Seamless user mobility in a short-range wireless networking environment

• US 20030195002A1
• Filed: 06/09/2003
• Published: 10/16/2003
• Est. Priority Date: 08/11/2000
• Status: Active Grant

• Current Assignee: Reefedge Networks LLC (IPNav)
• Original Assignee: Symantec Corporation (NortonLifeLock Inc.)
• Inventors: Singhal, Sandeep Kishan, Gopal, Inder Sarat, Gopal, Ajei Sarat
• Granted Patent: US 6,975,864 B2
• Time in Patent Office: Days
• US Class Current: 455/436
• CPC Class Codes: H04L 61/00 Network arrangements, protocols or services for addressing or naming
• CPC Class Codes: H04L 61/50 Address allocation
• CPC Class Codes: H04L 61/5014 using dynamic host configuration protocol [DHCP] or bootstrap protocol [BOOTP]
• CPC Class Codes: H04L 67/04 specially adapted for terminals or networks with limited capabilities; specially adapted for terminal portability
• CPC Class Codes: H04L 69/329 in the application layer [OSI layer 7]
• CPC Class Codes: H04W 36/0011 for data sessions of end-to-end connection
• CPC Class Codes: H04W 36/0019 adapted for mobile IP [MIP]
• CPC Class Codes: H04W 60/00 Affiliation to network, e.g. registration; Terminating affiliation with the network, e.g. de-registration
• CPC Class Codes: H04W 8/04 Registration at HLR or HSS [Home Subscriber Server]
• CPC Class Codes: H04W 8/26 Network addressing or numbering for mobility support
• CPC Class Codes: H04W 80/04 Network layer protocols, e.g. mobile IP [Internet Protocol]
• CPC Class Codes: H04W 88/182 Network node acting on behalf of an other network entity, e.g. proxy
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

The present invention provides methods, systems, and computer program instructions for enabling a variety of devices, particularly low-power hand-held devices, to travel seamlessly through a networking environment such as that encountered within a building by establishing connectivity to a plurality of network access points. The illusion of seamless network connectivity is provided by having these access points coordinate with a core server to perform user authentication, device address assignment, and handoff services.

Claims

1. A method of enabling seamless user mobility in a short-range wireless networking environment, comprising the steps of:

providing one or more portable client devices, each of the client devices equipped with a short-range wireless communications capability for communicating in the short-range wireless networking environment;

providing a plurality of Handoff Management Points (HMPs), each of the HMPs equipped with a short-range wireless link for communication with the client devices and a link to a networking environment wherein one or more application programs residing on one or more application servers can be accessed; and

providing a Handoff Core Server to manage the HMPs.

2. The method according to claim 1, wherein an installation and a configuration of an operational HMP requires no incremental intervention by a systems administrator.

3. The method according to claim 1, further comprising a process for dynamically making a selected one of the HMPs operational, comprising the steps of:

obtaining an Internet Protocol (IP) address for the selected HMP;

discovering, by the selected HMP, an identity of the Handoff Core Server; and

initiating, by the selected HMP, an HMP presence protocol exchange with the Handoff Core Server.

4. The method according to claim 3, wherein the step of obtaining an IP address further comprises issuing a Dynamic Host Configuration Protocol (DHCP) request.

5. The method according to claim 4, wherein the step of discovering an identity of the Handoff Core Server further comprises the step of inspecting a response to the DHCP request.

6. The method according to claim 3, wherein the step of discovering an identity of the Handoff Core Server further comprises the step of issuing a Service Location Protocol (SLP) request.

7. The method according to claim 3, wherein the step of initiating an HMP presence protocol exchange further comprises the step of:

sending a registration request to the Handoff Core Server to register the selected HMP with the Handoff Core Server; and

further comprising the steps of;

obtaining a registration response from the Handoff Core Server; and

if the registration response is successful, periodically refreshing the selected HMP'"'"'s registration with the Handoff Core Server.

8. The method according to claim 1, wherein Dynamic Host Configuration Protocol (DHCP) requests generated by the client devices are received by a selected HMP and then forwarded by the selected HMP to the Handoff Core Server for processing.

9. The method according to claim 8, further comprising the steps of:

selecting, by the Handoff Core Server responsive to receiving a particular one of the forwarded DHCP requests, an Internet Protocol (IP) address for a particular client device;

forwarding the selected IP address from the Handoff Core Server to the selected HMP; and

forwarding, by the selected HMP, a DHCP response to the particular client device.

10. The method according to claim 9, wherein the step of selecting an IP address for a particular client device further comprises executing a table lookup in an Active User Location (AUL) Registry.

11. The method according to claim 1, wherein the Handoff Core Server maintains a record of a current location of each client device.

12. The method according to claim 11, wherein the record is maintained in an Active User Location (AUL) Registry.

13. The method according to claim 11, wherein the Handoff Core Server also maintains a historical record of one or more locations of each client device as the client device moves throughout the short-range wireless networking environment.

14. The method according to claim 11, further comprising the steps of:

receiving at least one of (1) traffic generated by a particular client device and (2) traffic destined for a particular client device at the Handoff Core Server; and

filtering the received traffic, by the Handoff Core Server, according to a destination of the traffic.

15. The method according to claim 11, further comprising the steps of:

Receiving at least one of (1) traffic generated by a particular client device and (2) traffic destined for a particular client device at the Handoff Core Server; and

filtering the received traffic according to a current location of the particular client device.

