Interworking procedure with external network in wireless lan and message format for the same

The present invention relates to a wireless LAN (Wireless Local Access Network, WLAN), and more particularly to an interworking procedure with an external network in a wireless LAN, a station supporting the procedure, and a message format for this purpose.

With the development of information and communication technology, various wireless communication technologies are being developed. Of these, wireless LAN (Wireless Local Access Network, WLAN) is a personal digital assistant (PDA), laptop computer (Laptop Computer), and portable multimedia player (Portable) based on radio frequency technology. To be able to wirelessly connect to the Internet and / or intra network in specific service areas such as homes, businesses or aircraft using portable terminals such as Multimedia Player, PMP) It is a technology to do.

In response to the increased utilization of wireless LAN, mobile terminal users, such as laptop computer users, can now work with increased mobility. For example, a user can take a laptop computer from his desk to a conference room to join a conference while still connected to his local network to receive data, regardless of wired connection. You can connect to the Internet via a modem or gateway on your local network. Similarly, business travelers can use their mobile devices to receive or send emails and connect to their email accounts to check emails.

Early wireless LAN technology supported speeds of 1-2 Mbps via frequency hopping, spread spectrum, infrared communication, etc. using the 2.4 GHz frequency via IEEE 802.11. Recently, with the development of wireless communication technology, Orthogonal Frequency Division Multiplex (OFDM) technology can be applied to wireless LAN to support speeds of up to 54 Mbps. In addition, IEEE 802.11 has improved quality of service (QoS), access point (AP) protocol compatibility, security enhancement, radio resource measurement, and radio resource measurement. Wireless Access in Vehicular Environment, Fast Roaming, Mesh Network, Inter-working With External Network), wireless communication technology for wireless network management (Wireless Network Management) has been developed and put into practical use, and is still under development.

On the other hand, the IEEE802.11u standard, which is one of the wireless LAN standards, describes the interworking service in wireless LAN. The main purpose of the interworking service is to enable information transmission from the external network for wireless LAN users, to assist in the selection of connected networks, and to enable emergency services. .. The IEEE802.11u standard specifies the Medium Access Control (MAC) and Physical Layer (PHY) protocols required to achieve these goals.

<p> As mentioned above, one of the purposes of interworking services is to enable emergency services using wireless LAN. Emergency services can be provided in a variety of ways, one of which is an emergency call to an emergency service center such as a fire department or emergency room in the event of an emergency for the user. Call) is to be possible.</p><p> In order for the terminal to make an emergency call with the emergency service center, the user must know the information for identifying the emergency service center, for example, the emergency call number. Or, even if the user does not know the emergency call number, if the user requests an emergency call through the user interface of the terminal, such an emergency call number must be stored in the terminal. Unable to make an emergency call to the emergency service center.</p><p> However, the emergency call number may be set differently for each country or even for each region even if it is the same country. For example, in the case of South Korea, the emergency call number used in the event of a fire or emergency situation is '119', but in the case of the United States,' 911' is used, and in the case of Italy, the fire is '444 44'. , Ambulances use '118', and in the UK, use '999'. Also, even within the same country, emergency service center call numbers for fires, distresses, emergency medical conditions, etc. may vary from region to region.</p><p> In this way, the emergency call number may differ by country and / or region. As a result, in order to make an emergency call to the emergency service center using a wireless LAN terminal, the user and / or the terminal is trying to associate or is connected via the currently connected base station. You must know the emergency call number of the external network that can be. However, since it is practically impossible for the terminal to store all the emergency call numbers that differ for each country and / or region, or for the user to remember all of them, each base station has this in the terminal. You need to give us an emergency call number like this. In particular, it is even more necessary to give the emergency call number to roaming terminals connected to the Visited Network.</p><p> Therefore, one problem to be solved by the present invention is a procedure for interworking with an external network capable of notifying a terminal of an emergency call number of an external network in a wireless LAN, and a station supporting the procedure. In addition, it is to provide a new type of message format for this purpose.</p><p> Another problem to be solved by the present invention is an external network capable of providing an emergency call number to a terminal without asking or requesting a distribution system or a server of the external network at a base station. It is to provide a procedure for interworking with and stations to support it, as well as a new type of message format for this purpose.</p>

