Read about NAC Other related papers	NAC: A Basic Core for the Adaptation and Negotiation of Multimedia Services Tayeb Lemlouma and Nabil Layaïda

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	What is the NAC architecture? Learn more about NAC
	Providing adaptable services for different clients in heterogeneous environments is very important since the use of a wide diversity of digital storage and small devices is nowadays increasing. Making multimedia services understandable and usable by this range of clients is a hard task to achieve. This last requires the knowledge of users, servers and network contexts; but also demands efficient mechanisms that allow delivering the aimed service in the best way. NAC (Negotiation and Adaptation Core) is a new basic core for multimedia services adaptation and negotiation in heterogeneous environments. Our objective is to ensure that the diversity of clients existing in the global system can access to services provided by servers. To allow a maximum of heterogeneity tolerance, we have built our core on the base of no assumptions neither on the client context nor on the player (or the browser) used in the communication with the rest of the environment
	Another fixed target is to make the core extensible for other models and kind of adaptation. Hence, the same architecture can be reused to meet the needs of other particular environments with their proper specifications. The implemented core allows different players to use a multimedia content which is adapted automatically to their preferences and capacities. Client profiles are declared in a CC/PP structure stored in XML documents and can be modified at anytime. NAC is designed to be not limitted to any particular kinde of services (HTML, SMIL, etc.) or protocoles (HTTP, WAP, etc.), this is why the framework can support the concept of "protocol adaptation", for example in the case where the original request is written in HTTP and the target request is a WAP request one. NAC supports actually the HTTP protocol in services delivery and the exchange of requests. It can adapt HTML and SMIL services according to the constraints of the end user. The proposed core doesn't make any assumption on the existing platform. Indeed, to use our solution, players must only point to the proxy used by our core; services will be then adapted automatically. The architecture of NAC is flexible to be used at any particular system, and enriched by transformation programs or style sheets to meet particular needs.
	This repository describes real devices. Many recent models in today's mobile market are included. Take a look on the repository
	The Adaptation and Negotiation Module (ANM) Proxy	The Last Version of ANM
	UCM Configuration User Profiles Selection UCM in action
	UCM in a Pocket PC About UCM UCM Configuration User Profiles Selection
	PocketSMIL Player	Last Version of PocketSMIL Player
	The universal profiling schema (UPS) was defined to have a central role in the generation of adapted content. UPS identifies three main categories of contexts: the client category, the server category and the network category. From the content side, the server category includes the document instance profile that describes the document characteristics and functionalities. It includes also the resource profile that describes a used media resource and the adaptation method profile that describes an available adaptation method that exist in the server or the proxy side. Take a look on UPS and The UPSProfiles Package
	Example of filtering: HTML filtering (filter images from the HTML content)
	HTML to WML Structural Transformation
	The content (w2.html) received from the proxy using an IE client	The content (w2.html) received from the proxy using a WAP client
	The content (w.html) received from the proxy using an IE client	The content (w.html) received from the proxy using a WAP client
	The content (Swarzchild1.mml) received from the proxy using a client (Amaya) that supports MathML The content (Swarzchild1.mml in the form of SVG) received from the proxy using a client (IE) that does not support MathML but supports SVG The content (Swarzchild1.mml in the form of JPEG) received from the proxy using a client (Pocket IE) that does not support MathML but supports JPEG images
	The adaptation of a SMIL document
	Using a remote entity for the adaptation
	An application of the daptation: Text to SMS
	Images resizing application
	Images resizing application: Here the proxy resize images used by HTML documents
	Adding some new content to the original requested document
	Generating video presentations from SMIL sepcifications (learn more about this application)
	Original content First adapted content (before the user navigation) The user navigates inside the received content (See the Next link) The user navigate inside the received content (See the Next and Previous links)
	SOAP Architecture
	Evaluation of XQuery Delay	Evaluation of RPC calls
	Evaluation of UPS components exctraction
	For further information about NAC, please mail us at : Tayeb.Lemlouma@inrialpes.fr
		Author: Tayeb Lemlouma Last revised date: 2003/09/20