Data link layer protocol for transport of ATM cells over a wireless link
AssigneeLucent Technologies Inc.
InventorEnder Ayanoglu
Life of this patent
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Abstract
The present invention is a reliable data link layer protocol to transport ATM cells over a wireless point-to-point link. The protocol ensures that the cells are transported reliably by use of a sliding window transport mechanism with selective repeat automatic repeat request (ARQ) and forward error correction (FEC). The protocol minimizes ATM header overhead by means of header compression and provides per-cell FEC whose size can be changed adaptively. The protocol also provides parity cells for recovery from errors that cannot be corrected using the per-cell FEC field. The number of these cells as well as the size of a window or frame can also be adaptively changed. In addition, the window can be terminated to request an immediate acknowledgment.
Claims27
A data format for use in transmitting ATM cells in a communications network, wherein said communications network includes wireless mobile devices, said wireless mobile devices having memory for storing and processing said ATM cells using said data format, said data format comprising:
- a variable length message frame including one or more individual messages, said message frame including,
- at least one beginning-of-frame (BOF) message indicative of the beginning of said message frame;
- at least one information message, said information message including user information pertaining to a connection in said network;
- and
- at least one parity message selectively inserted in said message frame when error recovery is required, said at least one parity message including parity information in regard to said message frame, wherein said BOF message includes one or more fields including values indicative of a number of said individual messages in said message frame.
A data protocol for use in transmitting ATM cells in a communications network, wherein said communications network includes portable base station (PBS) switches configurable into an ad-hoc backbone network, said PBS switches adapted to communicate with wireless mobile devices, said PBS switches and said wireless mobile devices having memory for storing and processing said ATM cells using said data protocol, said data protocol comprising:
- a variably sized message window, said message window including,
- at least one control message including processing information regarding said message window, wherein variable combinations of control, information and parity messages are selectively inserted within said message window based on service requirements, and wherein specific ones of said control messages are indicative of the size of said message window.
A method for transmitting ATM cells in a communications network, wherein said communications network includes portable base station (PBS) switches configurable into an ad-hoc backbone network, said PBS switches adapted to communicate with wireless mobile devices, said method comprising the steps of:
- assembling a variable length message frame including one or more individual messages for transmission within said network;
- transmitting at least one beginning-of-frame (BOF) message indicative of the beginning of said message frame;
- transmitting at least one information message, said information message including user information pertaining to a connection in said network;
- and
- selectively inserting at least one acknowledgment (ACK) message in said message frame to thereby acknowledge receipt of previously transmitted information messages, and wherein said BOF message includes one or more fields including values indicative of a number of said individual messages in said message frame.
Dependencies are inferred from the claim text.