<p> In one aspect of the present invention, an interworking procedure for a non-AP station in a wireless LAN (Wireless Local Access Network) is provided. The interworking procedure transmits a request message including an advertisement protocol ID and a native question information ID, the notification protocol ID is set to a value indicating a native query protocol, and the native question is set. The information ID is set to a value indicating emergency call number information and includes receiving a response message containing zero or more emergency call numbers from the AP (access point).</p><p> In another aspect of the invention, an access point (AP) interworking procedure in a wireless LAN is provided. The interworking procedure receives a request message from the non-AP station including an advertisement protocol ID and a native question information ID, and the notification protocol ID is set to a value indicating the native query protocol. The native Q &amp; A ID is set to a value indicating emergency call number information, and includes transmitting a response message containing zero or more emergency call numbers to the non-AP station. ..</p><p> In another aspect of the present invention, there is provided a method of constructing a GAS (generic advertisement service) initial request message used for an interworking procedure in a wireless LAN. The GAS initial request message is a category field set to a value indicating a public action frame; an action field set to a value indicating a GAS initial response action; GAS which is a response to the GAS initial request frame and the GAS initial request frame. A dialog token field set by the requesting station to identify an exchange with an initial response frame; a notification protocol information element containing a notification protocol ID set to a value indicating the native Q &amp; A protocol; and a value indicating emergency call number information. Includes a Q &amp; A field containing the configured Native Q &amp; A ID.</p><p> In another aspect of the present invention, there is provided a method of constructing a GAS (generic advertisement service) initial response message used for an interworking procedure in a wireless LAN. The GAS initial response message is a category field set to a value indicating a public action frame; an action field set to a value indicating a GAS initial request action; a dialog token set to the same value as the corresponding GAS initial request frame. Fields; Notification Protocol Information Elements containing the Notification Protocol ID set to a value indicating the native Q &amp; A Protocol; and Q &amp; A fields containing the Emergency Call Number element.</p><p> In another aspect of the invention, a non-AP (access point) station is provided that supports interworking procedures in a wireless LAN. The non-AP station includes a processor that generates and processes frames; and a transmitter / receiver that is coupled to the processor to transmit and receive the frame by the processor, which is a native query. GAS (generic advertisement) including the native question information ID set to a value indicating the protocol ID and the emergency call number information set to a value indicating the protocol. service) Generate an initial request frame and forward the GAS initial request frame to the transmitter / receiver, the transmitter / receiver transmits the GAS initial request frame, and the GAS initial request frame is transmitted from the AP. As a response to the solicited frame, a GAS initial response frame containing one or more emergency call numbers is received, the received GAS initial response frame is forwarded to the processor, and further, the processor. Processes the GAS initial response frame.</p><p> In another aspect of the invention, an access point (AP) is provided that supports an interworking procedure in a wireless LAN. The access point includes a processor that generates and processes frames; and a transmitter / receiver that is coupled to the processor to transmit and receive the frame by the processor, which is a native question from a non-AP station. GAS (generic advertisement) including the notification protocol ID set to a value indicating a protocol (native query protocol) and the native question information ID set to a value indicating emergency call number information. service) Receives the initial request frame and forwards the GAS initial request frame to the processor, which processes the GAS initial request frame and also responds to the GAS initial request frame. As the GAS initial response frame containing one or more emergency call numbers is generated, the GAS initial response frame is forwarded to the processor, and the transmitter / receiver further receives the GAS initial response. The frame is transmitted to the non-AP station.</p>

<p> According to the embodiment of the present invention, the terminal (station) may request the base station for an emergency call number supported by the network even before the connection to the wireless LAN via the base station (access point). it can. In addition, at the request of the terminal, the base station can notify the terminal of one or more emergency call numbers. According to such an embodiment of the present invention, even before the association, the user knows the contact information of the emergency service center assisted through the network, or when necessary. Can store this in the terminal. In addition, in the event of an emergency situation, an emergency call can be made using this contact information.</p><p> In this case, the emergency call number may be data pre-configured in the base station. According to this, even when there is an emergency call number request from the terminal, the base station can provide the emergency call number to the terminal without separately communicating with the distribution system or the server of the external network.</p>

