Discovery Protocols for FMC devices

Mobile computers include additional features such as Java, Bluetooth, Smart Covers, WAP 2.0, and JavaScript enabled Web pages and with embedded SOAP, 3GPP with SIP, and other technologies that make it possible to provide sophisticated, distributed applications. These new application need Discovery tools to learn about the nearby networks or network-accessible resources available to them.

In FMC, PnP devices (Plug and Play) will be commonly available. When a user bring a new device home, the device will be able to automatically integrate itself into the home network. Discovery protocols are the mechanisms that make this possible.

Discovery protocols are network protocols used to discover services, devices, or other networked resources. The ability to discover networked resources at runtime makes it possible to dynamically configure distributed systems.

The main topics for discovery protocols are scalability, security, and awareness.

Usually, a discovery protocol allows a service to be discovered on the basis of its type, its Application Programming Interfaces (APIs), and other properties -- not joust its name. For example , DNS is a name service. It resolves domain names to Internet Protocol (IP) addresses. For example SLP(Service Location Protocol) clients can ask for services that match certain constraints, and servers respond with the names of services that match those constraints.

In general, there are four basic mechanisms that discovery protocols use for "discovery"

1. Advertisement

2. Inquiry

3. Directories

4. Description

Today's systems implement multiple discovery protocols. However, Mobile phones users may be concerned inefficient protocols designed for LANs -- both the financial cost of using the cellular network and the drain on their batteries of using any network.

It is common for discovery protocols to come as an integrated part of a distributed middleware toolkit. In addition to discovery, distributed middleware toolkits provide for remote invocation and events. Jini is a distributed middleware toolkit that provides its own services discovery protocol.

Distributed middleware toolkits make it possible to create smart controllers that

1. use discovery protocols to integrate themselves with the home devices.

2. aware the device state and display information from the device to the user

3. receive responses from control messages

4. authenticate themselves as authorized for the device

5. coordinate the actions of many devices.

参考：Technologies for Home Networking