Method and apparatus for providing mobile and other intermittent connectivity in a computing environment
View Patent ↗A seamless solution transparently addresses the characteristics of nomadic systems, and enables existing network applications to run reliably in mobile environments. 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. An interface-based listener uses network point of attachment information supplied by a network interface to determine roaming conditions and to efficiently reestablish connection upon roaming. The Mobility Management Server can distribute lists to Mobile End Systems specifying how to contact it over disjoint networks.
1. In a mobile computing network including at least one mobile computing device coupled to the network via a network point of attachment, an improvement comprising an interface-assisted listener disposed on the mobile computing device that detects, based at least in part on identification of the network point of attachment, whether said mobile computing device has moved to a different network segment while managing application and transport layer communications endpoints used for data communications, said mobile computing device including a data-store that the mobile computing device dynamically populates with network topology information comprising a plurality of network points of attachment said mobile computing device visits, said mobile computing device dynamically building said network topology information as said mobile computing device visits said network points of attachment, said mobile computing device interface-assisted listener employing said dynamically constructed network topology information to detect mobile computing device location, the interface-assisted listener maintaining the network topology information to assist it in deciding correct roam signaling, the listener, upon detecting that the mobile computing device has moved to a different network point of attachment, signaling a roam condition and if necessary prompting the mobile computing device to acquire or register an address usable on the current network segment.
2. A network as in claim 1 wherein said mobile computing device includes at least one network interface adapter, and said listener obtains said network point of attachment identification from said network interface adapter.
3. A network as in claim 1 wherein said listener maintains a network topology map storing information that correlates said network point of attachment identification with further information concerning a network connection.
4. A network as in claim 1 wherein said listener detects when communications with said network is interrupted or reestablished.
5. A network as in claim 4 wherein said listener generates a roam signal in response to detection of (a) network communications interruption and re-establishment, and/or (b) change of said network point of attachment identification.
6. An interface-based listener for use in a mobile computing device, said interface-based listener integrating information from at least one network interface adapter with information available from at least one network stack to determine whether said mobile computing device has moved to a new network point of attachment while managing application and transport layer communications endpoints used for data communications between the mobile computing device and a peer computing system, said mobile computing device including a data-store that said mobile computing device dynamically populates with a network topology map comprising a plurality of network points of attachment visited by said mobile computing device and associated network addresses, said mobile computing device dynamically building said network topology map as said mobile computing device visits said network points of attachment, said mobile computing device interface-assisted listener employing said dynamically constructed network topology map to detect where said mobile computing device has moved, the interface-assisted listener maintaining the network topology map to assist in deciding correct roam signaling, the listener, upon detecting that the mobile computing device has moved to a different network point of attachment, signaling a roam condition and if necessary prompting the mobile computing device to acquire or register an address usable on the current network segment.
7. The interface-based listener of claim 6 wherein the network topology map provides network connection information including network points of attachment information.
8. The listener of claim 7 wherein said listener dynamically constructs said network topology map based on learned information.
9. The interface-based listener of claim 6 including a status checker that checks status based on occurrence of an event.
10. The interface-based listener of claim 9 wherein said event comprises any of a timer timeout, a low level roaming driver callback, and a network level activity hint.
11. The interface-based listener of claim 6 including a connection information searcher that queries the interface adapter as to whether the mobile computing device has already visited a current network point of attachment.
12. The interface-based listener of claim 6 including a connection arrangement that registers or reacquires a current address to be valid on a new network segment.
13. The interface-based listener of claim 6 including a roam signal generator that generates a roam signal in response to detection, based at least in part on information provided by the interface adapter, that the mobile computing device has roamed to a different network segment.
14. The interface-based listener of claim 13 further including a heuristic analyzer that determines whether a previously assigned network address is still valid.
15. A method of determining whether a mobile computing device node has moved to a new network point of attachment, comprising the following steps performed by the mobile computing device node:
(a) said mobile computing device node receiving network point of attachment identification information from a network interface;
(b) the mobile computing device node using said network point of attachment identification information to determine at said mobile computing device node whether said mobile computing device node has moved to a new network point of attachment; and
(c) said mobile computing device node generating signaling in response to said step (b) while managing application and transport layer communications endpoints used for data communications,
said using step (b) including the mobile computing device node dynamically populating, at the mobile computing device node, stored network topology comprising a plurality of network points of attachment visited by said mobile computing device node, and dynamically building said stored network topology as said mobile computing device node visits said network points of attachment, wherein said using step (b) further includes employing said dynamically constructed network topology to detect where said mobile computing device node has moved to and to assist in deciding correct roam signaling, and
upon detecting that the mobile computing device node has moved to a different network point of attachment, signaling a roam condition and if necessary prompting to acquire or register an address usable on the current network segment.
16. A method as in claim 15 further including the mobile computing device node maintaining a network topology map, and using said map to perform step (c).
17. A method as in claim 15 wherein said step (c) includes the mobile computing device node generating a roam signal.
18. A method as in claim 15 wherein said step (b) includes the mobile computing device node obtaining said network point of attachment information from at least one network adapter.
19. A method as in claim 15 further including the mobile computing device node falling back to an alternative location detection mechanism if a network interface is not available that supports generic signaling.
20. A method as in claim 15 further including the mobile computing device node selecting, at least in part in response to said network point of attachment information, between alternate network connection paths.
21. A process for providing least cost routing in a network having plural disjoint segments, comprising:
(a) establishing communications between the network and a temporarily-attached mobile computing device;
(b) using a mechanism on the mobile computing device to allow the mobile computing device to move between said plural disjoint segments; and
(c) enforcing at least one policy parameter to enable the mobile computing device to efficiently automatically select alternate valid network paths for re-establishing communication with the network in response to mobile computing device movement, including the mobile computing device dynamically constructing a network topology at the mobile computing device as said mobile computing device visits network points of attachment, and using said dynamically constructed network topology to determine where said mobile computing device has moved,
(d) maintaining the network topology to assist in deciding correct signaling to send, and
(e) upon the mechanism detecting that the mobile computing device has moved to a different network segment, signaling a roam condition and if necessary prompting the mobile computing device to acquire or register an address usable on the current network segment.
22. The process of claim 21 wherein the policy parameter comprises an element selected from the following group: bandwidth, cost per data unit and quality of service.