Transmitting a version number associated with higher layer information in a layer 2 frame

0001This application is incorporated herein by reference in its entirety, as described herein by US Patent Provisional Application No. 61 / 991,992, filed May 12, 2014, entitled "System and Method for Utilizing." It claims the priority of "Stored Higher Layer Information" and US Patent Non-Provisional Application No. 14 / 702,309, named "System and Method for Utilizing Stored Higher Layer Information" filed on May 1, 2015.

0002The present disclosure relates generally to digital communications, and more specifically to systems and methods for using stored upper layer information.

0003The IEEE 802.11 family of technical standards and associated technologies, commonly referred to as Wi-Fi, are evolving towards a service-centric model of connectivity to which devices connect for specific purposes. A purposeful connection is triggered by the application looking for a network and / or peer device that supports a particular service. Examples of these services include file sharing, printing, media streaming, sensor information, and analogs.

<p num="0004"> Embodiments of the examples of the present disclosure provide systems and methods for utilizing stored upper layer information.</p><p num="0005"> An embodiment of the present disclosure provides a method for operating a station during the discovery process. This method is a step in which the station sends a first layer 2 frame to the access point (AP), where the first layer 2 frame is associated with the first version number associated with the first higher layer information. The second version number associated with the second upper layer information is the first, depending on the step and station, including the protocol identifier associated with both the first upper layer information and the first version number. A step of receiving a second Layer 2 frame from the AP, including an indication that it is the same as the version number, and a step of determining whether the station should perform the network selection process according to the first higher layer information. Including.</p><p num="0006"> According to an embodiment of another example of the present disclosure, a method for operating an access point is provided. This method is a step of receiving the first layer 2 frame from the station by the access point, and the first layer 2 frame is the first version number related to the first upper layer information and the first. A step that includes the protocol identifier associated with both the upper layer information and the first version number of the access point, and the step of obtaining the second version number associated with the second upper layer information from the server by the access point. And the step of determining whether the first version number and the second version number match by the access point, and the first when the access point matches the first version number and the second version number. A step of transmitting a second layer 2 frame to a station, wherein the second layer 2 frame includes a step that includes an indication that the first version number and the second version number match.</p><p num="0007"> According to an embodiment of another example of the present disclosure, a station configured to perform a discovery process is provided. The station includes a processor and a computer-readable storage medium that stores programming for execution by the processor. Programming is an instruction to send a first layer 2 frame to an access point (AP), where the first layer 2 frame is the first version number associated with the first higher layer information and the first. The instruction and the second version number associated with the second higher layer information are the same as the first version number, including the protocol identifier associated with both the upper layer information of 1 and the first version number. It includes an instruction to receive a second Layer 2 frame from the AP, including an indication of something, and an instruction to determine whether the network selection process should be performed according to the first higher layer information.</p><p num="0008"> According to an embodiment of another example of the present disclosure, an access point configured to participate in the discovery process is provided. This access point includes a processor and a computer-readable storage medium that stores programming for execution by the processor. Programming is an instruction to receive the first layer 2 frame from the station, and the first layer 2 frame is the first version number related to the first upper layer information and the first upper layer. An instruction that includes a protocol identifier associated with both the information and the first version number, an instruction to obtain a second version number associated with the second upper layer information from the server, and a first An instruction to determine if the version number matches the second version number, and to send a second Layer 2 frame to the station when the first version number and the second version number match. The second layer 2 frame includes an instruction that includes an indication that the first version number and the second version number match.</p><p num="0009"> According to an embodiment of another example of the present disclosure, a method for operating a communication device configured to transmit a frame is provided. This method is a step in which the communication device generates a Layer 2 frame containing at least one Common Advertisement Group (CAG) tuple field, where at least one CAG tuple field contains the CAG version number. It includes a step that includes a CAG version number field, a scope field that includes a scope value, and an identifier for an advertisement protocol field, and a step that sends a Layer 2 frame by a communication device.</p><p num="0010"> According to an embodiment of another example of the present disclosure, a station is provided. The station includes a processor and a computer-readable storage medium that stores programming for execution by the processor. Programming is an instruction to generate a Layer 2 frame containing at least one Common Advertisement Group (CAG) tuple field, where at least one CAG tuple field contains a CAG version number field containing the CAG version number and a scope. Includes instructions, including scope fields containing values, identifiers for advertisement protocol fields, and instructions for sending Layer 2 frames.</p><p num="0011"> According to an embodiment of the first further example of the present disclosure, a station is provided. This station It is a means for transmitting the first layer 2 frame to the access point (AP), and the first layer 2 frame is the first version number related to the first upper layer information and the first upper layer. Means, including protocol identifiers associated with both layer information and the first version number, A means for receiving a second layer 2 frame from the AP, including an indication that the second version number associated with the second upper layer information is the same as the first version number, As a means of deciding whether to perform the network selection process according to the first upper layer information including.</p><p num="0012"> In the first aspect according to the first further example, the station obtains the first upper layer information and the first version number, and provides a means for storing the first upper layer information and the first version number. Further can be included.</p><p num="0013"> In the second aspect according to the first further example or the first aspect according to the first further example, the first version number is contained within the advertisement protocol element within the first layer 2 frame.</p><p num="0014"> In the third aspect according to the first further example or the first aspect according to the first further example, the first version number is contained within the common advertisement group (CAG) number element within the first layer 2 frame. Is done.</p><p num="0015"> In the fourth aspect according to the first further example or the first aspect according to the first further example, the first layer 2 frame further includes a query request for the second upper layer information.</p><p num="0016"> In a fifth aspect according to the first further example or any preceding aspect according to the first further example, the first layer 2 frame is an IEEE 802.11 GAS Initial Request frame and a second layer. The two frames are IEEE 802.11 GAS Initial Response frames.</p><p num="0017"> According to an embodiment of the second further example of the present disclosure, an access point is provided. This access point is It is a means for receiving the first layer 2 frame from the station, and the first layer 2 frame is a first version number related to the first upper layer information, and the first upper layer information and the first layer information. Means, including protocol identifiers associated with both the version number of 1 and A means to obtain the second version number related to the second upper layer information from the server, A means for determining whether the first version number and the second version number match, and A means for transmitting a second layer 2 frame to the station when the first version number and the second version number match, and the second layer 2 frame is the first version number and the second. Means and means, including indication that the version number of including.</p><p num="0018"> In the first aspect according to the second further example, the access point is a means for transmitting a third layer 2 frame to the station when the first version number and the second version number do not match. , The third layer 2 frame includes means, including an indication that the first version number and the second version number do not match.</p><p num="0019"> In the second aspect of the second further example or the first aspect of the second further example, the access point receives a fourth layer 2 frame from the station and the fourth layer 2 frame makes a query request. A means for including, forwarding a query request to a server, receiving a query response from the server, and sending a fifth layer 2 frame to the station, the fifth layer 2 frame containing the query response. including.</p><p num="0020"> In either the third aspect according to the second further example or the first and second aspects according to the second further example, the access point does not match the first version number and the second version number. Sometimes by means of extracting a query request from a first layer 2 frame, forwarding the query request to a server according to a protocol identifier, receiving a query response from the server, and sending a sixth layer 2 frame to a station. So, the sixth layer 2 frame contains the means, including the query response.</p><p num="0021"> In any of the fourth aspect according to the second further example or the first aspect, the second aspect, and the third aspect according to the second further example, the first version number and the second version number are The indication of match is contained within the status code field within the second Layer 2 frame.</p><p num="0022"> According to a third further example, a station is provided. This station A means for generating a Layer 2 frame containing at least one Common Advertisement Group (CAG) tuple field, where at least one CAG tuple field contains a CAG version number field containing the CAG version number and a scope value. Means, including scope fields and identifiers for advertisement protocol fields, Means for sending Layer 2 frames including.</p><p num="0023"> In the first aspect according to the third further example, the CAG version number field is 8 bits in size.</p><p num="0024"> In a second aspect according to a third further example, the identifier of the advertisement protocol field is a partial advertisement protocol identifier field that includes a partial advertisement protocol identifier and is 5 bits in size, and the partial advertisement protocol identifier is The five least significant bits of the advertisement protocol's advertisement protocol identifier associated with the CAG version number and scope value in the same CAG taple field, and the scope field is 3 bits in size.</p><p num="0025"> In the third aspect according to the second aspect according to the third further example, the advertisement protocol is an access network query protocol (ANQP) and the partial advertisement protocol identifier field contains a value of 0. ..</p><p num="0026"> In the fourth aspect according to the second aspect according to the third further example, the advertisement protocol is a registered location query protocol (RLQP) and the partial advertisement protocol identifier field has a value of 4. Including.</p><p num="0027"> In the practice of the above embodiment, when the upper layer information version number stored by the STA is the same as the current upper layer information version number of the server, the AP is started by the STA to the server supporting the upper layer service. It allows the specified query request to be short-circuited, thus providing a quick response to the STA and allowing the STA to make quick decisions such as network selection decisions.</p><p num="0028"> In addition, the tradition that APs are not required to understand the content of a higher layer query request or higher layer query response is to use signaling means outside the container field that carries the higher layer query request or higher layer query response. For example, using an advertisement protocol element or CAG number element to carry the higher layer information version number, and the stored higher layer information version number is the current higher layer information version number of the server that supports the higher layer service. It is maintained by using a status code value to indicate that it is (or is different from) the same as.</p><p num="0029"> For a more complete understanding of the present disclosure and its advantages, reference is made to the following description as interpreted in connection with the accompanying drawings.</p>

