The following descriptions relate to a wireless communication system and, more specifically, to a method and apparatus for transmitting/receiving neighboring network information.
With the growth of information communication technology, various wireless communication technologies are under development. Among the wireless communication technologies, wireless local area network (WLAN) technology enables wireless Internet access at home or in offices or specific service provision areas using a mobile terminal such as a personal digital assistant (PDA), laptop computer, portable multimedia player (PMP) or the like on the basis of radio frequency technology.
To overcome the limitations of communication rate, which have been cited as a weak point of WLAN, recent technical standards have introduced systems with increased network rate and reliability and extended wireless network coverage. For example, IEEE 802.11n supports high throughput (HT) of a data rate of 540 Mbps or higher and introduces MIMO (Multiple Input Multiple Output) technology which uses multiple antennas for both a transmitter and a receiver in order to minimize a transmission error and optimize a data rate.
IEEE 802.11ai is developed as a new standard for supporting fast initial link setup for stations (STAs) that support IEEE 802.11 at a MAC (Medium Access Control) layer of IEEE 802.11 systems. IEEE 802.11ai aims to provide technologies for supporting high-speed link setup in a situation in which so many people leave previously connected WLAN coverage and substantially simultaneously access a new WLAN in the case of public transportation transfer, for example. In addition, IEEE 802.11ai has characteristics of security framework, IP address assignment, fast network discovery, etc.
Technology providing fast link setup (or fast session setup) is required when many users substantially simultaneously attempt network access or a very large number of terminals substantially simultaneously a random access procedure, as described above. However, a detailed scheme for fast link setup has not yet been provided.
An object of the present invention devised to solve the problem lies in a method for remarkably decreasing a time required for a generic advertisement service (GAS) procedure by optimizing the GAS procedure, association operations and the like and/or increasing speeds thereof for fast link setup.
The technical problems solved by the present invention are not limited to the above technical problems and those skilled in the art may understand other technical problems from the following description.
The object of the present invention can be achieved by providing a method for performing, by a station (STA), fast link setup in a wireless communication system, including: transmitting, to an access point (AP), a request frame including a generic advertisement service (GAS) configuration change query; and receiving, from the AP, a response frame including response information with respect to the GAS configuration change query, wherein the response information includes GAS procedure skip indication information when AS information stored in the STA matches GAS information stored in the AP.
In another aspect of the present invention, provided herein is an STA for performing fast link setup in a wireless communication system, including: a transceiver; and a processor, wherein the processor is configured to transmit, to an AP, a request frame including a GAS configuration change query using the transceiver and to receive, from the AP, a response frame including response information with respect to the GAS configuration change query using the transceiver, wherein the response information includes GAS procedure skip indication information when AS information stored in the STA matches GAS information stored in the AP.
The following is commonly applicable to the aforementioned embodiments of the present invention.
The response information may include one or more of a GAS procedure perform indicator, changed GAS information and association deferment indication information when the AS information stored in the STA does not match the GAS information stored in the AP.
An association request frame may be transmitted from the STA after a predetermined time when the response information includes the association deferment indication information.
The association request frame may be transmitted using the changed GAS information included in the response frame.
The association deferment indication information may be represented using a status code of the response frame.
The GAS information stored in the STA may be service information of an access network, the service information being obtained by the STA through request and response procedures with respect to an advertisement server (AS) of the access network via the AP.
The request and response procedures of the STA with respect to the AS may be performed according to an access network query protocol (ANQP).
The GAS information stored in the AP may be information obtained from an AS of an access network before the AP receives the request frame or GAS query information obtained through request and response procedures with respect to the AS after the AP receives the request frame.
The AP may determine whether the AS information stored in the STA matches the GAS information stored in the AP.
The request frame may include one or more of an association request frame, a reassociation request frame and a probe request frame.
The probe request frame may include a service set identifier (SSID), wherein the AP determines whether the AS information stored in the STA matches the GAS information stored in the AP when the SSID matches an SSID of the AP.
The response frame may include one or more of an association response frame, a reassociation response frame, a probe response frame and an association ACK frame.
The method may further include: the STA performing scanning and discovering the AP; the STA transmitting a GAS initial request frame to the AP; and the STA receiving a GAS initial response frame from the AP.
The AP may request the AS to provide GAS query information upon reception of the GAS initial request frame from the STA, and the AP may transmit the GAS query information to the STA through the GAS initial response frame upon acquisition of the GAS query information from the AS.
