KR101005017B1 - A processing method of unprediction based handoff of heterogeneous wireless networks - Google Patents

Abstract

In a wireless communication system of at least one WLAN base station in a WiBro / WiMAX network including at least one WiBro / WiMAX base station according to an embodiment of the present invention, a method for processing non-prediction-based handoff between heterogeneous wireless networks is provided. The terminal accesses the wireless LAN network without performing the preparation process required for handoff, and the terminal transmits the ID information of the WiBro / WiMAX base station in the combined request message.

Description

A processing method of unprediction based handoff of heterogeneous wireless networks

The present invention relates to the field of mobile communications, and more particularly, to a handoff method between heterogeneous wireless networks and a wireless communication system including heterogeneous networks.

Recently, the WiBro / WiMAX service, which enables internet access while on the go, using a portable device, has become popular. Wireless broadband (WiBro) and worldwide interoperability for microwave access (WiMAX) support a range of kilometers and fast mobility (up to 60 km / h), similar to mobile networks, and are much higher than traditional mobile networks. It has the advantage of supporting speed. This has the advantage of providing a service over a wide area since the cell radius is larger than that of the WLAN.

Nevertheless, WiBro / WiMAX has a disadvantage in that the transmission speed is lower than that of WLAN. In case of WLAN, it supports 11 ~ 54Mbps of transmission speed, so it can provide sufficient data service to users compared with wired internet. However, in the case of WLAN, the cell coverage is tens to hundreds of meters, and since it does not basically provide handoff, the existing data service is disconnected when the hot spot is left.

If the WLAN network is included in the WiBro / WiMAX network by making the most of the advantages and disadvantages of these two networks, the capacity of the WiBro / WiMAX base station may be increased, or the wireless LAN network may be used to compensate for the shadow area that the base station cannot cover. May be used.

In this situation, the handoff needs to be performed from the WiBro / WiMAX network to the WLAN network. Currently, each of the wireless networks only considers a handoff from a single network. Should be. In addition, in supporting handoffs between heterogeneous wireless networks, it is required to make a substantial portion of the handoff technology by the WLAN base station to make minimal modifications while maintaining the current infrastructure of WiBro / WiMAX.

However, the WiBro / WiMAX standard only defines handoffs between homogeneous networks, and the WLAN standard defines only a few simple connection messages without proposing a clear handoff algorithm.

Accordingly, an object of the present invention is to provide a method for processing unpredictable based handoff from a WiBro / WiMAX network to a WLAN network.

Another object of the present invention is to provide a wireless communication system capable of processing handoff from a WiBro / WiMAX network to a WLAN network.

In order to achieve the above object of the present invention, in a wireless communication system of the interworking network provided with at least one WLAN base station in the WiBro / WiMAX network including at least one WiBro / WiMAX base station according to an embodiment of the present invention In the method of processing non-prediction-based handoff between heterogeneous wireless networks, when a terminal accessing the WiBro / WiMAX base station determines a handoff to a WLAN network including the WLAN base station, the terminal performs a preparation process necessary for the handoff. The connection to the wireless LAN network is not performed. The terminal transmits the ID information of the WiBro / WiMAX base station in a combined request message.

When the WLAN base station receives the WLAN combining request message, the WLAN base station transmits the MAC context information request message of the terminal to the WiBro / WiMAX base station by using ID information of the WiBro / WiMAX base station.

When the WiBro / WiMAX base station receives the MAC context information request message, the WiBro / WiMAX base station includes the information on the terminal in the MAC context information report message and transmits the information to the WLAN base station. When the WLAN base station receives the MAC context information report message, it interprets the received MAC context information report message.

After the WLAN base station interprets the received MAC context information report message, the WLAN base station is included in the WiBro / WiMAX network and connects the WiBro / WiMAX base station and the WLAN base station to a data path according to the WiBro / WiMAX standard. Send a connection request message.

When the gateway receives the data path connection request message, after setting the data path, the gateway transmits a data path connection request response message to the WLAN base station. The WLAN base station receiving the data path connection request response message interprets the received data path connection request response message.

After the WLAN base station interprets the data path connection request response message, the WLAN base station constructs a data path connection response message according to the WiBro / WiMAX standard and transmits the data path connection response message to the gateway.

When the WLAN base station completes the handoff process for the terminal, the WLAN base station configures and transmits a handoff completion message to the WiBro / WiMAX standard.

In an embodiment, the WLAN base station may support some functions of the WiBro / WiMAX standard.

In an embodiment, the terminal may be a dual mode terminal supporting both the WiBro / WiMAX standard and the WLAN standard.