0030<figref num="1">It is a figure which shows the communication system of the 1st example by embodiment of the example described in this specification.</figref><figref num="2">It is a figure which shows the communication system of the 2nd example which emphasizes the GAS and ANQP operation by the embodiment of the example described herein.</figref><figref num="3a">It is a figure which shows the frame body format of the example of a GAS initial request frame.</figref><figref num="3b">It is a figure which shows the format of the example of the advertisement protocol element.</figref><figref num="4">It is a figure which shows the common format of ANQP element.</figref><figref num="5">A list showing example ANQP elements.</figref><figref num="6">It is a figure which shows the format of the example of a query list ANQP element.</figref><figref num="7">It is a figure which shows the frame body format of the example of a GAS initial response frame.</figref><figref num="8">It is a figure which shows the format of the example of a CAG number element.</figref><figref num="9">It is a figure which shows the format of the example of a CAG ANQP element.</figref><figref num="10">FIG. 1000 is a message exchange highlighting an example message exchange during a network discovery process taking place between such STA, AP, and ANQP servers, according to an embodiment of the example described herein.</figref><figref num="11">It is a figure which shows the format of the advertisement protocol element of the example when the advertisement protocol element is contained in a GAS initial request frame according to the embodiment of the example described herein.</figref><figref num="12">In a message exchange diagram that highlights the example message exchange during the network discovery process, service discovery process, or information discovery process that occurs between the STA, AP, and server, according to the embodiment of the example described herein. is there.</figref><figref num="13">A message exchange diagram that highlights the message exchange of alternative examples during a network discovery process, service discovery process, or information discovery process that occurs between STAs, APs, and servers, and STAs are described herein. It is also optimized to save network capacity by efficiently using the signaling overhead according to an embodiment of the example.</figref><figref num="14a">FIG. 5 is a flow diagram illustrating operation 1400 of the first example that occurs when the STA participates in a network discovery process, a service discovery process, or an information discovery process according to an embodiment of the example described herein.</figref><figref num="14b">FIG. 5 is a flow diagram illustrating operation 1450 of a second example that occurs when the STA participates in a network discovery process, service discovery process, or information discovery process according to an embodiment of the example described herein.</figref><figref num="15a">FIG. 5 is a flow diagram illustrating operation 1500 of the first example that occurs when an AP participates in a network discovery process, service discovery process, or information discovery process according to an embodiment of the example described herein.</figref><figref num="15b">FIG. 5 is a flow diagram illustrating operation 1550 of a second example that occurs when an AP participates in a network discovery process, service discovery process, or information discovery process, according to an embodiment of the example described herein.</figref><figref num="16">FIG. 5 illustrates the example CAG number IE 1600 by including the ID of the advertisement protocol associated with the CAG version number according to an embodiment of the example described herein.</figref><figref num="17">It is a figure which shows the alternative embodiment CAG number IE of the example by embodiment of the example described herein.</figref><figref num="18">It is a flow chart which shows the operation 1800 of the example which occurs when the communication device transmits the frame containing the CAG number IE according to the embodiment of the example described in this specification.</figref><figref num="19">FIG. 5 illustrates a computing platform that can be used to implement the devices and methods described herein, eg, according to an embodiment.</figref>

0031The behavior and structure of the embodiments of the current example are discussed in detail below. However, it should be understood that the present disclosure provides embodiments of a number of applicable examples that can be implemented in a variety of specific contexts. The embodiments of the examples discussed merely illustrate the particular structure of the present disclosure and the forms in which the present disclosure operates, and do not limit the scope of the present disclosure.

0032One embodiment of the present disclosure relates to the use of stored upper layer information. For example, the station sends a first layer 2 frame to the access point (AP) (the first layer 2 frame is the first version number associated with the first higher layer information and the first higher layer. Includes a protocol identifier associated with both the information and the first version number), and an indication that the second version number associated with the second higher layer information is the same as the first version number. Receives a second Layer 2 frame from the AP and determines if the network selection process should be performed according to the first higher layer information.

0033The present disclosure is a communication system that supports an embodiment of an example in a particular context, namely a service centric connection and a pre-association for discovering a service before establishing the connection. Will be explained. This disclosure supports IEEE 802.11ai, IEEE 802.11af, IEEE 802.11aq, Wi-Fi Alliance (WFA) Optimized Connectivity Experience (OCE) specifications, and WFA TV White Space (TVWS) specifications that support service-centric connectivity and pre-association discovery. , WFA Application Service Platform-Infrastructure (ASP-I) specification, Third Generation Partnership Project (3GPP) Device-to-Device (D2D) specification, and standards-compliant communication systems, technical standards, and non-compliant ones. Can be applied to standards-compliant communication systems.

0034FIG. 1 shows the communication system 100 of the first example. The communication system 100 includes an access point (AP) 105 servicing a plurality of devices such as device 110, device 112, device 114, device 116, and device 118. APs are also commonly referred to as base stations, communication controllers, controllers, NodeBs, evolved NodeBs (eNBs), and analogs. Devices are also commonly referred to as stations (STAs), user equipment (UEs), mobile stations, mobiles, users, subscribers, terminals, and analogs. In the first communication mode, the device can communicate over the AP 105 by transmitting a frame to the AP 105, which forwards the frame to the intended receiver. In the second communication mode, the first device can send frames directly to the second device without having to go through the AP 105.

0035It is understood that the communication system may use multiple APs capable of communicating with multiple stations, but in Figure 1 there is only a single AP and multiple stations for simplicity. It is illustrated.

0036The STA typically performs a network discovery and selection (NDS) procedure before accessing the AP and the services it provides. The NDS procedure precedes the authentication and association procedure and typically involves the discovery of the AP.

0037The IEEE technical standard 802.11u states that the STA subscribes to the access network and / or the AP before associating it with the AP in order for the STA to make informed decisions about network selection. Defines Layer 2 transport means called access network query protocol (ANQP) and generic advertisement service (GAS) frames to enable discovery of network, SSPN) features, services, and parameters. did. The GAS transport mechanism provides additional advertising protocols such as media-independent handover (MIH) defined in IEEE Standard 802.11 and Registered Location Query Protocol (RLQP) defined in IEEE 802.11af Amendment. Extended to support. Currently IEEE The 802.11aq project is also considering using GAS to support the pre-association discovery protocol for service information discovery prior to association.

0038FIG. 2 shows a second example communication system 200 that emphasizes GAS and ANQP behavior. First, the user of the device initiates the intent to connect to Wi-Fi, and the user's device scans for available access points, also known as Wi-Fi hotspots. In IEEE 802.11u, GAS frames are advertising protocol query request and query response data between a client on a user's device and an AP connected to a server in the network before authentication and association with the AP. Used to provide Layer 2 transport for. Query request data and query response data are further transported between the AP and the server, typically utilizing IP transport and higher layer protocols such as Diameter or Remote Authentication Dial In User Service (RADIUS). To. IEEE In 802.11u, ANQP is a specific advertising protocol used to discover different characteristics of access networks and available services. After receiving the ANQP query response data, the user's device selects a particular AP and then proceeds to an authentication and association procedure that results in establishing a connection with the AP.

0039The communication system 200 can be an example of a Wi-Fi compliant communication system. Communication system 200 can utilize communication services and communication protocols such as GAS and ANQP to support operations including scanning and network selection. In general, a GAS frame is a layer of request and response data for an advertisement protocol such as ANQP between a terminal and a server in a communication system, such as Communication System 200, before or after authentication and association (eg, of the terminal). 2 Can be used to provide transport. Generally, ANQP can be used to discover different features and / or services of a communication system. The device compares information about different networks or access points, for example to select the best one for the association. The device can continue the authentication process.

