Method and apparatus for detecting and recovering from errors occurring in a transmission of digital information

• US 5,958,080 A
• Filed: 05/12/1997
• Issued: 09/28/1999
• Est. Priority Date: 05/10/1996
• Status: Expired due to Term

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Kang, Sung-Min
• Primary Examiner(s): Chung, Phung M.
• Application Number:
  US08/854,722
• Time in Patent Office: 869 Days
• Field of Search: 371/53, 371/54, 371/48, 714/807, 714/799, 714/808
• US Class Current: 714/807
• CPC Class Codes: H03M 13/00 Coding, decoding or code conversion, for error detection or error correction; Coding theory basic assumptions; Coding bounds; Error probability evaluation methods; Channel models; Simulation or testing of codes error detection or error correction for analogue/digital, digital/analogue or code conversion H03M1/00 – H03M11/00; specially adapted for digital computers G06F11/08; for information storage based on relative movement between record carrier and transducer G11B, e.g. G11B20/18; for static stores G11C
• CPC Class Codes: H04L 1/0078 Avoidance of errors by organising the transmitted data in a format specifically designed to deal with errors, e.g. location forward error control, e.g. FEC, CRC H04L1/004; adaptive formatting H04L1/0006; mappings H04L27/00
• CPC Class Codes: H04L 1/1809 Selective-repeat protocols

Abstract

A method of detecting errors and losses in transmitting digital information from a sending unit to a receiving unit, including the steps of: receiving header information indicating the transmission size from the sending unit at an early stage of the transmission process; counting the number of pieces of information transmitted while receiving the information; and comparing the result of the counting step with the size indicated in the header information. In one embodiment of the invention, the method is adapted for use with transmissions of information from an upper processor to a lower processor in a digital cellular system base station.

Claims

1. A method of transmitting digital information, comprising the steps of:

receiving from a sending unit at a receiving unit header information during an early stage of transmission for digital information, said header information including a physical quantity representing an amount of said digital information, with said header information indicating a size value representing a size of said amount of said digital information;

accumulating a measure of a first quantity of information of said digital information received at said receiving unit during a later stage of said transmission, wherein said first quantity of information of said digital information includes first pieces of information, and said measure of said first quantity of information of said digital information is a count of said first pieces of information;

detecting occurrence of losses in said later stage of said transmission by comparing said size value to said measure of said first quantity of information of said digital information; and

indicating that a second quantity of information of said digital information was lost during said later stage of said transmission whenever said size value does not correspond to said measure of said first quantity of information of said digital information, wherein said second quantity of information of said digital information corresponds to second pieces of information included in said amount of digital information, and said size value corresponds to said count of said first pieces of information when said size value equals said count of said first pieces of information.

2. The method of claim 1, wherein

a set including said first pieces of information and said second pieces of information has a cardinal number, and said size value represents said cardinal number.

3. The method of claim 2, further comprising the step of retransmitting at least a portion of said amount of said digital information when said size value exceeds said count of said first pieces of information.

4. The method of claim 3, further comprising the step of determining whether said size value exceeds said count of said first pieces of information by a predetermined value when said size value does not equal said count of said first pieces of information.

5. The method of claim 4, wherein said step of retransmitting includes:

retransmitting an entirety of said amount of said digital information when said size value exceeds said count of said first pieces of information by at least said predetermined value; and

retransmitting information corresponding to said second pieces of information when said size value does not exceed said count of said first pieces of information by at least said predetermined value.

6. The method of claim 5, wherein each one of said first pieces of information and said second pieces of information includes a sequence number, each said sequence number indicating a respective position of a corresponding one of said first pieces of information and said second pieces of information in said amount of said digital information, and further comprising the steps of:

initializing a signal check table at a storage location in communication with said receiving unit and said signal check table having a table position corresponding to each said sequence number;

marking one said table position corresponding to one said sequence number when each one of said first pieces of information is received to indicate that a corresponding one of said first pieces of information was received; and

determining said count of said first pieces of information by checking said signal check table after all of said amount of said digital information has been transmitted.