In an embodiment, the WLAN base station may include a message conversion module between a control message of the WiBro / WiMAX network and a control message of the WLAN network including the WLAN base station.

After the WLAN base station analyzes the control message of the WiBro / WiMAX network, the configuration value for the response message according to the WiBro / WiMAX standard may use information of the WLAN standard.

In order to achieve the above object of the present invention, a wireless communication system according to an embodiment of the present invention includes a terminal capable of accessing a WiBro / WiMAX network and a WLAN network, and at least one WiBro / WiFi / WiFi / WiMAX network. WiMAX base station; The WiBro / WiMAX network provided in the WiBro / WiMAX network and the Wi-Fi / WiMAX gateway that connects the Wi-Fi / WiMAX network and the wireless LAN network and the Wi-Fi / WiMAX network to handle the handoff from the WiBro / WiMAX network to the WLAN network. At least one WLAN base station. When the terminal accesses the wireless LAN network without performing the preparation process required for the handoff, the terminal transmits the ID information of the WiBro / WiMAX base station in the association request message.

In at least one example embodiment, the at least one WLAN base station may be located within cell coverage of the at least one WiBro / WiMAX base station.

In order to achieve the above object of the present invention, heterogeneous in a wireless communication system of an interworking network provided with at least one WLAN base station in a WiBro / WiMAX network including at least one WiBro / WiMAX base station according to an embodiment of the present invention. In the non-prediction-based handoff processing method between wireless networks, the terminal communicates with the WiBro / WiMAX base station. The terminal discovers the WLAN base station via the WiBro / WiMAX base station. The terminal informs the WLAN base station that it will perform a join request. The WLAN base station requests information necessary for handoff to the WiBro / WiMAX base station.

In an embodiment, the base station advertisement message periodically received from the WiBro / WiMAX base station may include information on the WiBro / WiMAX base station and information on the WLAN base station.

According to embodiments of the present invention, it is based on a tightly coupled network structure that can take full advantage of the WiBro / WiMAX network and the WLAN network, and supports handoff for heterogeneous wireless networks through modification of the WLAN base station. Can be. In addition, when the handoff from the WiBro / WiMAX network to the WLAN network is performed, handoff according to the WiBro / WiMax standard can be performed to minimize the modification of the terminal.

Hereinafter, a method of manufacturing a semiconductor device in accordance with embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the following embodiments, and has ordinary skill in the art. It will be apparent to those skilled in the art that the present invention may be embodied in various other forms without departing from the spirit of the invention.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, the terms "comprise" or "having" are intended to indicate that there is a feature, number, step, action, component, part, or combination thereof that is described, and that one or more other features or numbers are present. It should be understood that it does not exclude in advance the possibility of the presence or addition of steps, actions, components, parts or combinations thereof. Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art. Terms such as those defined in the commonly used dictionaries should be construed as having meanings consistent with the meanings in the context of the related art and shall not be construed in ideal or excessively formal meanings unless expressly defined in this application. Do not.

On the other hand, when an embodiment is otherwise implemented, a function or operation specified in a specific block may occur out of the order specified in the flowchart. For example, two consecutive blocks may actually be performed substantially simultaneously, and the blocks may be performed upside down depending on the function or operation involved. Like reference numerals in the drawings denote like elements.

1 shows an uncontrolled handoff process in WiBro / WiMAX.

In FIG. 1, an uncontrolled handoff means that the mobile terminal 10 (MS) does not go through the handoff preparation step due to the rapid movement or the handoff preparation process, but does not complete the handoff preparation process due to the failure of the message delivery. In this situation, the overall handoff delay time may increase. However, if the information on the previous serving base station is transmitted in the ranging request (RNG-REQ) message, which is the beginning of the network entry process, a large part of the handoff process may be omitted and optimized. 1 shows a handoff procedure in this situation.

Referring to FIG. 1, in a handoff of WiBro / WiMAX, a mobile terminal 10 (MS) is first provided from a serving base station (BS) 20 that provides wireless connectivity to a corresponding network when the network is located anywhere. A base station advertisement (MOB_NBR-ADV: Neighbor Advertisement) message that is periodically transmitted is received (S11). This base station advertisement (MOB_NBR-ADV) message contains information about all base stations in the adjacent location and network attributes of the base station. Therefore, when the mobile station 10 receives the base station advertisement (MOB_NBR-ADV) message, the mobile station 10 acquires IDs, quality of service (QoS) parameters, and channel information of neighboring base stations, and uses the information to perform handoff later. Can be. Another method for acquiring network information by the mobile terminal 10 is a scanning procedure performed by the mobile terminal 10 to measure downlink signal quality received from neighboring base stations 20. to be. The mobile terminal 20 acquires a list of neighbor base stations through a base station advertisement (MOB_NBR-ADV) message and manages the list as candidate base stations for handoff by selecting an appropriate base station based on real-time link information acquired through scanning. can do.

