Method and system for admission control in communication networks, related network and computer program product therefor

• US 20050220019A1
• Filed: 01/21/2005
• Published: 10/06/2005
• Est. Priority Date: 01/26/2004
• Status: Active Grant

• Current Assignee: STMicroelectronics SRL (STMicroelectronics NV)
• Original Assignee: STMicroelectronics SRL (STMicroelectronics NV)
• Inventors: Melpignano, Diego
• Granted Patent: US 7,471,629 B2
• Time in Patent Office: Days
• US Class Current: 370/232
• CPC Class Codes: H04L 67/14 Session management for real-time applications in data packet communications networks H04L65/1066
• CPC Class Codes: H04L 67/60 Scheduling or organising the servicing of application requests, e.g. requests for application data transmissions using the analysis and optimisation of the required network resources admission control or resource allocation H04L47/70
• CPC Class Codes: H04L 69/329 in the application layer [OSI layer 7]
• CPC Class Codes: H04W 28/065 using assembly or disassembly of packets
• CPC Class Codes: H04W 28/24 Negotiating SLA [Service Level Agreement]; Negotiating QoS [Quality of Service]
• CPC Class Codes: H04W 72/54 based on quality criteria
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]

Abstract

A system for admission control in a wireless local area network adapted to serve a set of stations and manage real time transmission as well as and TCP/IP sessions includes an access point (AP) configured for: when either a new station joins the network or a new TCP/IP session is being initiated, checking if sufficient bandwidth is available in the network for the new traffic flow associated with the new station or TCP/IP session without interfering with any ongoing real time transmission in the network, and in case no sufficient bandwidth is found to be available, whereby said new traffic flow could interfere with said ongoing real time transmission, blocking such new traffic flow.

Claims

1. A method for admission control in a network adapted to serve a set of stations and manage real time transmission as well as TCP/IP sessions, comprising:

checking whether sufficient bandwidth is available when a new station joins the network, for new traffic flow associated with said new station without interfering with any ongoing real time transmission in the network;

blocking said new traffic flow associated with the new station when sufficient bandwidth is not available;

checking whether sufficient bandwidth is available when a new TCP/IP session is being initiated for new traffic flow associated with the new TCP/IP session without interfering with any ongoing real time transmission in the network; and

blocking said new traffic flow associated the new TCP/IP session when sufficient bandwidth is not available.

2. The method of claim 1, further comprising detecting real time audio/video streaming flows in the network by at least one of:

inspecting source and destination MAC headers of forwarded Ethernet frames;

checking an IP header protocol type;

checking a UDP payload and recognizing RTP headers; and

examining inter-arrival time statistics of consecutive packets that belong to a same flow as well as a flow average bit rate.

3. The method of claim 1, further comprising:

providing in the network an access point configured as an Ethernet learning bridge; and

detecting active stations in said set of stations by monitoring MAC addresses in a forwarding table of said Ethernet learning bridge.

4. The method of claim 1, further comprising, when a new TCP/IP session is initiated:

recognizing a related sequence;

inserting a respective tuple in a list; and

applying to a session flow a respective managing policy as identified by said tuple.

5. The method of claim 1, further comprising:

determining a presence of an interfering flow by monitoring a number of packet retransmissions for a link in said network.

6. The method of claim 1, further comprising:

determining a remaining available bandwidth in the network when a new TCP/IP session is initiated.

7. The method of claim 1, further comprising:

calculating a bit rate of recognized real-time traffic in the network; and

determining remaining available bandwidth as a function of wireless channel conditions for the stations in said set of stations.

8. The method of claim 1, further comprising:

determining remaining available bandwidth in the network as a function of;

a real time flow bit rate;

relative positions of an access point to the network and the other stations in said set of stations; and

a presence of other interfering equipment in a same ISM band.

9. The method of claim 1, further comprising:

applying a fragmentation threshold to transmit shorter packets having a smaller retransmission probability in response to high bit error rates on a link between an access point to the network and any of the stations of said set of stations; and

applying the fragmentation threshold in response to interference on a link between the access point to the network and any of the stations of said set of stations.

10. The method of claim 1, further comprising configuring an access point to the network as a state machine having:

a network monitoring state, where said access point tracks flow bit rates and wireless link conditions;

a classification state, where characteristics of a traffic flow are estimated;

a call admission control policy, to specify when a new traffic flow is to be blocked; and

a network protection state, wherein said access point monitors said network.

11. The method of claim 1, further comprising:

performing traffic shaping by smoothing packet inter transmission times in response to incoming burst-like traffic.

12. The method of claim 1, further comprising:

blocking new traffic by MAC-layer disassociation.

