Universal multimedia access from wired and wireless systems

Personal computing and communication devices such as computers, personal di gital assistants (PDAs), and mobile phones are moving to their next generat ion in which the end user will be able to access a multitude of information with a single device either locally or through a network. One likely trend in future personal computing and personal communication is that there will not be a single but several equivalent devices available to users allowing access to information in various forms. Each user, depending on his/her ne eds would access one or several among them depending on the situation and h is/her preference. Using existing protocol mechanisms, in this case, a mapp ing and negotiation of resources during connection setup would be performed , which would remain in place throughout the life of the connection. This paper provides an overview of universal multimedia access (UMA), a con cept for accessing multimedia content through a variety of possible schemes , and discusses some of the issues that arise regarding its deployment. In particular, UMA will provide a solution for adapting the delivered content when users attempt to access their choice irrespective of their terminal ch aracteristics and communication infrastructure, as opposed to the assumptio n that the content remains fixed and the objective is to deliver the origin al content at all times. This recognition represents the impetus for the de velopment of media descriptions and hence UMA; that is, the notion that val uable information can be derived from a variety of conversions of a multime dia content source. The issues discussed are future requirements on content servers and multime dia viewers, media conversions, UMA protocols, and UMA network architecture s. The problems addressed are quality of service issues in network solution s for multimedia communications and reconfigurable architectures and networ k control based on source adaptations through media conversions and transco ding.