The mobile terminal 10 starts the network entry by including the ID information of the serving base station 20 in the ranging request (RNG-REQ) message (S21, S22).

Based on the ID, the target base station 40 transmits a MAC context information request (CONTEXT_REQ) message for the mobile terminal 10 to the serving base station 20 (S31). The serving base station 20, which has received the MAC context information request (CONTEXT_REQ) message, responds (S32) with a MAC context information report (CONTEXT_RPT) message containing the MAC context for the UE, and instead of a large part of the network entry process as such information. can do.

From this point after the data path setting process (S41, S42, S43) between the target base station 40 and the gateway 30 and the data path removal process (S51, S52, S53) between the existing serving base station 20 is performed. The target base station 40 may initiate a service to the mobile terminal 10.

After the data path setting process (S41, S42, S43) and the data path removal process (S51, S52, S53) with the gateway 30, the target base station 40 performs a handoff completion (HO_COMPLETE) to the serving base station (S20). S60 and this completes the handoff.

2 schematically illustrates a configuration of a wireless communication system according to an embodiment of the present invention.

Referring to FIG. 2, the wireless communication system 100 includes a terminal 110, a WiBro / WiMAX base station 120, a BS, a gateway 140, an ASN GW, and a WLAN base station 130 or an access point (AP). )). In the wireless communication system 100, the gateway 140 is connected to the Internet 150. In addition, the WiBro / WiMAX base station 120 and the gateway 140 may configure the WiBro / WiMAX network, and the WLAN base station 130 and the gateway 140 may configure the WLAN network. In addition, the wireless communication system 100 may have a tightly-coupled interworking network structure in which the WLAN base station 140 is included in the cell coverage of the WiBro / WiMAX base station 120.

The terminal 110 may be connected to both the WiBro / WiMAX base station 120 and the WLAN base station 130 and may be a dual mode terminal supporting both the WiBro / WiMAX standard and the wireless LAN standard. In addition, the WLAN base station 130 may support some functions of the WiBro / WiMAX standard. Thus, the WLAN base station 130 processes a handoff from the WiBro / WiMAX network to the WLAN network. Although not shown, the WLAN base station 130 may include a message conversion module between the control message of the WiBro / WiMAX network and the control message of the WLAN network.

The terminal 110 has a protocol structure as shown in FIG. 3 to support both the WiBro / WiMAX standard and the wireless LAN standard.

Referring to FIG. 3, the protocol structure 200 of the terminal 110 includes an IP layer 20 as a top layer and then an interface selection layer 220. Subsequently, sub-layers of the Service-Specific Convergence Sublayer 230, the MAC Common Part Sublayer 240, and the Security Sublayer 250 are included. The protocol structure 200 of the terminal 110 also includes a PHY 260 and a WiMAX 270.

4 illustrates a method for processing non-prediction-based handoff between heterogeneous wireless networks in a wireless communication system according to an embodiment of the present invention.

In the non-prediction-based handoff processing method 300 between heterogeneous wireless networks of FIG. 4, the wireless communication system includes an interworking network including a WiBro / WiMAX base station 120 and a WLAN base station 130 in a WiBro / WiMAX network as shown in FIG. 2. And includes a gateway 140 connected to the Internet.

When the terminal 100 is in any position of the network, the terminal 100 receives a base station advertisement (MOB_NBR-ADV: Neighbor Advertisement) message periodically transmitted from the base station providing wireless connectivity to the network (S311). This base station advertisement (MOB_NBR-ADV) message contains information about all base stations in the adjacent location and network attributes of the base station. Thus, when the terminal 110 receives a base station advertisement (MOB_NBR-ADV) message, the terminal 110 acquires ID, quality of service (QoS) parameter, and channel information of neighboring base stations, and may use such information to perform handoff later. have. This message may set information about a neighbor base station by an administrator in advance. At this time, the administrator sets the information on the WLAN base station 130 as well as the WiBro / WiMAX base station 120, so that the terminal 110 thinks of the WLAN base station 130 as the WiBro / WiMAX base station 120 and additionally. Handoff to the WLAN network can be performed without modification.

