Apparatus for mediating communication between controller and transponders of many moving objects and method for controlling the same

• US 20030231105A1
• Filed: 06/09/2003
• Published: 12/18/2003
• Est. Priority Date: 06/11/2002
• Status: Active Grant

• Current Assignee: Digitalsis Inc.
• Original Assignee: Digitalsis Inc.
• Inventors: Kim, Jong-Ho, Kim, Yong-Deak
• Granted Patent: US 7,239,228 B2
• Time in Patent Office: Days
• 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

Disclosed are a communication mediation apparatus and a method for controlling the same for performing communication mediation while reducing a communication miss rate caused by collision of data. A performance of a moving object recognition system unavoidably varies with the number of moving objects to be recognized by a controller, and with a mediation parameter for use in a communication mediation algorithm. The apparatus/method dynamically varies a mediation parameter according to a difference in numbers of many moving objects, thus reducing a communication miss rate regardless of the difference (i.e., traffic volume variation) in numbers of the moving objects.

Claims

1. A communication mediation apparatus for allowing a controller to communicate with each transponder of a plurality of moving objects in a system for recognizing the moving objects using the controller communicating with the transponder contained in each of the moving objects, comprising:

an arrival rate sensor for recognizing each current arrival rate of the moving objects by counting the number of moving objects arriving within a predetermined time;

a memory for storing an optimum mediation parameter having the best performance for every arrival rate;

a selector for selecting an optimum mediation parameter corresponding to the current arrival rate; and

control means for adding the optimum mediation parameter corresponding to the selected current arrival rate to a control signal, and transmitting an acknowledge (ACK) signal within a communicable range upon receiving a response signal having no error from a corresponding transponder.

2. The apparatus as set forth in claim 1, wherein the memory further stores mediation algorithm information corresponding to the optimum mediation parameter, the selector further selects the mediation algorithm information stored in the memory, and the control means further adds the mediation algorithm information to the control signal.

3. A communication mediation apparatus for allowing each transponder of a plurality of moving objects to communicate with a controller in a system for recognizing the moving objects using the controller communicating with the transponder contained in each of the moving objects, comprising:

control means for receiving a control signal from the controller, recognizing a mediation parameter and mediation algorithm information associated with the mediation parameter that are contained in the control signal, transmitting a response signal to the controller upon receiving a transmission time determination signal, and determining whether an acknowledge (ACK) signal is received from the controller; and

transmission time determination means for performing a mediation algorithm corresponding to the recognized mediation algorithm information, determining a transmission time of the response signal according to the mediation parameter and the result of indicating reception of the ACK signal within a predetermined period of time, and transmitting the transmission time determination signal.

4. A communication mediation method for allowing a controller to communicate with each transponder of a plurality of moving objects in a system for recognizing the moving objects using the controller communicating with the transponder contained in each of the moving objects, comprising the steps of:

a) recognizing each current arrival rate of the moving objects by counting the number of moving objects arriving within a predetermined time;

b) adding an optimum mediation parameter having the best performance in the recognized arrival rates of the moving objects to a control signal, and transmitting the control signal within a communicable range;

c) waiting for a response signal generated from a transponder; and

d) returning to the step (a), and transmitting an acknowledge (ACK) signal in the communicable range when a correct response signal is received within a predetermined time.

5. The method as set forth in claim 4, wherein the step (b) further includes the step of:

adding mediation algorithm information corresponding to the optimum mediation parameter to the control signal.

6. The method as set forth in claim 4 or 5, wherein the response signal and the ACK signal include identification (ID) information of a corresponding transponder.

7. A communication mediation method for allowing each transponder of a plurality of moving objects to communicate with a controller in a system for recognizing the moving objects using the controller communicating with the transponder contained in each of the moving objects, comprising the steps of:

a) determining whether a control signal is received from the controller;

b) upon receiving the control signal, recognizing a mediation parameter and mediation algorithm information associated with the mediation parameter that are contained in the control signal;

c) determining a transmission time of a response signal according to a corresponding mediation algorithm;

d) enabling the controller to transmit a response signal;

e) if an acknowledge (ACK) signal is not received from the controller within a predetermined time, returning to the step (c), and re-transmitting the response signal; and

f) upon receiving the ACK signal from the controller within the predetermined time, controlling the transponder to be disabled by the next control signal received from the controller.

8. The method as set forth in claim 7, wherein the step (c) re-executed when the ACK signal is not received at the step (e) includes the steps of:

c-1) generating random numbers on the basis of the mediation parameter; and

c-2) creating a delayed time by counting a predetermined time corresponding to the created random numbers.

9. The method as set forth in claim 8, wherein the step (c) executed after performing the step (b) includes the steps of:

c-3) generating random numbers; and

c-4) creating a delayed time by counting a predetermined time corresponding to the created random numbers.

10. A method for mediating communication between a controller and each transponder of a plurality of moving objects in a system for recognizing the moving objects using the controller communicating with the transponder contained in each of the moving objects, comprising the steps of:

a) determining whether a control signal is received from the controller;

b) upon receiving the control signal, recognizing a mediation parameter and mediation algorithm information associated with the mediation parameter that are contained in the control signal;

c) determining a transmission time of a response signal according to a corresponding mediation algorithm;

d) transmitting the response signal to the controller;

e) if an acknowledge (ACK) signal is not received from the controller within a predetermined time, returning to the step (a), and re-transmitting the response signal; and

f) upon receiving the ACK signal from the controller within the predetermined time, controlling the transponder to be disabled by the next control signal received from the controller.

11. The method as set forth in claim 10, wherein the step (c) includes the steps of:

c-1) generating random numbers;

c-2) comparing the random numbers with the mediation parameter to determine whether a response signal transmission condition is satisfied;

c-3) if the response signal transmission condition is satisfied, returning to the step (d); and

c-4) if the response signal transmission condition is not satisfied, returning to the step (a).