WO2006127197A2

WO2006127197A2 - Mechanism to support transparent roaming in heterogeneous service discovery systems

Info

Publication number: WO2006127197A2
Application number: PCT/US2006/015606
Authority: WO
Inventors: John Buford; Alan Kaplan
Original assignee: Matsushita Electric Industrial Co., Ltd.
Priority date: 2005-04-26
Filing date: 2006-04-25
Publication date: 2006-11-30
Also published as: WO2006127197A3

Abstract

A method allows a device or client to perform service discovery, service advertisement, and/or service invocation during a roaming transition from a first network or network domain employing a first service discovery, advertisement, and/or invocation protocol to a second network or network domain employing a second service discovery, advertisement, and/or invocation protocol. The method includes issuing service discovery requests and receiving service discovery responses, and receiving service discovery requests and issuing service discovery responses. It also includes issuing service advertisements and receiving service advertisements. It further includes issuing service descriptions and receiving service descriptions across multiple service discovery protocols and in multiple service description formats.

Description

MECHANISM TO SUPPORT TRANSPARENT ROAMING IN HETEROGENEOUS SERVICE DISCOVERY SYSTEMS

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application claims the benefit of U.S. Provisional

Application No. 60/674,875, filed on April 26, 2005. This application also claims the benefit of International Application PCT/US2005/027491, filed August 3, 2005, which, in turn, claims the benefit of U. S. Utility Application No. 10/930,043, filed August 30, 2004. The disclosures of the above applications are incorporated herein by reference in their entirety for any purpose.

FIELD

[0002] The present disclosure generally relates to service discovery, advertisement, and/or invocation, and relates in particular to a method whereby a device or client performs service discovery, service advertisement, and service description during a roaming transition from a first network or network domain employing a first service discovery, advertisement, and/or invocation protocol to a second network or network domain employing a second service discovery, advertisement, and/or invocation protocol.

BACKGROUND

[0003] The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.

[0004] Service discovery is a basic mechanism in networked applications. However there are many service discovery protocols and it is not likely that a single protocol will be the dominant one. Hence it is important to support multiple service discovery, advertisement, and/or invocation protocols, and there may not be server or gateway mechanisms in every environment.

[0005] Device roaming is a particularly important consumer electronics (CE) use case. However, no existing approaches provide a solution for roaming devices transitioning between networks or network domains that employ different service discovery mechanisms, perhaps due to complications that cause difficulty in implementing such a solution. Providing such a solution is complicated because of many differences in individual service discovery mechanisms, including: (1) varying formats, categories, attributes, and identifiers for service description; (2) different notions of what a "service" is; (3) push vs. pull; (4) multicast vs. unicast; and (5) incompatible protocols. [0006] Therefore, the need remains for a solution to the problems encountered by roaming devices that successfully deals with the many differences between individual service discovery mechanisms. The present invention fulfills this need.

SUMMARY

[0007] The method according to the present teachings allows a device or client to perform service discovery, service advertisement, and/or service invocation during a roaming transition from a first network or network domain employing a first service discovery, advertisement, and/or invocation protocol to a second network or network domain employing a second service discovery, advertisement, and/or invocation protocol. The method includes issuing service discovery requests and receiving service discovery responses, and receiving service discovery requests and issuing service discovery responses. It also includes issuing service advertisements and receiving service advertisements. It further includes issuing service descriptions and receiving service descriptions across multiple service discovery protocols and in multiple service description formats.

[0008] Further areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.

DRAWINGS

[0009] The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way.

[0010] Figure 1 is a block diagram illustrating different types of service discovery, advertisement, and/or invocation SD/SA/SI mechanisms. [0011] Figure 2 is a block diagram illustrating roaming in a heterogeneous SP1 to SP2 case.

[0012] Figure 3 is a block diagram illustrating roaming in a heterogeneous ad hoc or PAN case. [0013] Figure 4 is a block diagram illustrating roaming in heterogeneous SP 1 to SP2 where a gateway is available.

DETAILED DESCRIPTION [0014] The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses.

