Method for selecting frame encoding parameters in a frame-based communications network

• US 20020080886A1
• Filed: 04/04/2001
• Published: 06/27/2002
• Est. Priority Date: 04/07/2000
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: Trachewsky, Jason Alexander, Ojard, Eric, Ptasinski, Henry S., Bagchi, Amit G.
• Granted Patent: US 6,988,236 B2
• Time in Patent Office: Days
• US Class Current: 375/295
• CPC Class Codes: H04L 1/0003 by switching between different modulation schemes
• CPC Class Codes: H04L 1/0005 applied to payload information
• CPC Class Codes: H04L 1/0006 by adapting the transmission format
• CPC Class Codes: H04L 1/0009 by adapting the channel coding H04L1/1812 takes precedence
• CPC Class Codes: H04L 1/0025 Transmission of mode-switching indication
• CPC Class Codes: H04L 1/0061 Error detection codes
• CPC Class Codes: H04L 1/0072 Error control for data other than payload data, e.g. control data
• CPC Class Codes: H04L 1/08 by repeating transmission, e.g. Verdan system H04L1/1858 and H04L1/189 take precedence
• CPC Class Codes: H04L 1/18 Automatic repetition systems, e.g. Van Duuren systems
• CPC Class Codes: H04L 1/1809 Selective-repeat protocols
• CPC Class Codes: H04L 1/1848 Time-out mechanisms
• CPC Class Codes: H04L 1/1877 for semi-reliable protocols, e.g. for less sensitive applications like streaming video buffer level management for video bitstream control arrangements H04N21/44004
• CPC Class Codes: H04L 1/1883 using multiple timers
• CPC Class Codes: H04L 1/1887 Scheduling and prioritising arrangements
• CPC Class Codes: H04L 1/20 using signal quality detector
• CPC Class Codes: H04L 12/40032 Details regarding a bus interface enhancer
• CPC Class Codes: H04L 12/4013 Management of data rate on the bus systems modifying transmission characteristics according to link quality H04L1/0001
• CPC Class Codes: H04L 12/40136 Nodes adapting their rate to the physical link properties LAN switches H04L49/351
• CPC Class Codes: H04L 12/40156 by using dedicated slots associated with a priority level
• CPC Class Codes: H04L 12/40163 by assigning priority to messages according to a message field
• CPC Class Codes: H04L 12/403 : with centralised control, e.g. polling
• CPC Class Codes: H04L 12/4035 : in which slots of a TDMA packet structure are assigned based on a contention resolution carried out at a master unit TDM/TDMA multiplex systems per se H04J3/1694; hybrid switching systems H04L12/64
• CPC Class Codes: H04L 12/407 : with decentralised control
• CPC Class Codes: H04L 12/413 : with random access, e.g. carrier-sense multiple-access with collision detection [CSMA-CD]
• CPC Class Codes: H04L 12/417 : with deterministic access, e.g. token passing
• CPC Class Codes: H04L 2001/0093 : Point-to-multipoint
• CPC Class Codes: H04L 2001/125 : Arrangements for preventing errors in the return channel
• CPC Class Codes: H04M 11/00 : Telephonic communication systems specially adapted for combination with other electrical systems
• CPC Class Codes: H04M 11/06 : Simultaneous speech and data transmission, e.g. telegraphic transmission over the same conductors
• CPC Class Codes: Y02D 30/50 : in wire-line communication networks, e.g. low power modes or reduced link rate

Abstract

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.

Claims

1. 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, comprising the receiving station:

receiving and decoding the header and payload segments of each transmitting frame, the decoding including computing frame statistics;

selecting a plurality of sets 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, generating, based upon the frame statistics, an estimate of network performance characteristics expected if the transmitting station were to transmit the transmitting frame using that set of payload encoding parameters;

selecting, based upon the estimates of expected network performance for each set of payload encoding parameters in the possible set of payload encoding parameters, a set of payload encoding parameters having optimized network performance characteristics.

2. The method of claim 1, wherein the frame statistics include a slicer sum of squared error for the header segment and a slicer sum of squared error for the payload segment.

3. The method of claim 1, wherein the frame statistics include error indicators for the header segment and the payload segment.

4. The method of claim 1, wherein the frame statistics include an indication of the one set of the variable set of payload encoding parameters used.

5. The method of claim 1, wherein the expected network performance characteristic estimates include an estimate of system throughput and an estimate of packet error rate.

6. The method of claim 1, wherein generating an estimate includes calculating a weighted average of the frame statistics for a predetermined number of received frames.

7. The method of claim 6, wherein calculating a weighted average includes applying a weighting function based upon number of symbols in a received frame, order of frame reception, and time of frame reception.

8. The method of claim 1, wherein:

the expected network performance characteristic estimate includes a product of symbol rate and bits per symbol, and

the optimized network performance characteristic estimate includes a maximum product of symbol rate and bits per symbol and an estimated packet error rate at or below a predetermined packet error rate.

9. The method of claim 8, wherein the estimated packet error rate is generated by:

computing a mean square error estimate as a weighted average of a slicer sum of squared error for the header segment and a slicer sum of squared error for the payload segment;

resealing the mean squared error for a symbol rate of interest to provide a rescaled error; and

comparing the rescaled error to a threshold for a symbol constellation of interest.

10. The method of claim 9, wherein the threshold is weighted by results of previous threshold comparisons.