Repeat request signal transmission method for multi-station packet communication

• US 4,888,767 A
• Filed: 07/07/1988
• Issued: 12/19/1989
• Est. Priority Date: 12/25/1984
• Status: Expired due to Term

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Akashi, Fumio, Furuya, Yukitsuna
• Primary Examiner(s): Olms, Douglas W.
• Assistant Examiner(s): KUNTZ, CURTIS A
• Application Number:
  US07/217,090
• Time in Patent Office: 530 Days
• Field of Search: 370/110.1, 370/96, 370/124, 370/69.1, 370/104, 370/94, 370/60, 370/17, 371/4.5, 371/32, 371/33, 371/45, 455/67, 340/825.5
• US Class Current: 370/243
• CPC Class Codes: H04L 1/0061 Error detection codes
• CPC Class Codes: H04L 1/1692 Physical properties of the supervisory signal, e.g. acknowledgement by energy bursts
• CPC Class Codes: H04L 1/1809 Selective-repeat protocols
• CPC Class Codes: H04L 1/1835 Buffer management
• CPC Class Codes: H04L 1/1874 Buffer management
• CPC Class Codes: H04L 12/1868 Measures taken after transmission, e.g. acknowledgments
• CPC Class Codes: H04L 12/189 in combination with wireless systems selective distribution or broadcast in wireless communication networks H04W4/06
• CPC Class Codes: H04L 2001/0093 Point-to-multipoint

Abstract

In a network wherein all the receive stations connected to a radio link or a bus type wire link are capable of observing information which is being transmitted over the link, a method of allowing each receive station to send back a repeat request signal in multi-station packet communication in which a single transmit station transmits the same message to a plurality of receive stations. The same number of frequencies as packets are used so that a sinusoidal wave having a particular one of the frequencies which is associated with a packet with an error is sent. Alternatively, the same number of time slots as packets are set up so that a burst signal is sent as a repeat request signal in a particular one of the time sots which is associated with information on a packet with an error. Utilizing the fact that the signals to be sent are repeat request signals, the method insures accurate delivery of retransmit request information to the transmit station even if repeat request signals sent back at the same time are in a conflict.

Claims

1. A repeat request signal transmitting method for use in a multi-station packet communication system, in which a same message is transmitted in packet form from a single transmitting station to each of a plurality of receive stations in a multi-access environment, said method comprising the steps of:

at each receive station, checking received packets for errors and sending back to the transmitting station repeat request signals, each repeat request signal comprising a frequency component which is determined at the receive station in response to packets found to be erroneous, the frequency of said components being based on a predetermined rule followed in the receive station and recognized in a transmitting station; and

at a transmitting station, sensing said respective frequency component of the said repeat request signal that is sent back from the receive station, comparing the energy level of the repeat request signal that is sent back from the receive station with a predetermined energy value, each of said frequency components being sensed to require a packet to be retransmitted if the received energy level is greater than said predetermined value, and determining which packets are to be retransmitted in the response to the received frequency components based on the said predetermined rule.

2. A repeat request signal transmitting method as claimed in claim 1, wherein the predetermined rule is that each frequency component corresponds to a packet, hence the receiving stations transmit frequency components corresponding to erroneous packets and the transmitting station determine which packets to retransmit by selecting packets corresponding to the received frequency components in response to the energy level of the packet.

3. A repeat request signal transmitting method as claimed in claim 1, wherein the predetermined rule is that each frequency component corresponds to the number of an erroneous packet, hence the receiving station transmits a frequency component corresponding to the number of the erroneous packets, and the transmitting station determines how many correction packets are to be retransmitted in response to a frequency component, the number of erroneous packets corresponding to the maximum number indicated by the received frequencies.

4. A repeat request signal transmitting method as claimed in claim 1, wherein the predetermined rule is that each time slot corresponds to each packet, hence the receiving station transmits signal bursts in time slots corresponding to erroneous packets and the transmitting station determines which packets are to be retransmitted by selecting packets corresponding to the received time slots.

5. A repeat request signal transmitting method as claimed in claim 1, wherein the predetermined rule is that each time slot corresponds to the number of erroneous packets, hence the receiving station transmit a signal burst in a time slot corresponding to the number of erroneous packets, and the transmitting station determines how many correction packets are to be retransmitted by identifying the received time slot, the number of erroneous packets corresponding to the maximum number indicated by the received time slots.

6. A repeat request signal transmitting method for a multi-station packet communication system in which a single transmit station transmits a same message in a packet format to a plurality of receive stations in a multi-access environment, said method comprising the steps of:

at each receive station, checking received packets for error and sending back to the transmitting station a repeat request signal identifying erroneous packets, said repeat request signal comprising signal bursts appearing in particular time slots which are determined from the erroneous packets based on a predetermined rule followed by said receive station and recognized in a transmitting station; and

at a transmitting station, sensing respective ones of said signal bursts in each time slot of said repeat request signals sent back by said receive station by comparing the received energy level of said signals with a predetermined value, each time slot being sensed to be a received repeat request signal if the received energy level is greater than said predetermined value and determining which of the packets is to be retransmitted in reponse to the time slots of the received signal, based on said predetermined rule.

7. A repeat request signal transmitting method for a multi-station packet communication system in which a signal transmit station transmits a same message in a packet form to a plurality of receive stations in a multi-access environment, said method comprising the steps of:

at each receive station, checking received packets for errors and sending back to the transmitting station repeat request signals comprising signal bursts appearing in particular time slots which are determined by encoding the number of erroneous packets into a binary code, each digit of which binary code corresponds to a time slot; and

packet communication system in which a single transmit station transmits a same message to a plurality of receive stations in a multi-access environment, said method comprising the steps of;

at a transmitting station, sensing respective ones of the signal burst in each time slot of said repeat request signal by comparing the received energy level with a predetermined value, each time slot being sensed as having been received if its received energy level is greater than said predetermined value, and determining the number of correction packets which are to be retransmitted by decoding the digits obtained from the received time slots.