RF-aware packet filtering in radio access networks

• US 8,175,534 B2
• Filed: 09/03/2004
• Issued: 05/08/2012
• Est. Priority Date: 09/03/2004
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Harper, Matthew H., Puthiyandyil, Sanil Kumar
• Primary Examiner(s): Thier, Michael
• Assistant Examiner(s): PEREZ, JULIO R
• Application Number:
  US10/934,166
• Publication Number:
  US 20060050668A1
• Time in Patent Office: 2,804 Days
• Field of Search: 370/229, 370/230, 370/235, 370/401, 370/328, 370/339, 370/265, 370/400, 370/466, 370/467, 370/278, 370/282, 370/338, 709/221, 709/220, 709/223, 709/245, 709/222, 709/225, 709/227, 709/218, 455/453
• US Class Current: 455/67.11
• CPC Class Codes: H04L 47/2416 Real-time traffic
• CPC Class Codes: H04L 47/74 measures in reaction to resource unavailability
• CPC Class Codes: H04L 63/0254 Stateful filtering
• CPC Class Codes: H04W 12/088 using filters or firewalls
• CPC Class Codes: H04W 28/02 Traffic management, e.g. flow control or congestion control
• CPC Class Codes: H04W 76/28 Discontinuous transmission [DTX]; Discontinuous reception [DRX]

Abstract

Methods and systems are provided for filtering packets in a wireless communication system in the to-mobile subscriber direction. This filtering is at least in part based on RF circuit state information. For example, a packet filter is used that either permits or denies packets from reaching a mobile subscriber based on whether there is already an established RF circuit to provide packets to the mobile subscriber. Alternatively, or in addition, the packet filter may consider the history of circuit state transitions associated with a particular mobile subscriber, the percentage (or aggregate number) of available airlink resources that are currently in use, and/or the length of time associated with the dormancy of a mobile subscriber'"'"'s RF connection. In various embodiments, the packet filter may cause one or more packets to be sent to a mobile subscriber using a special data channel that does not require the establishment of an RF circuit.

Claims

1. A wireless communication system comprising:

A network access server (NAS) for providing an interface between a radio access network (RAN) and an internet protocol (IP) network; and

a data packet filter for selectively permitting the passage of a data packet on an individual packet basis from the IP network to the RAN at least in part based on information regarding the data packet and on radio frequency (RF) data channel state information concerning the state of an RF data channel for transferring data between a mobile subscriber (MS) and the RAN using an airlink,

wherein the state of the RF data channel includes a dormant state and an active state;

wherein the dormant state includes when the RF data channel is not established to the MS, and

wherein the active state includes when there is an established RF data channel for transferring data between the MS and the RAN,

wherein the data packet filter causes the passage of the data packet when the RF data channel is determined to be in the active state and the data packet filter selectively passes or inhibits the data packet based on information regarding the data packet when the RF data channel is determined to be in the dormant state.

2. The wireless communication system of claim 1, further comprising a RAN that comprises a base transceiver station (BTS), a base station controller (BSC), and a packet control function (PCF).

3. The wireless communication system of claim 2, wherein the BSC and the PCF are co-located.

4. The wireless communication system of claim 1, wherein the NAS is a packet data service node (PDSN).

5. The wireless communication system of claim 1, wherein the NAS is a gateway general packet radio service support node (GGSN).

6. The wireless communication system of claim 1, wherein the data packet filter includes a static packet filter and the information regarding the data packet includes at least one of address information and protocol type.

7. The wireless communication system of claim 1, wherein the data packet filter denies the passage of the data packet from the IP network to the RAN when an RF data channel is not currently established in connection with the MS.

8. The wireless communication system of claim 1, wherein the state of the RF data channel comprises information regarding the amount of time that the MS has been RF-dormant.

9. The wireless communication system of claim 1, wherein the data packet filter is located within the NAS.

10. The wireless communication system of claim 1, wherein the data packet filter is located within a firewall device.

11. The wireless communication system of claim 10, wherein the data packet filter is located in the data path between the IP network and the NAS.

12. A wireless communication system comprising:

a network access server (NAS) for providing an interface between a radio access network (RAN) and an internet protocol (IP) network, wherein the RAN communicates with mobile subscribers (MS) using a radio frequency (RF) connection; and

a data packet filter for selectively permitting the passage of a data packet from the IP network to the RAN at least in part based on filtering criteria including information regarding the data packet that is obtained from the data packet in the data packet filter and on a determined usage of available radio frequency (RF) resources in the RAN based on information made available to the data packet filter in the wireless communication system for a particular mobile subscriber (MS) to which the data packet is destined including a percentage of available radio frequency (RF) resources that are currently in use at a radio site that communicates with the RAN using an RF connection on an airlink, wherein state information comprises an inactive state when sending a packet to the MS requires the reestablishment of an RF data channel and an active state when there is an allocated RF data channel for transferring data between the MS and the RAN.

13. The wireless communication system of claim 12, further comprising a RAN that comprises a base transceiver station (BTS), a base station controller (BSC), and a packet control function (PCF).

14. The wireless communication system of claim 12, wherein the NAS is a packet data service node (PDSN).

15. The wireless communication system of claim 12, wherein the NAS is a gateway general packet radio service support node (GGSN).

16. The wireless communication system of claim 12, wherein the data packet filter denies the passage of the data packet from the IP network to the RAN when the total number of available RF resources that are being used is above a predetermined number.

