms (S601).

In step S601, the sub-broadcast channel (SBCH) of the SFH may include a network topology information indicator (NTII) indicating whether heterogeneous network information is transmitted in a corresponding superframe. NTII may be called a topology information message indicator or a network topology information flag.

If NTII is activated, it indicates that heterogeneous network information is transmitted from the corresponding superframe to the terminal. However, if NTII is not activated, it indicates that heterogeneous network information required for handover between heterogeneous networks is not transmitted in the corresponding superframe. In FIG. 6, it is assumed that the base station already has heterogeneous network information, but NTII is not activated.

The terminal may transmit an inter-RAT network information request message for requesting heterogeneous network information to the base station to obtain heterogeneous network information (S602).

Step S602 may be performed even if the terminal receives abbreviated information such as an inter RAT BS ID through step S601. For example, even if the UE needs detailed information on heterogeneous base stations, step S602 may be performed.

In addition, step S602 may be performed when the terminal intends to handover to a heterogeneous network. For example, in step S602, if there is no homogeneous base station to which the terminal can handover, or if the terminal checks whether there is another heterogeneous network having a lower cost than the current connection network due to a handover policy. Can be performed.

In response to the request for heterogeneous network information from the UE, the base station may transmit an inter-RAT network information response message including information of a heterogeneous network capable of handover of neighboring heterogeneous networks (S603a).

Steps S601 and S602 of FIG. 6B are the same as those of FIG. 6A. However, in step S603b, unlike step S602a, the base station broadcasts a heterogeneous network information response message to one or more terminals. In this case, steps S601 to S603 in FIG. 6 may be performed in the same superframe.

If the base station does not transmit the heterogeneous network information response message in the corresponding superframe, the base station may broadcast the heterogeneous network information to the terminals using the next superframe header (SFH) (S604).

In FIG. 6, an inter RAT network may be included in a BCH of SFH and transmitted. For example, heterogeneous network information may be included in one of PBCH and SBCH of BCH. If the information amount of the heterogeneous network information is large, the base station may transmit an indicator indicating that the heterogeneous network information is to be transmitted in a specific subframe in the current superframe through the SBCH. In addition, the base station may transmit to the terminal a pointer indicating where the actual heterogeneous network information is to be transmitted in the superframe. Of course, the base station may transmit heterogeneous network information to the terminal in the subframe indicated by the indicator or pointer.

FIG. 7 shows another method of transmitting heterogeneous network information according to another embodiment of the present invention.

FIG. 7 illustrates a method of transmitting heterogeneous network information when the base station does not know heterogeneous network information, unlike FIG. 6. When the terminal performs network entry to the current base station, the terminal may negotiate mutual capability with respect to whether inter-RAT network information supported by the current base station can be obtained.

Referring to FIG. 7A, the base station may transmit a superframe header (SFH) that does not include network topology information to the terminal at predetermined intervals (Network Topology Information Indicator not set; S701).

In step S701, the base station may transmit the SFH in a specific superframe. In addition, the base station may transmit the SFH for each superframe according to the channel environment. In another embodiment of the present invention, the predetermined period during which the SFH is broadcasted is preferably a time corresponding to a superframe. Therefore, in the embodiments of the present invention, when using the superframe structure of FIGS. 2 and 3, the base station may transmit the SFH to the terminal in a period of 20ms.

If the terminal MS does not acquire topology information including heterogeneous network information through the SFH, the terminal may transmit an inter-RAT network information request to the base station in order to request the heterogeneous network information (S702). ).

In step S702, a heterogeneous network handover, such as when there is no homogeneous base station capable of handover or when the terminal wants to search for another heterogeneous network which is less expensive than the current connected network due to a communication policy, etc. It may also be performed when it is necessary to perform.

In addition, even if the base station transmits the abbreviated information such as the neighbor heterogeneous network base station identifier to the terminal through the superframe header (SFH) in step S701, when the terminal wants to obtain detailed information about the heterogeneous network base stations S702 process This can be done.

Currently, the serving base station does not have heterogeneous network information. Accordingly, the serving base station transmits a query REQ message for requesting heterogeneous network information to a target network information server (or another network entity) having heterogeneous network information, and sends a query response from the target network information server (Query RSP). In step S703, a procedure for acquiring heterogeneous network information may be performed by receiving a message.

When the base station obtains heterogeneous network information from the target network information server, the base station may transmit an Inter RAT Network Information Response message including the heterogeneous network information to the terminal (S704a).

