Data packet fragmentation in a wireless communication system

• US 20070086484A1
• Filed: 10/11/2006
• Published: 04/19/2007
• Est. Priority Date: 10/30/1998
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: Chen, Feng, Denney, Lisa, Samueli, Henry, Lu, Fang, Jones, Christopher, Quigley, Thomas, Min, Jonathan, Nazareth, Sean
• Granted Patent: US 7,512,154 B2
• Time in Patent Office: Days
• US Class Current: 370/468
• CPC Class Codes: H04B 1/1027 assessing signal quality or detecting noise/interference for the received signal
• CPC Class Codes: H04B 1/1036 with automatic suppression of narrow band noise or interference, e.g. by using tuneable notch filters H04B1/123 takes precedence; filter circuits H03H
• CPC Class Codes: H04J 3/0655 using timestamps
• CPC Class Codes: H04J 3/0682 by delay compensation, e.g. by compensation of propagation delay or variations thereof, by ranging
• CPC Class Codes: H04L 1/0003 by switching between different modulation schemes
• CPC Class Codes: H04L 1/0009 by adapting the channel coding H04L1/1812 takes precedence
• CPC Class Codes: H04L 1/0045 Arrangements at the receiver end
• CPC Class Codes: H04L 1/0061 Error detection codes
• CPC Class Codes: H04L 1/203 Details of error rate determination, e.g. BER, FER or WER
• CPC Class Codes: H04L 12/2801 Broadband local area networks
• CPC Class Codes: H04L 2025/03808 Transmission of equaliser coefficients
• CPC Class Codes: H04L 25/03019 adaptive, i.e. capable of adjustment during data reception
• CPC Class Codes: H04L 25/03057 with a recursive structure H04L25/03031 takes precedence
• CPC Class Codes: H04L 25/03343 Arrangements at the transmitter end
• CPC Class Codes: H04L 27/0014 Carrier regulation of chaotic carriers H04L27/001; for multicarrier receivers H04L27/2657
• CPC Class Codes: H04L 27/2601 Multicarrier modulation systems
• CPC Class Codes: H04L 27/34 Amplitude- and phase-modulated carrier systems, e.g. quadrature-amplitude modulated carrier systems
• CPC Class Codes: H04L 41/142 using statistical or mathematical methods
• CPC Class Codes: H04L 5/003 Arrangements for allocating sub-channels of the transmission path
• CPC Class Codes: H04L 5/1446 of transmission speed
• CPC Class Codes: H04W 72/542 : using measured or perceived quality
• CPC Class Codes: Y02D 30/50 : in wire-line communication networks, e.g. low power modes or reduced link rate

Abstract

A number of features for enhancing the performance of a wireless communication system, in which data is transmitted between a central node and a plurality of subscriber nodes located remotely with respect to the central node, are presented. The power transmission level, slot timing, and equalization of the subscriber nodes are set by a ranging process. Data is transmitted by the subscriber nodes in fragmented form. Various measures are taken to make transmission from the subscriber nodes robust. The uplink data transmission is controlled to permit multiple access from the subscriber nodes.

Claims

1. A system that processes data packets to be transmitted via an uplink data channel, comprising:

means for sending via the uplink channel a request for an amount of bandwidth to transmit a data packet;

means for receiving a grant of an amount of bandwidth and a transmission time period to transmit data;

means for comparing the requested amount of bandwidth with the granted amount of bandwidth;

means for transmitting the entire data packet via the uplink channel during the transmission time period if the requested amount is less than or equal to the granted amount;

means for fragmenting the data packet into a plurality of portions and for transmitting one portion of the plurality of portions via the uplink channel during the transmission time period if the requested amount is larger than the granted amount, the one portion being less than or equal to the granted amount.

2. The system of claim 1, further comprising:

means for determining a burdened PHY length from a given total length associated with the data packet to be transmitted based on a burden imposed by a transmission format associated with the uplink data channel;

wherein the sending means comprises means for sending via the uplink channel a request for an amount of bandwidth to transmit a data packet having the burdened PHY length.

3. The system of claim 2, wherein the receiving means comprises means for receiving a grant of an amount of bandwidth that includes the burdened PHY length.

4. The system of claim 1, additionally comprising:

means for sending via the uplink channel an additional request for an amount of bandwidth to transmit a remaining portion of the data packet if the requested amount is larger than the granted amount;

means for receiving an additional grant of an amount of bandwidth and an additional transmission time period to transmit data in response to the additional request;

means for comparing the amount of bandwidth of the additional request with the amount of bandwidth of the additional grant; and

means for transmitting the entire remaining portion of the data packet via the uplink channel during the additional transmission time period if the amount of bandwidth of the additional request is less than or equal to the amount of bandwidth of the additional grant.

5. The system of claim 4, further comprising:

means for fragmenting the remaining portion of the data packet into a plurality of additional portions if the amount of bandwidth of the additional request is larger than the amount of bandwidth of the additional grant; and

means for transmitting one of the plurality of additional portions via the uplink channel during the additional transmission time period if the amount of bandwidth of the additional request is larger than the amount of bandwidth of the additional grant;

wherein said one of the plurality of additional portions is less than or equal to the amount of bandwidth of the additional grant.

6. The system of claim 4, wherein the means for sending an additional request comprises means for transmitting the additional request together with the one portion in a piggyback fashion via the uplink channel.

7. The system of claim 6, wherein the means for transmitting the additional request together with the one portion in a piggyback fashion via the uplink channel comprises:

means for encapsulating the additional request and the one portion in a packet protocol data unit (PDU) having a header that signals the presence of the additional request.

8. The system of claim 1, wherein the means for receiving the grant comprises means for receiving the grant in one of a plurality of messages, the system further comprising:

means for checking pending messages for an additional grant or a grant pending after receiving the grant if the requested amount is larger than the granted amount; and

means for sending via the uplink channel an additional request for an amount of bandwidth to transmit a remaining portion of the data packet if the pending messages contain no additional grant or grant pending.

9. The system of claim 8, in which the means for sending an additional request comprises means for transmitting the additional request with the one portion in a piggyback fashion via the uplink channel.

10. The system of claim 9, wherein the means for transmitting the additional request with the one portion in a piggyback fashion via the uplink channel comprises:

means for encapsulating the additional request and the one portion in a packet protocol data unit (PDU) having a header that signals the presence of the additional request.

11. The system of claim 1, further comprising:

means for storing data packets to be transmitted via the uplink channel in a queue;

means for checking the queue for data packets to be transmitted if the requested amount is less than or equal to the granted amount; and

means responsive to an indication from the checking means that there is at least one data packet in the queue for sending via the upstream link an additional request for an amount of bandwidth and transmission time period to transmit a data packet in the queue.

12. The system of claim 11, in which the means for sending an additional request comprises means for transmitting the additional request with the one portion in a piggyback fashion via the uplink channel.

13. The system of claim 12, wherein the means for transmitting the additional request with the one portion in a piggyback fashion via the uplink channel comprises:

means for encapsulating the additional request and the one portion in a packet protocol data unit (PDU) having a header that signals the presence of the additional request.

14. The system of claim 1, additionally comprising:

means for receiving request acknowledgments;

means for setting a timer each time a request is sent; and

means for resending the request after the timer expires if no acknowledgment has been received.

15. The system of claim 14, additionally comprising:

means for repeating the steps of receiving request acknowledgements, setting a timer each time a request is sent, and resending the request after the timer expires if no acknowledgment has been received;

means for counting the number of times the request is resent; and

means for discarding the data packet without upstream transmission and terminating the repeating step if the request is resent a predetermined number of times.