Abstract: Message formats and apparatus are described that serve to reserve access to a communication medium in a multi-cast system. A first message, a multicast request-to-send message, includes a duration field having information representing the reserved time for a communication medium, a multicast receiver address field, a multicast transmitter address field, a field that identifies the number of slots for a clear-to-send response, and a field that identifies the number slots for a not-clear-to-send response. A second message includes a duration field, and a multicast receive address field. The second message has a format that can be used as one of a clear-to-send message in response to a multicast request-to-send message, a cancel-clear-to-send message that cancels a data transmission after the clear-to-send message is sent, and a not-clear-to-send message in response to the multicast request-to-send message.

Abstract: A signal and apparatus for receiving the signal are described wherein the signal includes a duration field, a multicast receiver address field, a transmitter address field, a block acknowledgment request control field, a block acknowledgment request information field and an information field. Also described are a signal and apparatus for transmitting the signal wherein the signal includes a duration field, a multicast receiver address field, a transmitter address field, a block acknowledgment control field and a block acknowledgment information field.

Abstract: A method and apparatus are described including multicasting a plurality of data units and multicasting a request for acknowledging receipt of the plurality of data units, receiving signals responsive to the request. Also described are a method and apparatus including receiving a multicast request to acknowledge receipt of data, determining if a response to the request is required, determining status of the data, preparing the response based on the determining acts and transmitting the response.

Abstract: A method and apparatus are described including multicasting a plurality of data units and multicasting a request for acknowledging receipt of the plurality of data units, receiving signals responsive to the request. Also described are a method and apparatus including receiving a multicast request to acknowledge receipt of data, determining if a response to the request is required, determining status of the data, preparing the response based on the determining acts and transmitting the response.

Abstract: Message formats and apparatus are described that reserve access to a communication medium in a multicast system. A first message, a multicast request-to-send message, includes a duration field having information representing the reserved time for a communication medium, multicast receiver and transmitter address fields, and bits that specifies a destination that is expected to reply to the multicast digital message. The bits that specify a destination can be extended to a plurality of fields that each contain different destination identifiers. Example destination identifiers include association identifiers or media access control addresses. Alternately, the bits that specify a destination can have a first field containing an offset and a second field indicating destinations with respect to the offset. A second message includes a duration field and multicast receiver and transmitter address fields. The second message is used to cancel a data transmission resulting from a multicast request-to-send message.

Abstract: A signal and apparatus for receiving the signal are described wherein the signal includes a duration field, a multi-cast receiver address field, a transmitter address field, a block acknowledgment request control field, a block acknowledgment request information field and an information field. Also described are a signal and apparatus for transmitting the signal wherein the signal includes a duration field, a multicast receiver address field, a transmitter address field, a block acknowledgment control field and a block acknowledgment information field.

Abstract: Message formats and apparatus are described that serve to reserve access to a communication medium in a multi-cast system. A first message, a multicast request-to-send message, includes a duration field having information representing the reserved time for a communication medium, a multicast receiver address field, a multicast transmitter address field, a field that identifies the number of slots for a clear-to-send response, and a field that identifies the number slots for a not-clear-to-send response. A second message includes a duration field, and a multicast receive address field. The second message has a format that can be used as one of a clear-to-send message in response to a multicast request-to-send message, a cancel-clear-to-send message that cancels a data transmission after the clear-to-send message is sent, and a not-clear-to-send message in response to the multicast request-to-send message.

Abstract: A method and apparatus are described including multicasting a medium reservation message and receiving a response to the medium reservation message. Also described are a method and apparatus including receiving a medium reservation message, determining if a medium is idle and transmitting a response to the medium reservation message responsive to the determination. Further described are a method and apparatus including receiving a medium reservation message, determining if a received network allocation vector in the medium reservation message has a value greater than a current network allocation vector, determining if transmission over a medium during a time interval is detected and resetting the current network allocation vector responsive to the determination of transmission.

Abstract: A method and apparatus are described including multicasting a medium reservation message, receiving responses to the medium reservation message and determining if a ratio of the received responses to an expected number of responses exceeds a threshold. Also described are a method and apparatus including receiving a medium reservation message, determining if the medium reservation message specifies this receiver in a list of receivers from which a response is requested, determining if a medium is idle and transmitting the response to the medium reservation message responsive to the second determination.