Ahmed R. Bashandy

A combined approach for QoS based multicast routing and resource allocation

In this paper, we present a general framework for the problem of QoS multicast routing with resource allocation. Our framework uses functional forms derived from various queuing service disciplines for the QoS parameters rather than static metrics. We give formal definition of the QoS multicast routing problem with resource allocation. This problem is different from the minimum Steiner tree problem in networks which has been considered extensively. We show that QoS multicast routing with resource allocation problem is NP-complete. We present a 2-approximate greedy heuristic based on Prims minimum spanning tree algorithm which suboptimally solves the multicast routing with. resource allocation problem.

Network modeling and jitter control for multimedia communication over broadband network

For pre-orchestrated multimedia documents, the important QoS parameters are bandwidth, jitter and reliability. A data network may employ a large number of service disciplines that provide guaranteed QoS. In this paper, we propose a network model, which we call the jitter graph, to capture the bandwidth, jitter and reliability of a large number of service disciplines. The significance of this model is that it abstracts the properties of the network, which allows the design of QoS routing protocols, resource allocation policies, and traffic regulation schemes that are independent of the specific properties of each node. Based on this model, we propose a traffic regulation scheme that reduces, and possibly eliminates, jitter introduced by any service discipline that can be abstracted by the jitter graph network model. The proposed traffic regulation scheme, together with jitter graph model, are analyzed and simulated based on an existing service discipline.

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.

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.

Evaluation of filtering mechanisms for MPEG video communications

In this paper, we evaluate two video filtering mechanisms for MPEG-1 video, namely low-pass filtering and selective frame dropping. The evaluation provides tradeoffs between the reduction achieved in bandwidth requirements and the perceptual quality of the video sequences delivered to the client. Extensive experiments revealed that these filtering mechanisms result in a significant reduction in bandwidth requirements while maintaining acceptable perceptual quality.

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.

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.