<figref num="1">It is a diagram which shows the IEEE802.11 interworking architecture including the wireless LAN system to which the Example of this invention can be applied.</figref><figref num="2">It is a flow chart of a message for demonstrating the procedure for interworking with an external network which concerns on one Example of this invention.</figref><figref num="3">It is a block diagram which shows the format of the GAS initial request frame (Initial Request Frame) which accompanies one aspect of this embodiment.</figref><figref num="4">It is a block diagram which shows an example of the format of the notification protocol information element of FIG.</figref><figref num="5">It is a block diagram which shows an example of the format of the notification protocol set field of FIG.</figref><figref num="6">It is a block diagram which shows the format of the GAS initial response frame (GAS Initial Request Frame) which accompanies one aspect of this embodiment.</figref><figref num="7">It is a block diagram which shows an example of the format of the emergency call number information element which can be contained in the question-and-answer field of FIG.</figref><figref num="8">It is a block diagram which shows the format of the GAS initial response frame (GAS Initial Request Frame) which accompanies another aspect of this embodiment.</figref>

Hereinafter, examples of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention can be embodied in many other forms and is not limited to the examples described below. This embodiment is for ensuring that the disclosure is thorough and complete and conveys the ideas of the invention to those skilled in the art. In the embodiments and drawings, each element can be represented by a reference code for convenience. In the following examples, a wireless LAN (Wireless Local Access Network (WLAN)) system will be described as an example of a wireless communication system, but this is merely an example.

1, IEEE 802.11 interworking archetype includes a wireless LAN system capable of interworking procedure according to an embodiment of the present invention is applied is a diagram showing a ture. The Interworking Service is defined in the IEEE 802.11u standard. The main purpose of interworking services is to enable information transmission from the External Network, assist in network selection, and enable emergency services. The IEEE802.11u standard specifies various protocols for this purpose, such as the Interworking Interface. A terminal that is a non-AP STA in such an interworking service can connect to a service provided by the external network depending on the subscription of the external network and other characteristics.

With reference to Figure 1, an Interworking-capable access point (AP) in a wireless LAN system can interwork with an external network using a Logical Interworking Interface. it can. In FIG. 1, the external network is symbolically displayed as SSPN (Subscription Service Provider Network), and its specific configuration is not related to the embodiment of the present invention. The external network has an access point and AAA (Authentication, Authorization, and Accounting) and data connection (connection) via an interworking interface. The interworking interface also transparently passes through the Portal and 802.xLAN.

The wireless LAN system includes one or more Basic Service Sets (BSS). BSS is not a concept that indicates a specific area, even if it is a set of stations (Stations, STAs) that are successfully synchronized and can communicate with each other. BSS can be divided into infrastructure BSS (infrastructure BSS) and independent BSS (Independent BSS, IBSS). Infrastructure BSS (BSS1, BSS2) is one or more STAs (STA1, STA3, STA4), access points (APs) that are STAs that provide distribution services, and multiple APs. Includes a distribution system (DS) that concatenates. On the other hand, IBSS does not include AP, so all STAs consist of mobile stations (STA6, STA7, STA8). IBSS is not allowed to connect to the DS, so it is a self-contained network network). The embodiments of the present invention relate to infrastructure BSS.

In the set of reachable networks defined in the SSID (service set identifier), the set of BSSs that can be made from the BSS that has the service provided by the network to all BSSs is HESSID (homogeneous extended service set identifier). Indicated by. All BSSs identified by HESSID must belong to the same mobility domain if one BSS is defined.

STA is any functional medium, including Medium Access Control (MAC) according to the IEEE 802.11 standard and Physical Layer interface to wireless media, in a broad sense AP and non-AP STA (A P). Both with non-AP Station) are included. Of these, the portable terminals operated by the user are non-AP STAs (STA1, STA3, STA4, STA6, STA7, STA8), and the term STA may simply refer to non-AP STA. A non-AP STA is a wireless transmit / receive unit (WTRU), user equipment (UE), mobile station (MS), portable terminal, or mobile subscriber unit (Portable Terminal). It can also be called by other names such as Mobile Subscriber Unit).

