CHROMATIC SCHEDULER FOR NETWORK TRAFFIC WITH DISPARATE SERVICE REQUIREMENTS

• US 20110149879A1
• Filed: 12/23/2009
• Published: 06/23/2011
• Est. Priority Date: 12/23/2009
• Status: Active Grant

• Current Assignee: AT&T Mobility II LLC (AT&T, Inc.)
• Original Assignee: AT&T Mobility II LLC (AT&T, Inc.)
• Inventors: Brisebois, Arthur, Noriega, Dimas, De Rosa, Giuseppe
• Granted Patent: US 8,285,298 B2
• Time in Patent Office: Days
• US Class Current: 370/329
• CPC Class Codes: H04W 72/52 based on load
• CPC Class Codes: H04W 72/543 based on requested quality, e.g. QoS
• CPC Class Codes: H04W 84/045 using private Base Stations, e.g. femto Base Stations, home Node B

Abstract

System(s) and method(s) are provided for managing network capacity in a wireless network that serves various traffic flows with disparate quality of service requirements. Management is based on multi-stage scheduling in frequency-time domain. A first scheduling stage generates an allocation of radio resources that minimizes inter-cell interference amongst a plurality of base stations. Based on the first-stage allocation of radio resources, a second scheduling stage computes flow capacity for a set of radio resources specific to a base station, and acquires guaranteed-bit-rate (GBR) and non-guaranteed GBR traffic flows. GBR traffic flows are matched to computed flow capacity to generate an allocation of frequency-time resources. In second scheduling stage, GBR traffic flows are scheduled based at least in part on allocated resources and priority queuing. Based on allocation(s) in first and second scheduling stages, a third scheduling stage schedules non-GBR traffic flows based at least in part on fair scheduling.

Claims

1. A method, comprising:

employing at least one processor to execute code instructions retained in a memory, the code instructions, when executed by at least the processor, perform the following acts;

allocating a set of physical resource blocks (PRBs) for a set of base stations based at least in part on load condition of one or more base stations in the set of base stations;

scheduling a set of guaranteed-bit-rate (GBR) data flows based on the allocated set of PRBs; and

scheduling a set of non-GBR data flows based on available radio resource(s) subsequent to the scheduling of the set of GBR data flows.

2. The method of claim 1, wherein the allocating act is reiterated with a first period;

the first scheduling act is reiterated with a second period, and the second scheduling act is reiterated with a third period, the first period is longer than the second period, which is longer than the third period.

3. The method of claim 1, wherein allocating the set of PRBs for the set of base stations based at least in part on load condition of one or more base stations in the set of base stations includes:

exchanging load condition(s) with the set of base stations;

for a set of radio resources, analyzing one or more allocations of frequency and power for the set of base stations to achieve a satisfactory capacity;

based on the analyzing act, assigning a set of PRBs to each base station in the set of base stations.

4. The method of claim 3, further comprising:

configuring a resource exclusion list that spans the set of PRBs assigned to each base station.

5. The method of claim 1, wherein allocating the set of PRBs for the set of base stations based at least in part on load condition of one or more base stations in the set of base stations includes:

collecting load condition(s) from the set of base stations;

for a set of radio resources, analyzing one or more inter-base-station allocations of frequency and power to achieve a satisfactory capacity;

assigning a set of PRBs to each base station in the set of base stations;

for the set of base stations, configuring a resource exclusion list that spans the set of PRBs assigned to each base station; and

delivering the configured resource exclusion list.

6. The method of claim 1, wherein scheduling a set of guaranteed-bit-rate (GBR) data flows based on the allocated set of PRBs includes:

acquiring a channel quality indicator (CQI) and associated modulation and coding scheme (MCS) indicator for the set of PRBs; and

computing flow capacity based at least in part on at least one of the acquired CQI estimate and the associated MCS indicator, wherein the flow capacity is computed through one or more service functions.

7. The method of claim 6, further comprising:

acquiring a set of GBR flows;

generating a resource reservation list based on the computed flow capacity and bit requirements of the acquired set of GBR flows; and

scheduling the set of acquired GBR flows according to priority queuing and resources reserved through the resource reservation list.