Steps S701 to S703 in FIG. 7B are the same as those in FIG. 7A. However, in step S704b, unlike step S704a, the base station broadcasts a heterogeneous network information response message to one or more terminals. In this case, steps S701 to S704 in FIG. 7 may be performed in the same superframe.

If the base station does not transmit the heterogeneous network information response message in the corresponding superframe, the base station may broadcast the heterogeneous network information to the terminals using the next superframe header (SFH) (S705).

In FIG. 7, an inter RAT network may be included in a BCH of SFH and transmitted. For example, heterogeneous network information may be included in one of PBCH and SBCH of BCH. If the information amount of the heterogeneous network information is large, the base station may transmit an indicator indicating that the heterogeneous network information is to be transmitted in a specific subframe in the current superframe through the SBCH. In addition, the base station may transmit to the terminal a pointer indicating where the actual heterogeneous network information is to be transmitted in the superframe. Of course, the base station may transmit heterogeneous network information to the terminal in the subframe indicated by the indicator or pointer.

In addition, the SFH used in steps S604 and S705 preferably has the same structure as the SFH used in FIG. 5.

8 shows another method of transmitting heterogeneous network information according to another embodiment of the present invention.

8 illustrates a method of acquiring heterogeneous network information used in an emergency in which heterogeneous network information is acquired. 8 basically performs an operation similar to that of FIG. Therefore, in order to prevent waste of the ground, steps S802 and S804 which differ from FIG. 7A in steps S801 to S804 will be mainly described.

The terminal may receive the SFH from the base station in step S801. However, SFH does not contain heterogeneous network information. In this case, it may be necessary to urgently perform the heterogeneous network handover to the terminal. Therefore, the terminal sets the emergency information field (eg, an urgent bit) included in the heterogeneous network information request message to '1' and activates it (Urgent Bit setting). Can be informed (S802).

Accordingly, the base station acquires heterogeneous network information from the target network information server (S803), and upon receiving the heterogeneous network information, the base station may transmit the heterogeneous network information in a unicast format to the terminal that activated the emergency bit (S804). .

If the base station has heterogeneous network information, the base station can transmit the heterogeneous network information directly to the corresponding terminal without communicating with other network entities. The emergency bit is an identifier that heterogeneous network information should be delivered quickly, which can be interpreted as a unicast transmission request.

In FIG. 8, the emergency information field or emergency bit may be represented as one or more bits according to a user requirement or a channel environment. For example, the base station may use emergency bits of 2 bits or 3 bits.

9 illustrates another method of transmitting heterogeneous network information according to another embodiment of the present invention.

9 basically shows a process similar to that of FIG. 8. However, FIG. 9 illustrates a method of informing the terminal of an expected time point for transmission of heterogeneous network information when the terminal requests heterogeneous network information by setting an emergency bit to the base station, but the base station does not immediately obtain the heterogeneous network information.

Steps S901 and S902 of FIG. 9 are similar to steps S801 and S802 of FIG. 8. However, the base station transmits a query request message for requesting heterogeneous network information to the target network information server (S903), but has not yet obtained heterogeneous network information from the target network information server.

In this case, the base station may inform the terminal of the expected time when a response message including heterogeneous network information is transmitted to the terminal through a unicast response message (for example, Inter RAT Network Information Response). That is, the base station can inform the terminal when to transmit heterogeneous network information by using the Expected Delivery Time = xxx field (S904).

In step S904, the base station uses the transfer expected time field to determine the number of superframes to which a response message including heterogeneous network information is transmitted, or an offset value of a superframe to which current superframe and heterogeneous network information is transmitted. I can let you know. In addition, the base station may inform the number of subframes of a specific superframe using the forwarding expected field.

In step S904, the terminal receiving the response message including the expected delivery time field, scanning the other heterogeneous network while waiting for heterogeneous network information, or idle mode (or sleep mode) for power saving It can work as

The base station may receive a query response (Query RSP) message including the target network information from the target network information server during the period indicated by the expected delivery time (S905).

The base station may transmit a response message or SFH (Super Frame Header) including heterogeneous network information to the terminal in the superframe or subframe indicated by the forwarding time field. At this time, the BCH of the SFH may include information indicating whether heterogeneous network information is included (S906).