0040Stations typically include cell phones, laptop computers, tablets, smart sensors, handheld devices, consumer electronic devices, and other devices that have an interface (such as a Wi-Fi interface) that can interact with the communication system 200. It can be used to refer to any of the devices shown in FIG. 2, such as devices 205, 207, and 209, which can be included. Some or all of the stations may also be capable of interacting with other types of communication systems, such as cellular networks, Bluetooth®, proprietary networks, and analogs.

0041The AP 210 and one or more stations can form a basic service set (BSS), which is a basic building block of a Wi-Fi communication system. A BSS is a configured identifier that can be identified by a service set identifier (SSID) that can be broadcast by a BSS AP, such as AP 210. The AP 210 can communicate with the AP controller and / or ANQP server, which may or may not be co-located with the AP 210. AP 210 may be connected to service provider network 215 connected to one or more roaming hubs 220. The roaming hub 220 may be connected to a home location register (HLR) 225. The roaming hub 220 and HLR 225 provide device mobility or roaming support.

0042GAS frames have been specified since 802.11u and are now incorporated into the IEEE standard 802.11-2012. GAS frames include GAS initial request frames, GAS Comeback Request frames, GAS initial response frames, and GAS Comeback Response frames. The GAS initial request frame is sent by the requesting STA to start the query process. As shown in Figure 3a, the GAS initial request frame body is used together with category field 305 and action field 310 to indicate that this frame is a GAS initial request frame, and to match the response with the request. Includes a dialog token field 315 containing the sequence number, an advertisement protocol element 320, a query request field 360, and a query request length field 340 indicating the length of the query request field 360 in octets.

0043Advertisement protocol element 320 is used to indicate the advertisement protocol associated with the query request contained within the GAS initial request frame. When contained within the GAS initial response frame or within the GAS comeback response frame, the advertisement protocol element is also used to indicate the advertisement protocol associated with the query response contained within the GAS initial response frame or within the GAS comeback response frame. Will be done. As shown in FIG. 3b, the advertisement protocol element 320 includes a query response information field 325 and an advertisement protocol ID field 331. The advertisement protocol ID field 331 contains the identifier specified for the corresponding advertisement protocol. The query response information field 325 is a one-octet field consisting of a 7-bit query response length limit subfield 327 and a 1-bit PAME-BI subfield 329. The IEEE standard 802.11-2012 states that when an advertisement protocol element is contained within a beacon, probe response, GAS initial response frame, or GAS comeback response frame, the query response length limit subfield has one or more responders. Contains the value of the maximum number of octets that can be sent in the query response field contained within the GAS comeback response frame of, and 1 octet when an advertisement protocol element, such as advertisement protocol element 320, is contained within the GAS initial request frame. The entire query response information field 325 of is set to a value of 0, which specifies that the responder (such as AP) should ignore this field when receiving.

0044The query request field 360 is a comprehensive container that is typically placed on top of Layer 2 in the protocol stack and carries query requests for advertisement protocols that use the Layer 2 transport service provided by the GAS frame. Therefore, the AP that receives the GAS initial request frame is not required to interpret the contents of query request field 360. The AP simply retrieves the contents of query request field 360 based on the value in query request length field 340, and based on the value in advertisement protocol ID field 331, the protocol and transformer established between the AP and the server. The port means can be used to forward its contents to the corresponding advertisement protocol server. In a normal deployment, the AP is connected to the server via a wired connection using an IP-based transport. Examples of higher layer protocols used between the AP and the server include Diameter and RADIUS.

0045For ANQP, the query request contained within the query request field 360 typically includes a query list ANQP element that provides a list of identifiers of the ANQP element that the requesting STA wants to receive. The ANQP element is defined to have a common format consisting of a 2-octet information ID field, a 2-octet length field, and a variable-length element-specific information field, as shown in FIG. Figure 5 lists some of the example ANQP elements defined in 802.11-2012. Most of the ANQP elements listed in Figure 5 are used to form the ANQP query response. The query list ANQP element is one exception and is used to form ANQP query requests. Other advertising protocols can define protocol-specific elements that have a common format similar to that shown in Figure 4. For example, 802.11af Amendment defined some RLQP elements that are unique to RLQP.

0046The format of the query list ANQP element is shown in Figure 6. As shown in Figure 6, the query list ANQP element contains an information ID field 610 that contains the values corresponding to the query list ANQP element defined in Figure 5, and the octet units of the remaining fields in the query list ANQP element. With a length field 620 indicating the length of, and one or more ANQP query ID fields, such as ANQP query ID field 630 and ANQP query ID field 640, each containing the information ID of the ANQP element that the STA is requesting. including. Including the information ID in the query list ANQP element declares that the STA executing the ANQP query request wants to receive the ANQP element corresponding to the information ID in the ANQP query response.

0047After forwarding the query request to the corresponding advertisement protocol server, the AP can receive the query response from the server. The AP can use the GAS initial response frame to carry the query response to the requested STA if the query response size is within the size limit of a single GAS initial response frame. The query process can then be terminated. Otherwise, the AP will fragment the oversized query response into multiple GAS comeback response frames and request a GAS comeback to receive multiple GAS comeback response frames to retrieve all fragments of the query response. Send a GAS initial response frame with a non-zero comeback delay value without including part of the query response to prompt the requesting STA to send the frame. The STA then sends a GAS comeback request frame, receives a GAS comeback response frame in response, and repeats these steps until it receives a GAS comeback response frame carrying the last fragment of the query response. .. The STA can then reassemble the query response. The query process can then be terminated. The AP is not required to interpret the contents of the query response received from the advertisement protocol server. The AP simply retrieves the contents of the query response, fragmentes it if it has an excessive size, and sends it to the requesting STA using a GAS initial response frame or one or more GAS comeback response frames.

0048Figure 7 shows the frame body of the GAS initial response frame. As shown in Figure 7, the GAS initial response frame body has a category field 705 and an action field 710 that together indicate that this frame is a GAS initial response frame, and a dialog token field for the corresponding GAS initial request frame. Dialog token field 715 containing the same values obtained from, status code field 720 indicating the status of the corresponding query process, comeback delay field 730 containing the comeback delay value, and the same as the advertisement protocol element 320. Includes a structured advertisement protocol element 740 and a query response length field 750. The GAS initial response frame body can optionally include a query response field 760. A value of 0 in the query response length field 750 indicates the absence of the query response field 760. A non-zero value contained within the query response length field 750 indicates the presence of the query response field 760 and its length in octets.

0049Access network service features and parameters may remain unchanged for extended periods of time, during which the STA visits the same AP daily and through that AP the same access network or subscription service provider. It can be wasteful for the STA to repeatedly send ANQP query requests to the same ANQP server because it may visit the network (SSPN). In the 802.11ai project, the concept of ANQP Configuration Sequence Number was developed, which is also known as the Common ANQP Group version number and is now known as the CAG version number. Is the IEEE 802.11 Task Group Renamed by Ai to Common Advertisement Group Version Number (also abbreviated as CAG Version Number) and associated with a group of access network service features and parameters expressed in the form of ANQP elements. This group of ANQP elements is called the Common ANQP Group (CAG) and is now the IEEE 802.11 Task Group. Renamed to Common Advertisement Group (CAG) by Ai. ANQP server vendors and access networks can determine which ANQP elements are in the CAG and can maintain the CAG version number. The CAG version number is incremented each time the member ANQP element in the CAG changes or the value of one of the attributes of the member ANQP element in the CAG changes. During a previous visit to the AP, the STA obtains the AP's associated CAG (ie, a group of ANQP elements), the corresponding CAG version number and scope value, the AP's BSSID, HESSID, and / or ESSID from the AP and / Or may have been obtained from the ANQP server behind the AP. This information is sometimes referred to as higher layer information. The STA can store higher layer information for later use.

0050The CAG number element is an IEEE Draft 802.11ai Amendment for the AP to indicate the current CAG version number to the STA. Defined in D2.0. The AP can get the current CAG version number from the corresponding ANQP server. An AP can include a CAG number element within the beacon frame or probe response frame it emits. The CAG number element indicates the CAG information (upper layer information), that is, the group of ANQP elements that the STA remembered about the AP during a previous visit and whether the values in these ANQP elements are still valid. It can be used by the STA to determine by comparing the stored CAG version number with the CAG version number in the received CAG number element. If the two CAG version numbers are equal, the STA uses the stored CAG information to remember the query response that the STA would otherwise get without starting the ANQP query process. The NDS procedure can be continued (because it will be the same as the one). In this way, the number of ANQP query requests and ANQP query responses and the number of associated GAS frames can be reduced.