[0015] The present teachings are part of results of ongoing efforts by the assignee of the present invention to address the needs of roaming devices in relation to competing and incompatible service discovery, advertisement, and/or invocation protocols that typically differ from one network or network domain to another. For example, a "federated peer-to-peer" concept, which includes federated service discovery, is under development by the assignee of the present invention. This approach is further detailed in: (a) U.S. Pat. App. No. 60/715,388, filed September 8, 2005 by the assignee of the present invention, entitled System and Method for Meta-Discoverγ in Federated Peer-to-Peer Service Discovery Systems; (b) U.S. Pat. App. No. 60/682,607, filed May 19, 2005 by the assignee of the present invention, entitled System and Method for Multiprotocol Service Discovery in a Computer Network; and (c) U.S. Pat. App. No. 60/710,660, filed August 23, 2005 by the assignee of the present invention, entitled Method and System for Peer-to~Peer Services Architecture and Framework. The aforementioned patent applications are incorporated herein by reference in their entirety for any purpose.

[0016] Referring to Figure 1, an application 100 on one device uses SD/SA/SI protocol 102A to discover, advertise, and invoke services via network interface 104A. A service 106 on another device uses SD/SA/SI protocol 102B to discover, advertise, and invoke services via its network interface 104B. There are a variety of mechanisms by which a device can advertise its service using such protocols, including inserting a service advertisement entry in to a distributed hash table (DHT) 108, storing the service advertisement in a server 110 or set of servers, multicasting 112 or broadcasting the service advertisement, or acting as a service advertisement repository in an ad hoc 114 or personal area network (PAN) network. Similarly there are a corresponding set of mechanisms by which another device can discover service advertisements, including doing a lookup in a DHT, sending a request or query to a server or set of servers holding the advertisements, multicasting requests for a service, listening for multicast advertisements, and connecting to a local device's service repository in an ad hoc network or PAN. The use of service 106 can require a service invocation protocol. Such protocols include SOAP, http, message-based protocols, and RPC-style protocols.

[0017] Turning now to Figure 2, a mechanism allows a device 200 to obtain access to services in a service provider 2's network when roaming from service provider 1's network to service provider 2's network. This mechanism can involve, for example, swapping in the SD/SA/SI protocol 202 required by service provider 2's network, and swapping out the SD/SA/SI protocol 204 required by service provider 1's network, while retaining the application 206, SD/SA/SI interface 208, and native IP/OS/HW 210 layers. Additional details relating to this mechanism can be found in Buford et al., U.S. Pat. App. No. 10/930,043, entitled Mechanism to Support Transparent Roaming between IMP Service Providers in Wireless Networks, filed August 30, 2004 by the assignee of the present invention. The aforementioned patent application is incorporated herein by reference in its entirety for any purpose.

[0018] During the roaming transition, various steps can occur, such as detection of a new service provider, connection to the service provider 2's network, capability negotiation between the device and the service provider 2's equipment, accounting, and an indication of required SD/SA/SI protocols needed in service provider 2's network. In some embodiments, if the device does not already support the required protocols, then the mechanism can locate and install the software needed by the device. Thereafter the device is able to advertise, discover, invoke, and/or receive invocations according to the features of the SD/SA/SI protocols in SP2's network and the available services. [0019] Turning now to Figure 3, an alternative or additional embodiment involves a device A 300 and device B 302 communicating over an ad hoc network or PAN 304A using a first SD/SA/SI protocol 306A and 306B. Later device A 300 and device C 308 are communicating over a different ad hoc network or PAN 304B using a second SD/SA/SI protocol 310A and 310B. During this transition, device A 300 dynamically loads software for the second SD/SA/SI protocol 310.

[0020] Turning now to Figure 4, an alternative or additional embodiment allows device A 400 to continue a service invocation session with a service in SP1 after roaming to SP2, using an SD/SA/SI gateway 402. In addition, the gateway can further provide the ability for device A 400 to discover services in SP1 network when device A is in SP2's network. In addition, the gateway can further provide the ability for a service advertisement in SP1 network to be accessed in SP2 network, and a service advertisement in SP2 network to be accessed in SP1 network. Further, the gateway can provide the ability for a service discovery request in SP2 network to be sent to SP1 network and replies to the request from SP 1 network to be returned to requestors in SP2 network.