16. The method according to claim 11, further comprising the steps of:

Receiving at least one of (1) traffic generated by a particular client device and (2) traffic destined for a particular client device at the Handoff Core Server; and

Filtering the received traffic according to an identity of a user of the particular client device.

17. The method according to claim 1, further comprising the steps of:

detecting, by a particular HMP, an establishment of a new communication channel with a selected client device;

issuing a channel establishment notification to the Handoff Core Server, responsive to the detecting step; and

updating by the Handoff Core Server, an Active User Location (AUL) Registry, responsive to receiving the channel establishment notification.

18. The method according to claim 17, wherein the establishment is an explicit establishment.

19. The method according to claim 17, wherein the establishment is an implicit establishment.

20. The method according to claim 17, further comprising the steps of:

detecting, by the particular HMP, a termination of an existing communication channel with a particular client device;

issuing a channel termination notification to the Handoff Core Server, responsive to the step of detecting the termination; and

updating, by the Handoff Core Server, the AUL Registry, responsive to receiving the channel termination notification.

21. The method according to claim 20, wherein the termination is an explicit termination.

22. The method according to claim 20, wherein the termination is an implicit termination.

23. The method according to claim 1, wherein the Handoff Core Server maintains at least one of an HMP Registry or an Active User Location (AUL) Registry.

24. The method according to claim 23, wherein the Handoff Core Server provides a plurality of Application Programming Interfaces (APIs) through which the application programs may retrieve information from at least one of the HMP Registry or the AUL Registry.

25. The method according to claim 24, wherein a selected application program running on at least one of the application servers invokes one of the plurality of APIs.

26. The method according to claim 25, wherein the selected application program provides location-based services based on information obtained through the APIs.

27. The method according to claim 25, wherein the selected application program provides personalized services based on information obtained through the APIs.

28. The method according to claim 25, wherein the selected application program provides proximity-based printing.

29. The method according to claim 1, further comprising the steps of:

providing a plurality of Handoff Core Servers; and

providing a Core Management Server; and

wherein the Core Management Server is adapted for communicating with a plurality of Handoff Core Servers;

.

30. The method according to claim 29, wherein the Core Management Server can invoke requests to the plurality of Handoff Core Servers.

31. The method according to claim 29, wherein the plurality of Handoff Core Servers can request services from the Core Management Server.

32. A system for enabling seamless user mobility in a wireless networking environment, comprising:

one or more portable user devices, each equipped with a short-range wireless communications capability for communicating in the wireless networking environment;

one or more application programs residing on one or more application servers;

a plurality of Handoff Management Points (HMPs), each equipped with a wireless link for communication with the user devices and a link to a networking environment wherein the application programs and application servers reside;

a Handoff Core Server (HCS) to manage the HMPs;

means for dynamically registering each HMP with the HCS as the HMP becomes operational, wherein an installation and configuration of the operational HMP requires no incremental intervention by a human;

means for making a selected user device known to a first HMP when the selected user device comes into communication range with the first HMP;

means for handing the selected user device off from the first HMP to a second HMP when the selected user device leaves the communication range of the first HMP and enters communication range of the second HMP; and

means for maintaining, during and after the handing off, any on-going session that may be operating between the selected user device and one or more of the application programs.

33. The system according to claim 32, wherein the means for maintaining further comprises:

means for assigning an Internet Protocol (IP) address to the selected user device when the selected user device is in the communication range of the first HMP; and

means for continuing to use the IP address for the selected user device when the selected user device is in the communication range of the second HMP.

34. The system according to claim 32, further comprising means for re-registering each dynamically registered HMP after expiration of a particular period of time.

35. The system according to claim 33, wherein the means for assigning further comprises means for storing the IP address for the selected user device at the HCS, and wherein the means for continuing to use further comprises means for retrieving the stored IP address from the HCS.

36. Computer program instructions embodied on one or more computer readable media, the computer program instructions being adapted for causing a computer system to generate executable code for a computer program, the computer program enabling seamless user mobility in a wireless networking environment, the computer program instructions comprising:

computer program instructions for dynamically registering a plurality of Handoff Management Points (HMPs) with a Handoff Core Server (HCS) as the HMP becomes operational, wherein each HMP is equipped with a wireless link for communication with a plurality of user devices and a link to a networking environment wherein a plurality of application programs and application servers reside, wherein each of the user devices being equipped with a short-range wireless communications capability for communicating in the wireless networking environment, and wherein an installation and configuration of the operational HMP requires no incremental intervention by a human;

computer program instructions for causing the HCS to manage the HMPs;

computer program instructions for making a selected user device known to a first HMP when the selected user device comes into communication range with the first HMP;

computer program instructions for handing the selected user device off from the first HMP to a second HMP when the selected user device leaves the communication range of the first HMP and enters communication range of the second HMP; and

computer program instructions for maintaining, during and after the handing off, any on-going session that may be operating between the selected user device and one or more of the application programs.

37. The computer program instructions according to claim 36, wherein the computer program instructions for maintaining further comprise:

computer program instructions for assigning an Internet Protocol (IP) address to the selected user device when the selected user device is in the communication range of the first HMP; and

computer program instructions for continuing to use the IP address for the selected user device when the selected user device is in the communication range of the second HMP.

38. The computer program instructions according to claim 36, further comprising computer program instructions for reregistering each dynamically registered HMP after expiration of a particular period of time.

39. The computer program instructions according to claim 37, wherein the computer program instructions for assigning further comprises computer program instructions for storing the IP address for the selected user device at the HCS, and wherein the computer program instructions for continuing to use further comprises computer program instructions for retrieving the stored IP address from the HCS.