The stack resource protocol based on real time transactions

Current hard real time (HRT) kernels have their timely behaviour guaranteed at the cost of a rather restrictive use of the available resources. This makes current HRT scheduling techniques inadequate for use in a multimedia environment where one can profit by a better and more flexible use of the resources. It is shown that one can improve the flexibility and efficiency of real time kernels and a method is proposed for precise quality of service schedulability analysis of the stack resource protocol. This protocol is generalised by introducing real time transactions, which makes its use straightforward and efficient. Transactions can be refined to nested critical sections if the smallest estimation of blocking is desired. The method can be used for hard real time systems in general and for multimedia systems in particular

Multimedia big data computing for in-depth event analysis

While the most part of ”big data” systems target text-based analytics, multimedia data, which makes up about 2/3 of internet traffic, provide unprecedented opportunities for understanding and responding to real world situations and challenges. Multimedia Big Data Computing is the new topic that focus on all aspects of distributed computing systems that enable massive scale image and video analytics. During the course of this paper we describe BPEM (Big Picture Event Monitor), a Multimedia Big Data Computing framework that operates over streams of digital photos generated by online communities, and enables monitoring the relationship between real world events and social media user reaction in real-time. As a case example, the paper examines publicly available social media data that relate to the Mobile World Congress 2014 that has been harvested and analyzed using the described system.Peer ReviewedPostprint (author's final draft

The formal, tool supported development of real time systems

The language SDL has long been applied in the development of various kinds of systems. Real-time systems are one application area where SDL has been applied extensively. Whilst SDL allows for certain modelling aspects of real-time systems to be represented, the language and its associated tool support have certain drawbacks for modelling and reasoning about such systems. In this paper we highlight the limitations of SDL and its associated tool support in this domain and present language extensions and next generation real-time system tool support to help overcome them. The applicability of the extensions and tools is demonstrated through a case study based upon a multimedia binding object used to support a configuration of time dependent information producers and consumers realising the so called lip-synchronisation algorithm

Real-time systems development with SDL and next generation validation tools

The language SDL has long been applied in the development of various kinds of systems. Real-time systems are one application area where SDL has been applied extensively. Whilst SDL allows for certain modelling aspects of real-time systems to be represented, the language and its associated tool support have certain drawbacks for modelling and reasoning about such systems. In this paper we highlight the limitations of SDL and its associated tool support in this domain and present language extensions and next generation real-time system tool support to help overcome them. The applicability of the extensions and tools is demonstrated through a case study based upon a multimedia binding object used to support a configuration of time dependent information producers and consumers realising the so called lip-synchronisation algorithm

MULTIMEDIA STREAMING PLATFORM BANDWITH CONTROLL CONGESTION DETECTION AND BANDWIDTH ADAPTATION

We propose a platform for distributed multimedia systems. The proposed platform is implemented using the Netscape Portable Runtime (NSPR) and the Cross-Platform Component Object Model (XPCOM). This ensures system portability, flexibility and performance. The platform is equipped with a congestion detection algorithm and a bandwidth control mechanism thus controlling the transfer rates between the communication parties. Using this kind of bandwidth management this platform allows real-time streaming across multiple networks.real-time multimedia platform; XPCOM components; congestion detection; bandwidth control

Quality of service optimization of multimedia traffic in mobile networks

Mobile communication systems have continued to evolve beyond the currently deployed Third Generation (3G) systems with the main goal of providing higher capacity. Systems beyond 3G are expected to cater for a wide variety of services such as speech, data, image transmission, video, as well as multimedia services consisting of a combination of these. With the air interface being the bottleneck in mobile networks, recent enhancing technologies such as the High Speed Downlink Packet Access (HSDPA), incorporate major changes to the radio access segment of 3G Universal Mobile Telecommunications System (UMTS). HSDPA introduces new features such as fast link adaptation mechanisms, fast packet scheduling, and physical layer retransmissions in the base stations, necessitating buffering of data at the air interface which presents a bottleneck to end-to-end communication. Hence, in order to provide end-to-end Quality of Service (QoS) guarantees to multimedia services in wireless networks such as HSDPA, efficient buffer management schemes are required at the air interface. The main objective of this thesis is to propose and evaluate solutions that will address the QoS optimization of multimedia traffic at the radio link interface of HSDPA systems. In the thesis, a novel queuing system known as the Time-Space Priority (TSP) scheme is proposed for multimedia traffic QoS control. TSP provides customized preferential treatment to the constituent flows in the multimedia traffic to suit their diverse QoS requirements. With TSP queuing, the real-time component of the multimedia traffic, being delay sensitive and loss tolerant, is given transmission priority; while the non-real-time component, being loss sensitive and delay tolerant, enjoys space priority. Hence, based on the TSP queuing paradigm, new buffer managementalgorithms are designed for joint QoS control of the diverse components in a multimedia session of the same HSDPA user. In the thesis, a TSP based buffer management algorithm known as the Enhanced Time Space Priority (E-TSP) is proposed for HSDPA. E-TSP incorporates flow control mechanisms to mitigate congestion in the air interface buffer of a user with multimedia session comprising real-time and non-real-time flows. Thus, E-TSP is designed to provide efficient network and radio resource utilization to improve end-to-end multimedia traffic performance. In order to allow real-time optimization of the QoS control between the real-time and non-real-time flows of the HSDPA multimedia session, another TSP based buffer management algorithm known as the Dynamic Time Space Priority (D-TSP) is proposed. D-TSP incorporates dynamic priority switching between the real-time and non-real-time flows. D-TSP is designed to allow optimum QoS trade-off between the flows whilst still guaranteeing the stringent real-time component’s QoS requirements. The thesis presents results of extensive performance studies undertaken via analytical modelling and dynamic network-level HSDPA simulations demonstrating the effectiveness of the proposed TSP queuing system and the TSP based buffer management schemes

Avoiding DAD for Improving Real-Time Communication in MIPv6 Environments

Joint International Workshops on Interactive Distributed Multimedia Systems and Protocols for Multimedia Systems, IDMS/PROMS 2002 Coimbra, Portugal, November 26–29, 2002 ProceedingsCurrent specification of address configuration mandates the execution of the Duplicate Address Detection (DAD) mechanism to prevent address duplication. However, a proper support for real time multimedia applications in mobile IPv6 nodes is undermined by the disruption imposed by DAD. In order to overcome this limitation, the usage of randomly generated IPv6 Interface Identifiers without previously performing DAD is proposed, based on the statistic uniqueness of the addresses generated through this method. The address duplication risk is quantified through the calculation of the probability of an Interface Identifier collision among the nodes sharing a link. The calculated probability is deemed to be negligible compared to other causes of communication failure, such as network outages.This research was supported by the LONG (Laboratories Over Next Generation Networks) project IST-1999-20393 and Moby Dick (Mobility and Differentiated Services in a Future IP Network) project IST-2000-25394

Fuzzy approach to multimedia faulty module replacement

For non-real time multimedia systems, we present a fuzzy approach to replacing the faulty module. After analyzing the nature of the random and pseudo-random test sequences applied to a module under test, we obtain the aliasing fault coverage between the random and pseudo-random sequences. The activity probability features of intermittent faults in the module under test are discussed based on the Markov chain model. Results on real examples are presented to demonstrate the effectiveness of the proposed fuzzy replacement approac