The above description and the following detailed description of the present invention are exemplary and are for additional explanation of the invention disclosed in the claims.
According to the present invention, it is possible to provide a method and an apparatus for remarkably decreasing a time required for a GAS procedure by optimizing the GAS procedure, association operations and the like and/or increasing speeds thereof, thereby performing or supporting fast link setup.
The effects of the present invention are not limited to the above-described effects and other effects which are not described herein will become apparent to those skilled in the art from the following description.
The accompanying drawings, which are included to provide a further understanding of the invention, illustrate embodiments of the invention and together with the description serve to explain the principle of the invention. In the drawings:
The invention now will be described more fully hereinafter with reference to the accompanying drawings, in which embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.
Embodiments described hereinbelow are combinations of elements and features of the present invention. The elements or features may be considered selective unless otherwise mentioned. Each element or feature may be practiced without being combined with other elements or features. Further, an embodiment of the present invention may be constructed by combining parts of the elements and/or features. Operation orders described in embodiments of the present invention may be rearranged. Some constructions of any one embodiment may be included in another embodiment and may be replaced with corresponding constructions of another embodiment.
Specific terms used in the embodiments of the present invention are provided to aid in understanding of the present invention. These specific terms may be replaced with other terms within the scope and spirit of the present invention.
In some cases, to prevent the concept of the present invention from being obscured, structures and apparatuses of the known art will be omitted, or will be shown in the form of a block diagram based on main functions of each structure and apparatus. In addition, wherever possible, the same reference numbers will be used throughout the drawings and the specification to refer to the same or like parts.
The embodiments of the present invention can be supported by standard documents disclosed for at least one of wireless access systems, Institute of Electrical and Electronics Engineers (IEEE) 802, 3GPP, 3GPP LTE, LTE-A, and 3GPP2. Steps or parts that are not described to clarify the technical features of the present invention can be supported by those documents. Further, all terms as set forth herein can be explained by the standard documents.
Techniques described herein can be used in various wireless access systems such as Code Division Multiple Access (CDMA), Frequency Division Multiple Access (FDMA), Time Division Multiple Access (TDMA), Orthogonal Frequency Division Multiple Access (OFDMA), Single Carrier-Frequency Division Multiple Access (SC-FDMA), etc. CDMA may be implemented as a radio technology such as Universal Terrestrial Radio Access (UTRA) or CDMA2000. TDMA may be implemented as a radio technology such as Global System for Mobile communications (GSM)/General Packet Radio Service (GPRS)/Enhanced Data Rates for GSM Evolution (EDGE). OFDMA may be implemented as a radio technology such as IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Evolved-UTRA (E-UTRA) etc. For clarity, this application focuses on the IEEE 802.11 system. However, the technical features of the present invention are not limited thereto.
Configuration of WLAN System
IEEE 802.11 can be composed of a plurality of components and provide a WLAN supporting STA mobility transparent for higher layers according to interaction of the components. A basic service set (BSS) may correspond to a basic component block in an IEEE 802.11 LAN.
A most basic BSS in the IEEE 802.11 LAN is an independent BSS (IBSS). For example, the IBSS can have a minimum configuration including only 2 STAs. The IBSS has a simplest form and corresponds to the BSS (BSS1 or BSS2) shown in
When an STA is turned on or off, or enters or exits the coverage of a BSS, membership of the STA in the BSS can be dynamically changed. To become a member of the BSS, the STA can join the BSS using a synchronization process. To access all services based on the BSS, the STA needs to associate with the BSS. Association may be dynamically set and may use a distribution system service (DSS).
In a LAN, a direct station-to-station distance may be limited by PHY performance. While this distance limit can be sufficient in some cases, communication between stations having a long distance therebetween may be needed in some cases. The DS may be configured to support an extended coverage.
The DS refers to a structure in which BSSs are connected to each other. Specifically, BSSs may be present as components of an extended form of a network composed of a plurality of BSSs rather than being independently present as shown in
The DS is a logical concept and may be specified by characteristics of the DSM. IEEE 802.11 logically discriminates a wireless medium (WM) from the DSM. The logical media are used for different purposes and used by different components. IEEE 802.11 does not limit the media as the same medium or different media. The fact that plural media are logically different from each other can explain flexibility of IEEE 802.11 LAN (DS structure or other network structures). That is, the IEEE 802.11 LAN can be implemented in various manners and physical characteristics of implementations can independently specify corresponding LAN structures.
