Abstract: A method and apparatus for providing a key for secure communications is provided herein. During operation a node wishing to join a network, will authenticate with an authentication server and then derive a pairwise key (e.g., a Pair-wise Transient Key (PTK)) used for encryption of unicast traffic. The node will also create its own group transient key (GTK) for use in encrypting multicast or broadcast traffic. Once the GTK is generated, it will be provided to an authenticator as part of an association request message.

Abstract: The proposed method and apparatus reduces an amount of power required for nodes to both transmit and receive messages. In particular, broadcast packets are sent in an awake period (ATIM window) if the length of these messages is small. Because these packets do not need acknowledgment or they do not expect immediate reply, they may be broadcast in the ATIM window. Since all nodes are awake during the ATIM window, nodes may receive messages during this period of time which they ordinarily would need to stay awake to receive in the sleep period (post ATIM window).

Abstract: A method and apparatus for utilizing multiple group keys for secure communications among nodes is provided herein. During operation an access point will utilize a plurality of Medium Access Controller (MAC) Addresses, one for each service provided. Each MAC address has an associated lookup table containing encryption keys. From the perspective of nodes using a first service, group traffic sent using the MAC address for the second service is ignored, and no decryption attempt is made. Likewise, group traffic sent using the MAC address for the first service is ignored for group traffic using the second service.

Abstract: A method and apparatus for mutual authentication of a first and a second node is provided herein. During operation the first node sends a first authentication message to the second node comprising information needed for the second node to authenticate the first node and information needed by the second node for the second node to be authenticated by the first node. A second authentication message is received from the second node comprising information needed by the first node for the first node to be authenticated by the second node and information needed for the first node to authenticate the second node. Because the first and the second authentication messages comprise information needed for both the first and the second node to authenticate each other, messaging within the network is greatly reduced.

Abstract: A method is used by a mesh point that includes one or more step of receiving one of a beacon and probe response from an other mesh point; setting a state of whether the mesh point is already synchronized with one or more peers to true and performing a beacon timing synchronization function when the mesh point is in the unsynchronized state and the other mesh point requests synchronization from a peer mesh point; adding an identity of the other mesh point to a database of beacon senders maintained by the mesh point and performing a beacon timing synchronization function when the mesh point and the other mesh point are both synchronized; and providing indications of whether the mesh point supports synchronization, requests synchronization from a peer mesh point, and is already synchronized with one or more peer.

Abstract: Multi-mode link adaptation in a wireless communication network where a station calculates a current link quality, a minimum link quality, and an excess link quality based upon the current link quality and the minimum link quality to determine an operating mode that is related to the success or failure of recent transmissions from the station. If the calculated excess link margin is lower than a first threshold, the station operates in a first mode, otherwise in another mode. In any case, the station selects the link rate for a new transmission from the station based upon the selected mode.

Abstract: In the present invention, the subscriber unit (200) obtains a set of access point identifiers and measurement opportunity information for each access point identifier. A first measurement is performed on a first access point identified from the set of access point identifiers. A current timer value is determined after completing the step of performing, and a second access point identified from the set of access point identifiers in which to perform a second measurement is selected. Selecting the second access point is based on at least the measurement opportunity information for the second access point in relation to the current timer value.

Abstract: A wireless local area network system (100) supporting mobile radio telephony reduces the time to complete an authenticated handover from one access point (104) to another (108) by a mobile station (102) by performing some of the steps normally performed upon leaving one access point while still associated with that access point. More particularly, the mobile station causes a cryptographic key (204) to be preestablished (212) for use when handing over to a new access point. The cryptographic key is derived at the mobile station, and is also derived in the WLAN infrastructure and stored until the mobile station initiates a handover.

Abstract: A wireless local area network (WLAN) includes an access point (102) and a mobile station (106). The mobile station can operate in a low power mode by shutting down a WLAN subsystem (204) of the mobile station. While the mobile station is in a low power mode, the access point buffers data received at the access point destined for the mobile station (706). The mobile station wakes up to initiate a service period by transmitting a trigger frame to the access point, and identifies a traffic stream to be serviced in the presently initiated service period. The access point begins transmitting response frames to the mobile station, identifying the traffic stream requested by the mobile station, and in at least one response frame, the access point may indicate the buffer status of another traffic stream associated with the mobile station to allow the mobile station to make decisions regarding data retrieval and power save state.

Abstract: A mobile terminal (302, 304) wakes up from a low power state and initiates a frame exchange in a wireless local area network that supports voice traffic by transmitting a polling frame (602). If the mobile terminal had voice data to send, it is included in the polling frame. In response to receiving the polling frame, the access point transmits a delay frame (604) to acknowledge receipt of the polling frame. If the access point has data for the polling mobile terminal, it transmits a non-delay frame (606) including the voice data, otherwise it transmits a null frame (702). The mobile terminal acknowledges the data from the access point (608), and goes back to sleep until the beginning of the next service interval.

Abstract: A mobile station establishes a schedule by which data is exchanged with an access point. The schedule allows the mobile station to use a low power mode at times outside of the scheduled service periods. However, the mobile station may occasionally need to retrieve additional data from the access point, or transmit additional data to the access point, and so initiates an unscheduled service period to do so.

Abstract: A mobile station (106) establishes a real time communication link via an access point (102) for carrying voice or other time-sensitive data. A WLAN subsystem (204) of the mobile station is normally kept in a low power state. Upon initiating a communication link the mobile station signals to the access point that uplink poll-based power save delivery mode will be used (614), and the access point reserves resources to assure the necessary quality of service. The mobile station initiates a frame transaction by first powering up the WLAN subsystem (712), acquiring the WLAN channel (407), and transmitting a polling frame. Upon successful receipt of the polling frame the access point prepares to reply with a response frame at an unspecified time within service window, during which time the mobile station maintains the WLAN subsystem power up and ready to receive the response frame. Upon successful receipt of the response frame, the mobile station places the WLAN subsystem back into a low power state.

Abstract: A mobile station (106) establishes a real time communication link via an access point (102) for carrying voice or other time-sensitive data. A WLAN subsystem (204) of the mobile station is normally kept in a low power state. Upon initiating a communication link the mobile station signals to the access point that unscheduled power save delivery mode will be used (614), and the access point reserves resources to assure the necessary quality of service. The mobile station initiates a frame transaction by first powering up the WLAN subsystem (712), acquiring the WLAN channel (407), and transmitting a polling frame. Upon successful receipt of the polling frame the access point prepares to reply with an aggregate response. The aggregate response commences by transmitting all data in an aggregate buffer, including both reserved and unreserved data buffers. Upon successful receipt of the aggregate response, the mobile station places the WLAN subsystem back into a low power state.

Abstract: The invention provides an enhanced passive scanning method for a wireless local area network, including the steps of transmitting at least one of a beacon signal or a gratuitous probe response in a WLAN channel by an access point. The gratuitous probe response is a supplemental beacon signal that is transmitted at intervals between the occurrence of regular beacon signals, but contains only essential information to allow mobile station manage roaming and timing.

Abstract: An access point (11) for a wireless local area network (10) transmits a beacon message during a service interval period (21). This beacon message identifies, in a preferred embodiment, those subscriber units to whom the access point will shortly be transmitting data. Subscriber units that are not identified in the beacon message and that do not have data themselves to transmit to the access point can implement a power conservation mode of operation until the next beacon message. Subscriber units that have data, such as voice information, to transmit can utilize the beacon message contents to at least estimate a likely time by when the access point will have concluded making its transmissions to the subscriber units. That estimated time can then be used to facilitate scheduling a time at which a given subscriber unit will contend for an opportunity to transmit its data to the access point.