iTechNote

Jini and Universal Plug & Play are the prominent device coordination frameworks for information appliances. These architectures are essentially coordination frameworks that propose certain ways and means of device interaction with the ultimate aim of simple, seamless and scalable device interoperability.

Device coordination provide a subset of the following capabilities to a device:

• Ability to announce its presence to the network
• Automatic discovery of devices in the neighborhood and even those located remotely
• Ability to describe its capabilities as well as query/understand the capabilities of other devices
• Self configuration without administrative intervention
• Seamless interoperability with other devices wherever meaningful

The frameworks do not have much of a say on data communication protocols between devices. It will be tough for a framework to adapt umpteen different data protocols into a standard for different devices. However, a coordination framework can make devices become aware of one another in sufficient detail. The intelligence within a device can decide whether it can or should talk to another device and also what protocol(s) to use.

The framework can also provide protocol definitions in an attempt of standardization. In order for any coordination framework to work, it must introduce some standards into the operations of the devices. Otherwise the devices simply cannot coordinate. The essential problem here is maintaining a balance between standardization requirements and device autonomy.

Jini from Sun Microsystems is a coordination framework evolved and adapted from academic research and tailored specifically to Java. Jini network technology, which includes JavaSpaces Technology and Jini extensible remote invocation (Jini ERI) enables developers to create network-centric services — whether implemented in hardware or software — that are highly adaptive to change.

The JavaSpaces technology is a simple and powerful high-level tool for building distributed and collaborative applications. Based on the concept of shared network-based space that serves as both object storage and exchange area, it provides a simple API that is easy to learn and yet expressive for building sophisticated distributed applications.

The UPnP architecture offers pervasive peer-to-peer network connectivity of PCs, intelligent appliances, and wireless devices. The UPnP architecture is a distributed, open networking architecture that uses TCP/IP and HTTP to enable seamless proximity networking in addition to control and data transfer among networked devices in the home, office, and everywhere in between.

Unlike Java which “run anywhere”, UPnP is leveraging TCP/IP protocol suite which is implemented almost anywhere. UPnP works primarily with these lower layer network protocols suite, implementing standards at this level instead of at the application level. This primarily involves additions to the suite, certain optional protocols which can be implemented natively by devices. The keyword here is “natively”. UPnP attempts to make sure that all device manufacturers can quickly adhere to the proposed standard without major hassles.

Jini takes standardization to one extreme while UPnP takes autonomy to another extreme. Using the Jini Surrogate Architecture, Jini and Universal Plug and Play (UPnP) can work together. A UPnP device through a surrogate operating on its behalf could access a Jini technology-enabled network.

via CSWL