The DS can support mobile devices by providing seamless integration of a plurality of BSSs and logical services necessary to handle addresses to a destination.
The AP refers to an entity that enables associated STAs to access the DS through a WM and has STA functionality. Data can be transmitted between a BSS and the DS through the AP. For example, STA2 and STA3 shown in
Data transmitted from one of STAs associated with an AP to an STA address of the AP can be received at an uncontrolled port at all times and processed by an IEEE 802.1X port access entity. Furthermore, the transmitted data (or frame) can be delivered to the DS when a controlled port is authenticated.
A wireless network having an arbitrary size and complexity may be composed of a DS and BSSs. This type of network is called an ESS network in IEEE 802.11. The ESS may correspond to a set of BSSs connected to a DS. However, the ESS does not include the DS. The ESS network looks like an IBSS network at a logical link control (LLC) layer. STAs belonging to the ESS can communicate with each other and mobile STAs can move from a BSS to another BSS (in the same ESS) transparently to LCC.
IEEE 802.11 does not define relative physical positions of BSSs in
In the example of
In the following description, the non-AP STA may be called a terminal, wireless transmit/receive unit (WTRU), user equipment (UE), mobile station (MS), motile terminal, mobile subscriber station (MSS), etc. The AP corresponds to a base station (BS), node-B, evolved node-B, base transceiver system (BTS), femto BS, etc in other wireless communication fields.
Link Setup Procedure
To sets up a link to a network and transmit/receive data, an STA needs to discover the network, perform authentication, establish association and pass through an authentication procedure for security. The link setup procedure may be called a session initiation procedure and a session setup procedure. In addition, discovery, authentication, association and security establishment of the link setup procedure may be called an association procedure.
An exemplary link setup procedure will now be described with reference to
The STA may discover a network in step S510. Network discovery may include a scanning operation of the STA. That is, the STA needs to discover a network that can participate in communication in order to access the network. The STA needs to identify a compatible network prior to participating in a wireless network. A procedure of identifying a network present in a specific area is referred to as scanning.
Scanning includes active scanning and passive scanning.
The scanning operation may be performed in a passive manner, which is not shown in
Comparing active scanning with passive scanning, active scanning has advantages of smaller delay and lower power consumption than passive scanning.
Upon discovery of the network, authentication may be performed on the STA in step S520. This authentication procedure may be referred to as first authentication to be discriminated from security setup operation of step S540, which will be described later.
Authentication includes a procedure through which the STA transmits an authentication request frame to the AP and a procedure through which the AP transmits an authentication response frame to the STA in response to the authentication request frame. An authentication frame used for authentication request/response corresponds to a management frame and may include information as shown in Table 1.
In Table 1, the authentication algorithm number field indicates a single authentication algorithm, and has a length of 2 octets. For example, authentication algorithm number field values 0, 1, 2 and 3 respectively indicate an open system, a shared key, fast BSS transition and simultaneous authentication of equals (SAE).
The authentication transaction sequence number field indicates a current status from among multiple transaction steps and has a length of 2 octets.
The status code field is used in a response frame, indicates success or failure of a requested operation (e.g. authentication request) and has a length of 2 octets.
The challenge text field includes a challenge text in authentication exchange and has a length determined according to authentication algorithm and transaction sequence number.
The RSN (Robust Security Network) field includes cipher related information and has a length of up to 255 octets. An RSNE (RSN Element) is included in an FT (Fast BSS Transition) authentication frame. The mobility domain field includes mobility domain identifier MD ID, FT capability and policy fields and may be used for an AP to advertise an AP group (i.e. a set of APs that form a mobility domain) to which the AP belongs. The fast BSS transition field includes information necessary to perform an FT authentication sequence during fast BSS transition in an RSN. The timeout interval field includes a reassociation deadline interval. The resource information container (RIC) field refers to a set of one or more elements related to a resource request/response and may include a varying number of elements (i.e. elements indicating resources).
The finite cyclic group field indicates a cryptographic group used in SAE exchange and has an unsigned integer value indicating a finite cyclic group. The anti-clogging token field is used for SAE authentication for protection against denial-of-service and is composed of a random bit string. The send-confirm field is used for response prevention in SAE authentication and has a binary coded integer. The scalar field is used for exchange cipher related information in SAE authentication and has an encoded unsigned integer. The element field is used for exchange of a finite field element in SAE authentication. The confirm field is used to verify possession of an encryption key in SAE authentication and has an encoded unsigned integer.