7. The method of claim 6, wherein said predetermined value is not greater than 200.

8. The method of claim 2, wherein each one of said first pieces of information and said second pieces of information includes a sequence number, each said sequence number indicating a respective position of a corresponding one of said first pieces of information and said second pieces of information in said amount of said digital information, and further comprising the steps of:

initializing a signal check table at a storage location in communication with said receiving unit and said signal check table having a table position corresponding to each said sequence number;

marking one said table position corresponding to one said sequence number when each one of said first pieces of information is received to indicate that a corresponding one of said first pieces of information was received; and

determining said count of said first pieces of information by checking said signal check table after all of said amount of said digital information has been transmitted.

9. The method of claim 2, further comprising an error determining step of determining whether at least one of said first pieces of information contains error.

10. The method of claim 9, wherein:

said header information includes a total checksum corresponding to said set,

each one of said first pieces of information and said second pieces of information includes a correspond piece checksum, and said error determining step includes;

computing a computed checksum by summing each said piece checksum included in said first pieces of information,

comparing said computed checksum with said total checksum, and

indicating that at least one of said first pieces of information contains error when said computed checksum does not equal said total checksum.

11. The method of claim 10, further comprising the step of retransmitting an entirety of said amount of said digital information when said error determining step indicates that at least one of said first pieces of information contains error.

12. The method of claim 9, further comprising the step of retransmitting an entirety of said amount of said digital information when said error determining step indicates that at least one of said first pieces of information contains error.

13. The method of claim 3, wherein each one of said first pieces of information and said second pieces of information includes a sequence number, each said sequence number indicating a respective position of a corresponding one of said first pieces of information and said second pieces of information in said amount of said digital information, and further comprising the steps of:

initializing a signal check table at a storage location in communication with said receiving unit and said signal check table having a table position corresponding to each said sequence number;

marking one said table position corresponding to one said sequence number when each one of said first pieces of information is received to indicate that a corresponding one of said first pieces of information was received; and

determining said count of said first pieces of information by checking said signal check table after all of said amount of said digital information has been transmitted.

14. The method of claim 3, further comprising an error determining step of determining whether at least one of said first pieces of information contains error.

15. The method of claim 14, wherein:

said header information includes a total checksum corresponding to said set,

each one of said first pieces of information and said second pieces of information includes a corresponding piece checksum, and

said error determining step includes;

computing a computed checksum by summing each said piece checksum included in said first pieces of information,

comparing said computed checksum with said total checksum, and

indicating that at least one of said first pieces of information contains error when said computed checksum does not equal said total checksum.

16. The method of claim 15, further comprising the step of retransmitting an entirety of said amount of said digital information when said error determining step indicates that at least one of said first pieces of information contains error.

17. The method of claim 14, further comprising the step of retransmitting an entirety of said amount of said digital information when said error determining step indicates that at least one of said first pieces of information contains error.

18. The method of claim 4, wherein each one of said first pieces of information and said second pieces of information includes a sequence number, each said sequence number indicating a respective position of a corresponding one of said first pieces of information and said second pieces of information in said amount of a digital information, and further comprising the steps of:

initializing a signal check table at a storage location in communication with said receiving unit and said signal check table having a table position corresponding to each said sequence number;

marking o said table position corresponding to one said sequence number when each one of said first pieces of information is received to indicate that a corresponding one of said first pieces of information was received; and

determining said count of said first pieces of information by checking said signal check table after all of said amount of said digital information has been transmitted.

19. The method of claim 18, wherein said predetermined value is not greater than 200.

20. The method of claim 18, wherein said predetermined value is p such that 25≦

p≦

75.

21. The method of claim 4, wherein said predetermined value is not greater than 200.

22. The method of claim 4, wherein said predetermined value is p such that 25≦

p≦

75.

23. The method of claim 5, wherein said predetermined value is not greater than 200.

24. The method of claim 5, wherein said predetermined value is p such that 25≦

p≦

75.

25. The method of claim 5, further comprising an error determining step of determining whether at least one of said first pieces of information contains error.

