US 6,983,409 B1
Method of repeat transmission of messages in a centrally controlled communication network
Vasco Vollmer, Gartow (Germany); and Markus Radimirsch, Laatzen (Germany)
Assigned to Robert Bosch GmbH, Stuttgart (Germany)
Filed on Jun. 15, 2000, as Appl. No. 9/595,260.
Claims priority of application No. 199 27 639 (DE), filed on Jun. 17, 1999.
Int. Cl. G08C 25/02 (2006.01); H04L 1/18 (2006.01)
U.S. Cl. 714—748 12 Claims
OG exemplary drawing
 
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.