Proximity service discovery in wireless networks
Discovery of services between devices is provided prior to establishing a connection between devices, including wireless-enabled devices or devices that are communicatively coupled to wireless access points. Discovering services prior to establishing a connection may facilitate finding a desired service. The services that may be discovered may be, for example, print services, camera services, PDA services or any other suitable services. Services may be discovered using 802.11, UWB or any other suitable wireless technology. As one example, particular services may be requested. As another example, services that are provided by a device may be advertised.
1. A method of discovering by a first device services provided by a second device that is in a physical proximity of the first device, before establishing a connection between the first device and the second device, the method comprising:
receiving a first 802.11x Layer 2 wireless advertisement message, wherein the message includes a plurality of service information elements, and wherein at least a first of the service information elements comprises information related to a first service provided by the second device and a second of the service information elements comprises information related to a second service provided by the second device, and wherein the first service is different from the second service, and wherein at least a portion of each of the first and second service information elements is shortened, and wherein the first message is received prior to establishing a connection between the first device and the second device suitable for providing the first and second services;
extracting at least the first and second shortened service information elements from the received message;
determining that additional information related to the first service is desired;
sending a request message to the second device for additional information related to the first service;
receiving a second message from the second device, wherein the second message comprises additional information related to the first service;
determining if the first service is desired; and
establishing a connection between the first device and the second device, if the first service is desired.
2. The method of claim 1 , wherein the wireless advertisement message is received by the first device or by a device in communication with the first device.
3. The method of claim 1 , further comprising:
providing, to a user of the first device, on a human perceptible medium, information related to the first and second services provided by the second device.
4. The method of claim 1 , wherein the proximity of the first device is defined at least partially by a radio range of the first device.
5. The method of claim 1 , further comprising:
determining whether the second device is within the proximity of the first device, the proximity of the first device being limited to a region smaller than a region defined by a radio range of the first device;
wherein the connection is established if the second device is within the proximity of the first device.
6. The method of claim 1 , wherein the wireless advertisement message comprises an 802.11 beacon message.
7. A computer-readable medium storing computer-executable instructions for performing steps comprising:
receiving, by a first device and from a second device, a first 802.11x Layer 2 wireless advertisement message, wherein the message includes a plurality of service information elements, and wherein at least a first of the service information elements comprises information related to a first service provided by the second device and a second of the service information elements comprises information related to a second service provided by the second device, and wherein the first service is different from the second service, and wherein at least a portion of each of the first and second service information elements is shortened, and wherein the first message is received prior to establishing a connection between the first device and the second device suitable for providing the first and second services, the second device being in a physical proximity of the first device;
extracting at least the first and second shortened service information elements from the received message;
determining that additional information related to the first service is desired;
sending a request message to the second device for additional information related to the first service;
receiving a second message from the second device, wherein the second message comprises additional information related to the first service;
determining if the first service is desired; and
establishing a connection between the first device and the second device, if the first service is desired.
8. The computer-readable medium of claim 7 , wherein the wireless advertisement message is received by the first device or by a device in communication with the first device.
9. The computer-readable medium of claim 7 , further comprising:
providing, to a user of the first device, on a human perceptible medium, information related to the first and second services provided by the second device.
10. The computer-readable medium of claim 7 , wherein the proximity of the first device is defined at least partially by a radio range of the first device.
11. The computer-readable medium of claim 7 , further comprising:
determining whether the second device is within the proximity of the first device, the proximity of the first device being limited to a region smaller than a region defined by a radio range of the first device;
wherein the connection is established if the second device is within the proximity of the first device.
12. The computer-readable medium of claim 7 , wherein the wireless advertisement message comprises an 802.11 beacon message.
13. A computer-readable medium storing computer-executable instructions for performing steps comprising:
sending, to a first device, by a second device, a first 802.11x Layer 2 wireless message, wherein the message includes a plurality of service information elements, and wherein at least a first of the service information elements comprises information related to a first service provided by the second device and a second of the service information elements comprises information related to a second service provided by the second device, and wherein the first service is different from the second service, and wherein at least a portion of each of the first and second service information elements is shortened, and wherein the first message is sent prior to establishing a connection between the first device and the second device suitable for providing the first and second services, the second device being in a physical proximity of the first device;
extracting, by the first device, at least the first and second shortened service information elements from the message received;
determining, by the first device, that additional information related to the first service is desire;
receiving, by the second device, a request message for additional information related to the first service;
sending, to the first device, by the second device, a second message, wherein the second message comprises additional information related to the first service;
determining, by the first device, if the first service is desired; and
establishing a connection between the first device and the second device, if the first service is desired.
14. The computer-readable medium of claim 13 , wherein the wireless message is sent by a device in communication with the second device.
15. The computer-readable medium of claim 13 , wherein the wireless message is sent as at least a portion of an 802.11x beacon message.
16. The computer-readable medium of claim 13 , wherein the proximity of the first device is defined at least partially by a radio range of the first device.
17. The computer-readable medium of claim 13 , wherein a portion of the first service information element is hashed.
18. The computer-readable medium of claim 13 , wherein the first message is sent to the first device in response to a request from the first device.
19. The computer-readable medium of claim 13 , wherein the first wireless message is an advertisement message.
20. The method of claim 1 , wherein one or more of the service information elements comprises a sequence number, and wherein the sequence number reflects a change in the service provided by the second device.