0051Figure 8 shows the format of the CAG number element in IEEE Draft 802.11ai Amendment D2.0. As shown in FIG. 8, the CAG number element 800 has an element ID field 810 containing the element identifier value corresponding to the CAG number element and a length indicating the length in octets of the remaining fields in the CAG number element. Includes field 820, CAG version field 830 indicating the current CAG version number, and scope field 840. The value in the CAG version field 830 can always be a positive number, so a value of 0 in this field is ignored by the receiving STA. The scope field 840 contains a value indicating the valid scope of the CAG associated with the value contained within the CAG version field 830. A value of 0 in the scope field 840 indicates that the CAG is valid only within the current basic service set (BSS) identified by the BSSID value of the AP. A value of 1 in the scope field 840 is the Homogeneous Extended service set (Homogeneous Extended) in which the CAG is identified by the HESSID value of the AP. Indicates that it is valid in Service Set, ESS). A value of 2 in the scope field 840 indicates that the CAG is valid within the Extended Service Set (ESS), which is a combination of BSSs with the same SSID of the AP. Values from 3 to 255 are currently reserved for scope field 840.

0052As discussed earlier, including the CAG version (inside the CAG number element) in the beacon frame that the AP broadcasts periodically can help reduce the number of ANQP query requests and ANQP query responses. .. This technique is generally characterized as a "push". However, the inclusion of the CAG number element within the beacon frame also represents additional signaling overhead that the AP must periodically transmit. In places frequently visited by numerous Wi-Fi STAs, such as train stations and shopping malls, the benefits of frequent ANQP query exchange savings can outweigh the value of sending additional signaling overhead within the beacon frame. Given the potential, it may be worthwhile for the AP to "push" the current CAG version number to the STA by broadcasting within a beacon frame. However, most APs have high density Wi-Fi Given that in the absence of a STA, they do not actually receive ANQP queries as often as they send a beacon frame, these APs choose not to include the CAG number IE in that beacon frame. Can be done. Therefore, it may be better for STAs interested in knowing the current CAG version number to use a "pull" mechanism that sends a request for such information to be returned by the responder.

0053Draft 802.11ai Amendment D2.0 provided such a "pull" mechanism. Draft 802.11ai Amendment D2.0 defined the CAG ANQP element shown in Figure 9. As shown in FIG. 9, the CAG ANQP element 900 has an information ID field 910 containing an identifier value corresponding to the CAG ANQP element and a length indicating the total length in octets of the remaining fields in the CAG ANQP element 900. One or more (CAG), such as field 920, CAG version field 930 containing the current CAG version number associated with the CA, and information ID field 940 and information ID field 950 containing the identifier of the member ANQP element in the CAG. Member) Includes information ID field. CAG The number of (CAG member) information ID fields contained within ANQP element 900 is the length of the CAG version field 930 and the length of each (CAG member) information ID field (such as information ID field 940 and information ID field 950). Since it is fixed, it can be inferred from the values contained within the length field 920. This CAG The ANQP element can be pulled (meaning requested) by the STA using the query list ANQP element in the ANQP query request encapsulated within the GAS initial request frame. An alternative "pull" mechanism involves the STA sending a probe request frame requesting that the CAG number IE be returned and then waiting for a probe response. The difference between the two alternatives is that the probe request is answered by the AP, which can provide the current CAG version number in the response instead of the contents of the CAG, but the ANQP query response Finally answered by the ANQP server, this ANQP server is capable of further providing the contents of the CAG as well as additional ANQP elements that may be outside the CAG. Both of these two "pull" mechanisms can incur additional delays in making NDS decisions due to waiting for a response.

0054STA vendors tend to focus on optimizing STA designs for a better user experience rather than network capacity. Very often, in fact, this means that reducing network discovery and selection (NDS) delays has a higher priority than saving STA's associated signaling overhead. If the AP does not broadcast the CAG number IE within the beacon frame, the STA embodiment may have remembered the CAG information by initiating an ANQP query to get the latest CAG information directly from the server. It is very reasonable to choose to avoid probing delays or query delays by ignoring all of them.

0055Figure 10 shows a message exchange Figure 1000 highlighting an example message exchange during the network discovery process between such STA, AP, and ANQP servers, where the AP is broadcast periodically. Do not include the CAG number IE in the beacon. As shown in FIG. 10, message exchange Figure 1000 shows an example message exchange between STA 1005, AP 1010, and ANQP server 1015 and performed by STA 1005, AP 1010, and / or ANQP server 1015. Indicates the operation to be performed. Message exchange Figure 1000 can begin with STA 1005 acquiring the CAG and associated CAG version number from the ANQP server 1015 during a visit to AP 1010 (shown as event 1020). The STA 1005 can store CAG information (ie, higher layer information), CAG version number, and AP information for later use. Later, the STA 1005 revisits AP 1010 and receives a beacon frame from AP 1010 (shown as event 1025).

0056Due to the signaling overhead concerns discussed above, AP 1010 does not include CAG number IE in the beacon frame. From the BSSID, which is the MAC address of the AP, which is usually contained within the beacon frame, the STA 1005 confirms that it remembers the CAG information associated with the AP 1010. can be identified. However, since AP 1010 did not include the CAG number IE in the beacon frame, STA 1005 does not know if the CAG information it remembers related to the AP remains valid. To avoid probing or query delays, the STA 1005 chooses to ignore the stored CAG information and send a GAS initial request frame to encapsulate the ANQP query request (shown as event 1030). .. AP after receiving the GAS initial request frame 1010 retrieves the advertisement protocol ID in the advertisement protocol element (such as advertisement protocol element 320) and the query request contained in the query request field (such as query request field 360), and from the advertisement protocol ID, AP 1010 Used to carry query requests between ANQP server 1015 and AP 1010 and ANQP server 1015, which should forward query requests to, based on the earlier connection setup between AP 1010 and ANQP server 1015. Select the protocol frame and transport means to be done (shown as event 1035). Diameter and RADIUS are among the example protocols commonly used between APs and servers.

0057AP 1010 forwards ANQP query requests to ANQP server 1015 using selected protocol frames and transport means (shown as event 1040). After receiving the protocol frame from AP 1010, ANQP server 1015 retrieves the ANQP query request and generates an ANQP query response accordingly (shown as event 1045). The ANQP server 1015 then uses another protocol frame to send an ANQP query response to AP 1010 (shown as event 1050). After receiving the response protocol frame from ANQP server 1015, AP 1010 retrieves the ANQP query response and encapsulates the ANQP query response within a query response field (such as query response field 760) within the GAS initial response frame. Forward the ANQP query response to STA 1005 using the GAS initial response frame (shown as event 1055).

0058As shown in Figure 10, the STA 1005 is looking for a quick form that guarantees that it has access network information to make network selection decisions. Since AP 1010 does not include the CAG number IE in the beacon frame, the STA 1005 will not use the stored CAG information as it will incur additional delays if it first "pulls" the current CAG version number. select. In practice, it is quite plausible that many STAs take the same strategy and therefore make the CAG features defined in Draft 802.11ai Amendment D 2.0 less useful than possible.

0059To overcome the disadvantages described above, enhanced signaling mechanisms are provided in embodiments of the examples presented herein. According to an embodiment of the example, the STA provides the AP with a CAG version number associated with the AP stored by the STA while initiating a GAS query request, which is stored by the STA within the GAS initial request frame. Means to provide the CAG version number given. The AP then compares the CAG version number stored by the STA with the latest CAG version number received by the AP from the ANQP server. If the two CAG version numbers are equal, the AP requires that the stored CAG version number (and therefore the stored CAG information associated with it) remain the same as the current one. The query process by returning a GAS initial response frame that supports the display to the STA that the STA can use the stored CAG information when making network selection decisions and therefore requests that the ANQP query process be terminated. Is short-circuited. If the two CAG version numbers are different, the AP forwards the query request to the ANQP server as usual, followed by the remaining steps within the traditional ANQP query process.