26. The method of claim 25, wherein:

said header information includes a total checksum corresponding to said set,

each one of said first pieces of information and said second pieces of information includes a corresponding piece checksum, and

said error determining step includes;

computing a computed checksum by summing each said piece checksum included in said first pieces of information,

comparing said computed checksum with said total checksum, and

indicating that at least one of said first pieces of information contains error when said computed checksum does not equal said total checksum.

27. The method of claim 26, further comprising the step of retransmitting said entirety of said amount of said digital information when said error determining step indicates that at least one of said first pieces of information contains error.

28. The method of claim 25, further comprising the step of retransmitting said entirety of said amount of said digital information when said error determining step indicates that at least one of said first pieces of information contains error.

29. The method of claim 6, wherein said predetermined value is p such that 25≦

p≦

75.

30. The method of claim 6, further comprising an error determining step of determining whether at least one of said first pieces of information contains error.

31. The method of claim 30, wherein;

said header information includes a total checksum corresponding to said set,

each one of said first pieces of information and said second pieces of information includes a corresponding piece checksum, and

said error determining step includes;

computing a computed checksum by summing each said piece checksum included in said first pieces of information,

comparing said computed checksum with said total checksum, and

indicating that at least one of said first pieces of information contains error when said computed checksum does not equal said total checksum.

32. The method of claim 31, further comprising the step of retransmitting said entirety of said amount of said digital information when said error determining step indicates that at least one of said first pieces of information contains error.

33. The method of claim 30, further comprising the step of retransmitting said entirety of said amount of said digital information when said error determining step indicates that at least one of said first pieces of information contains error.

34. The method of claim 1, further comprising the step of retransmitting at least a portion of said amount of said digital information when said size value does not correspond to said measure of said first quantity of information of said digital information.

35. The method of claim 1, further comprising the step of retransmitting at least a portion of said amount of said digital information when said size value does not correspond to said count of said first pieces of information.

36. The method of claim 1, further comprising an error determining step of determining whether at least one of said first pieces of information contains error.

37. The method of claim 36, further comprising the step of retransmitting an entirety of said amount of said digital information when said error determining step indicates that at least one of said first pieces of information contains error.

38. An information transmitting device, comprising:

a receiving unit including an information receiver for receiving header information from a sending unit during an early stage of a transmission for digital information, said header information including a first physical quantity representing an amount of said digital information to be transmitted from said sending unit to said receiving unit, with said header information indicating a size value representing a size of said amount of said digital information;

an accumulator for accumulating first signals representative of a measure of a first quantity of information of said digital information received during a later stage of said transmission, wherein said first quantity of information of said digital information includes first pieces of information, and said measure of said first quantity of information of said digital information is a count of said first pieces of information;

a detector for detecting losses in said digital information in said later stage of said transmission by comparing said size value to said measure of said first quantity of information of said digital information; and

an indicator for indicating that a second quantity of information of said digital information was lost during said later stage of said transmission whenever said size value does not correspond to said measure of said first quantity of information of said digital information, wherein said second quantity of information of said digital information corresponds to second pieces of information included in said amount of said digital information, and said size value corresponds to said count of said first pieces of information when said size value equals said count of said first pieces of information.

39. The information transmitting device of claim 38, further comprising:

a retransmitter for retransmitting a second physical quantity representing at least a portion of said amount of said digital information when said size value does not correspond to said measure of said first quantity of information of said digital information.

40. The information transmitting device of claim 39, wherein:

a set including said first pieces of information and said second pieces of information has a cardinal number, and said size value represents said cardinal number.

41. The information transmitting device of claim 40, further comprising:

a discriminator, coupled to said retransmitter, for receiving said size value and said count of said first pieces of information and for generating second signals indicating whether said size value exceeds said count of said first pieces of information by at least a predetermined value; and

wherein said retransmitter retransmits said second physical quantity in response to said second signals, and wherein said second physical quantity represents an entirety of said amount of said digital information when said second signals indicate that said size value exceeds said count of said first pieces of information by at least said predetermined value, and wherein said second physical quantity represents information corresponding to said second pieces of information when said second signals indicate that said size value does not exceed said count of said first pieces of information by at least said predetermined value.

