Husni Fahmi

A model for secure multimedia document database system in a distributed environment

The Internet provides a universal platform for large-scale distribution of information and supports inter-organizational services, system integration, and collaboration. Use of multimedia documents for dissemination and sharing of massive amounts of information is becoming a common practice for Internet-based applications and enterprises. With the rapid proliferation of multimedia data management technologies over the Internet, there is growing concern about security and privacy of information. Composing multimedia documents in a distributed heterogeneous environment involves integrating media objects from multiple security domains that may employ different access control policies for media objects. In this paper, we present a security model for distributed document management system that allows creation, storage, indexing, and presentation of secure multimedia documents. The model is based on a time augmented Petri-net and provides a flexible, multilevel access control mechanism that allows clearance-based access to different levels of information in a document. In addition, the model provides detailed multimedia synchronization requirements including deterministic and non-deterministic temporal relations and incomplete timing information among media objects.

Wireless network resource management for Web-based multimedia document services

Advances in wireless technology and availability of portable devices with networking capabilities have enabled ubiquitous Web accessibility. This has created the need to provide advance Internet services to mobile users without causing service failures due to connection migration or handoffs. However, scarcity of wireless resources restricts the provision of multimedia services in wireless networks. We address the issue of managing wireless resources to support Web-based multimedia document services including MPEG-4-based applications, in wireless networks with a high degree of user mobility. In particular, we formulate the resource management problem in wireless networks as an optimization problem with an objective function comprising different quality of presentation parameters.

Dynamic Resource Allocation for Multimedia Document Retrieval over High Speed LANs

The emergence of gigabit local area networks (G-LANs) has spurred a tremendous interest in supporting networked multimedia applications over a LAN. In this paper, we propose a mechanism for dynamically allocating network resources in asynchronous LANs. Presentation of multimedia objects with required play-out quality requires Quality of Service (QoS) guarantees by the underlying networking infrastructure. Existing asynchronous LANs, such as Ethernet, do not support the notion of QoS due to their asynchronous media access protocol. For such networks, we propose a dynamic bandwidth management scheme that uses the concept of Time Division Multiple Access (TDMA). Significant performance improvement is observed through experimental results. In particular, the transmission rates for multimedia hosts improve significantly with low jitter variations in media streams. We also propose a framework for graceful degradation of play-out quality of multimedia objects in case the LANs total capacity is not sufficient to meet the overall demand.

Distributed framework for real-time multimedia object communication

We highlight major technical requirements for designing and developing future distributed multimedia information systems using Internet technology. The key requirements of this system are to allow users to access and search and to communicate multimedia documents consisting of text, audio, video and images. We emphasize the role of object-oriented technology for information management and real-time communication protocols to guarantee QoS. We present a reference architecture for a Web-based real-time distributed multimedia system which integrates enabling technologies including real-time streaming, multimedia indexing and searching and distributed object management.

A protocol architecture for guaranteed quality of service in collaborated multimedia applications

The role of multimedia applications in our day-to-day life has dramatically increased in the last few years. In this paper, we present an architectural framework for the distributed multimedia systems. The architecture consists of three layers: the application layer, the configuration and synchronization layer, and the network layer. The three layers are backed up by two backbone layers, namely, the database and the computational backbone. We present a precise description of each layer together with formal specifications using finite state automata.

Real-time resource reservation for synchronized multimedia object over wireless LAN

We propose a proxy-based framework that provides QoS support to mobile users. We describe the overall QoS architecture and implement a number of key QoS functions, including bandwidth allocation and synchronization. In this architecture, admission control is exercised to ensure the long-term availability of resources to mobile clients, where the resources include bandwidth for supporting the required presentation rates and buffer for synchronizing media streams. Bandwidth allocation is implemented in Linux traffic control using stochastic fairness queueing and token bucket filter disciplines to provide bandwidth guarantees for the multimedia connections. An adaptive synchronization technique is also implemented in the proxy to synchronize multiple streams originating from different sources before transmitting them to the clients for presentation. Finally, a number of quality adaptation strategies that accommodate the diverse requirements and capabilities of clients are described.

A multimedia information system for document authoring, indexing and presentation

The authors present a multimedia management system that supports creation, storing, indexing and presentation of complex multimedia objects. An object-oriented data model is proposed to capture the content, spatial and temporal semantics of multimedia data. Based on this model, they design a query processor to perform multi-dimension search on multimedia data.

Real time resource allocation for multimedia object communication

We propose a dynamic bandwidth management scheme for asynchronous LANs that uses the concept of time division multiple access (TDMA). The scheme is to ensure quality of service (QoS) for multimedia applications. Significant performance improvement is observed through experimental results. In particular, the transmission rates for multimedia hosts improve significantly with low jitter variations in media streams. We also propose a framework for graceful degradation of play-out quality of multimedia objects in case the LANs total capacity is not sufficient to meet the overall demand.

A protocol architecture for multimedia document retrieval over high speed LANs

The emergence of gigabit local area networks (G-LANs) has spurred a tremendous interest in supporting networked multimedia applications over a LAN. Such LANs do not support the notion of QoS required by multimedia documents due to their asynchronous media access protocol. In this paper, we propose a dynamic bandwidth management scheme that uses the concept of time division multiple access (TDMA). A significant performance improvement is observed through experimental results, especially to transmission rates and jitter. We also propose a framework for graceful degradation of the playout quality of multimedia objects in cases where the LANs total capacity is not sufficient to meet the overall demand.

Ensuring quality of service for multimedia applications in a LAN environment

We present a mechanism for dynamically allocating network resources in asynchronous LANs for supporting multimedia applications that require quality of service guarantee. The approach is based on the concept of time division multiple access (TDMA). It uses a centralized controller as the bandwidth manager. The total bandwidth is partitioned into two segments: one is used for serving multimedia connections and the other for the normal CSMA/CD sessions. Experimental results reveal that the performance of the proposed scheme is substantially better than that of the random access mechanism. In particular, transmission rates for multimedia hosts are improved significantly with low jitter variations in media streams.