Multimedia Application

Heterogeneous Multiprocessor systems-on-chip (HMPSoC) are becoming popular as a means of meeting energy efficiency requirements of modern embedded systems. However, as these HMPSoCs run multimedia applications as well, they also need to meet realtime requirements. Designing HMPSoCs with predictable timing behavior is a key challenge, as the current design methods for these platforms are semi-automated, non-predictable, or support limited heterogeneity. In this demonstration, we present a design framework to rapidly generate and implement predictable HMPSoC designs. It takes the application specifications and the architecture model as input and generates the entire HMPSoC, for FPGA prototyping, that meets the throughput constraints of the application. We also present results of a case study that computes the performance-power tradeoffs of an industrial vision application. A tool-chain targeting the Xilinx Zynq FPGA is also presented.

The last decade a trend can be observed towards multi-processor Systems-on-Chip (MPSoC) platforms for satisfying the high computational requirements of modern multimedia applications. The research community has mainly focused on communication issues (e.g. bus vs. networks-on-chip). Real-time operating systems for MPSoCs however, have gotten very little attention. Existing techniques like rate-monotonic scheduling from the real-time community are rarely applicable, because contemporary high-performance media processors (like Cell, graphics processors) do not support preemption. Furthermore, rate-monotonic scheduling cannot deal with multiple (heterogeneous) processors, data dependencies, and dynamically varying execution times that characterize modern media applications. This paper proposes new techniques to manage the computational resources of MPSoCs at run-time. We compare a centralized resource manager (RM) to two versions (Credit based and Rate based) of a novel, more distributed RM. The distributed RMs are developed to cope with a larger number of processors as well as concurrently executing applications. Experiments show that our distributed resource managers are more scalable, deal better with application and user dynamics, and require less buffering, while effectively enforcing throughput constraints.

Real-timedisk scheduling (RTDS) is important for time-critical multimediaapplications. In conventional approaches of real-time disk scheduling,such as SCAN-EDF, the seek-optimizing SCAN scheme is appliedto reduce the disk service time of the real-time EDF schedule.Since only tasks with the same deadline are seek-optimized, theobtained improvement of SCAN-EDF is limited. In this paper, basedon the maximum-scannable-group (MSG) concept, a deadline-modification-scan (DMS or DM-SCAN) algorithm is proposed.Our algorithm uses MSG to automatically decide the suitable taskgroups for seek-optimizing. Based on the MSG concept, we repeatedlyapply DMS to further increase disk throughput to support moretasks. We have implemented the proposed algorithm on UnixWare2.01. The appropriate problem behaviors and parameter valuesto yield good solutions are investigated. Experiments show thatDMS is better than conventional approaches in both the obtaineddisk throughput and the supported tasks. Moreover, ...

The amounts of available resources such as memory buffer and network bandwidth are limited and varied for different multimedia systems. When a request is coming, the system needs to decide on request's admission based on available resources for providing guaranteed QoS. Assume that there are m smoothing-servers on the transmission path. Conventional approaches need O(m*n) time, where n is the number of frames, to measure the minimal amounts of resources required. Since n is large, these approaches are not acceptable for real systems that require fast responses. In this paper, an off-line computation scheme is introduced to pre-characterize the function of resource tradeoff for delivery of the requested video. Based on the pre-computed resource tradeoff, system resources required to serve different users can be easily measured by table hashing. This tool can highly reduce the waiting time spent for admission of multimedia applications.

This research paper introduces an innovative method for ensuring the security of video communication by implementing a video encryption and decryption system based on FPGA technology. The suggested system effectively employs programmable logic and fast processing capabilities of FPGAs to encrypt and decrypt video data, thereby safeguarding its integrity and confidentiality throughout transmission. Critical components include the video input preprocessing, video output interface, and encryption/decryption engines. By means of rigorous experimental evaluation and testing, this establishes the system's capability to deliver real-time performance and its resilience against security threats. Compared to software-based alternatives, this FPGA-based solution is ideal for a variety of applications requiring secure multimedia transmission due to its superior speed, efficiency, and security.

and Technology, "Without your unstinting encouragement and guidance, constant and energetic supervision, constructive criticism and invaluable advice there is just no way that I could have completed this thesis. You have always been there whenever I needed your helpfrom listening to my ideas, reading many inferior drafts to emending them at all stages. I thank you for everything".

