Method and apparatus for providing mobile and other intermittent connectivity in a computing environment

• US 20030120811A1
• Filed: 12/02/2002
• Published: 06/26/2003
• Est. Priority Date: 10/09/1998
• Status: Active Grant

• Current Assignee: Netmotion Wireless Holdings, Inc. (NetMotion Software, Inc.)
• Original Assignee: Netmotion Wireless Incorporated
• Inventors: Sturniolo, Emil A., Menn, Anatoly, Hanson, Aaron D., Savarese, Joseph T., Olson, Erik D.
• Granted Patent: US 6,981,047 B2
• Time in Patent Office: Days
• US Class Current: 709/245
• CPC Class Codes: H04L 1/1809 Selective-repeat protocols
• CPC Class Codes: H04L 1/188 Time-out mechanisms
• CPC Class Codes: H04L 1/1887 Scheduling and prioritising arrangements
• CPC Class Codes: H04L 67/133 Protocols for remote procedure calls [RPC]
• CPC Class Codes: H04L 67/14 Session management for real-time applications in data packet communications networks H04L65/1066
• CPC Class Codes: H04L 67/563 Data redirection of data network streams
• CPC Class Codes: H04L 67/59 Providing operational support to end devices by off-loading in the network or by emulation, e.g. when they are unavailable
• CPC Class Codes: H04W 36/08 Reselecting an access point
• CPC Class Codes: H04W 8/02 Processing of mobility data, e.g. registration information at HLR [Home Location Register] or VLR [Visitor Location Register]; Transfer of mobility data, e.g. between HLR, VLR or external networks
• CPC Class Codes: H04W 80/00 Wireless network protocols or protocol adaptations to wireless operation
• CPC Class Codes: H04W 80/04 Network layer protocols, e.g. mobile IP [Internet Protocol]
• CPC Class Codes: H04W 80/10 adapted for application session management, e.g. SIP [Session Initiation Protocol] connection management H04W76/00; arrangements for session management H04L67/14
• CPC Class Codes: H04W 88/182 Network node acting on behalf of an other network entity, e.g. proxy

Abstract

A seamless solution transparently addresses the characteristics of nomadic systems, and enables existing network applications to run reliably in mobile environments. The solution extends the enterprise network, letting network managers provide mobile users with easy access to the same applications as stationary users without sacrificing reliability or centralized management. The solution combines advantages of existing wire-line network standards with emerging mobile standards to create a solution that works with existing network applications. A Mobility Management Server coupled to the mobile network maintains the state of each of any number of Mobile End Systems and handles the complex session management required to maintain persistent connections to the network and to other peer processes. If a Mobile End System becomes unreachable, suspends, or changes network address (e.g., due to roaming from one network interconnect to another), the Mobility Management Server maintains the connection to the associated peer task—allowing the Mobile End System to maintain a continuous connection even though it may temporarily lose contact with its network medium. In one example, Mobility Management Server communicates with Mobile End Systems using Remote Procedure Call and Internet Mobility Protocols.

Claims

1. A mobile computing environment comprising:

at least one mobile computing device including;

a transport driver interface, and

a mobile interceptor coupled to said transport driver interface,

said mobile interceptor intercepting requests for network services at said transport driver interface, generating Remote Procedure Calls responsive to said requests for network services, and forwarding said Remote Procedure Calls to at least one proxy server;

said proxy server including at least one work dispatcher that receives and handles said Remote Procedure Calls forwarded by said mobile interceptor, said proxy server including a proxy queue that proxies a virtual session on behalf of said mobile computing device when the mobile computing device becomes temporarily disconnected from said mobile computing environment.

2. In a network of the type wherein devices acquire network addresses by transmitting discover messages and receiving responsive offer messages offering network addresses for use, among other parameters, said network including plural sub-networks wherein devices can move from one sub-network to another, a method of detecting when a device has moved between network point of attachments comprising:

listening for said discover messages and/or said responsive offer messages; and

determining whether devices have changed their network point of attachment based at least in part on said listening.

3. The method of claim 2 wherein said discover and responsive offer messages comprise DHCP messages.

4. The method of claim 2 further including maintaining a data structure based on said listening, said data structure including an identifier of the system(s) offering at least network addresses.

5. The method of claim 2 wherein said listening and determining are performed by said device while or after moving.

6. The method of claim 2 wherein said transmitting and determining are performed by at least one non-moving device connected to said network.

7. The method of claim 2 wherein said listening includes listening for an identifier.

8. The method of claim 2 wherein said listening includes ignoring messages not having a matching identifier of a recently received message.

9. The method of claim 2 wherein said determining includes determining a change in network point of attachment has occurred when said listening receives responsive messages different then previous one(s).

10. The method of claim 2 wherein said determining further includes detecting whether devices are out of range.

11. The method of claim 10 wherein said out-of-range detecting includes detecting the absence of messages.

12. The method of claim 2 wherein said determining includes waiting a configurable time-out period for the listening to listen for messages.

13. The method of claim 2 wherein said determining includes determining the presence of a packet relay identifier to aid in the detection of whether a change in network point of attachment has occurred.

14. The method of claim 2 wherein said determining includes determining whether a device has temporarily lost and then re-established contact with the same network point of attachment.

15. In a mobile end device of the type that communicates with a network having plural sub-networks associated therewith, a method of detecting movement between said sub-networks comprising:

(a) transmitting a discover message seeking a network identifier;

(b) listening for offer messages responsive to discovery message; and

(c) detecting movement based on the occurrence of said steps (a) and/or (b).

