Communication method in RFID or remote sensor systems

• US 8,054,162 B2
• Filed: 04/27/2005
• Issued: 11/08/2011
• Est. Priority Date: 04/28/2004
• Status: Expired due to Fees

• Current Assignee: Atmel Corporation (Microchip Technology Incorporated)
• Original Assignee: Atmel Corporation (Microchip Technology Incorporated)
• Inventors: Friedrich, Ulrich
• Primary Examiner(s): SYED, NABIL H
• Application Number:
  US11/115,185
• Publication Number:
  US 20050242927A1
• Time in Patent Office: 2,386 Days
• Field of Search: 340/3.41, 340/825, 340/10.41, 340/10.1, 340/10.2, 340/572.1, 340/10.3, 340/10.32, 340/10.31, 340/10.4, 340/10.42, 340/10.5, 340/9.1, 340/9.11, 340/1.1, 235/375, 235/384, 235/382
• US Class Current: 340/10.2
• CPC Class Codes: G06K 7/0008 General problems related to the reading of electronic memory record carriers, independent of its reading method, e.g. power transfer
• CPC Class Codes: G06K 7/10019 resolving collision on the communication channels between simultaneously or concurrently interrogated record carriers. collision between the communication channels used by wireless communication devices, where the solution is not particularly adapted for RFIDs or the like, H04W74/08

Abstract

A method for communicating between a control unit and a plurality of remote units located in the response area of the control unit is provided. The remote units are prompted to transmit a data sequence to the control unit upon receipt of a command sent by the control unit. The control unit transmits a control signal to the remote units substantially simultaneously with the transmission of the data sequence as a function of a communication state, such as the absence of a transmission of the data sequence by at least one remote unit or an at least partially simultaneous transmission of the data sequence by more than one remote unit. In this way, communication methods can be shortened, in particular in terms of time, without adversely affecting communication reliability.

Claims

1. A method for communicating between a control unit and a plurality of remote units located in a response area of the control unit, the method comprising the steps of:

transmitting a command from the control unit to the remote units, the command being a notch signal or a low bit count command structure;

determining at the remote units, in response to said command from the control unit, a first random number specifying a predetermined time window for the transmission of a data sequence by the remote unit, where said remote units transmit said first random number to said control unit unless said first random number corresponds to a time window of a common, first transmission and, in that instance the remote units whose first random number corresponds to the time window of the common, first transmission, determine a new random number without transmitting said first random number to the control unit;

transmitting the data sequence to the control unit upon receipt of the command sent by the control unit, wherein all of the remote units executing the command begin synchronously with the first transmission of the data sequence; and

transmitting a control signal from the control unit to the remote units substantially simultaneously with the transmission or expected transmission of the data sequence from the remote units on a basis of a communication state, the communication state being an absence of a transmission of the data sequence by at least one of the remote units or an at least partially simultaneous transmission of the data sequence by more than one of the remote units.

2. A method for communicating between a control unit and a plurality of remote units located in a response area of the control unit, the method comprising the steps of:

establishing a first series of time slots including a first time slot;

determining at the remote units a random number specifying a predetermined time slot of the first series of time slots for the transmission of a data sequence by the remote unit;

each time the random number specifies the first time slot in the first series of time slots, automatically determining a new random number;

transmitting a command from the control unit to the remote units, the command being a notch signal or a low bit count command structure;

transmitting synchronously in the first time slot in the first series of time slots by each of the remote units receiving the command a data sequence to the control unit upon receipt of the command sent by the control unit; and

transmitting a control signal from the control unit to the remote units substantially simultaneously with the transmission of the data sequence from the remote units upon the detection of an at least partially simultaneous transmission of the data sequence by more than one of the remote units.