Software method utilizing gateways for maintaining connectivity during communications over distinct wireless networks by mobile computer terminals

• US 20030227892A1
• Filed: 06/06/2002
• Published: 12/11/2003
• Est. Priority Date: 06/06/2002
• Status: Active Grant

• Current Assignee: Symbol Technologies, LLC (Zebra Technologies Corporation)
• Original Assignee: Symbol Technologies, Inc. (Zebra Technologies Corporation)
• Inventors: Cabana, Joseph
• Granted Patent: US 7,209,466 B2
• Time in Patent Office: Days
• US Class Current: 370/338
• CPC Class Codes: H04W 88/16 Gateway arrangements

Abstract

A method of operating a gateway to at least two distinct data communications networks at least one network being a wireless local are network including a plurality of stationary LAN base stations and a plurality of mobile computer units, each of the mobile units being capable of communicating with at least one base station when located within a predetermined range therefrom and being normally associated with an in communications with such base station, by (a) establishing communication and association between a first mobile unit and a first LAN base station; and (b) activating an authentication mode of operation in both the first mobile unit and the first LAN base station. The next steps include (c) authenticating the first mobile unit; (d) establishing a first communications channel with a remote station from the mobile unit through the gateway; and (e) determining in the gateway that communications between the remote station and the mobile unit on the wireless local area network has been impeded.

Finally, step (f) is utilizing the gateway to establish a separate and distinct second communications channel between the remote station and the mobile unit through a second data communications network, which is not a wireless local area network, and transferring communications between the remote station and the mobile unit to the second communications channel. The second data communications channel is preferably the public switched telephone network and a cellular telephone link to the mobile unit.

Claims

1. A method of operating a gateway to at least two distinct data communications networks at least one network being a wireless local area network including a plurality of stationary LAN base stations and a plurality of mobile computer units, each of the mobile units being capable of communicating with at least one base station when located within a predetermined range therefrom and being normally associated with and in communications with such base station, comprising the steps of:

(a) establishing communication and association between a first mobile unit and a first LAN base station;

(b) activating an authentication mode of operation in both the first mobile unit and the first LAN base station;

(c) authenticating the first mobile unit;

(d) establishing a first communications channel with a remote station from the mobile unit through the gateway,

(e) determining in the gateway, that communications between the remote station and the mobile unit on the wireless local area network has been impeded; and

(f) utilizing the gateway to establish a separate and distinct second communications channel between the remote station and the mobile unit through a second data communications network, which is not a wireless local area network, and transferring communications between the remote station and the mobile unit to said second communications channel.

2. A method as defined in claim 1, wherein the communications interface software module emulates a standard communications API so that calls to the standard communications API from legacy applications are capable of being processed by said software module.

3. A method as defined in claim 1, wherein the application in the first mobile computer is a data collection application utilizing a bar code reader to input data to the computer.

4. The method of claim 3, further including the step of temporarily storing information received from the data collection application and intended for the second computer during such time that the communication session is suspended, and transmitting the stored information to the second computer upon resuming the communication session.

5. The method of claim 4, wherein following the step of resuming communications, the communications interface software module forwards all information received from the data collection application and intended for the second computer to the second computer.

6. The method of claim 1, wherein the mobile computer reconfigures its communications by operating at a different data rate on the same channel.

7. The method of claim 1, wherein the mobile computer reconfigures its communications by operating at a different signal modulation on the same channel.

8. A method as defined in claim 1, wherein the application in the first mobile computer is a data display application utilizing a browser.

9. The method of claim 8, further including the step of temporarily storing information in the first mobile computer received from the second computer for the data display application, and during such time that the communication session is suspended, allowing the use of the first mobile computer to browse the stored information by executing the data display application.

10. The method of claim 8, wherein following the step of resuming communications, the communications interface software module forwards all request for data from the second computer from the browser application and intended for the first mobile computer to the first mobile computer.

11. A method of maintaining connectivity and synchronization of data from a first application resident in a first mobile computer to a second application resident in a second computer wherein the data is transmitted over a wireless data communications network including a plurality of stationary access points and at least one communications controller in communication with the access points, and a plurality of remote mobile computers, at least some of the mobile computers being capable of wirelessly communicating with at least two of the access points when located within a predetermined range therefrom and being normally associated with and in communications with a single one of such access points, each mobile computer having a unique user address, comprising:

(a) establishing communication and association over a wireless local area network between a first mobile computer with a first access point and with said communications controller associated with such access point through a gateway;

(b) registering the user address of said first mobile computer with said gateway;

(c) utilizing the gateway for processing messages destined for the first mobile computer and transferring such processed messages through the gateway to the associated access point and the first mobile computer;

(d) establishing a first virtual and real sockets in the first computer in response to each connection request by the first application for processing data originated by the first application and corresponding second virtual and real sockets in the second computer to enable a connection between the first computer to a second application in the second computer over a wired communication link;

(e) establishing in the second computer a second virtual socket for each connection request by the first application wherein the second virtual socket corresponds to a first virtual socket established in the first computer;

(f) subsequently determining, in said first mobile computer, that communications between the first mobile computer and the second computer has been impeded, and that association with a different access point or use of a different wired communication link should be attempted in order to continue communications;

(g) storing and queuing the messages while a new second link is established; and

(h) re-establishing a second link between said first and second virtual sockets in order to continue a session between the first and second applications in the first and second computer respectively.

12. A method as defined in claim 11, wherein the data communication network is a wireless local area network.

13. A method as defined in claim 11, wherein the step of determining includes detecting which other communication networks are available for establishing a new communication link.

14. A method as defined in claim 13, wherein the first link utilizes a wireless local area network and the second link is the public switched telephone network.

15. A method as defined in claim 13, wherein the first radio link couples to a packet switched network and the second radio link couples to a circuit switched network.