Seamless roaming among multiple networks including seamless transitioning between multiple devices

• US 6,201,962 B1
• Filed: 10/24/1997
• Issued: 03/13/2001
• Est. Priority Date: 05/14/1997
• Status: Expired due to Term

• Current Assignee: Symbol Technologies, LLC (Zebra Technologies Corporation)
• Original Assignee: Telxon Corporation (Zebra Technologies Corporation)
• Inventors: Seshadri, Krishna P., Sturniolo, Emil A., Ciotti, Frank D. Jr.
• Primary Examiner(s): MAUNG, NAY AUNG
• Application Number:
  US08/957,256
• Time in Patent Office: 1,236 Days
• Field of Search: 455/403, 455/414, 455/416, 455/417, 455/422, 455/432, 455/436, 455/437, 455/438, 455/439, 455/442, 455/507, 455/517, 455/552, 455/556, 455/557, 455/560, 455/561, 370/331, 370/328, 370/338, 370/401
• US Class Current: 455/432.2
• CPC Class Codes: H04L 61/4511 using domain name system [DNS]
• CPC Class Codes: H04L 67/14 Session management for real-time applications in data packet communications networks H04L65/1066
• CPC Class Codes: H04L 67/148 Migration or transfer of sessions
• CPC Class Codes: H04W 36/18 for allowing seamless reselection, e.g. soft reselection
• 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 76/10 Connection setup
• CPC Class Codes: H04W 76/20 Manipulation of established connections
• CPC Class Codes: H04W 8/087 for preserving data network PoA address despite hand-offs
• CPC Class Codes: H04W 8/26 Network addressing or numbering for mobility support
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]
• CPC Class Codes: H04W 88/16 Gateway arrangements
• CPC Class Codes: H04W 92/02 Inter-networking arrangements

Abstract

The present invention relates to wireless communication systems involving multiple local area networks. A communication system according to the present invention includes a plurality of local area networks (LANs). Each of the LANs includes: a network backbone; and at least one access point coupled to the network backbone which, when a mobile terminal is registered to the access point, enables the mobile terminal to communicate wirelessly with a device on the network backbone via the at least one access point. When the mobile terminal is registered to at least one access point in one of the plurality of LANs the mobile terminal is assigned a first network address, and when the mobile terminal is registered to at least one access point in another of the plurality of LANs the mobile terminal is assigned a second network address in place of the first network address, the second network address being different from the first network address. The mobile communication system also includes a system backbone interconnecting the plurality of LANs for permitting communications between the plurality of LANs. Furthermore, the system includes a gateway controller, operatively coupled to one of the plurality of LANs, for serving as an intermediary for communications between the mobile terminal and a device on one of the system backbones in order that in the event the mobile terminal is assigned a different network address by virtue of registering with an access point in another of the LANs, the device is able to maintain communications with the mobile terminal without requiring knowledge of a change in the network address of the mobile terminal. In addition, the gateway controller permits sessions to be suspended temporarily and resumed using a different mobile terminal.

Claims

1. A communication system, comprising:

a network backbone;

a gateway controller, operatively coupled to the network backbone, for serving as an intermediary for communications between mobile terminals and devices coupled to the network backbone through respective communication sessions;

a first mobile terminal operative to establish a communication session with a device coupled to the network backbone through the gateway controller, the first mobile terminal being configured to request selectively that the gateway controller suspend the communication session, and the gateway controller being configured to carry out such request; and

the gateway controller being further configured to accept a request from a second mobile terminal and to cause the suspended communication session to be resumed between the device and the second mobile terminal without requiring that the communication session be terminated from the perspective of the device and without the device being aware that the communication session has been suspended with the first mobile terminal and resumed with the second mobile terminal.

2. The communication system of claim 1, wherein the first mobile terminal and the second mobile terminal each comprise at least one of a data terminal, a telephone and a pager.

3. The communication system of claim 1, wherein the gateway controller establishes first and second connections with the first mobile terminal and the second mobile terminal, respectively, and a third connection with the device, and wherein communications involving the first and third connections are replaced by communications involving the second and third connections as part of the suspending and resuming of the communication session.

4. The communication system of claim 3, wherein at least the first connection and the second connection involve wireless transmissions.

5. The communication system of claim 1, further comprising a server connected to the network backbone responsible for maintaining a listing of suspended sessions and corresponding gateway controllers.

