METHOD AND APPARATUS FOR MULTICAST SCHEDULING IN WIRELESS NETWORKS

• US 20080273458A1
• Filed: 05/04/2007
• Published: 11/06/2008
• Est. Priority Date: 05/04/2007
• Status: Active Grant

• Current Assignee: WSOU Investments, LLC (WSOU Holdings, LLC)
• Original Assignee: Alcatel-Lucent SA (Nokia Corporation)
• Inventors: Guo, Katherine H., Netravali, Arun N., Sabnani, Krishan K.
• Granted Patent: US 9,107,236 B2
• Time in Patent Office: Days
• US Class Current: 370/229
• CPC Class Codes: H04L 47/10 Flow control; Congestion control
• CPC Class Codes: H04L 47/70 Admission control; Resource allocation
• CPC Class Codes: H04L 47/806 Broadcast or multicast traffic
• CPC Class Codes: H04L 47/824 Applicable to portable or mobile terminals
• CPC Class Codes: H04W 28/22 Negotiating communication rate
• CPC Class Codes: H04W 72/30 Resource management for broadcast services
• CPC Class Codes: H04W 72/535 based on resource usage policies
• CPC Class Codes: H04W 84/042 Public Land Mobile systems, e.g. cellular systems

Abstract

The invention includes a method and apparatus for scheduling multicast transmissions in a wireless network by selecting one of a plurality of multicast groups of a cellular region that is permitted to transmit information during a current timeslot. A method includes receiving data rate request values from wireless user terminals of each of a plurality of multicast groups, assigning a data rate to each multicast group using the data rate request values of wireless user terminals belonging to the respective multicast groups, selecting one of the multicast groups using the assigned data rates, and transmitting information to the selected one of the multicast groups at the associated assigned data rate. In one embodiment, the multicast scheduling algorithm may be a multicast proportional fairness (MPF) scheduling algorithm which attempts to maximize utility value of data received by individual users. In one embodiment, the multicast scheduling algorithm may be an inter-group proportional fairness (IPF) scheduling algorithm which attempts to maximize utility value of data received by multicast groups.

Claims

1. A method for scheduling multicast transmissions in a wireless network, comprising:

receiving data rate request values from wireless user terminals of each of a plurality of multicast groups of a cellular region;

assigning a data rate to each multicast group using the data rate request values of wireless user terminals belonging to the respective multicast groups;

selecting one of the multicast groups using the assigned data rates of the multicast groups; and

transmitting information toward the selected multicast group at the assigned data rate.

2. The method of claim 1, wherein, for each multicast group, assigning the data rate to that multicast group comprises:

for each data rate request value received from wireless user terminals in the multicast group, selecting that data rate request value and computing a weighted aggregate data rate for the selected data rate request value; and

assigning one of the selected data rate request values as the data rate for the multicast group using the weighted aggregate data rates.

3. The method of claim 2, wherein, for each multicast group, for each selected data rate request value, computing the weighted aggregate data rate comprises:

identifying ones of the wireless user terminals in the multicast group for which the associated received data rate request value is equal to or greater than the selected data rate request value; and

computing the weighted aggregate data rate for the selected data rate value by summing the weighted aggregate data rates associated with respective identified ones of the wireless user terminals.

4. The method of claim 3, wherein the weighted data rate associated with one of the wireless user terminals for which the associated received data rate request value is equal to or greater than the selected data rate request value is computed by dividing the selected data rate request value by an average throughput associated with the wireless user terminal.

5. The method of claim 1, wherein selecting one of the multicast groups using the assigned data rates of the respective multicast groups comprises:

for each of the multicast groups, selecting one of the weighted aggregate data rates of the multicast group, wherein the selected one of the weighted aggregate data rates comprises the weighted aggregate data rate associated with the assigned data rate of the multicast group; and

selecting the one of the multicast groups using the selected ones of the weighted aggregate data rates.

6. The method of claim 1, wherein, for each multicast group, assigning the data rate to that multicast group comprises:

for each data rate request value received from wireless user terminals in the multicast group, selecting that data rate request value and computing an aggregate data rate for the selected data rate request value; and

assigning one of the selected data rate request values as the data rate for the multicast group using the computed aggregate data rates.

7. The method of claim 6, wherein, for each multicast group, for each selected data rate request value, computing the aggregate data rate comprises:

identifying ones of the wireless user terminals in the multicast group for which the associated received data rate request value is equal to or greater than the selected data rate request value; and

computing the aggregate data rate for the selected data rate request value by multiplying the selected data rate request value by a number of the identified ones of the wireless user terminals.

8. The method of claim 6, wherein the one of the selected data rate request values assigned as the data rate for the multicast group comprises the selected data rate request value associated with the maximum aggregate data rate.