The terminal 110 receives the base station advertisement (MOB_NBR-ADV) message to determine the handoff from the WiBro and WiMAX networks to the WLAN network and to prepare for the handoff, but the weakening of the signal strength causes the If the mobile station attempts to connect to the WLAN network without completing the handoff preparation process due to poor transfer or fast movement, the WLAN base station 140 may not respond to the handoff. This problem can be solved by sending the ID information of the serving base station 120, which is the previous access base station, to the ASSOCIATION REQUEST message transmitted by the terminal 110 to the WLAN base station 140 (S321). The configuration of the ASSOCIATION REQUEST message delivered at this time is shown in Table 1 below.

TABLE 1

The terminal 110 may optimize the handoff procedure by sending ID information of a serving base station, that is, a WiBro / WiMAX base station 120, which is a previous access base station in an ASSOCIATION REQUEST message.

Upon receiving the ASSOCIATION REQUEST message from the terminal 110, the WLAN base station 140 transmits an ASSOCIATION RESPONSE message to the terminal 110 in response to the request (S322). In this process, access to the WLAN network is completed and additional handoff process is provided before service is possible.

The WLAN base station 140 transmits a MAC context information request (CONTEXT_REQ) message for the terminal 110 based on the ID of the previous serving base station transmitted in the ASSOCIATION REQUEST message (S331). In this case, the WLAN base station 140 may configure a MAC context information request (CONTEXT_REQ) message according to the WiBro / WiMAX standard. Table 2 below shows information about the WLAN network included in the MAC context information request (CONTEXT_REQ) message transmitted from the WLAN base station 140 to the terminal 110. The configuration value for the MAC context information request (CONTEXT_REQ) message may use information of a WLAN standard.

TABLE 2

When the serving base station, that is, WiBro.WiMAX base station 120, receives the MAC context information request (CONTEXT_REQ) message (S331), the serving base station, that is, the WiBro.WiMAX base station 120, contains the MAC context information for the terminal 110. In response to the MAC context information report (CONTEXT_RPT) message (S332). When the WLAN base station 140 receives the MAC context information report (CONTEXT_RPT) message, it should be able to interpret the MAC context information report (CONTEXT_RPT) message. Table 3 below shows the contents of the MAC context information report (CONTEXT_RPT) message that the WLAN base station 140 should know.

[Table 3]

The WLAN base station 140 may map the transmitted QoS parameters to the Access Category of the WLAN as shown in Table 4 below. In addition, in case of SF ID, the table in [Table 5] below is mapped with the TID (Traffic ID) of each Access Category according to the transmitted QoS Parameters, and the service to the corresponding SF ID is then mapped through the mapped value. Serviced by TID. TID allocation by access category is used in [Table 4] below.

[Table 4]

TABLE 5

The WLAN base station 140 receiving the MAC-Contest information of the terminal 140 transmits a data path connection request (PATH_REQ_REQ) message to the gateway 140 in order to establish a data path with the gateway 130 (ASN GW) (S341). ). Information on the WLAN network to be delivered by the data path connection request (PATH_REQ_REQ) message is shown in Table 6 below. The data path connection request (PATH_REQ_REQ) message may be configured according to the WiBro / WiMAX standard. The configuration value for the data path connection request (PATH_REQ_REQ) message may use information of a WLAN standard.

TABLE 6

The gateway 140 receiving the data path connection request (PATH_REG_REQ) message from the WLAN base station 130 responds with a data path connection request response (PATH_REG_RSP) message (S342). Information that should be interpreted by the WLAN base station 130 among the information included in the data path connection request response (PATH_REG_RSP) message is not significantly different from the previously transmitted data path connection request (PATH_REG_REQ) message.

Upon receiving the data path connection request response (PATH_REG_RSP) message, the WLAN base station 130 responds through the data path connection response (PATH_REG_ACK) message (S343). The data path connection response (PATH_REG_ACK) message may be configured according to the WiBro / WiMAX standard. In addition, the configuration value for the data path connection response (PATH_REG_ACK) message may use a WLAN standard. The information of the WLAN network included in the data path connection response (PATH_REG_ACK) message is not significantly different from the contents of the previously transmitted message.

The data path removal process between the gateway 140 and the serving base station, that is, the WiBro / WiMAX base station 120 is performed while the data path is established between the gateway 140 and the target base station, that is, the WLAN base station 130. (S351, S352, S353). From the time point at which the data path is removed between the gateway 140 and the serving base station, that is, the WiBro / WiMAX base station 120, the WLAN base station 130 may start a service to the terminal 110.

