UPS: Frequently Asked Questions

Q: Why the definition of such schema?
A: The Universal Profiling Schema (UPS) was created in order to resolve the problem of the content negotiation and adaptation of multimedia services in heterogeneous systems; i.e. where there is a wide diversity of clients. In such situation, services and documents providers must be able to deliver a well adapted document that respects the end-user preferences and capabilities. To achieve that task properly, an efficient solution needs to know some information about the set of elements that play a role in services delivery. UPS is created to be a model that responds to such need. In UPS, elements concerned by the content negotiation and adaptation are identified and so profiles can be defined easily.

Q: Is there any implementations behind UPS?
A: The need of the definition of universal profiling framework for the content negotiation problem was encountered initially during the implementation of an architecture (NAC) that aims to deliver adapted services for heterogeneous devices: i.e. devices like PDA, phones, laptops, etc. UPS was defined to respond to NAC needs but also to be an extensible and flexible tool, indispensable for content authors, application developers, universal services providers, etc. and for those who aim to enable the universal access to their content.

Q: Is the definition of UPS is finished?
A: Not yet. Other new elements and structures will be defined.

Q: Is it realy necessary to include the element 'document profile' in UPS?
A: Yes, if we aim to provide an advanced content negotiation and adaptation strategy we must provide the document profile, which is simply the description of the characteristics and the content of the document and may also include, in some architectures, its semantic. People who work in the context of the content adaptation feel better the importance of such descriptions. In fact, to adapt a content, and to choose the appropriate method to apply according to the delivery context, we need to know the nature of the content that we will process. An example of some of the adaptation efforts, the one introduced in where the adaptation focuses on synchronized multimedia presentations, note that the need of the document profile (or 'content descriptions', see section 4.1 ) was well identified.

Q: Why a new schema while other schemas exist such as WAG UAProf?
A: UPS is defined in the context of the content negotiation. This means simply that any content negotiation solution, whatever its own matching algorithm or strategy, can use UPS as a base that provide utile information required in the matching and the content deliverance. UPS is not dependent to any particular service or document kind such as WML. Indeed, services can be in the form of WML, XHTML, HTML, or other. Furthermore, UPS don't disregard the "document profile" concept that includes a description of the document structure and semantic; this concept is very important if we aim to ensure an advanced content negotiation solution. Finally, the UPS includes other components such as the network description, the capabilities of servers in term of adaptation and transformation methods etc.

Q: hello, my name is Norberto Chatlani, from Spain, and i have started to study xml, xsl, and finally found cc/pp. while i was doing this trip, tried to understand cc/pp how works it. the information is in xml format. the webserver looks the request and what kind of client do the request (User Agent Profile). According to this profile, use the stylesheet apropiated. the question that i have is: This operation can be done by a proxy or an intermediary element? for example, the proxy do a xml (http) request to the server, and the conversion is made in the proxy. I have heard it but i am not sure that it would be true. thanks norberto chatlani (norberto chatlani)?
A: Applying a style sheet or another kind of adaptation method is called the "content adaptation" and can be applied by the original server or an intermediate proxy. The content adaptation is applied when: 1- The original content can't be used directly by the client and 2- There is no existed version (or 'variant' using the HTTP vocabulary!) that meet the need of the client and 3- The service or document provider has an adaptation method which can transform the original content to another content that respects the target context.
-NC-- for example, the proxy do a xml (http) request to the server, and the
-NC-- conversion is made in the proxy.
-NC-- I have heard it but i am not sure that it would be true.
Before choosing the adaptation method to apply or the selected version to deliver, the content negotiation step must be achieved. To achieve this task, some information are needed such as information about: the user agent profile, the requested content, the server capabilities etc. The more suitable situation to use an advanced content negotiation is to include the negotiation module at the server side, and to provide other required information such as the document profiles (document characteristics, document meta data, etc.). The use of the proxy based architecture can be more suitable if we target some well known adaptation or transcoding. This why in the literature we find proxies like image transcoding proxies, HTML to WML proxies etc. Hope this will help.

Q: Hi Tayeb, I took a look to your UPS and I have just a coment/question about it. You named attributes (like DeviceName, PixelStretch, etc.) without taking care of the "interCap" naming convention ( Why did you act this way ? (to differentiate some meanings ?) Best regards, Luc. (Luc Pezet)?
A: To clarify the ideas about the UPS schema, I'd like to give some important notes: - The UPS schema was created mainly to resolve the problem of the content negotiation over internet and heterogeneous networks. - The UPS schema presents the idea of the creation of profiles for different elements which are required during the content negotiation task such as the client profile, the document profile (functionalities, metadata..), etc. Elements and attributes that exists actually can change and be extended in the future. - Each element in a profile following the UPS schema defines a constraint (atomic or composite) about the described component. - Constraints are resolved during the matching and the process of content negotiation by the content server. For the server constraints resolution that concerns UPS attributes, the name style such as the "interCap" one is not important. Simply to retrieve the constraint semantic, the server ignores the style of attributes included in the profile and that are preceded by the "neg" namespace.

Q: I would like to use CC/PP to describe different kinds of profile which would contain context information useful for those content adapation mechanism.
By taking a look at your work, I came up with a couple of questions:

1) Is your schemata has a xml or a rdfs extension? 2) Does it make any difference since your schemata are using RDF sintax and schema?
3) Would you mind to explain me how your client schemata defines a property as NonSupportedResources and one of your instance shown below the Schema uses a rdf:ParseType property? Is this rdf:ParseType a RDF attribute or element? Where is this rdf:ParseTYpe defined? By reading the RDF Model And Syntax and RDF Schema, I was not able to find this attribute. I am very interested to understand this structure because I was trying to create such a similar structure and I thought RDF would not give support for that. I thought I would have to create each attribute as a separate list.
4) UAPROF has used the rdfs:comment property to store some profile resolution rule as you might be aware. How do you solve this problem within your profiles?
5) I noticed you have created an API for profiles creation. Could you explain the benefit of creating profiles using your API instead of creating them manually and then parsing it on Jena?
6) Have you implemented your NAC architecture

I spent the last couple of days reading your articles and trying to understand your proposal on UPS. I found it excellent and very much interesting. Is it possible to use your UPS profiles in my master thesis? If you give me authorization, I may have a couple of new properties to add, is this possible too?

7) When I made my sixth question asking you if you if you had implemented the NAC architecture what I was trying to understand was
- if you have created an API that implements your Negotiation Module, Adaptation Module, UCM and the component that contains the players and users context listeners. Have you? Is it an open source code that anyone could have access? If this is the case, would you mind to give the link?
8) Regard my third question, I read the RDF Primer specification and I think I understood how to use the rdf:ParseType. This is a functionality that RDF has to allow representing a structured information within a list format, is this correct?
9) With UAPROF, the rdfs:comment of each property was used to store data type and the resolution rule (override, append, lock). On your NAC architecture, I didn´t understand if it had a CC/PP repository. In case it has, how have you addressed the problem related to the profile resolution?
10) When you built the UPS Profiles, did you intend the Client Resource Profile to be previous stored in a repository or sent by the client device along with its client profile?

Best regards (Claudia Alvarez Rolins)

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