8. The method of claim 7, further comprising:

producing a list of available PRBs for non-GBR traffic based at least in part on the generated resource reservation list.

9. The method of claim 1, wherein scheduling a set of non-GBR data flows based on available radio resource(s) subsequent to the scheduling of the set of GBR data flows includes:

acquiring CQI and allowable MCS per PRB in a set of PRBs allocated to non-GBR traffic;

if current or nearly-current load condition(s) require additional PRBs for the non-GBR traffic;

unmasking a set of unused PRBs reserved for GBR traffic; and

allocating the unmasked PRBs to the non-GBR traffic to augment the set of PRBs allocated to non-GBR traffic; and

based on the allocated PRBs to non-GBR traffic, scheduling non-GBR traffic according to fair queuing.

10. The method of claim 9, further comprising:

if current or nearly-current load condition(s) does not require additional PRBs for the non-GBR traffic, scheduling the non-GBR traffic according to fair queuing based on the set of PRBs allocated to the non-GBR traffic.

11. The method of claim 7, wherein the generating act includes extracting a service curve that bounds an available guaranteed bit rate from below, the service curve is based in part on the computed flow capacity.

12. A computer-readable medium with code instructions stored thereon that, when executed by a processor, cause the processor to perform the following acts:

allocating a set of radio resources for a set of base stations based at least in part on load condition of one or more base stations in the set of base stations;

scheduling a set of GBR data flows based on the allocated set of radio resources; and

scheduling a set of non-GBR data flows based on available radio resources subsequent to the scheduling of the set of GBR data flows.

13. The computer-readable medium of claim 12, wherein the allocating act is reiterated with a first period;

the first scheduling act is reiterated with a second period, and the second scheduling act is reiterated with a third period, the first period is longer than the second period, which is longer than the third period.

14. A system, comprising:

a first component that periodically supplies an allocation of physical resource blocks (PRBs) for each base station in a set of base stations;

a second component that periodically schedules one or more guaranteed-bit-rate (GBR) traffic flows based on the allocation of PRBs; and

a third component that periodically schedules one or more non-GBR traffic flows based on available radio resource(s) subsequent to the scheduling of the one or more GBR data flows.

15. The system of claim 14, a first period with which the first component supplies the allocation of PRBs is longer than a second period with which the second component schedules the one or more GBR traffic flows, and the second period is longer than a third period with which the third component schedules the one or more non-GBR traffic flows.

16. The system of claim 15, wherein, to supply the allocation, the first component analyzes allocations of frequency resources and power to achieve a satisfactory capacity of the set of base stations.

17. The system of claim 14, wherein, to schedule the one or more GBR traffic flows based on the allocation of PRBs, the second component performs the following:

computes a flow capacity for the allocation of PRBs based on one or more service curves;

acquires the one or more GBR traffic flows and computes an arrival curve;

based on the arrival curve, matches bit-rate requirement(s) of the one or more acquired GBR traffic flows to the computed flow capacity for the allocation of PRBs;

generates a resource reservation list for the one or more GBR traffic flows; and

schedules the one or more GBR traffic flows in accordance with priority queuing and the generated resource reservation list.

18. The system of claim 14, wherein, to schedule the one or more non-GBR traffic flows based on available radio resource(s) subsequent to the scheduling of the one or more GBR data flows, the second component performs the following:

acquires channel quality indicators (CQIs) and modulation and coding scheme (MCS) indicators for at least one frequency-time resource allocated to the one or more non-GBR traffic flows; and

when load condition(s) determined based at least in part on the CQIs and MCS indicators require additional frequency-time resource(s) for the one or more non-GBR traffic flows;

augment the at least one frequency-time resource allocated to the one or more non-GBR with unused radio resources available to the set of GBR traffic flows; and

based on the augmented frequency-time resources, schedule one or more non-GBR traffic flows in accordance with fair scheduling.

19. The system of claim 14, wherein the first component receives the allocation of physical resource blocks (PRBs) for each base station in a set of base stations.

20. The system of claim 15, wherein the first period is two orders of magnitude longer than the second period, which is one order of magnitude longer than the third period.