The vendor specific field may be used for vendor-specific information that is not defined in IEEE 802.11.
Table 1 shows some information that may be included in an authentication request/response frame and the authentication request/response frame may further include additional information.
The STA may transmit the authentication request frame including one or more fields shown in Table to the AP. That AP may determine to permit authentication of the STA on the basis of information included in the received authentication request frame. The AP may provide an authentication result to the STA through the authentication response frame including one or more fields shown in Table 1.
Upon successful authentication of the STA, association may be performed in step S530. Association includes a procedure through which the STA transmits an association request frame to the AP and a procedure through which the AP transmits an association response frame to the STA in response to the association request frame.
For example, the association request frame may include information related to various capabilities, a beacon listen interval, a service set identifier (SSID), supported rates, supported channels, RSN, mobility domain, supported operating classes, TIM (Traffic Indication Map) broadcast request, interworking service capability, etc.
For example, the association response frame may include information related to various capabilities, a status code, AID (Association ID), supported rates, EDCA (Enhanced Distributed Channel Access) parameter set, RCPI (Received Channel Power Indicator), RSNI (Received Signal to Noise Indicator), mobility domain, timeout interval (association comeback time), overlapping BSS scan parameter, TIM broadcast response, QoS map, etc.
The aforementioned information is part of information that may be included in the association request/response frame and additional information may be further included in the association request/response frame.
Upon successful association of the STA with the network, security setup may be performed in step S540. Security setup in step S540 may be regarded as authentication through an RSNA (Robust Security Network Association) request/response. Authentication of step S520 may be referred to as first authentication and security setup of step S540 may be referred to as authentication.
Security setup of step S540 may include private key setup through 4-way handshaking using an EAPOL (Extensible Authentication Protocol over LAN) frame. In addition, security setup may be performed according to a security scheme that is not defined in IEEE 802.11.
State 1 is an unauthenticated and unassociated state of the STA. The STA in this state can transmit/receive class-1 frames only to/from other STAs. The class-1 frames include management frames such as a probe request/response frame, beacon frame, authentication frame, deauthentication frame and the like, for example.
Upon successful authentication of the STA in state 1 (e.g. authentication corresponding to 5520 of
When the STA in state 2 is deauthenticated, state 2 is changed to state 1. When the STA in state 2 is successfully associated and RSNA is not required or in the case of fast BSS transition, state 2 is directly changed to state 4.
Upon successful association (or reassociation) of the STA in state 2, state 2 is changed to state 3. That is, state 3 is an authenticated and associated state in which RSNA authentication (e.g. security setup corresponding to step S540 of
When the STA is deassociated or fails to be associated in state 3, state 3 is returned to state 2. When the STA is deauthenticated in state 3, state 3 is returned to state 1.
Upon successful 4-way handshaking of the STA in state 3, state 3 is changed to state 4. In state 4, the STA is authenticated and associated and thus can transmit class-1, 2 and 3 frames, and the IEEE 802.1x control port is unblocked.
When the STA is deassociated or fails to be associated in state 4, state 4 is returned to state 2. When the STA is deauthenticated in state 4, state 4 is returned to state 1.
GAS (Generic Advertisement Service) Procedure
A method of advertising an access network type (e.g. private network, free network, charged network, etc.), roaming consortium, location information and the like is used for an STA to discover and select an appropriate network prior to association with an AP (e.g. a system according to IEEE 802.11u standards). In addition, GAS that enables an STA to transmit/receive an advertisement protocol frame (e.g. second layer (Layer 2) or MAC frame) to/from a network server prior to authentication may be used. According to GAS, an AP may function to relay a query of the STA to a network server (e.g. advertisement server (AS)) and to transmit a response from the network server to the STA. In addition, an access network query protocol (ANQP) may be used to acquire various types of network information that the STA desires.
Specifically, the ANQP may be indicated in a GAS query frame to request information about an access network that the STA desires. Accordingly, the STA can obtain network service information (e.g. service information provided by an IBSS, local access service information, available subscription service provider, external network information, etc.) that is not provided through a beacon frame or a probe response frame.
An STA may detect an AP by performing passive scanning of receiving a beacon frame or active scanning of transmitting a probe request frame and receiving a frame response frame. The beacon frame or the probe response frame may include information such as an interworking element, a roaming consortium element and the like.
