Optimisation of Multimedia over wireless IP links via X-layer design
OPTIMIX project studies innovative solutions enabling enhanced video streaming for point to multi-point in an IP based wireless heterogeneous system, based on cross layer adaptation of the whole transmission chain. The project partners are Thales, Siemens A.G., VTT, Cefriel, CNIT, Univ. of Southampton, Budapest (BME) and NXP semiconductors.
Following the path opened by FP6 IST PHOENIX project which was shown allowing an optimised allocation of resources for multimedia transmission over wired/wireless links in a joint source-channel coding approach, OPTIMIX project proposes to study innovative solutions enabling enhanced video streaming in a point to multi-point context for an IP based wireless heterogeneous system, based on cross layer adaptation of the whole transmission chain. Cross-layer mechanisms proposed by OPTIMIX enable efficient joint approach between application world and transmission world.
To achieve this goal, it is proposed to develop a scheme including all elements of major importance in a point to multi-point video streaming chain, in particular video coding, networking modules, MAC layer and physical layer, efficiently communicating together through the use of joint controllers (at the server side) and mobile unit observers (at the client side). The OPTIMIX project will consequently:
· consider innovative techniques to improve the efficiency of scalable video codecs when used in a wireless multi user environment with respect to robustness, efficient compression and intelligent use of scalability schemes. This will lead to the design of novel controlling strategies in the scope of point to multi-point scenarios, taking in consideration the aggregation of multiple feedbacks and the overall optimisation criteria in a multi user context.
· develop cross-layer mechanisms to enable the communication between application world and transmission world through the use of enhanced transport and network protocols.
· validate the overall system with respect to end to end quality optimization, and innovative techniques developed in all the fields of interest of the project will be evaluated. Efficient bandwidth use, real time constraints, robustness and video quality will be amongst the major evaluation criteria
Aiming to intervene in all parts of a communication chain, OPTIMIX needed the broad range of competences, offered by its consortium grouping industrial and academics, and will act to ensure that its innovations will be proposed to adequate standardization bodies.
OPTIMIX is organised into five packages (WP) which enable parallel work during the project timeframe. Obviously, parallel work does not prevent interrelations between WPs.
WP1 “Requirements and exploitation” first role is to identify requirements to develop a fully exploitable and user needs fitting system, and to translate them into architecture specifications. It also deals with the relation with the external world, in terms of communication, standardisation and exploitation.
WP2 “Coding and modulation” is about the conception, development and analyse of algorithms for source coding, channel coding, modulation, joint controlling algorithms and joint observers.
WP3 “Transmission over the network” corresponds to the networking aspects that arise when considering video transmission over wireless IP links and the overall network infrastructure. Its objective is to address the impacts linked to the point to multipoint architecture and design accordingly efficient end-to-end protocol stack with cross-layer capability.
WP4 “System evaluation and demonstration” corresponds to the project implementation and demonstration activities. Algorithms selected in WP2 and WP3 are implemented there, through progressive steps, into a final demonstrator and the results are analysed via several tests scenarios for further work and exploitation.
WP5 “Management activities”’ is dedicated to the management and administrative issues of the project. It also deals with the technical management of the project and interacts logically with all other work-packages.