In operation S906, heterogeneous network information may not be available even at the time indicated by the expected delivery time field. At this time, the base station may inform the terminal of the expected time (subframe # = zzz) to transmit heterogeneous network information through a response message transmitted in a BCH or a unicast format transmitted to the beginning of the superframe.

The base station may transmit a response message (Inter RAT Network Information Response) including the heterogeneous network information to the terminal at the expected transmission time zzz (S907).

In step S904, another method for informing the terminal of the expected transmission time to the terminal will be described. In this case, the base station may inform the terminal of the expected time point for the transmission of the heterogeneous network information by using the counter.

For example, the base station may decrement the counter every time the BCH is transmitted in every superframe after transmitting the response message including the transmission expected time field in step S904, and may transmit a heterogeneous network alarm to the terminal when the counter value becomes zero. . In addition, the base station increases the counter value every time the BCH is transmitted, and when the counter value reaches the threshold, the base station may transmit heterogeneous network information to the terminal. In this case, the base station may transmit a response message including heterogeneous network information to the terminal in unicast format.

If the base station fails to transmit the heterogeneous network information to the terminal even when the counter value reaches a threshold or becomes zero, the base station may set the transfer expected time field again and transmit it to the terminal.

FIG. 10 illustrates another method of transmitting heterogeneous network information according to another embodiment of the present invention.

FIG. 10 illustrates a method in which a base station delivers heterogeneous network information when the terminal is not urgently obtaining heterogeneous network information. Referring to FIG. 10, the base station may transmit a superframe header (SFH) that does not include network topology information to the terminal at predetermined intervals (Network Topology Information Indicator not set; S1001).

In step S1001, the base station may transmit the SFH in a specific superframe. In addition, the base station may transmit the SFH for each superframe according to the channel environment. In another embodiment of the present invention, the predetermined period during which the SFH is broadcasted is preferably a time corresponding to a superframe. Therefore, in the embodiments of the present invention, when using the superframe structure of FIGS. 2 and 3, the base station may transmit the SFH to the terminal in a period of 20ms.

In this case, the terminal may indicate that the emergency information field (for example, an urgent bit) included in the heterogeneous network information request message is set to '0' to indicate that it is not an emergency (S1002). .

The base station may check the emergency information field included in the heterogeneous network information request message to determine the degree of urgency of the heterogeneous network information, and determine a time point for transmitting the heterogeneous network information to the terminal. Accordingly, the base station may transmit a response message including information on a time point (eg, a superframe number to transmit heterogeneous network information) to the terminal (S1003).

If the base station does not have the heterogeneous network information, the base station may request the heterogeneous network information from the target network information server to obtain the heterogeneous network information used in the target network (S1004). Of course, if the base station has heterogeneous network information in advance, step S1004 may be omitted.

In FIG. 10, an inter RAT network may be included in a BCH of SFH and transmitted. For example, heterogeneous network information may be included in one of PBCH and SBCH of BCH. If the information amount of the heterogeneous network information is large, the base station may transmit an indicator indicating that the heterogeneous network information is to be transmitted in a specific subframe in the current superframe through the SBCH. In addition, the base station may transmit to the terminal a pointer indicating where the actual heterogeneous network information is to be transmitted in the superframe. Of course, the base station may transmit heterogeneous network information to the terminal in the subframe indicated by the indicator or pointer.

When the base station transmits a response message including heterogeneous network information to the terminal, the base station may deliver the heterogeneous network information request message together with the heterogeneous network information response message to the terminals in consideration of other terminals that do not request the heterogeneous network information.

The base station may not be ready to deliver heterogeneous network information to the terminal when the heterogeneous network information transmission is expected. In this case, the base station may transmit the information on the time point at which the heterogeneous network information is expected to be transmitted to the terminal using a broadcast message in which BCH or additional information is transmitted.

FIG. 11 is a diagram illustrating a method for randomly transmitting heterogeneous network information to a terminal by another embodiment of the present invention.

11 illustrates a method for transmitting heterogeneous network information in an unsolicited form. Referring to FIG. 11, the base station may transmit a superframe header (SFH) not including network topology information to the terminal at predetermined intervals (S1101).

The serving base station does not have heterogeneous network information. Accordingly, the serving base station transmits a query REQ message for requesting heterogeneous network information to a target network information server (or another network entity) having heterogeneous network information, and sends a query response from the target network information server (Query RSP). The heterogeneous network information can be obtained by receiving the message (S1102).

