Method and device for prompt and efficient service discovery in wireless networks

• US 6,961,560 B2
• Filed: 05/07/2002
• Issued: 11/01/2005
• Est. Priority Date: 05/23/2001
• Status: Expired

• Current Assignee: Wistron Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Moser, Michael, Husemann, Dirk, Hermann, Reto, Nidd, Michael Elton
• Primary Examiner(s): Moise, Emmanuel L.
• Assistant Examiner(s): Afshar, Kamran
• Application Number:
  US10/141,050
• Publication Number:
  US 20020176391A1
• Time in Patent Office: 1,274 Days
• Field of Search: 455/414.1, 455/414.3, 455/3.01, 455/3.06, 455/458, 455/41.2, 455/426.2, 455/466, 455/456.3, 705/1, 705/10, 705/14, 707/202
• US Class Current: 455/414.1
• CPC Class Codes: H04L 67/51 Discovery or management thereof, e.g. service location protocol [SLP] or web services

Abstract

Methods, system and apparatus are provided for advertising service offerings in a communication system. An example embodiment comprises at least one device. A first device broadcasts a message of a first type, chooses a value for a time limit and listens for a message sent by a second device. If no message has been received before time limit, elapse, it again broadcasts a message of a first type. Otherwise, the message received from said second device is analyzed and if said message includes valid information about said first device chooses a value for the time limit. However, if said message received does not include valid service description about said first device, a message of a second type is broadcast. This reduces useless broadcast of a complete service list. Broadcast may be initiated more often and, service discovery for new devices coming into proximity takes less time.

Claims

1. A method comprising advertising service offerings in a wireless communication system including at least one device wherein a first device performs the steps of:

broadcasting a message of a first type,

choosing a value for a time limit,

listening and waiting for a message from a second device,

if no message has been received until elapse of said time limit, continuing with the step of broadcasting a message of a first type, otherwise

analyzing the message received from said second device and if message includes valid information about said first device, continuing with the step of choosing a value for a time limit, and

broadcasting a message of a second type, if said message received from said second device does not include valid service description about said first device,

wherein the first device maintains a counter for each service description, and further comprising the step of incrementing the counter for service descriptions broadcast with a message, and further comprising the step of analyzing counter values and deriving a value indicating a distance between the first device and any of the other known devices.

2. The method according to claim 1, wherein said message of the first type comprises a digest of a service description of the first device.

3. The method according to claim 2, wherein said message of the first type comprises a digest of service descriptions of other devices, the service descriptions being stored in said first device.

4. The method according to claim 1, wherein said message of the second type comprises the service description of the first device.

5. The method according to claim 1, wherein said message of the second type comprises the service descriptions of other devices, the service description of which are stored in said first device.

6. The method according to claim 4, wherein only a digest of the service description is sent for all devices, for which information received from the second device is valid.

7. The method according to claim 1, wherein the information received by the second device is formed by one of the service description, a service description digest.

8. The method according to claim 1, wherein the step of analyzing counter values includes the step of filtering out devices having a counter value higher than a predetermined threshold.

9. The method according to claim 1, wherein the step of marking a service to be too far away in response to a message indicating such service is too far away, whereby the message originates from a service considered not too far away.

10. The method according to claim 1, wherein messages of the first and the second type include counter values related to the service descriptions.

11. A system for advertising service offerings in a communication system comprising at least one device, the device comprising means adapted to perform the method according to claim 1.

12. A computer program product stored on a computer usable medium, comprising computer readable program means for causing a computer to perform a method according to claim 1.

13. An article of manufacture comprising a computer usable medium having computer readable program code means embodied therein for causing advertisement of service offering in a wireless communication system including at least one device, the computer readable program code means in said article of manufacture comprising computer readable program code means for causing a computer to effect the steps of:

a first device performs the steps of;

broadcasting a message of a first type,

choosing a value for a time limit,

listening and waiting for a message from a second device,

if no message has been received until elapse of said time limit, continuing with the step of broadcasting a message of a first type, otherwise

analyzing the message received from said second device and if message includes valid information about said first device, continuing with the step of choosing a value for a time limit, and

broadcasting a message of a second type, if said message received from said second device does not include valid service description about said first device,

wherein the first device maintains a counter for each service description, and further comprising the step of incrementing the counter for service descriptions broadcast with a message, and

further comprising the step of analyzing counter values and deriving a value indicating a distance between the first device and any of the other known devices.

14. A program storage device readable by machine, tangibly embodying a program of instructions executable by the machine to perform method steps for advertising service offerings, said method steps comprising the steps of:

a first device performs the steps of;

broadcasting a message of a first type,

choosing a value for a time limit,

listening and waiting for a message from a second device,

if no message has been received until elapse of said time limit, continuing with the step of broadcasting a message of a first type, otherwise

analyzing the message received from said second device and if said message includes valid information about said first device, continuing with the step of choosing a value for a time limit, and

broadcasting a message of a second type, if said message received from said second device does not include valid service description about said first device,

wherein the first device maintains a counter for each service description, and further comprising the step of incrementing the counter for service descriptions broadcast with a message, and

further comprising the step of analyzing counter values and deriving a value indicating a distance between the first device and any of the other known devices.