Search, retrieval, and management of multimedia contents are challenging tasks for users and researchers alike. We introduce a software-hardware system for the global management of the multimedia contents produced by Spanish Civil Courts. The ultimate goal is to obtain an automatic classification of images and segments of the audiovisual records that, coupled with textual semantics, allows an efficient navigation and retrieval of judicial documents and additional legal sources. This paper describes our knowledge acquisition process, sets a typology of Spanish Civil hearings as performed in practice, and a preliminary procedural ontology at its actual stage of development (e-Sentencias ontology). A discussion on procedural, contextual and multimedia ontologies is also provided.

Semantic Search and Ontologies are one of the key technologies that can improve content management. Nonetheless, in order to be widely diffused, these technologies lack real-time capabilities, that speed up both the indexing and the retrieval processes. This contribution presents the approach and strategy proposed to tackle this problem, within the Spanish project E-Sentencias; a project for the development of a management system for lawyers that includes documentation and multimedia related to the management of their legal cases.

This work presents a traffic characterization procedure for Traffic Engineering (TE) in converged networks. An analytical model, focused in a selfsimilar aggregated traffic characterization is proposed, which considers QoS restrictions for delay metrics. The model, together with evolutionary techniques, is used for the optimization of the link capacity assignment task in network planning with multi-service applications. The results show that the traffic characterization model is reliable as a part of the optimization of costs in converged networks.

The growth of multimedia applications and wireless systems requires a new behavior of routing protocols for Wireless Mesh Networks (WMNs). It is necessary to provide not only the minimum requirements for Quality of Service (QoS), but also to assure the Quality of Experience (QoE) support for multimedia applications. In this context, the usage of only one link quality metric for routing different types of packets within the network is not enough to ensure applications with suitable QoS and QoE levels. This paper presents a variation of the WMN routing protocol Optimized Link State Routing (OLSR), to achieve QoS and QoE requirements for multimedia applications. It is based on the dynamic choice of metrics and in a Fuzzy Link Cost (FLC) to determine the best routes for multimedia packets. The proposed FLC metric is based on a fuzzy system that uses two link quality metrics, namely Expected Transmission Count (ETX) and Minimum Delay (MD), to define a new metric. Simulations were performed to demonstrate the performance of the proposed metric compared to the ones present in the original OLSR and other current versions of this protocol. For comparison purposes, it was considered different performance evaluation QoS metrics and the quality of videos received by the user in a higher competition scenario.

The video compression algorithms based on the 3D wavelet transform obtain excellent compression rates at the expense of huge memory requirements, that drastically affects the execution time of such applications. Its objective is to allow the real-time video compression based on the 3D fast wavelet transform. We show the hardware and software interaction for this multimedia application on a general-purpose processor. First, we mitigate the memory problem by exploiting the memory hierarchy of the processor using several techniques. As for instance, we implement and evaluate the blocking technique. We present two blocking approaches in particular: cube and rectangular, both of which differ in the way the original working set is divided. We also put forward the reuse of previous computations in order to decrease the number of memory accesses and floating point operations. Afterwards, we present several optimizations that cannot be applied by the compiler due to the characteristics of the algorithm. On the one hand, the Streaming SIMD Extensions (SSE) are used for some of the dimensions of the sequence (y and time), to reduce the number of floating point instructions, exploiting Data Level Parallelism. Then, we apply loop unrolling and data prefetching to specific parts of the code. On the other hand, the algorithm is vectorized by columns, allowing the use of SIMD instructions for the y dimension. Results show speedups of 5x in the execution time over a version compiled with the maximum optimizations of the Intel C/C++ compiler, maintaining the compression ratio and the video quality (PSNR) of the original encoder based on the 3D wavelet transform. Our experiments also show that, allowing the compiler to perform some of these optimizations (i.e. automatic code vectorization), causes performance slowdown, demonstrating the effectiveness of our optimizations.