Although the base station does not request heterogeneous network information, when the heterogeneous network information is obtained from the target network information server, the base station may arbitrarily transmit the heterogeneous network information to the terminal (S1103).

In step S1103, the base station may transmit a heterogeneous network information response message including heterogeneous network information to a specific terminal in a unicast format, or in a broadcast form to one or more terminals.

If the base station does not transmit the heterogeneous network information response message to the terminal within the corresponding superframe, the base station may broadcast the heterogeneous network information to the terminals using the next superframe header (SFH) (S1104).

Hereinafter, as another embodiment of the present invention, a method for transmitting heterogeneous network information using a topology information message indicator is disclosed.

In embodiments of the present invention, whether the network topology information message indicator includes a current network topology information message (or, in a specific super frame, or a specific frame) is included in the network topology information message indicator (Networf Topology Information Message Indicator). Can be represented. In addition, a start frame number (SFN) field may indicate a start number of a frame in which a network topology information message is transmitted.

FIG. 12 is a diagram illustrating one of methods for transmitting heterogeneous network information using a network topology information message indicator according to another embodiment of the present invention.

Referring to FIG. 12, a network topology information indicator (NTIMI) included in a superframe header may indicate whether a topology information message is transmitted in a current superframe. In FIG. 12, NTIMI is set to '1' to indicate that a network topology information message is transmitted within a current superframe.

In this case, when the terminal decodes the network topology information message indicator, it can be seen that the topology information message exists in the current superframe. Accordingly, the UE can know the frame number where the actual topology information message exists by decoding the SFN field. The UE may decode the topology information message in the frame (or subframe) indicated by the SFN field.

In embodiments of the present invention, the base station may transmit a network topology information message to the terminal in a specific subframe. That is, the base station may indicate the subframe in which the network topology information message is transmitted using SFN. In this case, the SFN field may indicate the number of a specific subframe.

FIG. 13 is a diagram illustrating another method of transmitting heterogeneous network information using a network topology information message indicator according to another embodiment of the present invention.

13 is basically the same as FIG. 12. In FIG. 13, the current network topology information message indicator is '0', indicating that the network topology information message is not transmitted in the current superframe (the UE may not decode the SFN field). In this case, the UE may decode a Next Superframe Number (NSN) field included in the superframe header (SFH). The superframe number field may indicate the next superframe number including network topology information. Accordingly, the UE can decode the network topology information message in the superframe indicated by the NSN field by decoding the NSN field.

FIG. 14 is a diagram illustrating still another method for transmitting heterogeneous network information using a topology information message indicator according to another embodiment of the present invention.

In FIG. 14, the base station may transmit a network topology information message indicator (hereinafter, referred to as a message indicator) and a start frame number (SFN) field in the superframe header to the terminal. In FIG. 14, the network topology information message may include a multicarrier information message and a heterogeneous network handover information message.

In this case, the superframe header includes a multi-carrier information SFN field indicating a frame number on which multi-carrier information is transmitted and a heterogeneous inter-network handover information SFN (multi-carrier) indicating a frame number on which inter-network handover information is transmitted. RAT Information SFN) field may be further included. In this case, the multi-carrier information SFN field and the inter-network handover information SFN field may be included in the SFN field.

Referring to FIG. 14, the base station may transmit a superframe header (SFH) including a message indicator and a start frame number (SFN) field to the terminal in the first superframe. In this case, it is assumed that the message indicator is set to '1'.

The terminal may decode the SFN field when the message indicator is '1'. Accordingly, the terminal may decode the multicarrier information message in a frame (or subframe) indicated by the multicarrier information SFN field in the SFN field. In addition, the terminal may decode a multi-RAT information message in a frame (or subframe) indicated by the inter-network handover information SFN field.

The base station may transmit a superframe header (SFH) including a message indicator and a superframe offset field to the terminal in the second and third superframes. In this case, it is assumed that the message indicator is set to '0 (off)'.

When the UE decodes the message indicator, it can recognize that the network topology information message is not transmitted in the current superframe. Accordingly, the terminal may decode a super frame offset (SFO) field indicating a super frame number through which network topology information is transmitted. The UE may receive a network topology information message in the superframe indicated by the SFO field.

FIG. 15 is a diagram illustrating another method for transmitting heterogeneous network information by using a topology information message indicator to a terminal in an idle mode according to another embodiment of the present invention.

