35 results about "Point coordination function" patented technology

Active scanning method in a wireless network for fast determining available access points (106, 806) using inter-AP (Access Point) communication is described. In the scanning method, a mobile station (102, 802) sends Probe Request for Proxy frame to the current AP (104, 804) serving the mobile station (102, 802). In response to the Probe Request for Proxy frame, the current AP (104, 804) send Proxy Probe Request packet to the appropriate APs (106, 806). In response to the Proxy Probe Request packet, the neighbor APs (106, 806) send Probe Response frame to the mobile station (102, 802) on its operating channel. Since the mobile station (102, 802) moves to the channel being examined after sending the Probe Request for Proxy frame, it receives the Probe Response frame if it is in the coverage area of the neighbor AP (106, 806). The content of Probe Response frame provides the mobile station (102, 802) with the information to be used in handoff decision and network join procedures. Thus, the mobile station (102, 802) neither has to move to the channel to be examined nor send Probe Request frame on that channel. This enables active scan to be initiated even when the neighbor AP (106, 806) is operating in PCF (Point Coordination Function) and the network is in CFP (Contention Free Period), during which unassociated mobile stations (including the scanning mobile station) cannot send packets.

A method and system for a bandwidth efficient medium access control (MAC) protocol is provided, which may comprise communicating a request to transmit (RTS) signal to a receiving station to determine if a channel is available for transmission. A clear to send (CTS) acknowledgement signal may be received from the receiving station if the channel is available for transmission. A plurality of medium access control (MAC) protocol data unit (MPDU) fragments separated by a point coordination function (PCF) interframe space (PIFS) interval may be transmitted in response to the received CTS acknowledgement signal.

The present invention provides a method and system for providing quality-of-service to VoIP over a wireless local access network by providing periodic, contention-free access to a wireless link for voice packets. This is achieved by coupling Session Initiation Protocol (“SIP”) signaling for call setup with the Point Coordination Function mode of operation of the 802.11 medium access control. The result is that VoIP call signaling via SIP is tied with availability of periodic time-slots on the wireless medium. The periodic time-slots are used to guarantee contention-free access to the wireless link for voice packets. Accordingly, the present invention, in effect, merges two networking technologies: SIP-based VoIP and 802.11-based wireless LANs.

A wireless network (1) comprises mesh devices and non-mesh devices. A medium access control architecture incorporates at least a point coordination function as an access method, wherein the point coordination function starts a contention-free period (30) with a beacon (32) so that a non-polled transmission by the non-mesh devices is prevented. Further, the mesh devices are enable to communicate during the contention-free period (30). Hence, communication between the mesh devices is priorisized so that a high reliability is achieved and utilization of the wireless network (1) is optimized.

The invention discloses a media access control method based on a WLAN system in an 802.11ac protocol. The method mainly is used for solving the problem of low spectrum utilization rate resulted from overlapped basic service sets. The method comprises that a wireless access point AP invokes a carrier monitoring mechanism on a master channel so as to determine the busy and idle states of the master channel; when the master channel is in an idle condition, the wireless access point and stations STA access the master channel by a distributed coordination functional channel access method; when the master channel is in a busy condition, the wireless access point selects a first channel in non-master channels as a virtual master channel and sends system notice information SNI to the stations in a basic service set in which the wireless access point is located; SNI copies are sent to the other non-master channels; and the stations access the non-master channels on the virtual master channel according to a point coordination functional interframe interval channel access algorithm. According to the method provided by the invention, the non-master channel is utilized fully; the spectrum utilization rate and system throughput are improved; and the method can be used for optimizing the MAC layer protocol in the 802.11ac protocol.

The invention belongs to the technical field of a wireless communication network and relates to a distributed antenna system MAC protocol improvement method based on IEEE802.11. Under a point coordination function PCF mechanism, conflicts among RAU coverage areas are reduced. The method comprises the steps of S1, establishing a network topology structure diagram; S2, dividing priorities and node types of basic service sets, wherein the BSSs are divided into high priority BSSs and low priority BSSs, interior nodes of the high priority BSSs are divided into edge nodes and non-edge nodes, and the interior nodes of the low priority BSSs are divided into non-conflict nodes and conflict nodes; S3, establishing a polling list according to the network topology structure diagram and marking the nodes in the polling list, the high priority BSSs carry out conventional polling according to the polling list; and S4, the low priority BSSs adjust own polling processes according to the polling processes of the high priority BSSs. According to the method, under the condition of sacrificing the time delay performance in a relatively low degree, the total retransmission performance of the system is reduced, and the edge node throughput is improved.