9. The method of claim 1, wherein selecting one of the multicast groups using the assigned data rates of the respective multicast groups comprises:

for each multicast group, computing an aggregate throughput of the multicast group;

for each multicast group, computing a group satisfaction function value using the assigned data rate for the multicast group, the aggregate data rate associated with the assigned data rate for the multicast group, and the aggregate throughput of the multicast group; and

selecting the one of the multicast groups using the group satisfaction function values.

10. The method of claim 9, wherein, for each multicast group, computing the group satisfaction function value comprises:

selecting one of the aggregate data rates of the multicast group, wherein the selected one of the aggregate data rates comprises the aggregate data rate associated with the assigned data rate of the multicast group; and

dividing the selected one of the aggregate data rates of the multicast group by the aggregate throughput of the multicast group.

11. An apparatus for scheduling multicast transmissions in a wireless network, comprising:

means for receiving data rate request values from wireless user terminals of each of a plurality of multicast groups of a cellular region;

means for assigning a data rate to each multicast group using the data rate request values of wireless user terminals belonging to the respective multicast groups;

means for selecting one of the multicast groups using the assigned data rates of the multicast groups; and

means for transmitting information toward the selected multicast group at the assigned data rate.

12. The apparatus of claim 11, wherein the means for assigning the data rates to the multicast groups comprises:

means for selecting, for each multicast group, each data rate request value received from wireless user terminals in the multicast group;

means for computing, for each multicast group, for each selected data rate request value, a weighted aggregate data rate for the selected data rate request value; and

means for assigning, for each multicast group, one of the selected data rate request values as the data rate for the multicast group using the weighted aggregate data rates.

13. The apparatus of claim 12, wherein the means for computing comprises:

means for identifying, for each multicast group, for each selected data rate request value, ones of the wireless user terminals in the multicast group for which the associated received data rate request value is equal to or greater than the selected data rate request value; and

means for computing, for each multicast group, for each selected data rate request value, the weighted aggregate data rate for the selected data rate request value by summing weighted aggregate data rates associated with respective identified ones of the wireless user terminals.

14. The apparatus of claim 13, wherein the weighted data rate associated with one of the wireless user terminals for which the associated received data rate request value is equal to or greater than the selected data rate request value is computed by dividing the selected data rate request value by an average throughput associated with the wireless user terminal.

15. The apparatus of claim 11, wherein the means for selecting one of the multicast groups using the assigned data rates of the respective multicast groups comprises:

means for selecting, for each of the multicast groups, one of the weighted aggregate data rates of the multicast group, wherein the selected one of the weighted aggregate data rates comprises the weighted aggregate data rate associated with the assigned data rate of the multicast group; and

means for selecting the one of the multicast groups using the selected ones of the weighted aggregate data rates.

16. The apparatus of claim 11, wherein the means for assigning the data rate to the multicast groups comprises:

means for selecting, for each multicast group, each data rate request value received from wireless user terminals in the multicast group;

means for computing, for each multicast group, for each selected data rate request value, an aggregate data rate for the selected data rate request value; and

means for assigning, for each multicast group, one of the selected data rate request values as the data rate for the multicast group using the aggregate data rates.

17. The apparatus of claim 16, wherein the means for computing the aggregate data rates comprises:

means for identifying, for each multicast group, ones of the wireless user terminals in the multicast group for which the associated received data rate request value is equal to or greater than the selected data rate request value; and

means for computing, for each multicast group, the aggregate data rate for the selected data rate request value by multiplying the selected data rate request value by a number of the identified ones of the wireless user terminals.

18. The apparatus of claim 11, wherein the means for selecting one of the multicast groups using the assigned data rates of the respective multicast groups comprises:

means for computing, for each multicast group, an aggregate throughput of the multicast group;

means for computing a group satisfaction function value for each multicast group using the assigned data rate for the multicast group, the aggregate data rate associated with the assigned data rate for the multicast group, and the aggregate throughput of the multicast group; and

means for selecting the one of the multicast groups using the group satisfaction function values.

19. The apparatus of claim 18, wherein the means for computing the group satisfaction function values comprises:

means for selecting, for each multicast group, one of the aggregate data rates of the multicast group, wherein the selected one of the aggregate data rates comprises the aggregate data rate associated with the assigned data rate of the multicast group; and

means for dividing, for each multicast group, the selected one of the aggregate data rates for the multicast group by the aggregate throughput of the multicast group.

20. A computer readable medium storing a software program, that, when executed by a computer, causes the computer to perform a method comprising:

receiving data rate request values from wireless user terminals of each of a plurality of multicast groups of a cellular region;

assigning a data rate to each multicast group using the data rate request values of wireless user terminals belonging to the respective multicast groups;

selecting one of the multicast groups using the assigned data rates of the multicast groups; and

transmitting information toward the selected multicast group at the assigned data rate.