Method of repeat transmission of messages in a centrally controlled communication network

• US 6,983,409 B1
• Filed: 06/15/2000
• Issued: 01/03/2006
• Est. Priority Date: 06/17/1999
• Status: Expired due to Fees

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Vollmer, Vasco, Radimirsch, Markus
• Primary Examiner(s): Lamarre, Guy J.
• Application Number:
  US09/595,260
• Time in Patent Office: 2,028 Days
• Field of Search: 714748-749, 714/750, 455/524, 455/503, 455/517
• US Class Current: 714/748
• CPC Class Codes: H04L 1/1635 Cumulative acknowledgement, i.e. the acknowledgement message applying to all previous messages
• CPC Class Codes: H04L 1/1809 Selective-repeat protocols
• CPC Class Codes: H04L 2001/0093 Point-to-multipoint

Abstract

In a method for repeat transmission of messages in a centrally controlled communication network including a plurality of terminals and a central station messages assigned sequence numbers are broadcast or multicast from the central station for reception by terminals of a participating group. As soon as a terminal detects loss of a transmitted message or an error in the transmitted message, it transmits a repeat request for repeat transmission of that message, which includes the sequence number of the lost or erroneous message, over another communication link, especially a point-to-point communication link. The central station repeats the message transmission of the lost or erroneous message but only until a predetermined maximum number of repetitions occurs within a predetermined time interval or until a positive acknowledgement of receipt of the previously lost or erroneous message is received.

Claims

1. A method for repeat transmission of messages in a centrally controlled communication network, in which several terminals (T1, T2, . . . ) are simultaneously configured to operate, said method comprising:

a) transmitting each of said messages once from a central station (ZE) for reception by each of said terminals (T1, T2, . . . ) of a participating group of said terminals and assigning respective sequence numbers (SN) to corresponding messages for detection of message loss or message error;

b) as soon as one of said terminals (T1, T2, . . . ) has detected an error in or loss of one of the messages, said one of said terminals detecting said error or said loss issues a repeat request for said one of said messages over a communication link between the central station (ZE) and the terminal (T1, T2, . . . ) detecting said error or said loss, said repeat request including one of said sequence numbers (SN) identifying said one of said messages detected as lost or erroneous;

c) said central station (ZE) performs repeat transmissions of said one of said messages with said one of said sequence numbers (SN) in response to the repeat request, but only within a predetermined time interval;

d) halting said repeat transmissions of said one of said messages within said predetermined time interval when a predetermined maximum number of repeat transmission of said one of said messages has been reached within said predetermined time interval; and

e) halting said repeat transmissions of said one of said messages within said predetermined lime interval when a positive acknowledgement of receipt of said one of said messages is received by said central station during said predetermined time interval from said terminal issuing said repeat request;

whereby clogging of said communication network by said repeat transmissions is effectively prevented.

2. The method as defined in claim 1, wherein said centrally controlled communication network is a radio network and said communication link is a point-to-point link.

3. The method as defined in claim 1, wherein said maximum number of said repeat transmissions is determined by a length of said predetermined time interval and a length of said message.

4. The method as defined in claim 1, wherein said repeat transmissions are limited by said one of said terminals detecting said loss or said error.

5. The method as defined in claim 1, further comprising positively acknowledging each correctly received message or issuing a negative acknowledgment (NACK) of each lost or erroneous message in order to inform said central station (ZE) whether or not message repetition is necessary.

6. The method as defined in claim 1, further comprising erasing or not using said one of said messages received by at least one other of said terminals of said participating group if said one of said messages was previously correctly received by said at least one other of said terminals.

7. The method as defined in claim 1, wherein only one of said sequence numbers is acknowledged in order to inform said central station (ZE) whether or not message repetition is necessary.

8. The method as defined in claim 1, wherein a plurality of said sequence numbers of all previous ones of said messages since an immediately preceding acknowledgment are positively or negatively acknowledged in order to inform said central station (ZE) whether or not message repetition is necessary.

9. The method as defined in claim 1, further comprising storing only a predetermined number of sequentially transmitted messages in a memory of said central station (ZE) for repeat transmission of said transmitted messages and controlling said memory so that a newly transmitted message overwrites an oldest one of said transmitted messages stored in said memory of said central station (ZE).

10. The method as defined in claim 1, wherein said participating group consists of all of or less than all of said terminals in said communication network.

11. The method as defined in claim 1, further comprising assigning a temporary address in said central station (ZE) to each of said terminals of said participating group.

12. The method as defined in claim 1, further comprising assigning at least one predefined address to each of said terminals of said participating group for simultaneous transmission of said messages to each of said terminals in a broadcast and/or multi-cast operation.