To acquire desired additional network information after detection of the AP, the STA may transmit a GAS initial request frame to the AP. The GAS initial request frame may include a dialog token, request IE and the like. Accordingly, the AP may transmit a GAS query request to an advertisement server (AS). When the AP does not receive a GAS query response from the AS for a predetermined time, the AP may transmit a GAS initial response frame including a dialog token, comeback delay information and the like to the STA. Accordingly, the STA may transmit a GAS comeback request frame including a dialog token to the AP after waiting for comeback delay. The AP may receive the GAS query response from the AS while the STA waits for the comeback delay. In this case, the AP may transmit a GAS comeback response frame including a dialog token, GAS query information and the like in response to the GAS comeback request of the STA.
Upon acquisition of network information through GAS query operation, the STA may associate with the AP of the corresponding network.
Enhanced GAS Procedure
In the aforementioned link setup scheme defined in the current wireless communication system (e.g. WLAN system), message exchange through a beacon or probe request/response (i.e. network discovery), authentication request/response (i.e. first authentication), association request/response (i.e. association) and RSNA request/response (i.e. authentication) needs to be performed.
In the conventional link setup procedure, the GAS procedure needs to be performed in order to obtain network information that the STA desires. However, an unnecessary GAS procedure may be performed when the STA knows the network information, resulting in a delay in the initial link setup procedure. For example, when the STA is reassociated with an AP with which the STA was associated, the STA can perform the GAS procedure again according to the operation defined in the conventional wireless communication system. However, when network service information that the STA desires has not been changed/updated, the STA does not newly obtain information through the GAS procedure and the GAS procedure become unnecessary. Accordingly, the present invention provides a new GAS operation scheme capable of improving initial link setup speed by preventing/skipping an unnecessary GAS/ANQP procedure.
In steps 1, 2 and 3 of
In steps 4 and 5 of
In steps 6 and 7 of
In steps 8 and 9 of
In step 10 of
In step 11 of
In steps 12 and 13 of
To achieve this, AP1 may obtain GAS/ANQP information from an AS periodically or in an event-triggered manner and locally store and update the GAS/ANQP information. In this case, AP1 may compare the version of the GAS/ANQP information stored therein with the version of GAS/ANQP information stored in the STA (e.g. acquired during the first authentication procedure) to determine whether the two versions match each other, upon reception of the association request frame including a GAS configuration change counter/query from the STA.
Alternatively, upon reception of the association request frame including the GAS configuration change counter/query from the STA, AP1 may request the AS to provide GAS query information and receive the GAS query information from the AS. Accordingly, AP1 may compare the version of the GAS/ANQP information stored in the STA (e.g. acquired during the first authentication procedure) with the version of the GAS/ANQP information obtained from AS to determine whether the two versions match.
Step 14 of
Upon reception of the association response frame, the STA may confirm validity of the GAS/ANQP information stored therein. Accordingly, the STA can perform the GAS/ANQP procedure, change/update the GAS/ANQP information on the basis of the IE containing the GAS/ANQP information, included in the association response frame, or use the GAS/ANQP information stored therein without changing the same.
Steps 1 to 9 of
In step 10 of
In step 11 of
In steps 12 and 13 of
To this end, the one or more APs may obtain GAS/ANQP information from an AS periodically or in an event-triggered manner and locally store and update the GAS/ANQP information. In this case, the one or more APs may compare the version of GAS/ANQP information stored therein with the version of GAS/ANQP information stored in the STA (e.g. acquired during the first authentication procedure) to determine whether the two versions match each other, upon reception of the probe request frame including a GAS configuration change counter/query from the STA.
Alternatively, upon reception of the probe request frame including the GAS configuration change counter/query from the STA, the one or more APs may request the AS to provide GAS query information and receive the GAS query information from the AS. Accordingly, the one or more APs may compare the version of the GAS/ANQP information stored in the STA (e.g. acquired during the first authentication procedure) with the version of the GAS/ANQP information obtained from AS to determine whether the two versions match.
Step 14 of
Upon reception of the association response frame, the STA may confirm validity of the GAS/ANQP information stored therein. Accordingly, the STA can perform the GAS/ANQP procedure, change/update the GAS/ANQP information on the basis of the IE containing the GAS/ANQP information, included in the association response frame, or use the GAS/ANQP information stored therein without changing the same.
