摘要:
A method for providing dynamic adjustment of frame encoding parameters to improve transmission performance for a transmitting frame being transmitted from a transmitting station to a receiving station over a transmission medium on a frame-based communications network, the transmitting frame having a header segment and a payload segment, the header segment being transmitted using a fixed set of encoding parameters, the payload segment being transmitted using a variable set of payload encoding parameters.
摘要:
A method and signal therfor embodied in a carrier wave for sending information from transmit stations to receive stations over a transmission medium of a frame-based communications network. The information is sent in transmit frames having a frame format comprising a fixed rate header, followed by a variable rate payload, followed by a fixed rate trailer. The fixed rate header includes a preamble. The preamble has a repetition of four symbol sequences for facilitating power estimation, gain control, baud frequency offset estimation, equalizer training, carrier sensing and collision detection. The preamble also includes a frame control field. The frame control field has scrambler control information for frame scrambling initialization, a priority field to determine the absolute priority a transmit frame will have when determining access to the transmission medium, a payload encoding field which determines constellation encoding of payload bits in the variable rate payload, and a header check sequence for providing a cyclic redundancy check. The variable rate payload is transmitted pursuant to dynamic adjustable frame encoding parameters for improving transmission performance for a transmit frame being transmitted from a transmitting station to a receiving station. The header also includes a destination address field, a source address field and an ethertype field.
摘要:
Methods and apparatus for data communication are disclosed. An example method includes encoding a first plurality of transmitting frames, where a header segment of each frame is encoded in accordance with a fixed set of header encoding parameters and a payload segment of each frame is encoded in accordance with a first set of a variable set of payload encoding parameters. The example method also includes transmitting the first plurality of transmitting frames to a receiving station and receiving a request from the receiving station to change the first set of payload encoding parameters to a second set of the variable set of payload encoding parameters. The example method further includes selecting the second set of payload encoding parameters based on the request and encoding a second plurality of transmitting frames, where a header segment of each frame of the second plurality of transmitting frames is encoded in accordance with the fixed set of header encoding parameters and a payload segment of each frame of the second plurality of transmitting frames is encoded in accordance with the second set of payload encoding parameters. The example method still further includes transmitting the second plurality of transmitting frames to the receiving station.
摘要:
Methods and apparatus for data communication are disclosed. An example method includes encoding a first plurality of transmitting frames, where a header segment of each frame is encoded in accordance with a fixed set of header encoding parameters and a payload segment of each frame is encoded in accordance with a first set of a variable set of payload encoding parameters. The example method also includes transmitting the first plurality of transmitting frames to a receiving station and receiving a request from the receiving station to change the first set of payload encoding parameters to a second set of the variable set of payload encoding parameters. The example method further includes selecting the second set of payload encoding parameters based on the request and encoding a second plurality of transmitting frames, where a header segment of each frame of the second plurality of transmitting frames is encoded in accordance with the fixed set of header encoding parameters and a payload segment of each frame of the second plurality of transmitting frames is encoded in accordance with the second set of payload encoding parameters. The example method still further includes transmitting the second plurality of transmitting frames to the receiving station.
摘要:
A method and apparatus for providing improved security and improved roaming transition times in wireless networks. The same pairwise master key (PMK) from an authentication server can be used across multiple access points and a new pairwise transition key (PTK) is derived for each association of a station to any of the access points. A plurality of access points are organized in functional hierarchical levels and are operable to advertise an indicator of the PMK cache depth supported by a group of access points (N) and an ordered list of the identifiers for the derivation path. Access points in each level in the cache hierarchy compute the derived pairwise master keys (DPMKs) for devices in the next lower level in the hierarchy and then deliver the DPMKs to those devices. An access point calculates the PTK as part of the security exchange process when the station wishes to associate to the access point. The station also computes the PTK as part of the security exchange process. The station calculates all the DMPKs in the hierarchy as part of computing the PTK. The method and apparatus allow the cache depth to vary per station, but it remains constant for a given station within a key circle.
摘要:
A method for selecting an operating mode for a frame-based communications network consisting of a plurality of stations attached to a transmission medium. The plurality of stations include both a first type station and a second type station. The first type station is capable of transmitting and receiving first protocol frames in accordance with a first protocol. The second type station is capable of transmitting and receiving both first protocol frames and second protocol frames in accordance with a second protocol. The first protocol and the second protocol each use different signals on the transmission medium. The first type station is not capable of reliably detecting second protocol frames. The first protocol has a first protocol frame format containing at least two reserved bits in a first protocol frame header which are ignored in received frames by first type stations and always sent with a same fixed value by first type stations. The first protocol frame format is redefined to provide an updated first protocol frame header wherein two reserved bits in the first protocol frame header are allocated as a mode selection indicator field in the updated first protocol frame header. The mode selection indicator field has meaning for second type stations.
