Method and system for data transmission over a network link between computers with the ability to withstand temporary interruptions

• US 5,835,721 A
• Filed: 07/25/1996
• Issued: 11/10/1998
• Est. Priority Date: 08/21/1995
• Status: Expired due to Term

• Current Assignee: Apple Inc.
• Original Assignee: Apple Computer Incorporated (Apple Inc.)
• Inventors: Bhatt, Nikhil, Donahue, Clark P.
• Primary Examiner(s): Shin, Christopher B.
• Application Number:
  US08/686,020
• Time in Patent Office: 838 Days
• Field of Search: 395/788, 395/161, 395/800, 395/200, 395/140, 395/200.54, 395/201.57, 395/200.47, 395/200.61, 395/200.64, 395/182, 370/60, 370/88.7, 370/248
• US Class Current: 709/224
• CPC Class Codes: H04L 43/0811 by checking connectivity
• CPC Class Codes: H04L 69/326 in the transport layer [OSI layer 4] H04L69/16 takes precedence
• CPC Class Codes: H04L 9/40 Network security protocols
• CPC Class Codes: H04W 24/00 Supervisory, monitoring or testing arrangements
• CPC Class Codes: H04W 48/08 Access restriction or access information delivery, e.g. discovery data delivery signalling during connection H04W76/00
• CPC Class Codes: H04W 76/10 Connection setup
• CPC Class Codes: H04W 76/19 Connection re-establishment

Abstract

A data transfer technique in which lossy connections or temporarily interrupted network links neither prevent data transfer nor substantially impair the ease with which a user can transfer data. A sender is advised of receivers on a network that are available to receive data over the network. Also, while data transfer from a sender to a receiver is being performed, the availability of the receiver is monitored. If, during the data transfer, the receiver becomes unavailable to receive the data, then the data transmission stops and the sender is informed that the receiver has become unavailable. The sender continues to monitor the network to determine if the receiver has regained its availability. If the receiver regains availability, the sender is able to automatically resume the data transmission, provided the availability is regained before the network connection is completely lost. The invention is useful for wireless networks as well as wired networks.

Claims

1. A method for transmitting data from a first computing device to a second computing device via a network, said method comprising:

(a) establishing a connection via the network from the first computing device to the second computing device;

(b) sending data from the first computing device to the second computing device over the network while monitoring the availability of the second computing device to receive the data over the network; and

(c) stopping said sending (b) of the data when the second computing device becomes unavailable;

(d) determining whether the second computing device regains availability before the connection is lost; and

(e) resuming said sending (b) of the data after a temporary interruption when said determining (d) determines that the availability of the second computing device is regained before the connection is lost.

2. A method as recited in claim 1, wherein the first and second computing devices are portable computers, and the network is a wireless network established between the portable computers.

3. A method for transmitting data from a first computing device to a second computing device via a network, said method comprising:

(a) searching the network for computing devices available to receive data over the network;

(b) displaying an indicator for each of the computing devices available to receive data on a display screen of the first computing device;

(c) establishing a connection via the network from the first computing device to the second computing device;

(d) sending data from the first computing device to the second computing device over the network while monitoring the availability of the second computing device to receive the data over the network;

(e) stopping said sending (d) of the data when the second computing device becomes unavailable;

(f) determining whether the second computing device regains availability before the connection is lost; and

(g) resuming said sending (d) of the data after a temporary interruption when said determining (f) determines that the availability of the second computing device is regained before the connection is lost.

4. A method as recited in claim 3, wherein the network is a wireless network.

5. A method as recited in claim 4, wherein the first and second computing devices are portable computers, and the wireless network is a dedicated wireless infrared link established between the portable computers.

6. A method as recited in claim 3, wherein when said (g) resuming of said sending (d) of the data is occurs, the sending continues to send the data from the point where the transmission of the data previously stopped.

7. A method as recited in claim 3, wherein said searching (a) comprises:

(a1) sending a lookup operation over the network;

(a2) receiving, over the network, responses to the lookup operation from the computing devices available to receive the data over the network; and

(a3) determining whether the computing devices available to receive the data has changed.

8. A method as recited in claim 3, wherein said displaying (b) causes indicators to be added or removed from the screen display of the first computing device as the computing devices available to receive the data changes.

9. A method as recited in claim 3, wherein the data being sent to the second computing device is associated with a file transfer from the first computing device to the second computing device.

10. A method as recited in claim 3, wherein the first and second computing devices are computers, and the network is a wireless network, and

wherein the data being sent to the second computing device is associated with a file transfer from the first computing device to the second computing device.

11. A method for transmitting data from a first computing device to a second computing device via a network, said method comprising:

(a) searching the network for computing devices available to receive data over the network;

(b) determining if the second computing device is one of the computing devices available to receive data over the network;

(c) establishing a connection via the network from the first computing device to the second computing device when the second computing device is available and when there is data to be transmitted from the first computing device to the second computing device;

(d) sending data from the first computing device to the second computing device over the network;

(e) monitoring the availability of the second computing device to receive the data over the network;

(f) suspending said sending (d) of the data to the second computing device if the second computing device loses availability;

(g) maintaining the connection from the first computing device to the second computing device via the network during said suspending (f);

(h) resuming said sending (d) of the data to the second computing device if the second computing device regains availability; and

(i) terminating the connection from the first computing device to the second computing device if the second computing device does not regain availability.