[0021] As discussed above, a method for supporting roaming in networks and network domains with different SD/SA/SI protocols can include one or more of the following roaming transitions: (a) roaming from SP1 to SP2; (b) roaming from ad hoc network 1 or PAN 1 to ad hoc network 2 or PAN 2; (c) roaming from one network administrative domain to another network administrative domain. This method can encompass service discovery, service advertisement, and service description in a device or client during a roaming transition. The method can include: (a) issuing service discovery requests and receiving service discovery responses; (b) receiving service discovery requests and issuing service discovery responses; (c) issuing service advertisements and receiving service advertisements; and (d) issuing service descriptions and receiving service descriptions across multiple SD protocols and in multiple service description formats. [0022] In some embodiments, the method can employ a common service classification, naming or type scheme, in which case service requests and service responses can be converted by an API implementation to native service requests and responses at lower layers. In alternative or additional embodiments, the method can employ a common service classification, naming or type scheme, in which case service advertisements can be converted by an API implementation from native service advertisements received at lower layers. In still further embodiments, the method can employ a common set of service attributes and service invocation rules, in which case service descriptions can be converted by an API implementation to native service attributes and service invocation rules.

[0023] In one or more embodiments in which common service classification, service attributes, and service invocation rules are not used, the application can issue service requests using native classification, and can interpret service descriptions and advertisements using native service description and advertisement according to the formats of the SD protocols in the client. Similarly, if common service description is not used, the application can receive service descriptions using native service descriptions according to the formats associated with the SD protocols in the client. [0024] A client in a roaming transition can compose new services that combine one or more local services with one or more services offered by another node through the SD protocols available in the network or domain. In addition, in the case of a gateway, the composition can involve services available in remote networks or domains that participate in the gateway. [0025] This method can also be described in terms of a system of transparent roaming service discovery and a medium of transparent roaming service discovery. The method can also be described in terms of transparent roaming transitions involving specific combinations of SD protocol configurations including: (a) UPnP SSDP and Bluetooth SDP; (b) SLP and UPnP SSDP; (c) UPnP SSDP and Web Services; (d) UPnP SSDP and DHT-based (JXTA, Chord, Pastry, etc.); (e) JXTA and Chord; (f) JXTA and NEMO; and (g) two or more peer-to-peer file sharing protocols, including Kazaa, Gnutella, Napster, WinMX, Audiogalaxy, BearShare, LimeWire. The method can further be described in terms of transparent roaming transitions involving specific types of combinations of SD protocols including: (a) local domain and multiple (widearea) domain (e.g., SLP and Chord); (b) client-server and peer-to-peer (e.g., SLP and Chord); (c) home network and PAN (e.g., UPnP, 802.15.3); and (d) network services and application services (e.g., SLP and Web Services). Yet further, the method can be described in terms of combinations of more than two SD protocols in one client.

[0026] In the federated roaming case, it is envisioned that transitions can occur in which a node sp1 uses n>1 protocols, and node sp2 uses m>1 protocols, where some of the n can overlap with some of the m. Accordingly, service discovery in this case and in other circumstances can include search and/or lookup by: (a) exact match; (b) wildcard or regular expression; (c) semantic search; (d) taxonomic; (e) meta search/match; (f) group based; (g) secure SD; (h) bloom filter or other approximation technique; and/or (i) federated. Moreover, service discovery protocols can include: (a) client-server; (b) broadcast; (c) multicast; (d) ad hoc; (e) wide area; (f) PAN; (g) home network; (h) service overlays; (i) peer-to-peer overlays; and/or (j) distributed hash tables.

Claims

CLAIMS What is claimed is:

1. A method whereby a device or client performs service discovery, service advertisement, and/or service invocation during a roaming transition from a first network or network domain employing a first service discovery, advertisement, and/or invocation protocol to a second network or network domain employing a second service discovery, advertisement, and/or invocation protocol, the method comprising: issuing service discovery requests and receiving service discovery responses; receiving service discovery requests and issuing service discovery responses; issuing service advertisements and receiving service advertisements; and issuing service descriptions and receiving service descriptions across multiple service discovery protocols and in multiple service description formats.

2. The method of claim 1 , wherein the roaming transition involves roaming from a first service provider's network to a second service provider's network.

3. The method of claim 2, further comprising obtaining access to services in the second service provider's network when roaming from the first service provider's network to the second service provider's network.