In step 1 of
In step 2 of
In steps 3 and 4 of
To this end, the AP may obtain GAS/ANQP information from an AS periodically or in an event-triggered manner and locally store and update the GAS/ANQP information. In this case, the AP may compare the version of the GAS/ANQP information stored therein with the version of GAS/ANQP information of the STA to determine whether the two versions correspond to each other, upon reception of the association request frame including the GAS configuration change counter/query from the STA. Alternatively, upon reception of the association request frame including the GAS configuration change counter/query from the STA, the AP may request GAS query information to the AS and receive the GAS query information from the AS. Accordingly, AP1 may compare the version of the GAS/ANQP information of the STA with the version of the GAS/ANQP information obtained from AS to determine whether the two versions correspond to each other.
Step 6-1 of
In step 6-1 of
In step 6-2 of
In steps 7 and 8 of
Since steps 1 to 6-1 of
In step 6-2 of
In steps 7 and 8 of
In the examples of the present invention, described with reference to
In Table 2, X denotes a status code value and may be set to an arbitrary value that does not correspond to existing status codes indicating other meanings.
An exemplary format of the association ACK frame in the example of
The association ACK frame may be defined such that the association ACK frame further includes information in addition to the information (or field) shown in Table 3.
a) shows an exemplary format of a GAS configuration change counter IE. The element ID field may have a length of 1 octet and may be set to a value indicating that the corresponding IE corresponds to GAS configuration change counter information. The length field may be defined to have a length of 1 octet and set to a value indicating the length of the following field. The configuration change counter field may be set to a value indicating the version of GAS/ANQP information of the corresponding STA. The GAS configuration change counter IE may be included in an association request frame and/or a probe request frame.
b) shows an exemplary format of a GAS configuration change query IE. The element ID field may have a length of 1 octet and may be set to a value indicating that the corresponding IE corresponds to a GAS configuration change query. The length field may be defined to have a length of 1 octet and set to a value indicating the length of the following field. The configuration change query field may be set to a value indicating whether GAS/ANQP configuration change is checked and/or the version of GAS/ANQP information of the corresponding STA. The GAS configuration change query IE may be included in an association request frame and/or a probe request frame.
c) illustrates an exemplary format of an SSID IE. The element ID field may have a length of 1 octet and may be set to a value indicating that the SSID IE corresponds to an SSID. The length field may be defined to have a length of 1 octet and set to a value indicating the length of the following field. The SSID1, SSID2, . . . , SSIDn fields may be set to values indicating APs that will check whether GAS/ANQP information is changed. When the SSID IE includes only one SSID field, a probe request frame is transmitted (i.e. unicast) to one AP to request the AP to check whether GAS/ANQP information has been changed. When the SSID IE includes a plurality of SSID fields, the probe request frame is transmitted (i.e. multicast) to a plurality of APs to request the APs to check whether GAS/ANQP information has been changed. The SSID IE may be included in the probe request frame.
a) shows an exemplary format of a GAS procedure perform indication IE. The element ID field may have a length of 1 octet and may be set to a value indicating that the GAS procedure perform indication IE corresponds to GAS procedure perform indication. The length field may be defined to have a length of 1 octet and set to a value indicating the length of the following field. The GAS procedure perform indication field may be set to a value indicating whether the corresponding STA performs a GAS procedure. The GAS procedure perform indication IE may be included in an association response frame and/or a probe response frame.
b) shows an exemplary format of a GAS procedure skip indication IE. The element ID field may have a length of 1 octet and may be set to a value indicating that the GAS procedure skip indication IE relates to GAS procedure skip indication. The length field may be defined to have a length of 1 octet and set to a value indicating the length of the following field. The GAS procedure skip indication field may be set to a value indicating whether the corresponding STA performs or skips a GAS procedure. The GAS procedure skip indication IE may be included in an association response frame and/or a probe response frame.
c) shows an exemplary format of a GAS/ANQP information IE. The element ID field may have a length of 1 octet and may be set to a value indicating that the GAS/ANQP information IE corresponds to GAS/ANQP information. The length field may be defined to have a length of 1 octet and set to a value indicating the length of the following field. The GAS/ANQP information field may include network service related information (e.g. service information provided by an IBSS, local access service, available subscription service provider, external network information, etc.) transmitted form an AP to the corresponding STA through a GAS initial response frame or a GAS comeback response frame. The GAS/ANQP information IE may be included in an association response frame and/or a probe response frame.
