Methods and apparatus for operating a wireless communications system

A method of operating a network station for use in a wireless communications system comprising at least the network station and a plurality of subscriber stations, the method comprising

• receiving and decoding codes transmitted respectively by each of a number of the subscriber stations as part of a network access procedure, each subscriber station having selected a time slot from a plurality of predefined time slots in which to transmit its code;
• broadcasting a preliminary decoding status report to the subscriber stations, the preliminary decoding status report comprising a plurality of preliminary decoding status indicators associated with respective time slots, each preliminary decoding status indicator comprising either a positive indicator indicating that one, some or all of the codes received in the respective time slot were decoded successfully, or a negative indicator indicating that none of the codes received in the respective time slot were decoded successfully, the network station associating each positive indicator with a respective detailed decoding status report;
• and
• broadcasting to the subscriber stations the respective detailed decoding status report associated with each time slot in which one or more codes were decoded successfully, each detailed decoding status report identifying each code that was decoded successfully amongst the codes received by the network station in the time slot with which the detailed decoding status report is associated.

A method of operating a subscriber station for use in a wireless communications system comprising at least one network station and a plurality of the subscriber stations, the method comprising

• as part of a network access procedure, selecting a time slot from a plurality of predefined time slots and transmitting an individual code to the network station in the selected time slot;
• receiving a preliminary decoding status report from the network station, the preliminary decoding status report comprising a plurality of preliminary decoding status indicators associated with respective time slots, each preliminary decoding status indicator comprising either a positive indicator indicating that one, some or all of the codes received in the respective time slot were decoded successfully, or a negative indicator indicating that none of the codes received in the respective time slot were decoded successfully, each positive indicator being associated with a respective detailed decoding status report;
• receiving from the network station any detailed decoding status reports associated with respective time slots in which one or more codes were decoded successfully, each detailed decoding status report identifying each code that was decoded successfully amongst the codes received by the network station in the time slot with which the detailed decoding status report is associated;
• and
• identifying successful decoding only if the preliminary decoding status indicator associated with the time slot in which subscriber station transmitted its code comprises a positive indicator, and if the detailed decoding status report associated with that positive indicator identifies the code transmitted by the subscriber station.

Apparatus for a network station for use in a wireless communications system comprising at least the network station and a plurality of subscriber stations, the apparatus comprising

• preliminary decoding status circuitry configured to prepare a preliminary decoding status report comprising a plurality of preliminary decoding status indicators associated with respective time slots, each preliminary decoding status indicator comprising either a positive indicator indicating that one, some or all of the codes received in the respective time slot were decoded successfully, or a negative indicator indicating that none of the codes received in the respective time slot were decoded successfully, the preliminary decoding status circuitry being configured to associate each positive indicator with a respective detailed decoding status report;
• and
• detailed decoding status circuitry configured to obtain data identifying one or more codes which have decoded successfully by decoding circuitry of the network station, the codes having been transmitted to the network station respectively by each of a number of the subscriber stations as part of a network access procedure, each subscriber station having selected a time slot from a plurality of predefined time slots in which to transmit its code;
• wherein
• the detailed decoding status circuitry is configured to prepare a respective detailed decoding status report associated with each time slot in which one or more codes were decoded successfully, each detailed decoding status report identifying each code that was decoded successfully amongst the codes received by the network station in the time slot with which the detailed decoding status report is associated, the detailed decoding status reports being for broadcast to the subscriber stations.

Apparatus for a subscriber station for use in a wireless communications system comprising at least one network station and a plurality of the subscriber stations, the apparatus comprising

• network access circuitry configured to obtain information identifying a time slot selected from a plurality of predefined time slots and an individual code transmitted from the subscriber station to the network station in the selected time slot as part of a network access procedure;
• the network access circuitry being configured to receive a preliminary decoding status report from the network station, the preliminary decoding status report comprising a plurality of preliminary decoding status indicators associated with respective time slots, each preliminary decoding status indicator comprising either a positive indicator indicating that one, some or all of the codes received in the respective time slot were decoded successfully, or a negative indicator indicating that none of the codes received in the respective time slot were decoded successfully, each positive indicator being associated with a respective detailed decoding status report;
• and
• wherein the network access circuitry is configured to receive from the network station any detailed decoding status reports associated with respective time slots in which one or more codes were decoded successfully, each detailed decoding status report identifying each code that was decoded successfully amongst the codes received by the network station in the time slot with which the detailed decoding status report is associated;
• and
• the network access circuitry being configured to identify successful decoding only if the preliminary decoding status indicator associated with the time slot in which subscriber station transmitted its code comprises a positive indicator, and if the detailed decoding status report associated with that positive indicator identifies the code transmitted by the subscriber station.