The Universal Multimedia Access (UMA) addresses the delivery of
multimedia resources under different and varying
network conditions, diverse
terminal equipment capabilities, specific user or creator preferences and needs and usage environment conditions.[1] UMA refers to the truly ubiquitous access to and consumption of multimedia content, aiming at guaranteeing unrestricted access to multimedia content:
Availability of useful descriptions about the content;
Availability of useful descriptions about the context (e.g., knowledge about the terminal capabilities);
Existence of content mediation/delivery systems able to use the above information to provide the intended value to their users independently of location, type of terminal devices being used or network connections, regardless of the format of the content, respecting user preferences, environmental conditions and content owners and usage rights.
Approach
One feasible approach to implement UMA, is to develop
context-aware systems that use the content and context descriptions to decide upon the need to adapt the content before delivering it to the end-user. The use of open ontologies and standards to structure, represent and convey those descriptions as well as to specify the kind of adaptation operations is vital for the success of UMA. This is especially true in loosely coupled environments such as the
Internet, where
heterogeneous end-users devices, varied content formats,
repositories and networking technologies co-exist. Standards from the
W3C such as OWL (
Web Ontology Language) or CC/PP (Content Capability/Preferences Profile) and from
ISO/
IEC such as
MPEG-7 and especially
MPEG-21, are well-suited for the implementation of UMA-enabler systems.[3]