16. The method of claim 15 further including allowing for only one device at a time to generate said discover messages.

17. In a computer network providing communication between plural devices, said network providing resources to said plural devices, a method of managing said resource consumption including:

enforcing globally, per-device, per-device group, per-user group, and/or peruser policy management for managing consumption of said resources by said devices; and

distributing the task of managing of said resource consumption between said devices, and a plurality of proxy server(s) for proxying communications between peers and said devices.

18. The method of claim 17 further including enabling said devices and/or a proxy server to either allow, deny and/or delay consumption of said network resources.

19. The method of claim 17 including assigning relative priority to different users, devices or tasks, and controls consumption of network resources based at least in part on said priority.

20. The method of claim 17 wherein said enforcing step includes prioritizing, granting, denying, and/or delaying access to said network resources

21. The method of claim 17 wherein said enforcing step comprises configuring said priority.

22. The method of claim 17 wherein said enforcing step comprises configuring access to said network resources.

23. The method of claim 17 wherein said enforcing step comprises assigning priority based on but not limited to user name, user group, device group, device identifier application name, process name, and/or transmit/receive path.

24. The method of claim 17 wherein said enforcing step includes selecting between plural priority levels.

25. In a network comprising plural sub-networks wherein devices can move between said sub-networks and receive different point of presence address assignments, an address management method that is essentially transparent to applications and peer computing systems and does not adversely affect and/or require modification to at least one of a plurality of network application communications session said method comprising:

associating a virtual address with a device that, in use, uses a point of presence address;

mapping said associated virtual address with the point of presence address currently used by said device;

allowing communications sessions to continue, terminate, and/or be established at the said virtual address independently of the point of presence address the device is currently using even during periods when said device is unreachable; and

allowing the maintenance of a secure communications session as the said device migrates to different network points of attachment.

26. The method of claim 25 wherein said allowing step includes proxying said virtual address.

27. A network of the type wherein devices acquire network addresses by transmitting discover messages and receiving responsive offer messages offering network addresses for use, among other parameters, said network including plural sub-networks wherein devices can move from one sub-network to another, a system of detecting when a device has moved between network point of attachments comprising:

a listener that listens for said discover messages and/or said responsive offer messages; and

a processor coupled to the listener, the processor determining whether devices have changed their network point of attachment based at least in part on said listening step.

28. The system of claim 27 wherein said discover and responsive offer messages comprise DHCP messages.

29. The system of claim 27 further including a memory coupled to the processor that maintains a data structure based on said listening, said data structure including an identifier of the system(s) offering at least network address parameters.

30. The system of claim 27 wherein said listener is included in a moving device.

31. The system of claim 27 wherein said listener is included in at least one non-moving device connected to said network.

32. The system of claim 27 wherein said listener listens for an identifier.

33. The system of claim 27 wherein said listener ignores messages not having a matching identifier of a recently received message.

34. The system of claim 27 wherein said processor includes means for determining a change in network point of attachment has occurred when said listener receives responsive messages different then previous one(s).

35. The system of claim 27 wherein said processor includes means for detecting whether devices are out of range.

36. The system of claim 35 wherein said detecting means includes means for detecting the absence of messages.

37. The system of claim 27 wherein said processor includes a timer that waits a configurable time-out period for the listener to listen for messages.

38. The system of claim 27 wherein said processor includes means for determining the presence of a packet relay identifier to aid in the detection of whether a change in network point of attachment has occurred.

39. The system of claim 27 wherein said processor includes means for determining whether a device has temporarily lost and then re-established contact with the same network point of attachment.

40. In a mobile end device of the type that communicates with a network having plural sub-networks associated therewith, a system of detecting movement between said sub-networks comprising:

a transmitter that transmits a discover message seeking a network identifier;

a listener that listens for offer messages responsive to discovery message; and

a processor coupled to said transmitter and said listener that detects movement in said mobile end device.

41. The system of claim 40 further including means for allowing for only one device to generate said discover messages.

42. In a computer network providing communication between plural devices, said network providing resources to said plural devices, a system of managing said resource consumption including:

means for globally, per-device, per-device group, per-user group, and/or per-user policy management for managing consumption of said resources by said devices; and

means for distributing the task of managing of said resource consumption between said devices, and a plurality of proxy server(s) for proxying communications between peers and said devices.

43. The system of claim 42 further including means for enabling said devices and/or a proxy server to either allow, deny and/or delay consumption of said network resources.

44. The system of claim 42 wherein said system assigns relative priority to different users, devices or tasks, and controls consumption of network resources based at least in part on said priority.

45. The system of claim 42 wherein said enforcing means includes means for prioritizing, granting, denying, and/or delaying access to said network resources

46. The system of claim 42 wherein said enforcing means comprises means for configuring said priority.

47. The system of claim 42 wherein said enforcing means comprises means for configuring access to said network resources.

48. The system of claim 42 wherein said enforcing means comprises means for assigning priority based on but not limited to user name, user group, device group, device identifier application name, process name, and/or transmit/receive path.

49. The system of claim 42 wherein said enforcing means includes means for selecting between plural priority levels.

50. A network comprising plural sub-networks wherein devices can move between said sub-networks and receive different point of presence address assignments, an address management system that is transparent to applications and peer computing systems without adversely affecting and/or requiring modification to at least one of a plurality of network application communications sessions said system comprising:

a mapper that associates a virtual address with a device and maps said associated virtual address with the point of presence address currently used by said device; and

a proxy server that allows communications sessions to continue, terminate, and/or be established at the said virtual address independently of the point of presence address the device is currently using even during periods when said device is unreachable, allows the maintenance of a secure communications session as the said device migrates to different network points of attachment.

51. The system of claim 50 wherein said proxy server proxies said virtual address.