0060The design challenge for carrying the STA's stored CAG version number within the GAS initial request frame was encapsulated in the query request field because the AP is not required to understand what is in the query request. It must not be supported within the ANQP element. Similarly, another design challenge regarding carrying a display that the stored CAG version number is the same as the current CAG version number in the GAS initial response frame is that this display is encapsulated in the query response field. It must not be supported within the ANQP element. In an embodiment of the example, the AP may construct an ANQP element and include it in the query response field to indicate that the stored CAG version number is the same as the current CAG version number. Doing so breaks the traditional protocol layering structure and adds additional functional requirements for the AP. In addition, with respect to the advertising protocol where query requests and query responses can be protected by end-to-end encryption between the requesting STA and the server, APs in between may not be able to successfully construct query responses. is there. Therefore, such embodiments may not be practical. On the other hand, the fields carried in the GAS initial request frame other than the query request field and the fields carried in the GAS initial response frame other than the query response field are fixed for backward compatibility reasons, which is new. This means that adding a field cannot be an option.

0061According to an embodiment of the example, the additional signaling required is provided by reusing existing fields within the GAS initial request frame and GAS initial response frame in a backward compatible manner.

0062In an embodiment of the example, the query response information field within the advertisement protocol element can be used to include the STA's stored CAG version number when the advertisement protocol element is contained within the GAS initial request frame. FIG. 11 shows the format of the advertisement protocol element 1100 as an example when the advertisement protocol element is included in the GAS initial request frame. Advertisement Protocol Element 1100 is an enhancement and modification of, for example, Advertisement Protocol Element 320. As shown in Figure 11, the improved advertisement protocol element 1100 contains the same element identifier values that the advertisement protocol element (such as the advertisement protocol element 320) currently does. It includes an ID field 1110, a length field 1120 indicating the total length of the remaining elements in the element in octets, a query response information-CAG version field 1130, and an advertisement protocol ID field 1140. The definition and value of the advertisement protocol ID field 1140 is currently the same as the definition and value of the advertisement protocol ID field (such as the advertisement protocol ID field 331). When included within the GAS initial request frame, query response information-CAG version field 1130 remembers the CAG (ie, higher layer information) and associated CAG version number that the STA corresponds to the AP and the advertisement protocol used. Includes the STA's stored CAG version number if it does, otherwise 0 if the STA does not have a stored CAG or associated CAG version number that corresponds to the AP or advertising protocol used. The value of is set. This is a Draft 802.11ai Amendment that 0 is not a valid CAG version number Consistent with the concept in D2.0. Note that the CAG version number is also relevant to the advertising protocol used. Therefore, the CAG version number contained within the query response information-CAG version field 1130 is related to the advertising protocol indicated by the value contained within the advertisement protocol ID field 1140. When contained within a beacon frame, probe response frame, GAS initial response frame, or GAS comeback response frame, query response information-CAG version field 1130 contains a query response field, which is a 7-bit query. It consists of a response length limit subfield (such as query response length limit subfield 327) and a 1-bit PAME-BI subfield (such as PAME-BI subfield 329).

0063In an embodiment of the alternative example, instead of modifying an existing query response information field (such as query response information field 325), the requesting STA initially GAS to indicate its stored CAG version number to the AP. The CAG number IE can be included in the request frame. However, this CAG number IE must be inserted after the query request field (such as query request field 360) in the GAS initial request frame to maintain backward compatibility, and the AP is the content inside the query request field. Must not be counted as part of the query request field, as it is not required to interpret (meaning that the value in the query request length field must not count the CAG number IE as part of the query request field. To do).

0064In another example embodiment, the new status code value contained within a status code field (such as status code field 720) in the GAS initial response frame has the same current CAG version number as the STA's stored CAG version number. Used to indicate to the STA that requires it to remain. Such a new status code value means that the stored CAG information of the requesting STA is still valid for making decisions such as network selection decisions, thus terminating the query process initiated by that STA. It also works as a display on the STA.

0065Figure 12 shows a message exchange Figure 1200 that highlights an example message exchange during a network discovery process, service discovery process, or information discovery process that occurs between STAs, APs, and servers, where STAs and APs are shown. Supports the enhanced signaling mechanism described herein. As shown in Figure 12, message exchange Figure 1200 is performed by an example message exchange between STA 1205, AP 1210, and server 1215 and by STA 1205, AP 1210, and / or server 1215. Shows the operation. The advertisement protocol used between STA 1205 and server 1215 is ANQP, or RLQP or Pre-Association Discovery Protocol (PADP), which will be defined by the 802.11aq project, or GAS frames or any optional means of Layer 2 transport. Public Action frame to be defined It can be any other advertising protocol such as any other upcoming advertising protocol that can use frame). Thus, server 1215 can be an ANQP server, an RLQP server, a PADP proxy, a PADP server, and an analog, or a server that supports a plurality of these protocols.

0066Message exchange Figure 1200 can begin with STA 1205 acquiring CAG information (ie, higher layer information) and associated CAG version numbers from server 1215 during a visit to AP 1210 (shown as event 1220). .. The STA 1205 can store CAG information, CAG version numbers, scope values, and AP / server information (AP identifiers, advertisement protocols used by the server, etc.) for later use. On the other hand, the AP 1210 can obtain the latest CAG version number updates from the server 1215 (shown as event 1225) periodically or when the CAG version number changes occur. Later, STA 1205 will be able to revisit AP 1210 and receive beacon frames from AP 1210 (shown as event 1230). Due to the signaling overhead concerns discussed earlier, AP 1210 may not include CAG number IE in the beacon frame. From the BSSID contained in the beacon frame, STA 1205 is AP It is possible to recognize that the CAG information related to 1210 and the associated CAG version number have been stored. The STA 1205 can send a GAS initial request frame to AP 1210 (shown as event 1235). The GAS initial request frame is in the query response information-CAG version field (for example, query response information-CAG version field 1130), in the advertisement protocol used in relation to AP 1210 (for example, in the advertisement protocol ID field 1130). Can include a stored CAG version number associated with (indicated by the value contained in). The GAS initial request frame can also encapsulate the query request that STA 1205 would normally request within a query request field (eg, query request field 360).

0067After receiving the GAS initial request from STA 1205, AP 1210 receives the STA's stored CAG version number, for example the latest CAG version number that AP 1210 received from server 1215 at event 1225 (received GAS initial request frame). It can be compared to the advertisement protocol associated with the same advertisement protocol as indicated by the value contained within the advertisement protocol ID field 1130 (shown as event 1240). If AP 1210 determines that the two CAG version numbers are the same, AP 1210 will STA the GAS initial response frame. This GAS initial response frame can be sent to 1205 and the stored CAG version number in the status code field (for example, status code field 720) must be the same as the current CAG version number that the AP has. And the stored CAG is still valid for making decisions (network selection decisions, server selection decisions, peer device selection decisions, etc.), and therefore the query request initiated by the requesting STA is terminated. It can contain a status code value that indicates that (shown as event 1245). The GAS initial response frame sent by AP 1210 at event 1245 does not include the query response field. A value of 0 contained within a query response length field (such as query response length field 750) indicates that the query response field is not included within the GAS initial response frame. After receiving the GAS initial response frame, STA 1205 can terminate the query process. STA 1205 can continue to make decisions, or initiate a query process to other APs and / or other servers before making a decision on how to continue the network selection process. Can be done.

0068If AP 1210 determines in event 1240 that the two CAG version numbers are not equal, AP 1210 requests a query request contained within a query request field (for example, query request field 360) in the GAS initial request frame. Can be taken out. From the advertisement protocol ID contained in the advertisement protocol ID field 1130, the AP 1210 should be used to carry the query request between the server 1215 to which the query request should be forwarded and between the AP 1210 and the server 1215. Select protocol frame and transport means. The AP 1210 can then use the selected protocol frame and transport means to forward the query request to the server 1215 (shown as event 1250). After receiving the protocol frame from AP 1210, server 1215 retrieves the query request from the protocol frame and generates a query response accordingly (shown as event 1255). Server 1215 then uses another protocol frame to AP Send a query response to 1210 (shown as event 1260).

0069After receiving the response protocol frame from server 1215, AP 1210 retrieves the query response and, if the query response is not oversized, queries the query response in the query response field (eg, query) in the GAS initial response frame. By encapsulating in response field 760 (for example), the query response can be forwarded to STA 1205 using the GAS initial response frame (shown as event 1265). The query process can then be terminated. If the query response is oversized, AP 1210 will fragment the query response into multiple GAS comeback response frames and request that multiple GAS comeback response frames be received to retrieve the entire query response. Send a GAS initial response frame to prompt the requesting STA. The STA 1205 then sends a GAS comeback request frame, receives a GAS comeback response frame in response, and takes these steps until it receives a GAS comeback response frame carrying the last fragment of the query response. repeat. Then STA 1205 can reassemble the query response. After that, the query process can be terminated.

