Method and apparatus in a two-way radio messaging unit for limiting a total transmission duration within a sliding time window

• US 6,470,003 B1
• Filed: 12/07/1999
• Issued: 10/22/2002
• Est. Priority Date: 12/07/1999
• Status: Expired due to Term

• Current Assignee: Google Technology Holdings LLC (Alphabet Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Smith, Brian Keith, Pieper, Michael Scott
• Primary Examiner(s): Urban, Edward F.
• Assistant Examiner(s): CRAVER, CHARLES R
• Application Number:
  US09/455,674
• Time in Patent Office: 1,050 Days
• Field of Search: 370/345, 370/235-236, 370/395--39, 370/400, 370/412-418, 455/466, 455/412, 455/426, 710/52-57
• US Class Current: 370/345
• CPC Class Codes: H04B 7/2656 for structure of frame, burst
• CPC Class Codes: H04L 1/16 in which the return channel carries supervisory signals, e.g. repetition request signals
• CPC Class Codes: H04W 84/025 with acknowledge back capability

Abstract

A processing system (206) defines (302) a plurality of bins (230) within a sliding time window, each bin for storing a total transmit duration of a predetermined number of frames assigned to each bin. The processing system then determines (310) a mean transmit duration per frame for a next one of the plurality of bins to be processed. The processing system subtracts (312) the mean transmit duration per frame from the total transmit duration of the one of the plurality of bins, when a next frame begins to be processed; and calculates (314) a transmit duty cycle for the sliding time window, the transmit duty cycle calculated as if a requested transmit duration for the next frame were to be allowed. The processing system also delays (316) a transmission of the next frame, when the transmit duty cycle is greater than a maximum allowable transmit duty cycle.

Claims

1. A method in a two-way radio messaging unit for limiting a total transmission duration within a sliding time window of a predetermined duration, the two-way radio messaging unit utilizing a protocol in which information is sent in a plurality of periodically transmitted frames, the method comprising the steps of:

defining a plurality of bins within the sliding time window, each bin for storing a total transmit duration of a predetermined number of frames assigned to each bin;

determining a mean transmit duration per frame for a next one of the plurality of bins to be processed;

subtracting said mean transmit duration per frame from the total transmit duration of the one of the plurality of bins, when a next frame begins to be processed;

calculating a transmit duty cycle for the sliding time window, the transmit duty cycle calculated as if a requested transmit duration for the next frame were to be allowed; and

delaying a transmission of the next frame, when the transmit duty cycle is greater than a maximum allowable transmit duty cycle.

2. The method of claim 1,

wherein the defining step comprises the step of designating a number of bins equal to said predetermined duration of the sliding time window, divided by a time required for transmitting said predetermined number of frames assigned to each bin, and

wherein the calculating step comprises the step of estimating the transmit duty cycle as a sum of the total transmit duration stored in each of the plurality of bins, divided by the predetermined duration of the sliding time window.

3. The method of claim 1, further comprising the step of limiting a length of a transmission, when the calculating step has determined that the transmit duty cycle is greater than a predetermined fraction of the maximum allowable transmit duty cycle.

4. The method of claim 1, further comprising the step of allowing a scheduled transmission of the next frame, when the transmit duty cycle is not greater than the maximum allowable transmit duty cycle.

5. The method of claim 4, wherein the allowing step further comprises the step of adding the requested transmit duration to the total transmit duration of the one of the plurality of bins, when the transmit duty cycle is not greater than the maximum allowable transmit duty cycle.

6. The method of claim 4, further comprising the step of repeating the subtracting, calculating, delaying, and allowing steps until the predetermined number of frames assigned to the one of the plurality of bins has been processed.

7. The method of claim 6, further comprising the step of continuing to execute the determining and repeating steps until all the information has been processed.

8. A two-way radio messaging unit for limiting a total transmission duration within a sliding time window of a predetermined duration, the two-way radio messaging unit utilizing a protocol in which information is sent in a plurality of periodically transmitted frames, the two-way radio messaging unit comprising:

a transceiver for receiving and transmitting information; and

a processing system coupled to the transceiver for processing the information and controlling the two-way radio messaging unit,

wherein the processing system is programmed to;

define a plurality of bins within the sliding time window, each bin for storing a total transmit duration of a predetermined number of frames assigned to each bin;

determine a mean transmit duration per frame for a next one of the plurality of bins to be processed;

subtract said mean transmit duration per frame from the total transmit duration of the one of the plurality of bins, when a next frame begins to be processed;

calculate a transmit duty cycle for the sliding time window, the transmit duty cycle calculated as if a requested transmit duration for the next frame were to be allowed; and

delay a transmission of the next frame, when the transmit duty cycle is greater than a maximum allowable transmit duty cycle.

9. The two-way radio messaging unit of claim 8, wherein the processing system is further programmed to:

designate a number of bins equal to said predetermined duration of the sliding time window, divided by a time required for transmitting said predetermined number of frames assigned to each bin; and

estimate the transmit duty cycle as a sum of the total transmit duration stored in each of the plurality of bins, divided by the predetermined duration of the sliding time window.

10. The two-way radio messaging unit of claim 8, wherein the processing system is further programmed to limit a length of a transmission, when the calculating step has determined that the transmit duty cycle is greater than a predetermined fraction of the maximum allowable transmit duty cycle.

11. The two-way radio messaging unit of claim 8, wherein the processing system is further programmed to allow a scheduled transmission of the next frame, when the transmit duty cycle is not greater than the maximum allowable transmit duty cycle.

12. The two-way radio messaging unit of claim 8, wherein the processing system is further programmed to add the requested transmit duration to the total transmit duration of the one of the plurality of bins, when the transmit duty cycle is not greater than the maximum allowable transmit duty cycle.

13. An apparatus for use in a two-way messaging unit including a transmitter, the apparatus for limiting a total transmission duration within a sliding time window of a predetermined duration, the apparatus utilizing a protocol in which information is sent in a plurality of periodically transmitted frames, the apparatus comprising:

a processing system for controlling the two-way messaging unit, wherein the processing system is programmed to;

define a plurality of bins within the sliding time window, each bin for storing a total transmit duration of a predetermined number of frames assigned to each bin;

determine a mean transmit duration per frame for a next one of the plurality of bins to be processed;

subtract said mean transmit duration per frame from the total transmit duration of the one of the plurality of bins, when a next frame begins to be processed;

calculate a transmit duty cycle for the sliding time window, the transmit duty cycle calculated as if a requested transmit duration for the next frame were to be allowed; and

delay a transmission of the next frame, when the transmit duty cycle is greater than a maximum allowable transmit duty cycle.

14. The apparatus of claim 13, wherein the processing system is further programmed to:

designate a number of bins equal to said predetermined duration of the sliding time window, divided by a time required for transmitting said predetermined number of frames assigned to each bin; and

estimate the transmit duty cycle as a sum of the total transmit duration stored in each of the plurality of bins, divided by the predetermined duration of the sliding time window.

15. The apparatus of claim 13, wherein the processing system is further programmed to limit a length of a transmission, when the calculating step has determined that the transmit duty cycle is greater than a predetermined fraction of the maximum allowable transmit duty cycle.

16. The apparatus of claim 13, wherein the processing system is further programmed to allow a scheduled transmission of the next frame, when the transmit duty cycle is not greater than the maximum allowable transmit duty cycle.

17. The apparatus of claim 13, wherein the processing system is further programmed to add the requested transmit duration to the total transmit duration of the one of the plurality of bins, when the transmit duty cycle is not greater than the maximum allowable transmit duty cycle.