Method and apparatus for selecting between a plurality of communication paths

• US 5,406,643 A
• Filed: 02/11/1993
• Issued: 04/11/1995
• Est. Priority Date: 02/11/1993
• Status: Expired due to Term

• Current Assignee: Motorola Mobility LLC (Lenovo Group Ltd.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Kee, Thomas E., Burke, Christopher J., Chaffee, Janice M., Nir, Erez
• Primary Examiner(s): Kriess, Kevin A.
• Application Number:
  US07/991,892
• Time in Patent Office: 789 Days
• Field of Search: 395/200, 395/700, 395/650, 395/800, 370/94, 370/94.1, 370/94.3, 370/60.1
• US Class Current: 709/243
• CPC Class Codes: H04L 41/0816 the condition being an adaptation, e.g. in response to network events
• CPC Class Codes: H04L 43/0894 Packet rate
• CPC Class Codes: H04L 67/14 Session management for real-time applications in data packet communications networks H04L65/1066
• CPC Class Codes: H04L 9/40 Network security protocols

Abstract

In a data communication system (100), a method is provided to distinguish between and select from multiple communication paths (4,6,and 8)to a designated end point (10). The communications path selection is done locally, on a portable subscriber unit (2). The communications path is transparent to requesting software application (30). The method manages a plurality of communications devices (42,44) using existing communications infrastructure.

Claims

1. A method for selecting one of a plurality of communications path between a subscriber unit and a destination, said subscriber unit comprising memory and a plurality of different communication resources, said method comprising the steps of:

at said subscriber unit;

storing in memory a list of communication paths to a plurality of destinations, each of said paths having associated therewith one of said plurality of different communications resources and a set of communication attributes;

receiving a connection command comprising destination information and a set of communications attributes;

selecting from said list at least one communications path based at least partly upon the received destination information and the set of received communications attributes; and

establishing a connection to said selected communications path via one of said plurality of different communication resources.

2. The method of claim 1 further comprising the steps of:

at said subscriber unit;

generating a communications command comprising said selected communications path;

executing said communication command by controllably putting into operation the communication resource associated with the selected communications path;

publishing a code indicating the success or failure of said communications command; and

terminating the connection to said selected communications path when communications to said destination is no longer desired.

3. The method of claim 1, wherein the steps of maintaining a list, issuing a connection command, and selecting from said list at least one communications path are performed by the subscriber unit before performing a communications related command.

4. The method of claim 1, wherein said communication resources are selected from the group of devices consisting of:

wireline transceivers and wireless transceivers.

5. The method of claim 1, wherein the steps of selecting at least one communications path further comprises the steps of:

comparing the set of stored communications attributes to the communication attributes as received in the connection command; and

selecting a communications path based upon the comparison.

6. The method of claim 1 wherein the communication attributes are selected from the group of parameters consisting of:

transfer cost, packet size, baud rate, directionality, transit time, and carrier ID.

7. A subscriber unit having memory and a plurality of different communications resources for communicating with a destination point via one of a plurality of communications paths between said subscriber unit and said destination point, and for selecting the communications path for use, said subscriber unit comprising:

a plurality of device drivers, each coupled to a different communications resource, for storing a list of records describing available communication paths to a destination point, each of said records having associated communication path attributes; and

a packet server, coupled to the plurality of device drivers, for receiving connection commands comprising a destination point and a plurality of communications attributes and selecting from said device driver lists at least one record, based at least partly upon destination point information and the received communications attributes, that describes the communications path and the one of said plurality of different communications resources for use.

8. The apparatus of claim 7 wherein the subscriber unit is a portable wireless terminal.

9. The apparatus of claim 7 wherein the communications resources are selected from the group of devices consisting of:

wireline transceivers and wireless transceivers.

10. The apparatus of claim 9 wherein the communications resources comprise:

telephone modems, radio frequency transceivers;

infrared transceivers; and

fiber-optic transceivers.

11. The apparatus of claim 7 wherein the device drivers and the packet server are software modules stored in memory.

12. The apparatus of claim 7 wherein at least one software application program resides in memory and requests a communications resources in order to communicate with a destination point via one of the plurality of communications paths between the subscriber unit and the destination point.

13. The apparatus of claim 7 wherein the communications attributes are selected from the group of parameters consisting of:

transfer cost, packet size, baud rate, directionality, transit time, and carrier ID.

14. The apparatus of claim 7 further comprising:

means for comparing connection command communications attributes with communications path attributes; and

means, coupled to the comparing means, for selecting a communications path based upon the comparison.