An unnecessary GAS procedure can be determined and skipped using the aforementioned examples of the present invention and/or IE formats to reduce link setup delay. Considering that GAS/ANQP information is not frequently changed/updated compared to other control information, when a network or an AP informs an STA as to whether the GAS/ANQP information has been changed prior to or during provision of the GAS/ANQP information to the STA, unnecessary control information overhead may be generated. Accordingly, the present invention can employ the method through which the STA quires the network or AP as to whether the GAS/ANQP information has been changed as necessary so as to minimize operation of determining whether the GAS/ANQP information has been changed, thereby reducing a load or delay in operations of the network or AP. Accordingly, link setup delay can be remarkably decreased.
According to the methods provided by the present invention, when GAS/ANQP information stored in the STA differs from GAS/ANQP information of the network or AP, the STA may defer association operation and retransmit the association request frame. Accordingly, time required for operations such as research, reassociation and the like and signaling overhead can be considerably reduced, thereby enabling fast link setup.
The aforementioned enhanced GAS operation and enhanced association operation according to the present invention may be implemented such that the above-described various embodiments of the present invention can be independently applied or two or more thereof can be simultaneously applied, and description of redundant parts is omitted for clarity.
An AP 10 may include a processor 11, a memory 12 and a transceiver 13. An STA 20 may include a processor 21, a memory 22 and a transceiver 23.
The transceivers 13 and 23 may transmit/receive RF signals and implement a physical layer according to IEEE 802, for example.
The processors 11 and 21 may be connected to the transceivers 13 and 23 and implement the physical layer and/or an MAC layer according to IEEE 802. The processors 11 and 21 may be configured to perform operations according to the aforementioned embodiments of the present invention or combinations of two or more thereof.
In addition, modules for implementing operations of the AP and the STA according to the aforementioned embodiments of the present invention may be stored in the memories 12 and 22 and executed by the processors 11 and 21. The memories 12 and 22 may be included in the processors 11 and 21 or provided to the outside of the processors 11 and 21 and connected to the processors 11 and 21 through known means.
Description of the AP 10 and the STA 20 may be respectively applied to a BS and a terminal in other wireless communication systems (e.g. LTE/LTE-A).
The aforementioned configurations of the AP and STA may be implemented such that the above-described various embodiments of the present invention are independently applied or two or more thereof are simultaneously applied, and description of redundant parts is omitted for clarity.
The embodiments of the present invention may be achieved by various means, for example, hardware, firmware, software, or a combination thereof.
In a hardware configuration, the methods according to the embodiments of the present invention may be achieved by one or more Application Specific Integrated Circuits (ASICs), Digital Signal Processors (DSPs), Digital Signal Processing Devices (DSPDs), Programmable Logic Devices (PLDs), Field Programmable Gate Arrays (FPGAs), processors, controllers, microcontrollers, microprocessors, etc.
In a firmware or software configuration, the embodiments of the present invention may be implemented in the form of a module, a procedure, a function, etc. For example, software code may be stored in a memory unit and executed by a processor. The memory unit is located at the interior or exterior of the processor and may transmit and receive data to and from the processor via various known means.
The configuration of the processors 11 and 21 from among components of the AP/STA will now be described in more detail.
The processor 11 or 21 of the AP or STA shown in
To provide correct MAC operation, a SME (Station Management Entity) 1430 is present in each STA. The SME 1430 is a layer independent entity which can be regarded as being present in a separate management plane or as being off to the side. While functions of the SME 1430 are not described in detail herein, the SME 1430 collects layer-dependent states from various layer management entities (LMEs) and sets layer-specific parameters to similar values. The SME 1430 may execute these functions and implement a standard management protocol on behalf of general system management entities.
The entities shown in
As shown in
Those skilled in the art will appreciate that the present invention may be carried out in other specific ways than those set forth herein without departing from the spirit and essential characteristics of the present invention. The above embodiments are therefore to be construed in all aspects as illustrative and not restrictive. The scope of the invention should be determined by the appended claims and their legal equivalents, not by the above description, and all changes coming within the meaning and equivalency range of the appended claims are intended to be embraced therein.
While the above-described embodiments of the present invention focus on IEEE 802.11, they are applicable to various mobile communication systems in the same manner.
Filing Document | Filing Date | Country | Kind |
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PCT/KR2013/001147 | 2/14/2013 | WO | 00 |
Number | Date | Country | |
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61598344 | Feb 2012 | US | |
61602591 | Feb 2012 | US | |
61637283 | Apr 2012 | US |