APs (AP1 and AP2) are functional individuals that provide a connection to the DS via a wireless medium for the associated STA (Associated Station). In the infrastructure BSS including AP, communication between non-AP STA is basically performed via AP, and when a direct link is set, direct communication is also possible between non-AP STA. In addition to the name of access point, AP can also be called a centralized controller (Convergence controller), a base station (Base Station, BS), a node B, a BTS (Base Transceiver System), or a site controller.

Multiple infrastructure BSSs can be interconnected via a distribution system (DS). Multiple BSSs linked via the DS are called Extended Service Set (ESS). The STAs included in the ESS can communicate with each other, and within the same ESS, the non-AP STA can move from one BSS to another while communicating without interruption.

DS is a system for one AP to communicate with another AP. According to this, the AP transmits frames for the STAs associated with the BSSs it manages, or transmits frames if any one STA moves to another BSS, or a wired network, etc. Can communicate frames with external networks such as. Such a DS has various types and / or characteristics because there are no restrictions on its form and characteristics as long as it can provide a predetermined distribution service specified in IEEE 802.11. Networking is possible.

For example, the DS may be a wireless network such as a mesh network, or a physical structure (wired network) that connects APs to each other. Wireless DS, such as IEEE 802.11s mesh networks, can significantly reduce end-to-end delay and throughput compared to wired networks. However, the wireless network can be installed in a more flexible structure in a place where a wired network is difficult to install. Regardless of whether it is a wired network or a wireless network, DS may have certain differences in the data transmission speed and bandwidth that it supports depending on its characteristics and performance, and it can also be connected to external networks such as the Internet. It may be different.

FIG. 2 is a flow chart of a message for explaining a procedure for interworking with an external network according to an embodiment of the present invention. This embodiment is a procedure in which a terminal acquires an emergency call number for an emergency service center used in a specific area from a base station in order to support an emergency service from an external network. An emergency service center is, for example, a Public Safety Answering Point (PSAP) in the area or a default emergency call center in the area.

Referring to FIG. 2, after performing the active scanning procedure (Active Scanning Procedure, S10 and S20) for exchanging the probe request frame and the probe response frame between the terminal (non-AP STA) and the base station (AP). , Perform the Generic Advertisement Service (GAS) procedure (S30 and S40). The active scanning procedures (S10 and S20) shown in FIG. 2 merely exemplify an example of a preliminary procedure of the general-purpose notification service procedure (S30 and S40). Preliminary procedures for general-purpose service procedures (S30 and S40), even if not shown in the drawings, include, for example, only scanning and authentication procedures, or other additional association procedures. ) And / or Reassociation Procedure) can be further included. Therefore, according to an embodiment of the present invention, the general-purpose notification service procedure (S30 and S40) includes a terminal (non-AP STA) and a base station (AP) in a state before or after the completion of the join or rejoin procedure. Can be carried out during.

In general, a scanning procedure refers to the process by which a non-AP STA seeks a candidate AP to join in a join or rejoin procedure. There are two types of such scanning procedures. The first method is a passive scan method, which uses a Beacon Frame that is periodically transmitted from the AP. According to this, the non-AP STA trying to connect to the wireless LAN can receive the beacon frame periodically transmitted from the AP that manages the corresponding BSS and search for the connectable BSS.

The second method is an Active Scan method as shown in steps S10 and S20 of FIG. According to this, the non-AP STA trying to connect to the wireless LAN system first transmits the probe request frame (S10). In addition, the AP that received the probe request frame is a probe response frame (Probe) that includes information such as the service set ID (Service Set ID, SSID) of the BSS that it manages and the ability value (Capability) that it supports. Response Frame) is transmitted to non-AP STA (S20). Therefore, the non-AP STA can know the existence of the candidate AP and various information about the candidate AP through the received probe response frame.

If the non-AP STA and / or AP is a device that assists the interworking service, the beacon frame, probe request frame, and / or probe response frame transmitted during the scanning process may contain an interworking information element. Can be included. The interworking information element is intended to provide information about the non-AP STA or AP's interworking service stats.