15. A method for selecting one of a plurality of communications paths between a subscriber unit and a destination point, the subscriber unit having a device driver, a packet server, a plurality of different communications media and at least one software application, said method comprising the steps of:

at said subscriber unit;

providing a predetermined name associated with said destination point known to said at least one software application and said device driver;

storing in device driver memory a plurality of records describing potential communication paths to said destination point, each of said records having associated therewith one of said plurality of different communications media and a set of communication attributes;

requesting connection to said destination point by sending a request from said at least one software application to said device driver, via said packet server, said request comprising said predetermined name and a second set of communication attributes;

publishing from device driver memory said plurality of records

comparing said published records with said request; and

selecting at said packet server a communications path to said destination point as a function of the comparison.

16. The method of claim 15 further comprising the steps of:

at said subscriber unit;

reserving said communications path for use by said at least one software application by issuing a request from said packet server to said device driver, said request identifying said communications path;

publishing an identification code from said device driver to said packet server as a confirmation of said reservation;

publishing a session number from said packet server to said at least one software application as a confirmation of said reservation;

sending communications commands from said at least one software application to said device driver via said packet server, wherein said commands comprise said session number; and

terminating the connection to said selected communications path when communications to said destination is no longer desired.

17. The method according to claim 16 wherein the step of terminating the connection further comprises the steps of:

relinquishing said communications path by issuing a request from said at least one software application to said device driver via said packet server, said request comprising said session number; and

publishing a code from said device driver to said at least one software application via said packet server indicating the success or failure of said termination.

18. A method for selecting a path for data communications between a subscriber unit and an end point, said subscriber unit having a plurality of communications resources, a plurality of device drivers, each device driver having a data link list, a packet server having a session list, and memory, wherein at least one software application requesting data communications to said end point is stored, said method comprising the steps of at said subscriber unit:

a. passing a first request from said at least one software application to said packet server, said first request comprising a first coded value corresponding to said at least one client application'"'"'s desire to create a new session and a pattern corresponding to the desirable characteristics of said new session, said pattern comprising an end point name component and a criteria component;

b. passing a second request from said packet server to said device manager, said second request comprising a second coded value and said end point name, said second coded value indicating said packet server'"'"'s desire to examine a prototype list stored in said memory of said subscriber unit;

c. passing a first response from said device manager to said packet server, said first response corresponding to said second request and comprising copies of only said prototypes found in said prototype list which comprise said end point name and a reference number for each copy;

d. selecting exactly one best prototype for further processing from said prototype list upon consideration of said criteria component and said copies of said prototypes from said prototype list;

e. passing a third request to said device manager from said packet server, said third request comprising a third coded value and said reference number corresponding to said one best prototype, said third coded value signifying said packet server'"'"'s desire to bind to a prototype;

f. said device manager marking said one best prototype as an in-use prototype;

g. said device manager allocating said communication resources using configuration information included in said one best prototype;

h. said device manager initializing said communication resources using said configuration information;

i. said device manager adding a data link to said data link list, said data link comprising said reference number and information describing said communication resources;

j. passing a second response from said device manager to said packet server, said second response corresponding to said third request and comprising a second reference number corresponding to said data link;

k. said packet server adding a session to said session list, said session comprising said second reference number and information describing resources owned by said packet server and used by said session;

l. passing a third response from said packet server to said at least one client application, said third response corresponding to said first request and comprising a third reference number corresponding to said session; and

m. retaining knowledge of said third reference number at said at least one client application for use in future requests to said packet server.

19. A method for deleting a path for data communication between a subscriber unit and end point, said subscriber unit having a plurality of communications resources, a plurality of device drivers, each device driver having a data link list, a packet server having a session list, and memory, wherein at least one software application requesting deletion of data communications to said end point is stored, said method comprising the steps of at said subscriber unit:

a. passing a first request from said at least one client application to said packet server, said first request comprising a first coded value indicating said at least one client application'"'"'s desire to delete a session from said session list and a first reference number corresponding to the session number to be deleted;

b. said packet server examining said session indicated by said first reference number to obtain a second reference number corresponding to a data link associated with said session;

c. passing a second request from said packet server to said device manager, said second request comprising a second coded value indicating said packet server'"'"'s desire to delete said data link corresponding to said second reference number;

d. said device manager examining said data link indicated by said second reference number and relinquishing said communication resources described in said data link;

e. said device manager examining said data link indicated by said second reference number to obtain a third reference number corresponding to an IN-USE prototype associated with said data link;

f. said device manager marking said IN-USE prototype as indicated by said third reference number as an AVAILABLE prototype;

g. said device manager deleting said data link indicated by said second reference number;

h. passing a first response from said device manager to said packet server, said first response indicating results of data link deletion and corresponding to said second request;

i. said packet server releasing said communication resources owned by said packet server used by said session;

j. said packet server deleting said session from said session list;

k. passing a second response from said packet server to said at least one client application, said second response indicating results of session deletion and corresponding to said first request; and

l. said at least one client application forgetting knowledge of said first reference number of said first request, and forgoing its use in future requests to said packet server.