Software method for maintaining connectivity between applications during communications by mobile computer terminals operable in wireless networks

• US 20030065784A1
• Filed: 09/28/2001
• Published: 04/03/2003
• Est. Priority Date: 09/28/2001
• Status: Active Grant

• Current Assignee: Symbol Technologies, Inc. (Zebra Technologies Corporation)
• Original Assignee: Symbol Technologies, Inc. (Zebra Technologies Corporation)
• Inventors: Herrod, Allan
• Granted Patent: US 7,225,260 B2
• Time in Patent Office: Days
• US Class Current: 709/227
• CPC Class Codes: H04L 67/02 based on web technology, e.g. hypertext transfer protocol [HTTP]
• CPC Class Codes: H04L 67/04 specially adapted for terminals or networks with limited capabilities; specially adapted for terminal portability
• CPC Class Codes: H04L 69/24 Negotiation of communication capabilities
• CPC Class Codes: H04W 28/18 Negotiating wireless communication parameters
• CPC Class Codes: H04W 56/00 Synchronisation arrangements
• CPC Class Codes: H04W 76/10 Connection setup
• CPC Class Codes: H04W 76/30 Connection release

Abstract

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 data communications network including a plurality of stationary access points, 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 radio channel should be attempted in order to continue communications; storing and queuing the messages while a new link is established; and re-establishing a link between first and second virtual sockets in the respective computers in order to continue a session between the first and second applications in the first and second computer respectively.

Claims

1. 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 remote second computer wherein the data is transmitted between the computers over a data communications network, comprising:

(a) establishing a first communications interface software module in the first mobile computer, and a corresponding second communications interface software module in the second computer, to enable a session between an application in the first mobile computer and a second application in the second computer;

(b) establishing data communications between the first mobile computer and the second computer over a communications channel having certain operational attributes;

(c) subsequently determining in the first mobile computer that the operational attributes of the channel have changed, and that communications between the first mobile computer and the second computer should utilize a channel with different characteristics in order to continue communication between the applications;

(d) temporarily suspending data transfer between applications in both the first computer and the second computer while the mobile computer reconfigures its communications configuration; and

(e) resuming communications between the first and second applications in the first and second computer respectively.

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 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 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 between a first mobile computer with a first access point and with said communications controller associated with such access point through an associated port of the communications controller;

(B) registering the user address of said first mobile computer with said communications controller;

(C) utilizing the communications controller for processing messages destined for the first mobile computer and transferring such processed messages through the communications controller 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 the external 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 radio channel should be attempted in order to continue communications;

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

(H) re-establishing a 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 radio link utilizes TDMA and the second radio link utilizes GSM.

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.