42. The information transmitting device of claim 41, wherein each one of said first pieces of information and said second pieces of information includes a sequence number, each said sequence number indicating a respective position of a corresponding one of said first pieces of information and said second pieces of information in said amount of said digital information, and further comprising:

a storage element, in communication with said receiving unit, for storing a signal check table having a table position corresponding to each said sequence number;

a marker for storing a marker character in one said table position corresponding to one said sequence number when each one of said first pieces of information is received, whereby said signal check table indicates that a corresponding one of said first pieces of information was received; and

a reader for determining said count of said first pieces of information by reading said signal check table after all of said amount of said digital information has been transmitted and for accumulating digits to indicate said count of said first pieces of information.

43. A method of detecting errors in loading information from an upper processor in a digital cellular system base station, comprising the steps of:

receiving header information, said header information including a size value representing a size of an amount of digital information of a transmission for said digital information at an early stage of loading said transmission for said digital information;

counting a number of information pieces of said digital information received from said transmission for said digital information while loading said information pieces of said digital information to provide a count of said number of information pieces of said digital information received;

ad

comparing said size value with a result of said step of counting, wherein said size value corresponds to said count of said number of information pieces of said digital information received when said size value equals said count of said number of information pieces of said digital information received.

44. The method of claim 43, further comprising the steps of:

determining, in accordance with an outcome of said step of comparing, whether at least one missed piece of said digital information was not received from said transmission for said digital information during loading of said digital information; and

retransmitting at least a portion of said digital information when a loss occurred during loading of said digital information.

45. The method of claim 44, wherein said step of retransmitting includes:

determining whether a cardinal number of a set including said at least one missed piece of said digital information exceeds at least a predetermined value,

retransmitting an entirety of said digital information when said cardinal number exceeds said predetermined value, and

retransmitting information corresponding to said at least one missed piece of said digital information when said cardinal number does not exceed said predetermined value.

46. A method of detecting errors in loading information, comprising the steps of:

dividing into pieces of a predetermined size information loaded from an upper processor in a digital cellular system base station;

including in each one of said pieces a piece checksum;

transmitting said pieces from said upper processor to a lower processor;

determining a total checksum by summing each said piece checksum;

including said total checksum in a final piece transmitted to said lower processor;

determining a computed checksum by summing each said piece checksum included in said pieces received by said lower processor; and

comparing said computed checksum with said total checksum.

47. The method of claim 46, further comprising the step of retransmitting an entirey of said information when said computed checksum does not equal said total checksum.

48. A method of detecting errors occurring in transmission of digital information, comprising the steps of:

receiving header information during an early stage of loading information from an upper processor in a digital cellular system base station, with said information is divided into a plurality of packets, said header information indicating a sent packet count corresponding to a cardinal number of said plurality of packets;

determining for each packet of said plurality of packets a packet checksum;

including in each packet of said plurality of packets a corresponding said packet checksum and a packet sequence number corresponding to a position of a respective packet of said plurality of packets in said information;

determining a total checksum by summing each said packet checksum;

transmitting said plurality of packets to a lower processor;

marking, for each packet of said plurality of packets received by said lower processor, a table position in a signal check table, with said table position corresponding to said packet sequence number respectively included in each packet of said plurality of packets received;

determining a computed checksum by summing each said packet checksum respective included in each packet of said plurality of packets received by said lower processor;

determining from said signal check table a received packet count;

comparing said received packet count with said sent packet count;

retransmitting at least a portion of said plurality of packets when said received packet count does not equal said sent packet count;

comparing said computed checksum with said total checksum; and

retransmitting an entirety of said plurality of packets when said computed checksum does not equal said total checksum.

49. The method of claim 48, wherein said step of retransmitting when said received packet count does not equal said sent packet count includes;

retransmitting said entirety of said plurality of packets when said sent packet count exceeds said received packet count by at least a predetermined value, and

retransmitting each packet of said plurality of packets not received by said lower processor when said sent packet count does not exceed said received packet count by at least said predetermined value.