0070As shown in Figure 12, if the STA 1205 has the same STA stored CAG version number as the current CAG version number, the AP 1210 will have the STA 1205 earlier for a better user experience. The query process can be shortcuts (shown as event 1245) to allow decisions (eg, regarding network selection) and are motivated to provide that stored CAG version number. AP 1210 faithfully forwards query requests to server 1215, even if the STA's stored CAG version number is different from the current CAG version number. STA 1205 keeps up with getting the latest query response from server 1215. Therefore, by using the enhanced signaling mechanisms shown in the embodiments of the examples presented herein, more STAs are motivated to utilize the CAG information they have stored.

0071Note that the GAS initial response frame sent at event 1245 does not include the query response field. Compared to using the probe request frame and probe response frame to obtain the current CAG version number described earlier, it supplies the stored CAG version number and the stored CAG version number is current. Using the GAS initial request frame to receive the GAS initial response frame with an indication of presence or absence is a very efficient alternative in terms of signaling overhead. However, some changes need to be made to the GAS initial request frame. As currently defined in IEEE Standard 802.11-2012 and Draft 802.11ai Amendment D2.0, the GAS initial request frame must include a query request field and the advertisement request of the advertisement protocol is encapsulated. Therefore, a value of 0 in the query request length field in the GAS initial request frame is currently not allowed.

0072According to an alternative example of an enhanced signaling mechanism, a GAS initial request frame without a query request field and a GAS initial response frame without a query response field request a probe to pull the CAG version number. Frame and probe Used as an alternative to the use of response frames. Strictly speaking, this is not a "pull" mechanism as the requesting STA does not get the current CAG version number. Instead, this means that the STA uses the GAS initial request frame to supply its stored CAG version number to the AP, and the CAG version number stored in response by the AP is the current CAG version number. Simply obtain that indication by providing an indication of whether or not it is identical to.

0073Figure 13 shows a message exchange Figure 1300 that highlights alternative examples of message exchanges during the network discovery process, service discovery process, or information discovery process that occur between the STA, AP, and server, where the STA and AP show. Supporting enhanced signaling mechanisms, STAs are also optimized to save network capacity by efficiently using signaling overhead. As shown in Figure 13, message exchange Figure 1300 is performed by an example message exchange between STA 1305, AP 1310, and server 1315 and by STA 1305, AP 1310, and / or server 1315. Shows the operation. Message exchange Figure 1300 can begin with STA 1305 acquiring the CAG and associated CAG version number from server 1315 during a visit to AP 1310 (shown as event 1320). The STA 1305 can store CAG information, CAG version numbers, scope values, and AP / server information for later use. On the other hand, AP The 1310 can get the latest CAG version number update from the server 1315 (shown as event 1325) periodically or when changes to the CAG version number occur.

0074Later, the STA 1305 can revisit AP 1310 and receive a beacon frame from AP 1310 (shown as Event 1330). Due to the signaling overhead concerns discussed above, AP 1310 may not include CAG number IE in the beacon frame. From the BSSID contained within the beacon frame, the STA 1305 can recognize that it has stored the CAG information associated with AP 1310 and the associated CAG version number. The STA 1305 then states that in the Query Response Information-CAG Version field (for example, Query Response Information-CAG Version Field 1130), the value contained in the advertisement protocol used in relation to the AP (Advertisement Protocol ID field 1130). GAS initial request frame containing the stored CAG version number associated with (indicated by), AP without query request fields Can be sent to 1310 (shown as event 1335). A value of 0 contained within a query request length field (such as query request length field 340) indicates that the query request field is not included, and the GAS initial request frame has a STA stored CAG version number of AP 1310. Sent to request an indication of whether it is the same as the current CAG version number that has.

0075After receiving the GAS initial frame from the STA 1305, the AP 1310 receives the stored CAG version number of the STA, for example the latest CAG version number that the AP 1310 received from the server 1315 at event 1325 (received GAS initial request frame). Can be compared to (shown as event 1340) of the same advertisement protocol as indicated by the value contained within the advertisement protocol ID field 1130. Then, according to the comparison result, AP 1310 sends a GAS initial response frame to STA 1305 (shown as event 1345). If AP 1310 determines that the two CAG version numbers are equal, AP 1310 gives a first status code value indicating that the stored CAG version number is the same as the current CAG version number that the AP has. It can be included within a status code field (for example, status code field 720). AP 1310 determines that the two CAG version numbers are not equal The 1310 includes a second status code value in the status code field (eg, status code field 720) indicating that the stored CAG version number is different from the current CAG version number that the AP has.

0076After receiving a GAS initial response frame from AP 1310, the STA 1305 can terminate the query process if the first status code value is included in the status code field. STA 1205 may continue to make decisions or initiate a query process to other APs and / or servers before making a decision on how to continue the network selection process. it can. If a second status code value is included in the status code field, the STA 1305 knows that its stored CAG information is out of date. Therefore, the STA 1305 can initiate a regular query request to get the latest CAG information (shown as event 1350). The remaining events of the normal query process, such as events 1355, 1360, 1365, 1370, and 1375, follow. As shown in Figure 13, the STA 1305 is the STA shown in Figure 12. Some signaling overhead can be saved in event 1335 if the two CAG version numbers are the same compared to 1205 (due to the exclusion of query requests from the GAS initial request frame). However, if the two CAG version numbers are different, you run the risk of incurring a longer delay (than STA 1205).

0077Currently IEEE Standard 802.11-2012 and Draft 802.11ai Amendment In D2.0, when the advertisement protocol element is included in the GAS initial request frame, the query response information field is set to 0 and APs receiving this query response information field must ignore it. .. Therefore, a legacy AP that receives a GAS initial request frame at event 1235 (for example, a GAS frame can be used, but a CAG feature or signaling enhancement cannot be used) is subject to the legacy 802.11u rule. Forward the query request to the server. The stored CAG version number provided by STA can be wasted, but the 802.11u query process remains untouched. In fact, if the requesting STA knows that the AP is a legacy AP, for example from the capabilities indicated in the beacon or probe response, the STA can set the query response information-CAG version field to 0. , It is possible to prevent sending the stored CAG version number within the GAS initial request frame. This is Draft 802.11ai that 0 is not a valid CAG version number Amendment Consistent with D2.0. Instead, the query response information in the GAS initial request-a value of 0 in the CAG version field is the stored CAG version number of the AP and the associated advertisement by the STA, which supports an enhanced signaling mechanism. It can be used to indicate that it does not have a protocol (and can be interpreted by an AP that supports an enhanced signaling mechanism). Enhancements because legacy STAs that send GAS initial request frames (for example, GAS frames can be used, but CAG features or signaling enhancements cannot be used) set the query response information field to 0. APs that support the signaled mechanism treat it as if the STA does not have the AP's stored CAG version number and associated advertising protocol. Therefore, the AP does not short the query process. Therefore, in summary, the embodiments of the examples presented herein do not have backwards compatibility issues with Legacy AP or Legacy STA. The communication system made using the embodiments of these examples can coexist with the legacy AP and the legacy STA.

0078Figure 14a shows a flow diagram of the operation 1400 of the first example that occurs when the STA participates in the network discovery process, service discovery process, or information discovery process. Action 1400 may indicate what happens within the STA when the STA participates in a network discovery process, a service discovery process, or an information discovery process. The operation 1400 can correspond to the message exchange diagram 1200.

0079Operation 1400 can begin with the STA getting the first higher layer information and CAG number from the server (block 1405). The first higher layer information and CAG number can be associated with networks, services, databases, and analogs. The STA can disconnect from the network (block 1407). Later, the STA can revisit the network and identify it according to the BSSID contained, for example, within the beacon frame transmitted by the AP (block 1409). The STA can send a GAS initial request frame containing the stored CAG version number (block 1411). The STA can receive a GAS initial response frame with an indicator indicating whether the stored CAG version number matches the current CAG version number (block 1413). This indicator can be placed within the status code field of the GAS initial response frame. If the stored CAG version number matches the current CAG version number, the GAS initial response frame does not contain any upper layer information. If the stored CAG version number does not match the current CAG version number, the GAS initial response frame received by the STA may include higher layer information and the current CAG number in the query response field. The STA can continue the network selection process (block 1415).

0080Figure 14b shows a flow diagram of the operation 1450 of the second example that occurs when the STA participates in the network discovery process, service discovery process, or information discovery process. Action 1450 may indicate the action taken within the STA when the STA participates in the network discovery process, service discovery process, or information discovery process. Operation 1450 can correspond to message exchange Figure 1300.