12. A method as recited in claim 11, wherein said maintaining (g) maintains the connection open only for a first predetermined period of time.

13. A method as recited in claim 11, wherein said monitoring (e) is performed on a periodic basis during said sending (d) and said suspending (f).

14. A method as recited in claim 11, wherein said resuming (h) is permitted only after the second computing device regains availability and remains available for a second predetermined period of time.

15. A method as recited in claim 11, wherein the data being sent to the second computing device is associated with a file transfer from the first computing device to the second computing device.

16. A method as recited in claim 11, wherein the first and second computing devices are computers, and the network is a wireless network, and

wherein the data being sent to the second computing device is associated with a file transfer from the first computing device to the second computing device.

17. A system for transmitting data from a first computing device to a second computing device, said system comprising:

a network capable of interconnecting the first computing device to a plurality of other computing devices including the second computing device;

search means for searching the network to determining which of other devices on the network are available to receive data from the first computing device;

a display screen, said display screen displaying at least an indicator for each of the available devices on the network;

data transfer means for transferring of data from the first computing device to the second computing device via a network link, provided one of the indicators on said display screen corresponds to the second computing device, with the network link supporting a connection between the first computing device and the second computing device;

a message window for displaying a message on said display screen of the first computing device when the second computing device becomes unavailable to receive the data after the transfer of data has began but before the transfer of data is complete; and

data transfer resumption means for resuming the transfer of data if the second computing device again becomes available,

wherein when the second computing device becomes unavailable during the transfer of the data to the second computing device, the transfer of the data stops but the connection from the first computing device to the second computing device via the network link temporarily remains open so that the transfer of the data can resume if the second computing device again becomes available before the connection is lost.

18. A system as recited in claim 17, wherein the first computing device and the second computing device are both portable computers, and the first and second computing devices are portable computers, and the network link is a wireless link.

19. A system as recited in claim 18, wherein the wireless network is a dedicated wireless infrared link established between the portable computers.

20. A system as recited in claim 17, wherein said search means continues to search the network to determine whether the second computing device remains available to receive data from the first computing device via the network.

21. A system as recited in claim 20, wherein said system further comprises:

a data queue for storing data transmission requests from the first computing device to other computing devices over the network.

22. A system as recited in claim 21,

wherein said data queue indicates availability of each of the data transmission requests stored therein, and

wherein said data transfer means selects one of the data transmission requests stored in the data queue for transmission over the network based on at least availability of the receiver.

23. A system as recited in claim 21,

wherein said data queue indicates availability of each of the data transmission requests stored therein as well as a busy state if the transmission request is to a computing device which is busy receiving another transmission request over the network, and

wherein said data transfer means selects one of the data transmission requests stored in the data queue for transmission over the network based on at least availability of the receiver.

24. A system as recited in claim 23, wherein said search means maintains a receiver availability list for use when determining whether receivers which were previously available have become unavailable.

25. A system as recited in claim 17, wherein the network is a wireless network.

26. A system as recited in claim 25, wherein the wireless network is an infrared wireless network.

27. A system as recited in claim 17, wherein said network is a wired network.

28. A computer readable medium containing program instructions for transmitting data over a network link, said computer readable medium comprising:

computer readable code devices for searching the network for computing devices available to receive data over the network;

computer readable code devices for displaying an indicator for each of the computing devices available to receive data on a display screen of a first computing device;

computer readable code devices for establishing a connection via the network from the first computing device to a second computing device; and

computer readable code devices for sending data from the first computing device to the second computing device over the network while monitoring the availability of the second computing device to receive the data over the networks;

computer readable code devices for stopping the sending of the data when the second computing device becomes unavailable;

computer readable code devices for determining whether the second computing device regains availability before the connection is lost; and

computer readable code devices for resuming the sending of the data after a temporary interruption when the determining operates to determine that the availability of the second computing device is regained before the connection is lost.

29. A user interface for a computer system, the user interface being visually displayed on a display screen of the computer system, the computer system being connected to a network of other devices, said user interface comprising:

search means for searching the network to determine the devices on the network available to receive data from the computer system;

display means for displaying on the display screen a window having an indicator for each of the available devices on the network;

means for periodically updating said window so that the indicators displayed provide an accurate account of the available devices;

means for invoking a transfer of data from the computer system to a selected one of the available devices;

a message window for displaying a message on the display screen of the computer system when the selected one of the available devices to which data is being sent becomes unavailable to receive the data before the transmission of the data is complete, the message indicating the stoppage of the transfer of the data when the selected one of the available devices becomes unavailable and that resumption of the transfer of data can be had if the availability of the selected one of the available devices returns within a predetermined period of time.