Towards a multimedia remote viewer for mobile thin clients

Be there a traditional mobile user wanting to connect to a remote multimedia server. In order to allow them to enjoy the same user experience remotely (play, interact, edit, store and share capabilities) as in a traditional fixed LAN environment, several dead-locks are to be dealt with: (1) a heavy and heterogeneous content should be sent through a bandwidth constrained network; (2) the displayed content should be of good quality; (3) user interaction should be processed in real-time and (4) the complexity of the practical solution should not exceed the features of the mobile client in terms of CPU, memory and battery. The present paper takes this challenge and presents a fully operational MPEG-4 BiFS solution

Optimized mobile thin clients through a MPEG-4 BiFS semantic remote display framework

According to the thin client computing principle, the user interface is physically separated from the application logic. In practice only a viewer component is executed on the client device, rendering the display updates received from the distant application server and capturing the user interaction. Existing remote display frameworks are not optimized to encode the complex scenes of modern applications, which are composed of objects with very diverse graphical characteristics. In order to tackle this challenge, we propose to transfer to the client, in addition to the binary encoded objects, semantic information about the characteristics of each object. Through this semantic knowledge, the client is enabled to react autonomously on user input and does not have to wait for the display update from the server. Resulting in a reduction of the interaction latency and a mitigation of the bursty remote display traffic pattern, the presented framework is of particular interest in a wireless context, where the bandwidth is limited and expensive. In this paper, we describe a generic architecture of a semantic remote display framework. Furthermore, we have developed a prototype using the MPEG-4 Binary Format for Scenes to convey the semantic information to the client. We experimentally compare the bandwidth consumption of MPEG-4 BiFS with existing, non-semantic, remote display frameworks. In a text editing scenario, we realize an average reduction of 23% of the data peaks that are observed in remote display protocol traffic

Design and Simulation of a Migration-based Architecture for Massively Populated Internet Games

In recent years many popular interactive computer games have gained online remote multiplayer functionalities, supported by standard Internet communication protocols and architectures. Due to the heterogeneous communication infrastructures and network asymmetries, some users (i.e. clients) may be suffering slow, congested and unreliable Internet connections, while others may have access to fast and reliable links. A different rate and latency in the delivery of users' commands and event notifications may lead to unfairness issues during the game play. Specifically, this happens in the class of real time and interactive games, which require frequent and prompt event notifications and reactions among all the users competing in the gaming environment. A dynamic adaptation of the gaming architecture to the limitations of the communication infrastructure could be exploited to reduce these problems. The communication network topology and performance should be considered in the management of the client allocation to the set of multiple servers. In this paper we present a simple client migration algorithm which can be adopted on a generic multi-player, multi-server online gaming architecture. Client migration among the servers of the gaming infrastructure is exploited to adapt to the dynamic performances of the general communication network infrastructure. The proposed mechanism has been modeled and simulated for the class of distributed multi-player and multi-server interactive games, implemented over a general communication network infrastructure. Results show a significant fairness improvement, more homogeneous performances, and the absence of significant overheads.\u

Procédés et appareils de production et de traitement de représentations de scènes multimedias

The representation of content, in a scene representation, is enriched with a view to the adaptive use of the latter according to a set of common parameters. A subgraph of the scene graph, which is suitable for variable processing, is identified. For this purpose, it is possible to define two new types of scene element one of which allows the identification of the subgraph and the second of which allows the set of common parameters to be imposed in conjunction with the subgraph. An example of the first type consists of a node of the so-called "AdaptivityControl" type which encompasses the entire subgraph, a list of the nodes describing the set of common parameters and a group of fields allowing a dynamic updating of the content of this node. An example of the second type consists of a node of the so-called "CompressedlmageStrategy" type which comprises information relating to the object to be coded and the parameters of the coding.La représentation de contenu, dans une représentation de scène, est enrichie au vue de l'utilisation adaptive de celle-ci selon un jeu de paramètres communs. Un sous-graphe du graphe de scène, lequel est susceptible d'un traitement variable, est identifié. A cette fin, on peut définir deux nouveaux types d'élément de scène dont un permet l'identification du sous-graphe et le second permet d'imposer le jeu de paramètres communs en relation avec le sous-graphe. Un exemple du premier type consiste en un noeud du type dit "AdaptivityControl" qui englobe le sous-graphe entier, une liste des noeuds décrivant le jeu de paramètres communs et un groupe de champs permettant la mise à jour dynamique du contenu de ce noeud. Un exemple du second type consiste en un noeud du type dit « CompressedlmageStrategy » qui comporte des informations concernant l'objet à coder et les paramètres du codage