In addition, the beacon frame and probe response frame transmitted by the AP can include an Advertisement protocol Information Element. The notification protocol information element is transmitted when the AP assists the interworking service and one or more general purpose notification service targets are defined. This includes information that identifies a particular notification protocol and its corresponding notification control. Further, the notification protocol information element may include a notification protocol ID (Advertise Protocol ID) that can be supported by the AP.

The authentication procedure is a process of negotiating an authentication procedure and an encryption method among individuals participating in wireless communication. For example, a non-AP STA can perform an authentication procedure with an AP that seeks to combine from one or more APs found in the scanning procedure (S10 and S20). Since WLAN mainly uses the Open System authentication method, the AP carries out the authentication process without any conditions in response to the authentication request from the non-AP STA. Further enhanced authentication methods include IEEE802.1x platform EAP-TLS (Extensible Authentication Protocol-Transport Layer Security), EAP-TTLS (Extensible Authentication Protocol-Tunneled Transport Layer Security), and EAP-FAST (Extensible Authentication Protocol-Flexible Authentication). via Secure Tunneling), PEAP (Protected Extensible Authentication Protocol), etc.

When the authentication procedure successfully completes the authentication, the non-AP STA can perform the join procedure with the AP. The coupling procedure means establishing an identifiable link between the non-AP STA and the AP, i.e. a wireless link. For the join procedure, the non-AP STA first sends an Association Request Frame to the AP that has successfully completed the authentication procedure, and the AP responds by saying'Successful'. The Association Response Frame with the state value is transmitted to the non-AP STA. The join response frame includes an identifier capable of identifying a join with a specific non-AP STA, for example, a join ID (Association ID, AID).

The non-AP STA is another good channel condition, such as when the connection between the non-AP STA and the AP becomes poor due to variable channel conditions, even after the successful completion of the join procedure. The binding process can be performed again with the AP. This is called the Reassociation Procedure. Such a recombination procedure is fairly similar to the binding procedure described above. More specifically, in the rejoin procedure, the non-AP STA succeeds in the authentication procedure from among the candidate APs found in the search process (S10 and S20) described above for other APs that are not currently bound. The rejoin request frame is transmitted to the completed AP), and the other AP transmits the rejoin response frame to the non-AP STA. However, the rejoin request frame contains more information about the previously joined AP, through which the rejoin AP can propagate the data buffered by the existing AP to the non-AP STA. ..

Also, referring to Figure 2, the non-AP STA attempting to obtain an emergency call number for a public safety response point (PSAP) or default emergency call center used in the area is a Native GAS Procedure. Progress with AP (S30 and S40). Native GAS procedures are procedures based on the native GAS protocol used by non-AP STAs to discover services supported through APs.

More specifically, the non-AP STA first transmits a request message requesting an emergency call number, for example, a general-purpose notification service initial request frame (GAS Initial Request Frame) to the AP (S30). The GAS initial request message has at least an Advertisement protocol ID set to a value that indicates the native query protocol and a native question information ID that is set to a value that indicates emergency call number information. It may be a message containing native query information ID). However, it is not limited to this.

FIG. 3 is a block diagram showing the format of the GAS Initial Request Frame according to one aspect of this embodiment. The GAS initial request frame is one of the public action frames, which is a communication or general-purpose notification service between BSS or between AP and non-AP STA that is not bound to this AP. Indicates the frame defined for. Public action frames include a GAS initial request frame, a GAS initial response frame, a GAS comeback request frame, and a GAS comeback response frame.

As shown in Figure 3, the GAS initial request frame is a Category field, an Action field, a Dialog token field, an Advertisement protocol information element field, and a Q &amp; A length (Query). Includes a Request length field and a Query Request field.

The category field is set to a value that indicates a public action frame. The action field is set to a value that indicates the GAS initial request action. The dialog token field is set to an arbitrary value selected by the non-AP STA that transmits the GAS initial request frame, and is used to identify the exchange between the GAS initial request frame and the corresponding GAS initial response frame. Is.