0081Operation 1450 can begin with the STA getting the first higher layer information and CAG number from the server (block 1455). The first higher layer information and CAG number can be associated with networks, services, databases, and analogs. The STA can disconnect from the network (block 1457). Later, the STA can revisit the network and identify it according to the BSSID contained, for example, within the beacon frame transmitted by the AP (block 1459). The STA can send a GAS initial request frame containing the stored CAG version number (block 1461). The STA can receive a GAS initial response frame with an indicator indicating whether the stored CAG version number is the same as the current CAG version number (block 1463). This indicator can be placed within the status code field of the GAS initial response frame. If the stored CAG version number matches the current CAG version number, the first indicator value is contained within the GAS initial response frame, for example in the status code field, otherwise. , The second indicator value is contained within the GAS initial response frame, for example in the status code field.

0082The STA can perform a check on the indicator in the received GAS initial response frame (for example, the value contained in the status code field) to determine if the first indicator value has been received (for example). Block 1465). If a first indicator value is received (for example, in the status code field) to indicate that the stored CAG version number matches the current CAG version number, the STA should continue the network selection process. Can be done (block 1469). If the first indicator value is not received, indicating that the stored CAG version number does not match the current CAG version number, the STA will send the latest higher layer information (updated CAG information) from the AP and The current CAG version number can be acquired and stored (block 1467). As an exemplary example, the STA can execute a regular query request to obtain the updated higher layer information (updated CAG information) and the current CAG version number from the AP. The STA can continue the network selection process (block 1469).

0083Figure 15a shows a flow diagram of the operation 1500 of the first example that occurs when an AP participates in a network discovery process, a service discovery process, or an information discovery process. Action 1500 may indicate the action that takes place within the AP as it participates in the network discovery process, service discovery process, or information discovery process. Operation 1500 can correspond to message exchange diagram 1200.

0084Operation 1500 can begin with the AP receiving a GAS initial request frame containing the stored CAG version number stored in the STA (block 1505). The AP can perform a check to determine if the stored CAG version number from the GAS initial request frame matches the current CAG version number associated with the same advertisement protocol (block 1507). ). If the two CAG version numbers match, the AP can send a GAS initial response frame with an indicator that the two CAG version numbers match (block 1509). If the two CAG version numbers do not match, the AP can retrieve the query request from the GAS initial request frame and forward the query request to the server to solicit a response (block 1511). The AP can receive a response from the server (block 1513). The response from the server can include a query response for the requesting STA. The content of the query response can include the latest CAG version number and higher layer information, which can be transparent to the AP. The AP can extract the query response from the response received from the server and send a GAS initial response frame with the query response (block 1515).

0085Figure 15b shows a flow diagram of operation 1550 in the second example that occurs when an AP participates in a network discovery process, service discovery process, or information discovery process. Action 1550 may indicate the action taken within the AP when the AP participates in a network discovery process, service discovery process, or information discovery process. The operation 1550 can correspond to the message exchange diagram 1300.

0086Operation 1550 can begin with the AP receiving a first GAS initial request frame containing the stored CAG version number stored in the STA (block 1555). The first GAS initial request frame may not contain a query request, for example, the query request length field contains a value of 0 and the query request field is null. The AP can perform a check to determine if the stored CAG version number from the GAS initial request frame matches the current CAG version number associated with the same advertisement protocol (block 1557). .. If the two CAG version numbers match, the AP can send a first GAS initial response frame with an indicator that the two CAG version numbers match (block 1559).

0087If the two CAG version numbers do not match, the AP can send a first GAS initial response frame with an indicator that the two CAG version numbers do not match (block 1561). The AP can receive a second GAS initial request frame containing the query request (block 1563). The content of the query request, which can be transparent to the AP, can include the latest CAG version number and higher layer information (CAG information) requests. The AP can retrieve the query request from the second GAS initial request frame and forward the query request to the server for response (block 1565). The AP can receive a response from the server (block 1567). The response from the server can include a query response for the requesting STA. The content of the query request, which can be transparent to the AP, can include the latest CAG version number and higher layer information (CAG information) requests. The AP can extract the query response from the response received from the server and send a second GAS initial response frame with the query response (block 1569).

0088It was noted earlier that the CAG number is also relevant to the advertising protocol used. Therefore, when the AP advertises the current CAG version number using the CAG number IE contained within the beacon frame or probe response frame, the AP must also indicate the advertising protocol associated with that CAG version number. It doesn't become. Figure 16 shows an example CAG number IE 1600 by including the ID of the advertisement protocol associated with the CAG version number. As shown in FIG. 16, the CAG number IE 1600 contains the element identifier value corresponding to the CAG number element. An ID field 1610, a length field 1620 indicating the total length of the remaining fields in the element in octets, and one or more CAG tuple fields such as the CAG tuple field 1630, the CAG tuple field 1650, and the CAG tuple field 1660. including. Each CAG tuple field (such as the CAG tuple field 1630) has a 1-octet CAG version subfield (CAG version subfield 1635), a 1-octet scope subfield (such as the scope subfield 1640), and a 1-octet advertisement protocol. Includes an ID subfield (Advertisement Protocol ID Subfield 1645). The number of CAG tuple fields contained within the CAG number element 1600 can be inferred from the values contained within the length field 1620.

0089FIG. 17 shows an example alternative embodiment CAG number IE 1700. As shown in Figure 17, the CAG number IE 1700 has an IE ID 1710 that contains the element identifier value that corresponds to the CAG number element and a length field 1720 that indicates the total length of the remaining fields in the element in octets. , CAG tuple field 1730, CAG tuple field 1750, and one or more CAG tuple fields such as CAG tuple field 1760. Each CAG tuple field (such as the CAG tuple field 1730) has a 1-octet CAG version subfield (such as the CAG version subfield 1735), a 3-bit scope subfield (such as the scope subfield 1740), and a 5-bit partial advertisement. Includes ment protocol ID subfields (such as partial advertisement protocol ID subfield 1745). The number of CAG tuple fields contained within the CAG number element 1700 can be inferred from the values contained within the length field 1720. CAG number IE The 1700 is a 1-octet scope subfield (scope subfield 1640) with the 1-octet advertisement protocol ID subfield (such as the advertisement protocol ID subfield 1645) replaced by the 5-bit partial advertisement protocol ID subfield 1745. Etc.) are replaced by the 3-bit scope subfield 1740, which differs from CAG number IE 1600 in that the two subfields are combined into one octet. Therefore, each CAG tuple field in CAG number IE 1700 has CAG number IE. It is 2 octets long instead of 3 octets in 1600. The 5-bit partial advertisement protocol ID can be the first 5 bits (ie, the least significant 5 bits) of the currently defined 1-octet advertisement protocol ID, which is a total of 32 1-octets. It means that only the advertisement protocol ID of can be assigned to avoid possible overlap between its partial advertisement protocol IDs. As an example, if the CAG version number contained within a CAG version subfield (such as CAG version subfield 1735) is related to ANQP, then a partial advertisement protocol ID subfield (partial) within the same CAG tuple field. The advertisement protocol ID subfield (for example, 1745) is 0 (or 00000 when expressed in binary) because the full advertisement protocol ID in ANQP is 0 (or 00000000 when expressed in binary). Contains the value of.

0090Table 1 below shows multiple example advertisement protocols and their associated full advertisement protocol ID values and partial advertisements that are applicable to the example formats shown in Figures 16 and 17, respectively. Provides the ment protocol ID value (all in decimal).

0091<tables num="1"><img id="000003" he="111" wi="170" file="JP2017519423A_D0001.tif" img-format="tif" img-content="drawing" /></tables>

0092The number of scope values that can be defined by a 3-bit scope subfield (such as scope subfield 1740) is also reduced to 8 compared to 256 by 1 octet length scope subfield (such as scope subfield 1640) values. Is done. One possible solution is to use a 3-bit scope based on the corresponding partial advertisement protocol ID value contained within the same CAG tuple field, as the number of scope values in the 3-bit scope subfield is significantly reduced. To reinterpret the meaning of each scope value contained within a scope subfield. As an example, if the partial advertisement protocol ID indicates that the associated advertisement protocol is ANQP, a value of 0 in the 3-bit scope subfield indicates that the CAG number is BSS-specific. A value of "1" can indicate that the CAG numbers are common within the same HESSID, and a value of "2" can indicate within the Extended Services Set (ESS) area with the same CAG number. Can be shown to be common in, values from 3 to 7 can be reserved for scope subfields for ANQP, while partial advertisement protocol IDs are associated advertisement protocols. If is an RLPQ (for TV whitespace technology), a value of 0, 1, 2, 3, 4, or 5 in the 3-bit scope subfield is the TV whitespace database or channel availability. The CAG numbers associated with the map can be shown to be common across countries, states, counties, cities, ESS, or BSS, respectively, and values 6 and 7 are for scope subfields for RLQP. Can be reserved.