4. The method of claim 3, further comprising, during the roaming transition: detecting the second service provider; connecting to the second service provider's network; performing capability negotiation between said device or client and equipment of the second service provider; performing accounting; and obtaining an indication of required protocols for service discovery, advertisement, and/or invocation in the second service provider's network.

5. The method of claim 4, further comprising: if the device or client does not already support the required protocols, then locating and installing software needed by the device or client in order for the device or client to advertise, discover, invoke, and/or receive invocations according to features of the second service discovery, advertisement, and/or invocation protocol of the second service provider's network and its available services.

6. The method of claim 4, further comprising: if the device or client does already support one or more of the required protocols, employing at least one of the required protocols that is already supported by the device or client to perform at least one of service discovery, advertisement, and/or invocation in the second network or network domain.

7. The method of claim 2, further comprising employing a service discovery, advertisement, and/or invocation gateway to render the device or client in the second service provider's network operable to continue a service invocation session with a service in the first service provider's network after roaming to the second service provider's network.

8. The method of claim 2, further comprising employing a service discovery, advertisement, and/or invocation gateway to render the device or client in the second service provider's network operable to discover services in the first service provider's network when the device or client is in the second service provider's network.

9. The method of claim 2, further comprising employing a service discovery, advertisement, and/or invocation gateway to render the device or client in the second service provider's network operable to access a service advertisement in the first service provider's network.

10. The method of claim 2, further comprising employing a service discovery, advertisement, and/or invocation gateway to render a service advertisement of the device or client in the second service provider's network accessible to the first service provider's network.

11. The method of claim 2, further comprising employing a service discovery, advertisement, and/or invocation gateway to render the device or client in the second service provider's network operable to send a service discovery request from the second service provider's network to the first service provider's network, and to receive replies to the request from the first service provider's network that are returned to the device or client in the second service provider's network via the gateway.

12. The method of claim 1 , wherein the roaming transition involves roaming from a first ad hoc network or personal area network to a second ad hoc network or personal area network.

13. The method of claim 12, further comprising dynamically loading software that renders the device or client operable to comply with the second service discovery, advertisement, and/or invocation protocol.

14. The method of claim 12, wherein the roaming transition involves roaming from a first network administrative domain to a second network administrative domain.

15. The method of claim 1 , further comprising: employing a common service classification, naming, or type scheme; and implementing an application program interface to convert service requests and service responses to native service requests and service responses at lower layers.

16. The method of claim 1 , further comprising: employing a common set of service attributes and service invocation rules; and implementing an application program interface to convert service descriptions to native service attributes and service invocation rules.

17. The method of claim 1 , further comprising: issuing service requests using a native classification; and interpreting service descriptions and advertisements using a native service description and advertisement according to formats of service description protocols in said device or client.

18. The method of claim 1, further comprising receiving service descriptions using native service descriptions according to formats associated with service protocols in said device or client.

19. The method of claim 1 , further comprising advertising services according to multiple service discovery protocols by sending the advertisements to each of several service discovery protocol stacks.

20. The method of claim 1, further comprising composing new services that combine one or more local services with one or more services offered by another network node through service discovery protocols available in one of said networks or domains.

21. The method of claim 20, further comprising employing a service discovery, advertisement, and/or invocation gateway to render the device or client operable to compose new services that include services available in remote networks or domains that participate in the gateway.

22. The method of claim 1 , wherein advertising services includes at least one of:

(a) inserting a service advertisement entry in to a distributed hash table (DHT); (b) storing a service advertisement in a server or set of servers;

(c) multicasting or broadcasting a service advertisement; or

(d) acting as a service advertisement repository in an ad hoc network or private access network.

23. The method of claim 1, further comprising employing a service invocation protocol, including utilizing at least one of: (a) SOAP; (b) http; (c) message-based protocols; or (d) remote procedure call (RPC)-style protocols.

24. The method of claim 1 , further comprising performing service discovery by search and/or lookup by at least one of: (a) exact match; (b) wildcard or regular expression; (c) semantic search; (d) taxonomic; (e) meta search/match; (f) group based; (g) secure SD; (h) bloom filter or other approximation technique; or (i) federated.