17. The wireless communication system of claim 12, wherein the data packet filter is located within the NAS.

18. A wireless communication system of at least one network access server and at least one data packet filter comprising:

a network access server (NAS) for providing an interface between a radio access network (RAN) and an internet protocol (IP) network, wherein the RAN communicates with mobile subscribers (MS) using a radio frequency (RF) connection to allow data packets to be communicated with mobile subscribers; and

a data packet filter configured to selectively mark data packets based on filtering criteria including information in the data packets that is obtained from the data packet in the data packet filter, based on a percentage of available radio frequency (RF) resources that are currently in use at a radio site, and based on state information regarding the MS including when the MS is RF-dormant and configured to permit the passage of a data packet from the IP network to the RAN, the marking resulting in the data packet being sent to a mobile subscriber (MS) using a special data channel, wherein the state information comprises an inactive state when sending a packet to the MS requires the reestablishment of an RF data channel and an active state when there is an allocated RF data channel for transferring data between the MS and the RAN.

19. The wireless communication system of claim 18, wherein the RAN recognizes the marking on the data packet and on the basis of the marking places the marked data packet on the special data channel.

20. The wireless communication system of claim 18, wherein the special data channel is a code-divisional multiple access (CDMA) short data burst channel.

21. The wireless communication system of claim 18, wherein the marking is performed by altering the IP header of the data packet.

22. The wireless communication system of claim 18, wherein the marking is performed by toggling the GRE header of the data packet.

23. A method for filtering data packets at a network access server (NAS) that is in communication with a radio access network (RAN) and an internet protocol (IP) network, the method comprising:

receiving one or more data packets destined for a mobile subscriber (MS) from the IP network;

determining radio frequency (RF) data channel state information concerning the state of an RF data channel on an airlink for transferring data between the MS and the RAN; and

permitting or denying the passage of the one or more packets from the IP network to the MS based at least in part based on information regarding the one or more packets and on the determined RF data channel state information, wherein the packet is denied passage when the RF data channel is in an inactive state and the information regarding the packet meets the packet filter criteria, and wherein the packet is permitted passage when the RF data channel is in an active state, which is when there is an established RF data channel for transferring data between the MS and the RAN.

24. The method of claim 23, wherein the determining comprises obtaining information regarding whether an RF data channel is currently established over an airlink in connection with the MS and if an RF data channel is not established, marking the one or more data packets to send over a special RF data channel.

25. The method of claim 23, wherein the permitting or denying comprising permitting the passage of the data packet from the IP network to the RAN when an RF data channel is currently established in connection with the MS and in an active state.

26. The method of claim 23, wherein the permitting or denying comprising denying the passage of the data packet from the IP network to the RAN when no RF data channel is currently established in connection with the MS.

27. The method of claim 23, wherein the determining comprises obtaining information regarding the amount of time that the RF data channel with the MS has been idle.

28. A data packet filter for use in a wireless communication system, the data packet filter receiving one or more data packets from an internet protocol (IP) network and, based at least in part on information regarding the one or more packets, on a percentage of available radio frequency (RF) resources that are currently in use at a radio site, and on radio frequency (RF) data channel state information concerning the state of an RF data channel for transferring data over an airlink between a mobile subscriber (MS) and a radio access network (RAN), permitting or denying the passage of the one or more packets from the IP network to the MS, wherein the RF data channel state information comprises an inactive state when sending a packet to the MS requires the reestablishment of the RF data channel and an active state when there is an allocated RF data channel for transferring data between the MS and the RAN.

29. The data packet filter of claim 28, wherein the data packet filter determines when the RF data channel is dormant and marks the one or more data packets for transmission to the MS using a special data channel.

30. The data packet filter of claim 28, wherein the data packet filter receives the RF data channel state information from an access device.

31. A wireless communication system comprising:

an access device for providing an interface between a radio access network (RAN) and an internet protocol (IP) network;

the interface with the RAN receiving an indication of the state of an RF connection regarding whether the RF connection is established on an airlink between a mobile subscriber (MS) and the RAN for transferring data; and

a data packet filter for selectively permitting the passage of a data packet from the IP network to the RAN at least in part based on information regarding the data packet, on a percentage of available radio frequency (RF) resources that are currently in use at a radio site, and on RF connection state information, wherein RF connection state information comprises an inactive state when sending a packet to the MS requires the reestablishment of an RF data channel and an active state when there is an allocated RF data channel for transferring data between the MS and the RAN.

32. The wireless communication system of claim 31, wherein the access device maintains a state variable as to how much bandwidth is allocated at a given time for a particular MS.

33. The wireless communication system of claim 31, wherein the data packet filter is configured to send the packets using a reestablished RF connection or a special data channel.

34. The wireless communication system of claim 31, wherein the RF connection state information comprises a dormant state when sending a packet to the MS requires the reestablishment of the RF connection and an established state when there is an allocated RF connection for transferring data between the MS and the RAN.

35. The wireless communication system of claim 31, wherein the data packet filter is located within the access device.

36. Logic encoded on a non-transitory medium that when executed configured to:

receive one or more data packets destined for a mobile subscriber (MS) from the IP network;

determine radio frequency (RF) data channel state information concerning the state of an RF data channel on an airlink for transferring data between the MS and the RAN; and

permit or deny the passage of the one or more packets from the IP network to the MS based at least in part based on information regarding the one or more packets and on the determined RF data channel state information, wherein the packet is denied passage when the RF data channel is in an inactive state and the information regarding the packet meets the packet filter criteria, and wherein the packet is permitted passage when the RF data channel is in an active state, which is when there is an established RF data channel for transferring data between the MS and the RAN.

37. The logic of claim 36, wherein the permitting or denying comprising permitting the passage of the data packet from the IP network to the RAN when an RF data channel is currently established in connection with the MS and in an active state.

38. The logic of claim 36, wherein the permitting or denying comprising denying the passage of the data packet from the IP network to the RAN when no RF data channel is currently established in connection with the MS.