0093FIG. 18 shows a flow chart of the operation 1800 that occurs when the communication device transmits a frame including the CAG number IE. Operation 1800 can indicate the operation that takes place within the communication device, such as the STA and / or AP, when the communication device transmits a frame containing the CAG number IE.

0094Operation 1800 can begin with the communication device generating a frame containing the CAG number IE according to FIG. 16 or FIG. 17 (block 1805). This frame can be a beacon frame, a probe response frame, a GAS initial request frame, a short beacon frame, a public action frame, and the like. The CAG number IE can contain one or more CAG tuples, each CAG tuple with a CAG version field and a scope field (which can be either 3 or 8 bits long) and an advertisement. Contains a protocol ID field (which can be either 5-bit or 8-bit long). The communication device can send this frame (block 1810).

0095Note that the GAS initial request frame and the GAS initial response frame are used merely as examples to illustrate the embodiment of the example. Layer 2 of other public action frames such as Service Discovery Request and Service Discovery Response frames defined in the WFA Wi-Fi Direct specification or higher layer query request and query response data. Any new public action frame that provides similar services as a transport is also possible.

0096The embodiment of the example described not only enhances the current 802.11ai CAG features defined in Draft 802.11ai Amendment D2.0, which is defined for ANQP only, but also 802.11af Amendment for TV White Space. RLQP defined in technology, media-independent handover (MIH) information service, media-independent handover (MIH) command and event service capability discovery, emergency alert system (EAS), access network discovery and selection. It can also be applied to enhance other existing advertisement protocols such as function, ANDSF), as well as upcoming defined advertisement protocols such as PADP, which is being investigated by the 802.11aq project for pre-association discovery. Thus, the server can be a server that supports one or more of ANQP, MIH, RLQP, PADP, ANDSF, and analogs. A CAG can be defined as any group of upper layer information associated with an upper layer protocol that uses Layer 2 frames as a means of transport between the STA and the AP to which the server connects. For example, the higher layer information can relate to a TV white space map or TV white space database of service information, protocol information, configuration information, channel availability information. The use of these techniques can be for all types of discovery purposes. For example, the discovery process can be network discovery, service discovery, information discovery, or discovery of available TV whitespace channels where the network is an access network, subscription service provider network (SSPN), and / or cellular network. it can. The decisions made after the discovery process can be all types of decisions, including network selection decisions, service selection decisions, peer device selection decisions, decisions to use TV whitespace channels available for communication, and more. it can. The CAG version number may also be referred to as the configuration change count, configuration sequence number, configuration set number, TV white space map index number, and so on.

0097Roughly speaking, stations (or devices, user devices, terminals, mobiles, and similar) use the Layer 2 transport provided between the station and the access point and between the access point and the server. Access point (or base station, controller, Nobe B, enhancement Node) to obtain higher layer information related to the server. It can be assumed that it is communicating with the server via B, and analogs). The index number (or version number, change count, configuration sequence number, etc.) can be associated with higher layer information. The index number and higher layer information can be provided to the station by the server and stored by the station, for example during a previous visit. The latest index number may also be provided to the access point by the server. On subsequent visits to the access point by the station, the station may provide the access point with its stored index number. Since the upper layer information can be associated with the upper layer protocol identified by the protocol identifier, the station can also provide the associated protocol identifier to the access point. The access point can compare the index number provided by the station with the index number provided by the server. The access point can use the protocol identifier provided by the station to select the server whose index number is compared to the index number provided by the station. If the two index numbers are the same, the access point tells the station what the higher layer information is used for (network selection, service discovery, etc.) without further reception of higher layer information from the server. ) Can be used to indicate to the station that the two index numbers are identical so that the stored upper layer information can be used. A station is a higher layer information or higher layer, even if higher layer information or higher layer queries of such higher layer information can be included within a Layer 2 frame sent between the station and the access point. Layer 2 visible to the access point so that the query can remain transparent to the access point

0098FIG. 19 is a block diagram of a processing system 1900 that can be used to implement the devices and methods disclosed herein. Certain devices may utilize all of the components shown or only a subset of the components, and the level of integration can vary from device to device. In addition, a device can include multiple instances of a component, such as multiple processing units, processors, memory, transmitters, receivers, and so on. The processing system is a processing unit with one or more I / O devices such as human interface 1915 (including speakers, microphones, mice, touch screens, keypads, keyboards, printers, and the like), displays 1910, and more. Can include 1905. The processing unit can include a central processing unit (CPU) 1920, memory 1925, mass storage device 1930, video adapter 1935, and input / output interface 1940 connected to bus 1945.

0099The bus can be one or more of multiple bus architectures of any type, including memory buses or memory controllers, peripheral buses, video buses, or analogs. The CPU can include any type of electronic data processor. Memory includes any type of system memory such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous DRAM (SDRAM), read-only memory (ROM), combinations thereof, or the like. be able to. In one embodiment, memory can include ROM for use during bootup and DRAM for use during program execution and data storage.

0100Mass storage devices can include any type of storage device that is configured to store data, programs, and other information and make the data, programs, and other information accessible over the bus. .. Mass storage devices can include, for example, one or more of solid state drives, hard disk drives, magnetic disk drives, optical disk drives, or analogs.

0101Video adapters and input / output interfaces provide an interface for connecting external input and output devices to the processing unit. As shown, examples of input and output devices include a display coupled to a video adapter and a mouse / keyboard / printer coupled to an input / output interface. Other devices may be coupled to the processing unit and additional or fewer interface cards may be utilized. For example, a serial interface such as Universal Serial Bus (USB) (not shown) can be used to provide an interface for the printer.

0102The processing unit also includes one or more network interfaces 1950 that can include wired and / or wireless links such as Ethernet cables or similar to access nodes or different networks 1955. The network interface allows the processing unit to communicate with the remote unit over the network. For example, a network interface can provide wireless communication via one or more transmitter / transmit antennas and one or more receiver / receiver antennas. In one embodiment, the processing unit is coupled to a local area network or wide area network for data processing and communication with the remote device using a remote device such as another processing unit, the Internet, a remote storage facility, or an analog. To.

0103Although this disclosure and its advantages have been described in detail, various modifications, substitutions, and substitutions may be made herein without departing from the spirit and scope of the disclosure as defined by the appended claims. Please understand what you can do.

0104100 communication system 105 Access Point (AP) 110,112,114,116,118 devices 200 communication system 205,207,209 devices 210 AP 215 Service Provider Network 220 roaming hub 225 Home location register 305 Category field 310 action field 315 Dialog Token Field 320 Advertisement Protocol Element 325 Query response information field 327 Query response length limit subfield 329 PAME-BI subfield 331 Advertisement Protocol ID Field 340 Query request length field 360 query request field 610 Information ID field 620 length field 630 ANQP query ID field 640 ANQP query ID field 705 Category field 710 action field 715 Dialog token field 720 status code field 730 Comeback Delay Field 740 Advertisement Protocol Element 750 query response length field 760 Query response field 800 CAG number element 810 Element ID field 820 length field 830 CAG version field 840 Scope field 900 CAG ANQP element 910 Information ID field 920 length field 930 CAG version field 940 Information ID field 950 Information ID field 1100 Advertisement Protocol Element 1110 IE ID field 1120 length field 1130 Query Response Information-CAG Version Field 1140 Advertisement Protocol ID Field 1600 example CAG number IE 1610 IE ID field 1620 length field 1630 CAG tuple field 1635 CAG version subfield 1640 Scope subfield 1645 Advertisement Protocol ID Subfield 1650 CAG tuple field 1660 CAG tuple field 1700 CAG number IE 1710 IE ID 1720 length field 1730 CAG tuple field 1735 CAG version subfield 1740 Scope subfield 1745 Partial Advertisement Protocol ID Subfield 1750 CAG tuple field 1760 CAG tuple field 1900 computing system 1905 processing unit 1910 display 1915 Human interface 1920 Central Processing Unit (CPU) 1925 memory 1930 mass storage device 1935 video adapter 1940 I / O interface 1945 bus 1950 network interface 1955 network