13. The method of claim 1 wherein said network comprises a wireless local area network.

14. A system for admission control in a network that serves a set of stations and manages real time transmission as well as TCP/IP sessions, the system comprising an access point configured to:

check, when a new station joins the network, whether sufficient bandwidth is available in the network for new traffic flow associated with said new station without interfering with an ongoing real time transmission in the network;

block said new traffic flow associated with said new station when the new traffic flow associated with the new station could interfere with an ongoing real-time transmission;

check, when a new TCP/IP session is being initiated, whether sufficient bandwidth is available for new traffic associated with said new TCP/IP session without interfering with an ongoing real-time transmission in the network; and

block said new traffic flow associated with said new TCP/IP session when said traffic flow associated with said new TCP/IP session could interfere with an ongoing real time transmission.

15. The system of claim 14 wherein said access point is further configured to detect real time audio/video streaming flows in the network by at least one of:

inspecting source and destination MAC headers of Ethernet frames forwarded;

checking an IP header protocol type;

checking a UDP payload and recognizing RTP headers; and

examining inter-arrival time statistics of consecutive packets that belong to a same flow and a flow average bit rate.

16. The system of claim 14 wherein said access point comprises an Ethernet learning bridge configured to detect active stations in said set of stations by monitoring MAC addresses in a forwarding table of said bridge.

17. The system of claim 14 wherein said access point is further configured to:

recognize, when a new TCP/IP session is initiated, a related sequence;

insert a respective tuple in a list; and

apply a respective managing policy as identified by said tuple to a session flow associated with the new TCP/IP session.

18. The system of claim 14 wherein said access point is further configured to determine a presence of an interfering flow by monitoring a number of packet retransmissions for a link in said network.

19. The system of claim 14 wherein said access point is further configured to determine a remaining available bandwidth in the network when a new TCP/IP session is initiated.

20. The system of claim 14 wherein said access point is further configured to:

recognize real time traffic in the network;

calculate a bit rate thereof; and

determine a remaining available bandwidth as a function of a wireless channel condition for the set of stations.

21. The system of claim 14 wherein said access point is further configured to determine a remaining available bandwidth in the network as a function of at least one of:

i) a real time flow bit rate;

ii) relative positions of said access point and other stations in said set of stations; and

iii) a presence of other interfering equipment in a same ISM band.

22. The system of claim 14 wherein said access point is further configured to:

apply a fragmentation threshold to transmit shorter packets having a smaller retransmission probability in response to a threshold bit error rate on a link from said access point to a station of said set of stations; and

apply a fragmentation threshold to transmit shorter packets having a smaller retransmission probability in response to interference on a link from said access point to a station of said set of stations.

23. The system of claim 14 wherein said access point is further configured as a state machine having:

a network monitoring state, where said access point tracks flow bit rates and wireless link conditions;

a classification state, where characteristics of flows are estimated;

a call admission control policy, to specify if a new traffic flow is to be blocked; and

a network protection state, wherein said access point monitors said network.

24. The system of claim 14 wherein said access point is further configured to perform traffic shaping by smoothing packet inter transmission times in response to incoming burst-like traffic.

25. The system of claim 14 wherein said access point is further configured to selectively block new traffic by MAC-layer disassociation.

26. The system of claim 14 wherein said access point is associated with a station in said set of stations.

27. The system of claim 14 wherein said access point is associated with at least one apparatus selected from the group consisting of a personal computer, a set top box, a TV set, and a laptop computer.

28. The system of claim 14 wherein said access point includes a dedicated packet classifier configured to perform packet classification by comparing header fields against a look-up-table.

29. A communication network that serves a set of stations and manages real time transmission as well as TCP/IP sessions, the network comprising an access point configured to:

check, when a new station joins the network, whether sufficient bandwidth is available in the network for new traffic flow associated with said new station without interfering with an ongoing real time transmission in the network;

selectively block said new traffic flow associated with said new station when the new traffic flow associated with the new station could interfere with an ongoing real-time transmission;

check, when a new TCP/IP session is being initiated, whether sufficient bandwidth is available for new traffic associated with said new TCP/IP session without interfering with an ongoing real-time transmission in the network; and

selectively block said new traffic flow associated with said new TCP/IP session when said traffic flow associated with said new TCP/IP session could interfere with an ongoing real time transmission.

30. The communication network of claim 29 wherein the network comprises a wireless local area network.

31. The communication network of claim 29 wherein said access point is further configured to:

recognize, when a new TCP/IP session is initiated, a related sequence;

insert a respective tuple in a list; and

apply a respective managing policy as identified by said tuple to a session flow associated with the new TCP/IP session.

32. The communication network of claim 29 wherein said access point is further configured to determine a presence of an interfering flow by monitoring a number of packet retransmissions for a link in said network.

