Systems and methods for optimizing the allocation of resources to serve different types of data flows in a wireless communication system

• US 7,382,744 B2
• Filed: 01/27/2005
• Issued: 06/03/2008
• Est. Priority Date: 01/27/2005
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Black, Peter J., Bhushan, Naga
• Primary Examiner(s): LE, DANH C
• Application Number:
  US11/045,199
• Publication Number:
  US 20060164990A1
• Time in Patent Office: 1,223 Days
• Field of Search: 370/328, 370/235, 370/229, 455/561, 455/550.1
• US Class Current: 370/328
• CPC Class Codes: H04L 1/0002 by adapting the transmission rate
• CPC Class Codes: H04L 1/0007 by modifying the frame length
• CPC Class Codes: H04L 1/0017 where the mode-switching is based on Quality of Service requirement
• CPC Class Codes: H04L 2001/0093 Point-to-multipoint
• CPC Class Codes: H04L 45/123 Evaluation of link metrics techniques for monitoring network metrics H04L43/08
• CPC Class Codes: H04W 28/06 Optimizing the usage of the radio link, e.g. header compression, information sizing , discarding information system modifying transmission characteristic according to link quality by modifying frame length H04L1/0007; dynamic adaptation of the packet size for flow control or congestion control H04L47/365
• CPC Class Codes: H04W 28/18 Negotiating wireless communication parameters
• CPC Class Codes: H04W 72/04 Wireless resource allocation
• CPC Class Codes: H04W 72/12 Wireless traffic scheduling
• CPC Class Codes: H04W 88/08 Access point devices

Abstract

Systems and methods for optimizing the allocation of resources to serve different types of data flows in a wireless communication system are disclosed. An exemplary method involves calculating data metrics for data in a plurality of queues. Each queue corresponds to a different data flow in the wireless communication system. The data metrics are used to determine a separate transmission metric for each of a plurality of possible transmission formats. The transmission metric for a given transmission format is dependent on the data metrics corresponding to allocated data for the given transmission format. A transmission format is selected that has an optimum transmission metric. The allocated data for the selected transmission format is transmitted on the forward link in accordance with the selected transmission format.

Claims

1. A base station configured for wireless communication with a plurality of remote stations in a wireless communication system, comprising:

a transmitter for transmitting a forward link to the plurality of remote stations;

a processor; and

memory in electronic communication with the processor;

the memory storing instructions being executable to implement a method comprising;

calculating data metrics for data in a plurality of queues, each queue corresponding to a different data flow in the wireless communication system;

using the data metrics to determine a separate transmission metric for each of a plurality of possible transmission formats, the transmission metric for a given transmission format being dependent on the data metrics corresponding to allocated data for the given transmission format; and

selecting a transmission format that has an optimum transmission metric.

2. The base station of claim 1, wherein the method further comprises transmitting the allocated data for the selected transmission format on the forward link in accordance with the selected transmission format.

3. The base station of claim 1, wherein the allocated data for the given transmission format is determined so that the transmission metric for the given transmission format is optimized in view of one or more constraints.

4. The base station of claim 3, wherein the one or more constraints comprise a packet capacity constraint which specifies that the allocated data for the given transmission format does not exceed a packet'"'"'s data capacity.

5. The base station of claim 4, wherein the packet capacity constraint for the j^th transmission format is expressed as:

$\underset{i=1}{\overset{N}{\sum <br><br>}}<br><br><br><br>\frac{b_i}{G_{i,j}}\le <br><br>1$

wherein b_i represents the number of allocated bits from the i^th queue, and wherein G_i,j represents the maximum number of bits from the i^th queue that are included in the packet if all channel resources are allocated to the i^th data flow.

6. The base station of claim 4, wherein the packet capacity constraint for the j^th transmission format is expressed as:

$\underset{i=1}{\overset{N}{\sum <br><br>}}<br><br><br><br>\frac{b_i}{G_{i,j}}\le <br><br>1$

wherein b_i represents the number of allocated bits for data flows residing on the i^th remote station, and wherein G_i,j represents the maximum number of bits from data flows residing on the i^th remote station that are included in the packet if all channel resources are allocated to data flows residing on the i^th remote station.

7. The base station of claim 3, wherein the one or more constraints comprise an addressing constraint which specifies that the allocated data for the given transmission format does not exceed a packet'"'"'s addressing capacity.

8. The base station of claim 7, wherein the addressing constraint for the plurality of queues is expressed as:

$\underset{i=1}{\overset{N}{\sum <br><br>}}<br><br>\lceil <br><br>\frac{b_i}{B_{i,j}}\rceil <br><br>\le <br><br>K_j$

wherein b_i represents the number of allocated bits from the i^th data flow'"'"'s queue, wherein B_i,j represents the data size at which the i^th data flow is treated as multiple virtual data flows for the purpose of addressing, and wherein K_j denotes the maximum number of virtual data flows that may be served at a time by the j^th transmission format.

9. The base station of claim 7, wherein the addressing constraint for the j^th transmission format is expressed as:

$\underset{i=1}{\overset{N}{\sum <br><br>}}<br><br>\lceil <br><br>\frac{b_i}{B_{i,j}}\rceil <br><br>\le <br><br>K_j$

wherein b_i represents the number of allocated bits to data flows residing on the i^th remote station, wherein B_i,j represents the data size at which the i^th remote station is treated as multiple virtual remote stations for the purpose of addressing, and wherein K_j denotes the maximum number of virtual remote stations that may be served at a time by the j^th transmission format.