FIG. 15 is basically similar to FIG. 14. However, in the case of FIG. 15, it is assumed that the terminal is in the idle mode. The UE wakes up from a paging listening interval (MS Paging Listen Interval) allocated to itself in the idle mode and can decode the superframe header (SFH).

At this time, if the message indicator included in the SFH is '0' (that is, off), the base station includes a superframe offset (SFO) field indicating the superframe number to which the network topology information message is transmitted in the paging indicator field. It can transmit to the terminal.

The terminal may decode the superframe header of the superframe indicated by the SFO by checking the superframe offset (SFO) field. Accordingly, the terminal can decode network topology information messages in the corresponding superframe.

FIG. 16 is a diagram illustrating another method of transmitting heterogeneous network information by using a topology information message indicator to a terminal in an idle mode according to another embodiment of the present invention.

16 is basically similar to FIG. 15. However, FIG. 16 illustrates a case in which the superframe offset (SFO) field is not included in the superframe header (SFH) and is transmitted in a map message or a predetermined position (eg, a specific frame or a specific subframe). In this case, it is assumed that the location where the SFO is transmitted is already known to the terminal and the base station. In addition, the SFO may be included in a specific frame header or subframe header.

Referring to FIG. 16, the terminal wakes up in a paging listening interval (MS Paging Listen Interval) allocated to it and can decode the messages transmitted from the base station. In FIG. 16, the UE wakes up in a paging listening period and decodes a superframe offset (SFO). The UE may wake up from the superframe indicated by the SFO and decode the network topology information message (eg, multi-carrier information message and / or inter-network handover information message) in a specific frame or a specific subframe indicated by the SFN. .

That is, in FIG. 16, the UE checks the SFH, but the topology information message indicator may be off (0). In this case, the UE may include a superframe offset (SFO: Super) included in a paging indicator at a map (MAP) to which a paging indicator is delivered or at a predetermined location (pre-defined location (frame or subframe)). Frame Offset) can be checked. Accordingly, the UE may decode next topology information scheduling information in the superframe indicated by the SFO.

Table 3 below shows an example of a superframe header format applicable to embodiments of the present invention.

Syntax Size (bit) Notes Super Frame Offset () { - - To Topology information message indicator 0: No topology information message exists in the current superframe 1: Topology information message exists in the current superframe If (Topology information message indicator == 1) {SFN (Start Frame Number)} SFN: Frame Number where Topology information message is located in current SuperFrame. Else {Next SuperFrame Number} Next SuperFrame Number: indicates the next SuperFrame Number to which topology information (topology information indicator, SFN of topology information message) is transmitted. To } // End of SFH

Referring to Table 3, the super frame header (SFH) may include one or more of a topology information message indicator (or network topology information message indicator), a superframe number (SFN) field, and a next superframe number (NSN) field. . In embodiments of the present invention, the topology information message indicator may be represented by a message indicator.

The topology information message indicator may have a size of 1 bit. In this case, when the topology information message indicator is set to '0', it indicates that no network topology information message exists in the current superframe, and when set to '1', it indicates that a network topology information message exists in the current superframe.

If the topology information message indicator is set to '1', the superframe header may include a superframe number (SFN) field. Accordingly, the UE can decode the network topology information message in the frame or subframe indicated by the superframe number field.

If the topology information message indicator is set to '0', the superframe header may include a next superframe number (NSN) field. In this case, the terminal may decode the network topology information message in the superframe indicated by the next superframe number field.

Indicators and fields (or parameters) of Table 3 may be included in a frame header or subframe header. In addition, the indicator and fields (or parameters) may be included in a map message and transmitted to the terminal.

The invention can be embodied in other specific forms without departing from the spirit and essential features of the invention. Accordingly, the above detailed description should not be construed as limiting in all aspects and should be considered as illustrative. The scope of the invention should be determined by reasonable interpretation of the appended claims, and all changes within the equivalent scope of the invention are included in the scope of the invention. It is also possible to form embodiments by combining claims that do not have an explicit citation in the claims or to include them as new claims by post-application correction.

1 is a diagram illustrating a method for delivering heterogeneous network information using a broadcast method.

2 is a diagram illustrating an example of a frame structure that may be used in embodiments of the present invention.

3 shows an example of a superframe structure and a superframe header structure according to an embodiment of the present invention.

4 is a diagram illustrating another example of a superframe header structure according to one embodiment of the present invention.

5 is a diagram illustrating a method of broadcasting SFH according to another embodiment of the present invention.

