Modified scheduling technique for a telecommunication system

• US 7,239,622 B2
• Filed: 09/19/2002
• Issued: 07/03/2007
• Est. Priority Date: 09/19/2002
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Black, Peter J.
• Primary Examiner(s): Shah; Chirag G.
• Application Number:
  US10/251,938
• Publication Number:
  US 20040057398A1
• Time in Patent Office: 1,748 Days
• Field of Search: None
• US Class Current: 370/338
• CPC Class Codes: H04W 16/00 Network planning, e.g. coverage or traffic planning tools; Network deployment, e.g. resource partitioning or cells structures

Abstract

Biasing and scheduling transmission of data for access point transceivers. A transmission period of the transceivers is biased in adjacent cells into a plurality of time slots such that the biasing reduces interference among adjacent cells. The transceivers are then scheduled to transmit data packets during a selected time slot of the plurality of time slots that is distinct from each other.

Claims

1. A method, comprising:

biasing access point transceivers in adjacent cells into a plurality of time slots such that the biasing adjusts transmission times of the access point transceivers to reduce interference among the transceivers in the adjacent cells; and

scheduling each transceiver to transmit data during a biased time slot of the plurality of time slots that is distinct from slots selected by other transceivers, wherein the scheduling includes;

generating transmission probabilities for the transceivers during the selected time slot, and wherein the generating transmission probabilities includes;

setting a probability curve for a first transceiver corresponding to the selected time slot at a constant level of maximum probability; and

configuring probability curves for other transceivers corresponding to time slots other than the selected time slot to be based on queue lengths of data packets in the other transceivers.

2. The method of claim 1, wherein the biasing includes:

dividing a transmission period into the plurality of time slots.

3. The method of claim 2, wherein the dividing is based on an average transmission load of the adjacent cells.

4. The method of claim 1, wherein the biasing includes:

adjusting transmission times of the access point transceivers so that a transceiver is most likely to transmit data during the selected time slot than other slots in the plurality of time slots.

5. The method of claim 1, wherein the configuring probability curves includes:

determining slopes of the probability curves as a function of quality of service of data traffic.

6. The method of claim 5, wherein the determining slopes of the probability curves includes:

selecting steeper slopes for delay sensitive data traffic than for non-delay sensitive data traffic.

7. A method, comprising:

biasing access point transceivers in adjacent cells into a plurality of time slots such that the biasing adjusts transmission times of the access point transceivers to reduce interference among the transceivers in the adjacent cells; and

scheduling each transceiver to transmit data during a biased time slot of the plurality of time slots that is distinct from slots selected by other transceivers, wherein the scheduling includes;

generating transmission probabilities for the transceivers during the selected time slot,

generating a random number; and

comparing the random number with the transmission probabilities for the transceivers.

8. The method of claim 7, wherein the scheduling includes:

transmitting data such that a probability of data transmission during the selected time slot is higher than a probability of data transmission during other time slots, when the transmission probability is greater than the random number.

9. A method, comprising:

biasing access point transceivers in adjacent cells into a plurality of time slots such that the biasing adjusts transmission times of the access point transceivers to reduce interference among the transceivers in the adjacent cells;

scheduling each transceiver to transmit data during a biased time slot of the plurality of time slots that is distinct from slots selected by other transceivers; and

performing an intra-cell bias such that, within a cell, transmission to remote stations within a weak coverage area is provided with a higher transmission probability during the selected time slot than during other time slots.

10. A method for biasing and scheduling transmission of data for access point transceivers in a cellular network, comprising:

biasing each transceiver of the transceivers in adjacent cells into a time slot;

generating transmission probabilities for the transceivers in the adjacent cells during the biased time slot;

generating a random number;

comparing the random number with the transmission probabilities for each transceiver during the corresponding time slot for the transceiver; and

transmitting data packets when the transmission probability is greater than the random number such that during a substantial portion of the biased time slot only one transceiver that is biased to transmit during the biased time slot is transmitting.

11. A computer readable media comprising:

code for causing a computer to bias access point transceivers in adjacent cells into a plurality of time slots such that the biasing adjusts transmission times to reduce interference among the transceivers of the adjacent cells; and

code for causing a computer to schedule each transceiver to transmit data during a selected time slot of the plurality of time slots that is distinct from slots selected by other transceivers, wherein the code for causing a computer to schedule further includes;

code for causing a computer to generate transmission probabilities for the transceivers during the selected time slot;

code for causing a computer to generate a random number; and

code for causing a computer to compare the random number with the transmission probabilities for the transceivers.

12. A wireless communication system comprising:

a plurality of transceivers, including a first transceiver and other transceivers, located in adjacent cells;

a biasing element configured to bias each transceivers in the adjacent cells into a time slot, the biasing element operating to adjust transmission times to reduce interference among adjacent cells; and

a plurality of schedulers, each scheduler corresponding to each transceiver, each scheduler transmits data during a biased time slot of the plurality of time slots that is distinct from slots selected by other transceivers, wherein each scheduler includes;

a generator for generating transmission probabilities for the transceivers during the selected time slot, and wherein the generator includes;

a plurlity of probability selectors to set a probability curve for the first transceiver corresponding to the selected time slot at a constant level of maximum probability, and to configure probability curves for the other transceivers corresponding to time slots other than the selected time slot to be based on queue lengths of data packets in the other transceivers.

13. The system of claim 12, wherein the biasing element includes:

a divider to divide the transmission period into the plurality of time slots based on an average transmission load of the adjacent cells.

14. The system of claim 12, wherein the plurality of probability selectors includes:

a calculator to determine slopes of the probability curves as a function of quality of service of data traffic.

15. A wireless communication system comprising:

means for biasing access point transceivers in adjacent cells into a plurality of time slots such that the biasing adjusts transmission times to reduce interference among the transceivers of the adjacent cells; and

means scheduling each transceiver to transmit data during a biased time slot of the plurality of time slots that is distinct from slots selected by other transceivers, wherein the means for scheduling includes;

means for generating transmission probabilities for the transceivers during the selected time slot, and wherein the means for generating includes;

means for selecting probabilities to set a probability curve corresponding to the selected time slot at a constant level maximum probability, and to configure probability curves corresponding to time slots other than the selected time slot to be based on queue lenghts of data packets.

16. The system of claim 15, wherein the means for biasing includes:

means for dividing the transmission period into the plurality of time slots based on an average transmission load of the adjacent cells.

17. A wireless communication system comprisig:

means for biasing each transceiver of the transeivers in adjacent cells into a time slot;

means for generating transmission probabilities for the transceivers in the adjacent cells during the biased time slot;

means for generating a random number;

means for comparing the random number with the transmission probabilities for each transceiver during the corresponding time slot for the transceiver; and

means for transmitting data packets when the transmission probability is greater than the random number such that during a substantial portion of the biased time slot only one transceiver that is biased to transmit during the biased time slot is transmitting.