10. The base station of claim 1, wherein calculating the data metrics comprises calculating a separate bit metric for each bit in each of the plurality of queues.

11. The base station of claim 10, wherein the bit metric of the k^th bit in the i^th data flow'"'"'s queue at time t with respect to transmission format j is expressed as:

${\mathrm{\alpha <br><br>}}_{i,j,k}<br><br>\left(t\right)=\left[\frac{F<br><br>\left(T_{i,k}<br><br>\left(t\right)-T_{\mathrm{desired},i,k},R_i<br><br>\left(t\right)\right)}{{\mathrm{\tau <br><br>}}_{i,j}}+G<br><br>\left(t+{\mathrm{\tau <br><br>}}_{i,j}-{\mathrm{\tau <br><br>}}_{\mathrm{Expedite},i,k},t+{\mathrm{\tau <br><br>}}_{i,j}-t_{\mathrm{Arrival},i,k}\right)\right]·<br><br>U<br><br>\left({\mathrm{\tau <br><br>}}_{\mathrm{DROP},i,k}-t-{\mathrm{\tau <br><br>}}_{i,j}\right)$

wherein t_Arrival,i,k is the arrival time of bit k of the i^th data flow'"'"'s queue;

wherein t_DROP,i,k is the deadline of bit k of the i^th data flow'"'"'s queue;

wherein τ

_Expedite,i,k is the expedite time of bit k of the i^th data flow'"'"'s queue;

wherein T_i,k(t) is the average throughput experienced by the i^th data flow'"'"'s queue containing bit k;

wherein T_desired,i,k is the average throughput desired by the i^th data flow'"'"'s queue containing bit k;

wherein R_i(t) is the average sustainable data rate/CQI of the i^th data flow'"'"'s channel based on received DRC/CQI feedback;

wherein G(x, y) is an increasing function of two arguments x and y; and

wherein U(·

) is the unit step function.

12. The base station of claim 11, wherein F(T−

T_desired, R) is expressed as;

$F<br><br>\left(T-T_{\mathrm{desired}},R\right)=\frac{1}{\max <br><br>\left(T-T_{\mathrm{desired}},T_{\min }\right)}.$

13. The base station of claim 11, wherein G(x, y) is expressed as:

G(x,y)=K·

U(x)+L·

(y−

Δ

)U(y−

Δ

).

14. The base station of claim 1, wherein the transmission metric for the given transmission format is also dependent on a penalty associated with the given transmission format.

15. The base station of claim 1, wherein the transmission metric for transmission format j is expressed as:

$M_j<br><br>\left(t\right)\equiv <br><br>\underset{i=1}{\overset{N}{\sum <br><br>}}<br><br>\underset{k\in <br><br>\left\{k_1,k_2,\mathrm{\cdots <br><br>}<br><br>,k_{b_i}\right\}}{\sum <br><br>}<br><br>{\mathrm{\alpha <br><br>}}_{i,j,k}<br><br>\left(t\right)-P_j$

wherein α

_i,j,k(t) is a bit metric of the k^th bit in the i^th data flow'"'"'s queue at time t with respect to transmission format j; and

wherein P_j is a penalty associated with transmission format j.

16. The base station of claim 1, wherein the method further comprises selecting the allocated data for the given transmission format so the transmission metric is optimized without violating a packet capacity constraint.

17. The base station of claim 16, wherein the method further comprises:

determining that an addressing constraint is violated; and

in response, adjusting the allocated data so the transmission metric is optimized without violating either the addressing constraint or the packet capacity constraint.

18. The base station of claim 1, wherein the method is performed at each transmission opportunity.

19. The base station of claim 1, wherein the wireless communication system operates in accordance with the 1xEV-DO standard.

20. A base station that is configured for wireless communication, comprising:

means for calculating data metrics for data in a plurality of queues, each queue corresponding to a different data flow;

means for using the data metrics to determine a separate transmission metric for each of a plurality of possible transmission formats, the transmission metric for a given transmission format being dependent on the data metrics corresponding to allocated data for the given transmission format;

means for selecting a transmission format that has an optimum transmission metric; and

means for transmitting the allocated data for the selected transmission format on the forward link in accordance with the selected transmission format.

21. In a base station that is configured for wireless communication, a method comprising:

calculating data metrics for data in a plurality of queues, each queue corresponding to a different data flow;

using the data metrics to determine a separate transmission metric for each of a plurality of possible transmission formats, the transmission metric for a given transmission format being dependent on the data metrics corresponding to allocated data for the given transmission format;

selecting a transmission format that has an optimum transmission metric; and

transmitting the allocated data for the selected transmission format on the forward link in accordance with the selected transmission format.

22. An apparatus for wireless communication, comprising:

a processor; and

memory in electronic communication with the processor;

the memory storing instructions, the instructions that are executable to implement a method comprising;

calculating data metrics for data in a plurality of queues, each queue corresponding to a different data flow;

using the data metrics to determine a separate transmission metric for each of a plurality of possible transmission formats, the transmission metric for a given transmission format being dependent on the data metrics corresponding to allocated data for the given transmission format; and

selecting a transmission format that has an optimum transmission metric.

23. A computer-readable medium for wireless communication comprising instructions executable to:

calculate data metrics for data in a plurality of queues, each queue corresponding to a different data flow;

use the data metrics to determine a separate transmission metric for each of a plurality of possible transmission formats, the transmission metric for a given transmission format being dependent on the data metrics corresponding to allocated data for the given transmission format;

select a transmission format that has an optimum transmission metric; and

transmit the allocated data for the selected transmission format on the forward link in accordance with the selected transmission format.