摘要:
A method and apparatus for providing improved security and improved roaming transition times in wireless networks. The same pairwise master key (PMK) from an authentication server can be used across multiple access points and a new pairwise transition key (PTK) is derived for each association of a station to any of the access points. A plurality of access points are organized in functional hierarchical levels and are operable to advertise an indicator of the PMK cache depth supported by a group of access points (N) and an ordered list of the identifiers for the derivation path. Access points in each level in the cache hierarchy compute the derived pairwise master keys (DPMKs) for devices in the next lower level in the hierarchy and then deliver the DPMKs to those devices. An access point calculates the PTK as part of the security exchange process when the station wishes to associate to the access point. The station also computes the PTK as part of the security exchange process. The station calculates all the DMPKs in the hierarchy as part of computing the PTK. The method and apparatus allow the cache depth to vary per station, but it remains constant for a given station within a key circle.
摘要:
A method and apparatus for providing improved security and improved roaming transition times in wireless networks. In the present invention, the same pairwise master key (PMK) from an authentication server can be used across multiple access points and a new pairwise transition key (PTK) is derived for each association of a station to any of the access points. A plurality of access points are organized in functional hierarchical levels and are operable to advertise an indicator of the PMK cache depth supported by a group of access points (N) and an ordered list of the identifiers for the derivation path. Access points in each level in the cache hierarchy compute the derived pairwise master keys (DPMKs) for devices in the next lower level in the hierarchy and then deliver the DPMKs to those devices. An access point calculates the PTK as part of the security exchange process when the station wishes to associate to the access point. The station also computes the PTK as part of the security exchange process. The station calculates all the DMPKs in the hierarchy as part of computing the PTK. The method and apparatus of the present invention allows the cache depth to vary per station, but it remains constant for a given station within a key circle.
摘要:
A method for selecting frame encoding parameters to improve transmission performance for a transmitting frame being transmitted from a transmitting station to a receiving station over a transmission medium of a frame-based communications network is provided, the transmitting frame having a header segment and a payload segment, the header segment being transmitted using a fixed set of encoding parameters such that the header segment can be received and decoded by all stations on the network, the payload segment being transmitted using a variable set of payload encoding parameters, the transmitting station sending the transmitting frame using one set of the variable set of payload encoding parameters at a time. The receiving station receives and decodes the header and payload segments of each transmitting frame. The decoding includes computing frame statistics. A plurality of sets from the variable set of payload encoding parameters are selected to form a possible set of payload encoding parameters. For each set of payload encoding parameters in the possible set of payload encoding parameters an estimate of network performance characteristics expected if the transmitting station were to transmit the transmitting frame using that set of payload encoding parameters is generated based upon the frame statistics. A set of payload encoding parameters having optimized network performance characteristics is selected based upon the estimates of expected network performance for each set of payload encoding parameters in the possible set of payload encoding parameters.
摘要:
A method for selecting frame encoding parameters to improve transmission performance for a transmitting frame being transmitted from a transmitting station to a receiving station over a transmission medium of a frame-based communications network, the transmitting frame having a header segment and a payload segment, the header segment being transmitted using a fixed set of encoding parameters such that the header segment can be received and decoded by all stations on the network, the payload segment being transmitted using a variable set of payload encoding parameters, the transmitting station sending the transmitting frame using one set of the variable set of payload encoding parameters at a time. The receiving station receives and decodes the header and payload segments of each transmitting frame. The decoding includes computing frame statistics. A plurality of sets are selected from the variable set of payload encoding parameters to form a possible set of payload encoding parameters. For each set of payload encoding parameters in the possible set of payload encoding parameters, an estimate of network performance characteristics expected if the transmitting station were to transmit the transmitting frame using that set of payload encoding parameters is generated based upon the frame statistics. A set of payload encoding parameters having optimized network performance characteristics is selected based upon estimates of expected network performance for each set of payload encoding parameters in the possible set of payload encoding parameters. The frame statistics include a slicer maximum squared error for the header segment and a slicer maximum squared error for the payload segment.