Per hop behavior for differentiated services in mobile ad hoc wireless networks

• US 20030058871A1
• Filed: 07/06/2001
• Published: 03/27/2003
• Est. Priority Date: 07/06/2001
• Status: Active Grant

• Current Assignee: SRI International, Inc.
• Original Assignee: SRI International, Inc.
• Inventors: Ogier, Richard G., Sastry, Ambatipudi R.
• Granted Patent: US 7,263,063 B2
• Time in Patent Office: Days
• US Class Current: 370/401
• CPC Class Codes: H04L 47/10 Flow control; Congestion control
• CPC Class Codes: H04L 47/17 Interaction among intermediate nodes, e.g. hop by hop
• CPC Class Codes: H04L 47/2408 for supporting different services, e.g. a differentiated services [DiffServ] type of service
• CPC Class Codes: H04L 47/283 in response to processing delays, e.g. caused by jitter or round trip time [RTT]
• CPC Class Codes: H04L 47/32 by discarding or delaying data units, e.g. packets or frames
• CPC Class Codes: H04L 47/50 Queue scheduling
• CPC Class Codes: H04L 47/521 Static queue service slot or fixed bandwidth allocation
• CPC Class Codes: H04L 47/522 Dynamic queue service slot or variable bandwidth allocation
• CPC Class Codes: H04L 47/6215 Individual queue per QOS, rate or priority
• CPC Class Codes: H04L 47/762 triggered by the network
• CPC Class Codes: H04L 47/805 QOS or priority aware
• CPC Class Codes: H04W 28/22 Negotiating communication rate
• CPC Class Codes: H04W 28/24 Negotiating SLA [Service Level Agreement]; Negotiating QoS [Quality of Service]
• CPC Class Codes: H04W 40/02 Communication route or path selection, e.g. power-based or shortest path routing
• CPC Class Codes: H04W 72/0453 Resources in frequency domain, e.g. a carrier in FDMA
• CPC Class Codes: H04W 84/18 Self-organising networks, e.g. ad-hoc networks or sensor networks

Abstract

Described are a system and method of providing quality of service assurances for transmitting packets over a channel capable of transmission at a nominal bandwidth. A plurality of classes is defined. Each class represents an aggregate behavior of packets and is allocated a nominal departure rate at which the packets of that class are transmitted when an available bandwidth of the channel is substantially at the nominal bandwidth. Each class is assured a minimum allocation of the available bandwidth for transmitting packets of that class if the available bandwidth of the channel is operating at less than the nominal bandwidth. The minimum allocations to each of the classes can be proportionally different than the nominal departure rates allocated to these classes.

Claims

1. In a network comprising a plurality of router nodes connected in the network by communication links, a method of providing quality of service assurances for transmitting packets over a channel capable of transmission at a nominal bandwidth, the method comprising:

defining a plurality of classes, each of the class representing an aggregate behavior of packets;

allocating to each of the classes a nominal departure rate at which the packets of that class are transmitted when an available bandwidth of the channel is substantially operating at the nominal bandwidth; and

assuring each of the classes a minimum allocation of the available bandwidth for transmitting packets of that class if the available bandwidth of the channel is operating at less than the nominal bandwidth.

2. The method of claim 1 wherein the step of assuring a minimum allocation to each of the classes comprises assigning a percentage to each of the classes that represents a minimum percentage of the available bandwidth that is allocated to that class.

3. The method of claim 1 wherein the minimum allocations assured to the classes are proportionally different than the nominal departure rates allocated to these classes.

4. The method of claim 1 further comprising establishing a drop precedence for each of the classes to determine a priority for dropping packets of that class.

5. The method of claim 1 wherein the nominal departure rate assigned to each of the classes by a given one of the router nodes is a percentage of a nominal bandwidth of an outgoing communication link of that router node.

6. The method of claim 1 wherein a given router node has a plurality of outgoing communication links and the nominal departure rate allocated to a given class is different for the different outgoing communication links.

7. The method of claim 1 wherein the nominal departure rate allocated to a given class is different for different router nodes.

8. The method of claim 1 wherein a given router node has a plurality of outgoing communication links and the nominal departure rate together with the assured minimum allocation allocated to a given class is different for the different outgoing communication links.

9. The method of claim 1 wherein the nominal departure rate together with the minimum allocation allocated to a given class is different for different router nodes.

10. The method of claim 1 further comprising dropping packets from queues to limit the delay at a given router node.

11. The method of claim 10 further comprising attaining the minimum allocations assured to each of the service classes by providing an alternate route for packets of service classes in accordance with the rate priorities assigned to the service classes.

12. The method of claim 1 wherein at least one of the communication links is a wireless link.

13. The method of claim 1 further comprising assigning scheduling priorities to the classes based on a criterion.

14. The method of claim 13 wherein the criterion is a delay that each class can tolerate.

15. The method of claim 1 further comprising dynamically changing the nominal departure rate allocations to one of the classes

16. The method of claim 1 further comprising dynamically changing the minimum allocations allocated to the classes.

17. In a network, a router node capable of supporting differentiated services, the router node comprising:

a classifier defining a plurality of classes, each of the classes representing an aggregate behavior of packets;

an allocater allocating to each of the classes a nominal departure rate at which the packets of that class are transmitted when an available bandwidth of the channel is substantially operating at the nominal bandwidth; and

a rate prioritizer assigning to each of the classes a minimum allocation of the available bandwidth for transmitting packets of that class if the available bandwidth of the channel is operating at less than the nominal bandwidth to provide quality of service assurances for transmitting packets over the network.

18. The router node of claim 17 further comprising a plurality of outgoing communication links, and wherein the nominal departure rate allocated to a given class is different for different outgoing communication links

19. The router node of claim 17 further comprising a plurality of outgoing communication links, and wherein the nominal departure rate together with the assured minimum allocation allocated to a given class is different for different outgoing communication links

20. An article of manufacture having computer-readable program means embodied thereon for providing quality of service assurances for transmitting packets over a channel capable of transmission at a nominal bandwidth, the article comprising:

computer-readable means for defining a plurality of classes, each of the class representing an aggregate behavior of packets;

computer-readable means for allocating to each of the classes a nominal departure rate at which the packets of that class are transmitted when an available bandwidth of the channel is substantially operating at the nominal bandwidth; and

computer-readable means for assuring each of the classes a minimum allocation of the available bandwidth for transmitting packets of that class if the available bandwidth of the channel is operating at less than the nominal bandwidth.