6 illustrates another method of transmitting heterogeneous network information according to another embodiment of the present invention.

FIG. 7 shows another method of transmitting heterogeneous network information according to another embodiment of the present invention.

8 shows another method of transmitting heterogeneous network information according to another embodiment of the present invention.

9 illustrates another method of transmitting heterogeneous network information according to another embodiment of the present invention.

FIG. 10 illustrates another method of transmitting heterogeneous network information according to another embodiment of the present invention.

FIG. 11 is a diagram illustrating a method for randomly transmitting heterogeneous network information to a terminal by another embodiment of the present invention.

FIG. 12 is a diagram illustrating one of methods for transmitting heterogeneous network information using a network topology information message indicator according to another embodiment of the present invention.

FIG. 13 is a diagram illustrating another method of transmitting heterogeneous network information using a network topology information message indicator according to another embodiment of the present invention.

FIG. 14 is a diagram illustrating still another method for transmitting heterogeneous network information by using a network topology information message indicator according to another embodiment of the present invention.

FIG. 15 is a diagram illustrating another method for transmitting heterogeneous network information by using a topology information message indicator to a terminal in an idle mode according to another embodiment of the present invention.

FIG. 16 is a diagram illustrating another method of transmitting heterogeneous network information by using a topology information message indicator to a terminal in an idle mode according to another embodiment of the present invention.

Claims (17)

In the method for transferring heterogeneous network information for handover between heterogeneous networks, Receiving the predetermined header including an indicator indicating whether the heterogeneous network information is transmitted in a superframe in which the predetermined header is transmitted; And Acquiring the heterogeneous network information using the indicator; And the predetermined header is transmitted periodically. The method of claim 1, The predetermined header includes a broadcast channel, And the indicator is assigned to the broadcast channel. The method of claim 2, The broadcast channel includes a main broadcast channel (PBCH) and a sub broadcast channel (SBCH), And the indicator is included in one of the main broadcast channel and the sub broadcast channel. The method of claim 3, wherein If the indicator indicates that the heterogeneous network information is transmitted in the superframe, The broadcast channel further includes a start frame number field indicating a start number of a subframe to which the heterogeneous network information is allocated. And the start frame number field is included in one of the main broadcast channel and the sub broadcast channel. The method of claim 4, wherein If the indicator indicates that the heterogeneous network information is transmitted in the superframe, And receiving the heterogeneous network information in a predetermined frame indicated by the start frame number field. The method of claim 2, If the indicator indicates that the heterogeneous network information is transmitted in the superframe, The broadcast channel included in the predetermined header further includes the heterogeneous network information. The method of claim 2, If the indicator indicates that the heterogeneous network information is not transmitted in the superframe, A terminal transmitting a request message for requesting the heterogeneous network information to a base station; And And receiving a response message including the heterogeneous network information from the base station. The method of claim 7, wherein And the response message is transmitted to one or more terminals in a broadcast form. The method of claim 7, wherein The request message is an information delivery method, characterized in that it comprises an emergency information field indicating whether or not the acquisition of the heterogeneous network information. The method of claim 9, If the base station does not have the heterogeneous network information, The response message further comprises information on the expected time to deliver the heterogeneous network information. The method of claim 9, If the base station does not have the heterogeneous network information, The base station obtains the heterogeneous network information from a target network information server and transmits the information to the terminal. The method of claim 2, And the predetermined header is one of a superframe header or a subframe header. In the method for delivering heterogeneous network information for handover between heterogeneous networks, Periodically transmitting, by the base station, a superframe header including an indicator indicating whether heterogeneous network information exists in a predetermined superframe; Requesting the heterogeneous network information from a terminal and receiving a request message including an emergency information field indicating whether an emergency situation exists; And And transmitting, by the base station, a first response message including the heterogeneous network information to the terminal. The method of claim 13, The super frame header includes a broadcast channel including a main broadcast channel and a sub broadcast channel. And the indicator is included in one of the main broadcast channel and the sub broadcast channel. The method of claim 13, If the base station does not know the heterogeneous network information, The base station further comprises the step of obtaining the heterogeneous network information from an information server. The method of claim 13, When the emergency information field is activated, And the base station transmits the first response message to the terminal immediately. The method of claim 13, When the emergency information field is activated, And transmitting, by the base station, a second response message immediately indicating the frame in which the first response message is to be transmitted to the terminal.

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