6. A method of carrying out communications within a system including a network backbone;

and a gateway controller, operatively coupled to the network backbone, for serving as an intermediary for communications between mobile terminals and devices coupled to the network backbone through respective communication sessions, the method comprising the steps of;

a first mobile terminal establishing a communication session with a device coupled to the network backbone through the gateway controller,

the first mobile terminal requesting that the gateway controller suspend the communication session, and the gateway controller carrying out such request; and

the gateway controller accepting a request from a second mobile terminal to cause the suspended communication session to be resumed between the device and the second mobile terminal without requiring that the communication session be terminated from the perspective of the device and without the device being aware that the communication session has been suspended with the first mobile terminal and resumed with the second mobile terminal.

7. The method of claim 6, wherein the first mobile terminal and the second mobile terminal each comprise at least one of a data terminal, a telephone and a pager.

8. The method of claim 6, wherein the gateway controller carries out a step of establishing first and second connections with the first mobile terminal and the second mobile terminal, respectively, and a third connection with the device, and wherein communications involving the first and third connections are replaced by communications involving the second and third connections as part of the suspending and resuming of the communication session.

9. The method of claim 8, wherein at least the first connection and the second connection involve wireless transmissions.

10. The method of claim 6, the system further comprising a server connected to the network backbone responsible for maintaining a listing of suspended sessions and corresponding gateway controllers.

11. A gateway controller for use in a communication system including a network backbone and a plurality of mobile terminals communicating with devices coupled to the network backbone via the gateway controller, the gateway controller comprising:

a network interface for coupling the gateway controller to the network backbone;

means for suspending a communication session established between a first of the plurality of mobile terminals and a device coupled to the network backbone; and

means for resuming the communication session between a second of the plurality of mobile terminals and the device without requiring that the communication session be terminated from the perspective of the device and without the device being aware that the communication session has been suspended with the first of the plurality mobile terminals and resumed with the second of the plurality mobile terminals.

12. The gateway controller of claim 11, wherein the means for suspending suspends the communication session between the first mobile terminal and the device in response to receiving a request from the first mobile terminal to suspend the communication session.

13. The gateway controller of claim 12, wherein the means for resuming resumes the communication session between the second mobile terminal and the device in response to receiving a request from the second mobile terminal to resume the communication session.

14. A method transferring a communication session between mobile terminals operating in a system including a network backbone, and a gateway controller, operatively coupled to the network backbone, for serving as an intermediary for communication between the mobile terminals and devices coupled to the network backbone, the method including the steps of:

receiving by the gateway controller a request by a first mobile terminal to suspend a communication session between the first mobile terminal and a device coupled to the network backbone;

suspending the communication session between the first mobile terminal and the device coupled to the network backbone;

receiving by the gateway controller a request by a second mobile terminal to resume the suspended communication session; and

resuming the suspended communication session between the second mobile terminal and the device without the device being aware that the communication session had been suspended with the first mobile terminal and resumed with the second mobile terminal.

15. The method of claim 14, further including the step of temporarily storing at the gateway controller information received from the device and intended for the first mobile terminal during such time that the communication session is suspended, and transmitting the stored information to the second mobile terminal upon resuming the communication session.

16. The method of claim 14, wherein following the step of resuming the suspended communication session the gateway controller forwards all information received from the device and intended for the first mobile terminal to the second mobile terminal.

17. A communication system, comprising:

a network backbone;

a gateway controller, operatively coupled to the network backbone, for serving as an intermediary for communications between mobile terminals and devices coupled to the network backbone through respective communication sessions;

a first mobile terminal operative to establish a communication session with a device coupled to the network backbone through the gateway controller, the first mobile terminal being configured to request selectively that the gateway controller suspend the communication session, and the gateway controller being configured to carry out such request; and

the gateway controller being further configured to accept a request from a second mobile terminal and to cause the suspended communication session to be resumed between the device and the second mobile terminal without requiring that the communication session be terminated from the perspective of the device;

wherein the gateway controller temporarily stores information received from the device and intended for the first mobile terminal during such time that the communication session is suspended, and transmits the stored information to the second mobile terminal upon resuming the communication session.

18. A communication system, comprising:

a network backbone;

a gateway controller, operatively coupled to the network backbone, for serving as an intermediary for communications between mobile terminals and devices coupled to the network backbone through respective communication sessions;

a first mobile terminal operative to establish a communication session with a device coupled to the network backbone through the gateway controller, the first mobile terminal being configured to request selectively that the gateway controller suspend the communication session, and the gateway controller being configured to carry out such request;

the gateway controller being further configured to accept a request from a second mobile terminal and to cause the suspended communication session to be resumed between the device and the second mobile terminal without requiring that the communication session be terminated from the perspective of the device;

a server connected to the network backbone responsible for maintaining a listing of suspended sessions and corresponding gateway controllers;

wherein the second mobile terminal queries the server prior to requesting the gateway controller to resume the session.