When the WLAN base station 130 starts service to the terminal 110 and all handoff processes are completed, the WLAN base station 130 includes a serving base station in a handoff complete (HO_COMPLETE) message about the handoff result. That is, the transmission to the WiBro / WiMAX base station 120 (S360). The handoff complete (HO_COMPLETE) message may be configured according to the WiBro / WiMAX standard. In addition, the configuration value for the drop off (HO_COMPLETE) message may use the WLAN standard. In this case, values to be set by the WLAN base station 130 are as shown in Table 7 below.

TABLE 7

According to embodiments of the present invention, when performing a handoff from a WiBro / WiMAX network to a WLAN network, the terminal has an effect of supporting a technology for receiving a service received in the WiBro / WiMAX network in the WLAN network. In addition, it is based on a tightly coupled network structure that can take full advantage of the WiBro / WiMAX network and the WLAN network, and can support handoffs for heterogeneous wireless networks by modifying the WLAN base station. In addition, when the handoff from the WiBro / WiMAX network to the WLAN network is performed, handoff according to the WiBro / WiMax standard can be performed to minimize the modification of the terminal. Accordingly, embodiments of the present invention can minimize the modification of the terminal or the modification of the network when the handoff between the heterogeneous wireless network in a mobile communication system including heterogeneous networks, so that the capacity of the wireless LAN network WiBro / WiMAX network or It can serve as a complement to shadowed areas that WiBro / WiMAX base stations cannot cover.

As described above, the present invention has been described with reference to a preferred embodiment of the present invention, but a person of ordinary skill in the art should understand the present invention without departing from the spirit and scope of the present invention as set forth in the claims below. It will be understood that various modifications and changes can be made.

1 shows the process for uncontrolled handoff in WiBro / WiMAX.

2 schematically illustrates a configuration of a wireless communication system according to an embodiment of the present invention.

3 shows a protocol structure of a terminal supporting both the WiBro / WiMAX standard and the WLAN standard.

4 illustrates a method for processing non-prediction-based handoff of a terminal in a wireless communication system according to an embodiment of the present invention.

Claims (11)

A non-prediction-based handoff processing method between heterogeneous wireless networks in a wireless communication system of at least one wireless LAN base station provided in a WiBro / WiMAX network including at least one WiBro / WiMAX base station, When the terminal accessing the WiBro / WiMAX base station determines a handoff to a WLAN network including the WLAN base station, Allowing the terminal to access the WLAN network without receiving the handoff message from the terminal or the WLAN base station not responding to the terminal with the handoff; And And transmitting, by the terminal, the ID information of the WiBro / WiMAX base station to the WLAN base station by including the ID information in the association request message. The wireless LAN base station of claim 1, wherein the wireless LAN base station receives the MAC context information request message of the terminal using the ID information of the WiBro / WiMAX base station when the wireless LAN base station receives the WLAN combining request message. The method of claim 1, further comprising the step of transmitting to the WiMAX base station. 3. The method of claim 2, wherein when the WiBro / WiMAX base station receives the MAC context information request message, transmitting the information about the terminal to the WLAN base station by including information on the terminal in a MAC context information report message; And And when the WLAN base station receives the MAC context information report message, interpreting the received MAC context information report message. The WiBro of claim 3, wherein the WLAN base station interprets the received MAC context information report message and is included in the WiBro / WiMAX network to connect the WiBro / WiMAX base station to the WLAN base station. The method of claim 1, further comprising the step of transmitting a data path connection request message according to the WiMAX standard. delete The method of claim 1, wherein the terminal is a dual mode terminal supporting both the WiBro / WiMAX standard and the WLAN standard. The wireless base station of claim 1, wherein the WLAN base station includes a message conversion module between the control message of the WiBro / WiMAX network and the control message of the WLAN network including the WLAN base station. Prediction-based handoff processing method. The heterogeneous wireless communication system of claim 1, wherein the WLAN base station analyzes a control message of the WiBro / WiMAX network, and a configuration value for a response message according to the WiBro / WiMAX standard uses information of a WLAN standard. Unpredictable based handoff processing method of manganese. A terminal capable of accessing a WiBro / WiMAX network and a wireless LAN network; At least one WiBro / WiMAX base station provided in the WiBro / WiMAX network; A gateway provided in the WiBro / WiMAX network and connecting the WiBro / WiMAX network and the WLAN network; And At least one WLAN base station provided in the WLAN network to handle handoff from the WiBro / WiMAX network to the WLAN network; When the terminal accessing the WiBro / WiMAX base station determines a handoff to a WLAN network including the WLAN base station, When the wireless LAN base station does not receive a handoff message from the terminal or the wireless LAN base station does not respond to the handoff for the handoff, the terminal accesses the wireless LAN network. And transmitting the ID information of the WiMAX base station to the wireless LAN base station by including the combined request message. delete delete

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