The notification protocol information element includes information that identifies a particular advertisement protocol and its corresponding advertisement control. An example of the format of the notification protocol information element is shown in Figure 4. Referring to FIG. 4, the notification protocol information elements are the Element ID field, the Length field, and N (but N is a natural number) Notification Protocol Tuple # 1, Advertisement. Includes protocol Tuple # 2, ..., Advertisement protocol Tuple # N).

The element ID field is set to a value that indicates the notification protocol information element. The length field is set to a value that indicates the sum of the lengths of the subsequent N notification protocol set fields. Each notification protocol set field also includes a Delivery Method subfield, a Query Response Length Limit subfield, and / or an Advertisement protocol ID subfield. An example of the format is shown in Figure 5.

The transmission method subfield is set to a value that indicates how the AP transmits frames to the notification protocol specified in the notification protocol ID subfield. For example, if the transmission method subfield is set to '1', it means that the transmission is performed by the multicast method, and if the transmission method subfield is set to '0', it means that the transmission is performed by the unicast method. .. The Q &amp; A length limit subfield is set to a value that indicates the maximum length of information that the AP will transmit in the Q &amp; A field contained in one or more GAS comeback response frames.

In addition, the notification protocol ID subfield is set to a value indicating the Native query protocol. The native Q &amp; A protocol is the mechanism by which the non-AP STA is used during Q &amp; A with the AP to acquire locally provided data. That is, when there is a question from the non-AP STA, the AP immediately responds to the received question without asking the server in the distribution system (DS) or the external network for the requested question.

With reference to FIG. 3, the Q &amp; A length field is set to a value that indicates the total length of the information contained in subsequent Q &amp; A fields. The Q &amp; A field is a GAS Q &amp; A and is formatted according to the protocol specified in the notification protocol information element. According to this embodiment, an ID value indicating emergency call number information is set in the question request field.

Referring to FIG. 2, the AP transmits a GAS Initial Response Frame to the requesting terminal, the non-AP STA, as a response to the received GAS initial request frame (S40). The GAS initial response frame may include one or more requested emergency call numbers, or may not include emergency call numbers. If the Q &amp; A request in the GAS initial request frame corresponds to the information provided in the AP, that is, if the emergency call number is stored in the AP, the request is received in the GAS initial response frame. Contains one or more emergency call numbers. On the other hand, if the Q &amp; A request in the GAS initial request frame does not correspond to the information provided in the AP, that is, if the emergency call number is not stored in the AP, the GAS initial response frame includes the emergency call number. I can't.

FIG. 6 is a block diagram showing the format of the GAS Initial Request Frame according to one aspect of this embodiment. As mentioned above, the GAS initial response frame is one of the public action frames. As shown in Figure 6, the GAS initial response frame is a Category field, an Action field, a Dialog token field, a Status Code field, a GAS Query ID field, and a GAS group. Includes GAS Group Address field, GAS Comeback Delay field, Advertisement protocol information element, Query Response length field, and Query Response field. ..

The category field is set to a value that indicates a public action frame. The action field is set to a value that indicates the GAS initial response action. The dialog token field is set to the same value set in the corresponding GAS initial request frame, i.e., the received GAS initial request frame.

The status code field is set to a value that represents the result of the response to the request. If the Q &amp; A request in the GAS initial request frame corresponds to the information provided in the AP and the GAS initial response frame contains the requested information (eg, emergency call number), the status code field. Is set to a value that indicates'Successful'. On the other hand, if the Q &amp; A request in the GAS initial request frame does not correspond to the information provided in the AP and the requested information (for example, emergency call number) is not included in the GAS initial response frame, the status code The field is set to a value that indicates'Request Info not configured'. An example of the values set in such a status code field is the value defined in subsection 7.3.1.9. Of the IEEE P802.11-REVma / D9.0 (revision of IEEE Std 802.11-1999) standard. is there.

The GAS Q &amp; A ID field is set to a value that indicates the Q &amp; A performed on behalf of the non-AP STA. In the case of this embodiment, the GAS Q &amp; A ID field is set to '0'. The GAS group address field is set to a value that indicates the multicast group address if the answer to the question is multicast, and is set to '0' if the answer is unicast. In addition, the GAS comeback delay field is for specifying the delay time.