19. A method of carrying out communications within a system including a network backbone;

and a gateway controller, operatively coupled to the network backbone, for serving as an intermediary for communications between mobile terminals and devices coupled to the network backbone through respective communication sessions, the method comprising the steps of;

a first mobile terminal establishing a communication session with a device coupled to the network backbone through the gateway controller,

the first mobile terminal requesting that the gateway controller suspend the communication session, and the gateway controller carrying out such request; and

the gateway controller accepting a request from a second mobile terminal to cause the suspended communication session to be resumed between the device and the second mobile terminal without requiring that the communication session be terminated from the perspective of the device;

wherein the gateway controller temporarily stores information received from the device and intended for the first mobile terminal during such time that the communication session is suspended, and transmits the stored information to the second mobile terminal upon resuming the communication session.

20. A method of carrying out communications within a system including a network backbone;

and a gateway controller, operatively coupled to the network backbone, for serving as an intermediary for communications between mobile terminals and devices coupled to the network backbone through respective communication sessions, the method comprising the steps of;

a first mobile terminal establishing a communication session with a device coupled to the network backbone through the gateway controller,

the first mobile terminal requesting that the gateway controller suspend the communication session, and the gateway controller carrying out such request;

the gateway controller accepting a request from a second mobile terminal to cause the suspended communication session to be resumed between the device and the second mobile terminal without requiring that the communication session be terminated from the perspective of the device;

wherein the system has a server connected to the network backbone responsible for maintaining a listing of suspended sessions and corresponding gateway controllers and the second mobile terminal queries the server prior to requesting the gateway controller to resume the session.

21. A method of carrying out communications within a system including a network backbone;

and a gateway controller, operatively coupled to the network backbone, for serving as an intermediary for communications between mobile terminals and devices coupled to the network backbone through respective communication sessions, the method comprising the steps of;

a first mobile terminal establishing a communication session with a device coupled to the network backbone through the gateway controller,

the first mobile terminal requesting that the gateway controller suspend the communication session, and the gateway controller carrying out such request;

the gateway controller accepting a request from a second mobile terminal to cause the suspended communication session to be resumed between the device and the second mobile terminal without requiring that the communication session be terminated from the perspective of the device;

wherein the step of the first mobile terminal establishing the communication session with the device comprises the steps of;

the first mobile terminal informing the gateway controller of a willingness to accept communications initiated by the device;

the gateway controller establishing a virtual circuit connection with the first mobile terminal, the gateway controller using the virtual circuit to forward unsolicited information received from the device to the first mobile terminal and to forward information received from the first mobile terminal to the device; and

notifying the gateway controller of charges in a network address of the first mobile terminal to permit seamless communications between the first mobile terminal and the device regardless of a change in the network address of the first mobile terminal.

22. The method of claim 21, wherein the first mobile terminal communicates with the gateway controller through at least one wireless link.

23. A gateway controller for use in a communication system including a network backbone and a plurality of mobile terminals communicating with devices coupled to the network backbone via the gateway controller, the gateway controller comprising:

a network interface for coupling the gateway controller to the network backbone;

means for suspending a communication session established between a first of the plurality of mobile terminals and a device coupled to the network backbone;

means for resuming the communication session between a second of the plurality of mobile terminals and the device without requiring that the communication session be terminated from the perspective of the device; and

means for temporarily storing information received from the device and intended for the first mobile terminal during such time that the communication session is suspended, and transmitting the stored information to the second mobile terminal upon resuming the communication session.

24. A mobile terminal for use in a communication system including a network backbone and a gateway controller coupled to the network backbone for interfacing the mobile terminal with devices coupled to the network backbone, the mobile terminal comprising:

means for establishing with the gateway controller a communication session between the mobile terminal and a device coupled to the network backbone;

means for requesting the gateway controller to suspend the communication session between the mobile terminal and the device without requiring that the communication session be terminated from the perspective of the device; and

means for requesting the gateway to resume with the mobile terminal a previously established communication session between an another mobile terminal and an another device coupled to the network backbone without requiring that the previously established communication session be terminated from the perspective of the another device.

25. The mobile terminal of claim 24, wherein the mobile terminal comprises at least one of a data terminal, a telephone and a pager.