Error correction in packet-based communication networks using data consistency checks
Bit errors in packets of data that are communicated in a network such as a wireless network can be corrected by processes that do not require any overhead in the data such as conventional error-detection codes or redundant information such as conventional error-correction codes. A validation-set process compares corrupted data against values in a set of known valid values and selects one of the known valid values to replace the corrupted data. A consistency-check process uses data correlation characteristics of two or more parameters to determine if values obtained from a packet are consistent with one another. If not, values are changed to make them consistent.
1. A method for correcting errors in data conveyed by a communications network comprising one or more transmitters and one or more receivers, wherein the method comprises:
receiving one or more packets of data each including data representing a plurality of parameters;
checking consistency of data representing two or more specified parameters that are included in the one or more packets of data using correlation characteristics of the two or more specified parameters, wherein the consistency is checked using a process that is independent of error-correction codes, and wherein the specified parameters are communication control parameters or application parameters;
if the check indicates the data are not consistent, selecting a parameter from the two or more specified parameters that is represented by data having the highest probability of corruption according to an error model that describes probabilities of data corruption in packets of data during transmission of the packets; and
modifying the data representing the selected parameter such that the data representing the two or more specified parameters are consistent according to the check.
2. The method of claim 1 , wherein the correlation characteristics are reflected in a set of distinctive patterns of values for a plurality of the specified parameters and a set of corresponding values for the selected parameter.
3. The method of claim 2 , wherein
each transmitter and each receiver has a network address;
the two or more specified parameters include the network address of a source of the one or more packets of data, the network address of a designated transmitter for the one or more packets of data, the network address of a designated receiver for the one or more packets of data, and a direction flag indicating whether the one or more packets of data are destined to the designated receiver or the designated transmitter; and
the direction flag is the selected parameter.
4. The method of claim 1 , wherein:
the one or more packets of data each include error detection information;
the method comprises using the error detection information to determine if a respective packet of data has errors; and
the steps of applying the consistency check, selecting the parameter and modifying the data are performed if the respective packet of data is corrupted.
5. A storage medium recording a program of instructions that is executable by a device to perform a method for correcting errors in data conveyed by a communications network comprising one or more transmitters and one or more receivers, wherein the method comprises:
receiving one or more packets of data each including data representing a plurality of parameters;
checking consistency of data representing two or more specified parameters that are included in the one or more packets of data using correlation characteristics of the two or more specified parameters, wherein the consistency is checked using a process that is independent of error-correction codes, and wherein the specified parameters are communication control parameters or application parameters;
if the check indicates the data are not consistent, selecting a parameter from the two or more specified parameters that is represented by data having the highest probability of corruption according to an error model that describes probabilities of data corruption in packets of data during transmission of the packets; and
modifying the data representing the selected parameter such that the data representing the two or more specified parameters are consistent according to the check.
6. The medium of claim 5 , wherein the correlation characteristics are reflected in a set of distinctive patterns of values for a plurality of the specified parameters and a set of corresponding values for the selected parameter.
7. The medium of claim 6 , wherein
each transmitter and each receiver has a network address;
the two or more specified parameters include the network address of a source of the one or more packets of data, the network address of a designated transmitter for the one or more packets of data, the network address of a designated receiver for the one or more packets of data, and a direction flag indicating whether the one or more packets of data are destined to the designated receiver or the designated transmitter; and
the direction flag is the selected parameter.
8. The medium of claim 5 , wherein:
the one or more packets of data each include error detection information;
the method comprises using the error detection information to determine if a respective packet of data has errors; and
the steps of applying the consistency check, selecting the parameter and modifying the data are performed if the respective packet of data is corrupted.
9. An apparatus for correcting errors in data conveyed by a communications network comprising one or more transmitters and one or more receivers, wherein the apparatus comprises:
means for receiving one or more packets of data each including data representing a plurality of parameters;
means for checking consistency of data representing two or more specified parameters that are included in the one or more packets of data using correlation characteristics of the two or more specified parameters, wherein the consistency is checked using a process that is independent of error-correction codes, and wherein the specified parameters are communication control parameters or application parameters;
means for selecting a parameter from the two or more specified parameters that is represented by data having the highest probability of corruption according to an error model that describes probabilities of data corruption in packets of data during transmission of the packets, wherein the means for selecting performs its functions if the check indicates the data are not consistent; and
means for modifying the data representing the selected parameter such that the data representing the two or more specified parameters are consistent according to the check.
10. The apparatus of claim 9 , wherein the correlation characteristics are reflected in a set of distinctive patterns of values for a plurality of the specified parameters and a set of corresponding values for the selected parameter.
11. The apparatus of claim 10 , wherein
each transmitter and each receiver has a network address;
the two or more specified parameters include the network address of a source of the one or more packets of data, the network address of a designated transmitter for the one or more packets of data, the network address of a designated receiver for the one or more packets of data, and a direction flag indicating whether the one or more packets of data are destined to the designated receiver or the designated transmitter; and
the direction flag is the selected parameter.
12. The apparatus of claim 9 , wherein:
the one or more packets of data each include error detection information;
the apparatus comprises means for using the error detection information to determine if a respective packet of data has errors; and
the means for applying the consistency check, selecting the parameter and modifying the data are performed performs its functions if the respective packet of data is corrupted.