33. The communication network of claim 29 wherein said access point is further configured to:

recognize real time traffic in the network;

calculate a bit rate thereof; and

determine a remaining available bandwidth as a function of a wireless channel condition for the set of stations.

34. The communication network of claim 29 wherein said access point is further configured to determine a remaining available bandwidth in the network as a function of at least one of:

i) a real time flow bit rate;

ii) relative positions of said access point and other stations in said set of stations; and

iii) a presence of other interfering equipment in a same ISM band.

35. The communication network of claim 29 wherein said access point is further configured as a state machine having:

a network monitoring state, where said access point tracks flow bit rates and wireless link conditions;

a classification state, where characteristics of flows are estimated;

a call admission control policy, to specify if a new traffic flow is to be blocked; and

a network protection state, wherein said access point monitors said network.

36. A computer program product loadable in a memory of a processor, comprising software code portions for causing the processor to:

check, when a new station joins a network, whether sufficient bandwidth is available in the network for new traffic flow associated with said new station without interfering with an ongoing real time transmission in the network;

selectively block said new traffic flow associated with said new station when the new traffic flow associated with the new station could interfere with an ongoing real-time transmission;

check, when a new TCP/IP session is being initiated, whether sufficient bandwidth is available for new traffic associated with said new TCP/IP session without interfering with an ongoing real-time transmission in the network; and

selectively block said new traffic flow associated with said new TCP/IP session when said traffic flow associated with said new TCP/IP session could interfere with an ongoing real time transmission.

37. The computer program product of claim 36, wherein the instructions further cause the processor to operate as a state machine having:

a network monitoring state, where said processor tracks flow bit rates and wireless link conditions;

a classification state, where characteristics of a traffic flow are estimated;

a call admission control policy, to specify when a new traffic flow is to be blocked; and

a network protection state, wherein said processor monitors said network.

38. The computer program product of claim 36 wherein the instructions further the processor to:

recognize, when a new TCP/IP session is initiated, a related sequence;

insert a respective tuple in a list; and

apply a respective managing policy as identified by said tuple to a session flow associated with the new TCP/IP session.

39. The computer program product of claim 36 wherein the instructions further cause the processor to determine a presence of an interfering flow by monitoring a number of packet retransmissions for a link in said network.

40. The computer program product of claim 36 wherein the instructions further cause the processor to:

recognize real time traffic in the network;

calculate a bit rate thereof; and

determine a remaining available bandwidth as a function of a wireless channel condition for the network.

41. The computer program product of claim 36 wherein the instructions further cause the processor to determine a remaining available bandwidth in the network as a function of at least one of:

i) a real time flow bit rate;

ii) relative positions of said processor and other stations in said network; and

iii) a presence of other interfering equipment in a same ISM band.

42. A system for controlling a network, comprising:

means for determining whether a new data traffic on the network would interfere with an ongoing real time transmission in the network; and

means for selectively blocking the new data traffic coupled to the means for determining whether a new data traffic on the network would interfere with an ongoing real time transmission in the network.

43. The system of claim 42, wherein the new network traffic flow is associated with a new station joining the network.

44. The system of claim 42, wherein the new network traffic is associated with an initiation of a new TCP/IP session.

45. The system of claim 44 wherein the means for determining whether a new data traffic on the network would interfere with an ongoing real time transmission comprises a processor configured to:

recognize, when a new TCP/IP session is initiated, a related sequence; and

insert a respective tuple in a list.

46. The system of claim 42 wherein the means for determining whether a new data traffic on the network would interfere with an ongoing real time transmission comprises a processor configured to determine a presence of an interfering flow by monitoring a number of packet retransmissions for a link in said network.

47. The system of claim 42 wherein the means for determining whether a new data traffic on the network would interfere with an ongoing real time transmission comprises a processor configured to:

recognize real time traffic in the network;

calculate a bit rate thereof; and

determine a remaining available bandwidth as a function of a wireless channel condition for the set of stations.

48. The system of claim 42 wherein the means for determining whether a new data traffic on the network would interfere with an ongoing real time transmission comprises a processor configured to determine a remaining available bandwidth in the network as a function of at least one of:

i) a real time flow bit rate;

ii) relative positions of said access point and another station in said set of stations; and

iii) a presence of other interfering equipment in a same ISM band.

49. The system of claim 42 wherein the means for determining whether a new data traffic on the network would interfere with an ongoing real time transmission comprises a processor configured as a state machine having:

a network monitoring state, where said processor tracks flow bit rates and wireless link conditions;

a classification state, where characteristics of a traffic flow are estimated; and

a network protection state, wherein said processor monitors said network.

50. The system of claim 42 wherein the means for determining whether a new data traffic on the network would interfere with an ongoing real time transmission comprises a packet classifier.