The notification protocol information element includes information that identifies a particular advertisement protocol and its corresponding advertisement control. An example of the format of the notification protocol information element has been described above with reference to FIG. 4, and detailed description thereof will be omitted. The Q &amp; A length field is set to a value that indicates the total length of the information contained in the subsequent Q &amp; A field.

The Q &amp; A field is a general purpose container whose value is the response to the GAS Q &amp; A and is formatted according to the protocol specified in the notification protocol information element. According to this embodiment, the Q &amp; A field contains an emergency call number information element. The emergency call number information element is intended to provide a list of Public Safety Answering Points (PSAPs) or default emergency call centers used in a particular area. An example for the format of the emergency call number information element is shown in Figure 7.

Referring to FIG. 7, the emergency call number information element includes an information ID, a Length field, a Status Code field, and M (M is a natural number) emergency call number Unit #. 1, Emergency call number Unit # 2, ..., Emergency call number Unit # M) is included. The information ID field is set to a value that indicates emergency call number information. The length field is set to a value that indicates the total length of subsequent fields. The status code field is set to a value that indicates one of the Meaning disclosed in Table 1.

<tables num="1"><img file="JP2010532619A_D0001.tif" /></tables> Each emergency call number unit contains an Emergency call number Length subfield and an Emergency call number subfield. The emergency call number length subfield is set to a value that indicates the length of the emergency call number subfield. In addition, the emergency call number subfield is set to a value indicating the emergency call digits supported by the corresponding network.

FIG. 8 is a block diagram showing the format of the GAS initial response frame according to other aspects of this embodiment.

As shown in Figure 8, the GAS initial response frame is the Element ID field (100), which indicates that this message is a generic notification service response message, followed by the length of the field item. It also includes a Length field (110), a field containing an Advertisement protocol information element (120), and a response information field (130).

The response information field (130) is an element identifier (Element ID) field (131) representing the response information field, a length field (132) representing the length of the field item after that, and a native information element. Includes field (133). This native information element field (133) may be plural. Further, in this case, each native information element field (133) may include a plurality of information elements of the same type for each item.

On the other hand, if any one of the native information element fields or one native information element field is present, the corresponding native information element field is an emergency call number list element representing emergency call information as described above. (Emergency call number list element) is included. The emergency call number may be, for example, a telephone number or a URI.

This emergency call number list element contains an information identifier (info ID) field (133a) that represents the emergency call number list element, a length field (133b) that represents the length of subsequent subfields, and an emergency call number list. Includes a Status code field (133c) that represents the status to inform the terminal. It is also followed by a field (133d) that represents the length of emergency number # 1 and a field (133e) that represents the emergency call number # 1.

In addition, the field indicating the length of the emergency number (133d) and the field indicating the emergency call number (133e) are paired, and when there is only one emergency call number, the field indicating the length of the emergency call number and the emergency call number Each field is also included, but if the AP transmits multiple emergency call numbers to the non-AP STA, the length of emergency call numbers # 2 to # n ) And fields (133g, 133i) representing emergency call numbers # 2 to # n.

The examples of the present invention described in detail above are merely examples for showing the technical idea of the present invention, and should not be construed as limiting the technical idea of the present invention by the above examples. The scope of protection of the present invention is specified by the scope of claims of the present invention.

Although the present invention is characteristically described and described by exemplary embodiments, those skilled in the art will appreciate the form and details as long as they do not deviate from the ideas and scope of the invention defined in the claims. It can be changed in various ways.

The present invention is related to networking and communication protocols related to wireless communication technology and communication procedures in wireless communication systems, and is also related to the construction of wireless communication systems and equipment and devices (radio stations and bases) constituting the wireless communication systems. It can be applied to the manufacture of (including both with stations). In particular, the present invention is related to interworking with an external network in a wireless communication system.

100, 131 Element ID field 110, 132, 133b Length field 120 Advertisement protocol information element field 130 Response information field 133 Native information element field 133a Information identifier (info ID) field 133c Status code field 133d Length of emergency number # 1 field 133e Emergency call number # 1 field