Link to publication Disclaimer This document contains a student thesis (bachelor's or master's), as authored by a student at Eindhoven University of Technology. Student theses are made available in the TU/e repository upon obtaining the required degree. The grade received is not published on the document as presented in the repository. The required complexity or quality of research of student theses may vary by program, and the required minimum study period may vary in duration. Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights. • Users may download and print one copy of any publication from the public portal for the purpose of private study or research. • You may not further distribute the material or use it for any profit-making activity or commercial gain Electronic Systems, Department of Electrical Engineering

We analyze the I/O behavior of iBench, a new collection of productivity and multimedia application workloads. Our analysis reveals a number of differences between iBench and typical file-system workload studies, including the complex organization of modern files, the lack of pure sequential access, the influence of underlying frameworks on I/O patterns, the widespread use of file synchronization and atomic operations, and the prevalence of threads. Our results have strong ramifications for the design of next generation local and cloud-based storage systems.

Parallel computing is currently the dominating architecture in embedded systems. Concurrency improves the performance of the system rather without increasing the clock speed which affects the power consumption of the system. However, concurrency needs to be exploited in order to improve the system performance in different applications environments. Multimedia applications (real-time conversational services such as video conferencing, video phone, etc.) have many new features that require complex computations compared to previous video coding standards. These applications have a challenging workload for future multiprocessors. Exploiting parallelism in multimedia applications can be done at data and functional levels or using different instruction sets and architectures. In this research, we design new parallel algorithms and mapping methodologies in order to exploit the natural existence of parallelism in multimedia applications, specifically the H.264/AVC video decoder. We mainly target symmetric shared-memory multiprocessors (SMPs) for embedded devices such as ARM Cortex-A9 multicore chips. We evaluate our novel parallel algorithms of the H.264/AVC video decoder on different levels : memory load, energy consumption, and execution time.

The phenomenal growth of multimedia applications imposes scalable and efficient network support. The DiffServ and MPLS architectures were developed to provide QoS. The combination of both architectures presents a very attractive strategy to backbone network providers. However, integrating native IP multicasting with MPLS supports DiffServ is a quite comple issue. Major problems are: the lack of labels in MPLS networks, the core routers simplicity in DiffServ and the multicast state scalability problems, since it requires routers to keep a forwarding state for every multicast tree passing through it. In addition, the number of states grows with the number of groups. Under such circumstance, we propose an hybrid label aggregation algorithm in order to solve multicast scalability problem and provide a solution for multicast in MPLS support DiffServ. In the proposed scheme, one label is assigned per multicast groups (logical aggregation) and different multicast groups sharing the same output interface in a router are aggregated locally (physical aggregation). Also, in order to support the proposed algorithm, we propose a separate treatment and labels space (prime numbers range) for multicast traffic. The proposed solution allows consuming fewer labels, reducing the forwarding table and consequently the total packet processing delay.

Providing guaranteed quality of service (QoS) in wireless networks is a key issue for deploying multimedia applications. To support such a QoS, an arduous problem concerning how to find a feasible end to end path to satisfy multiple QoS constraints should be studied. In general, multi-constrained path selection, with or without optimization, is an NP-complete problem that cannot be exactly solved in polynomial time. Approximation algorithms and heuristics with polynomial and pseudopolynomial time complexities are often used to deal with this problem. However, existing solutions suffer either from excessive computational complexities that cannot be used for multimedia applications in ad hoc networks characterized by mobility and performance constraints (e.g., limited energy, wireless medium, etc.). Recently a promising heuristic algorithm H_MCOP using a non linear Lagrange relaxation path

An explosion in the internet and other sharing technologies has made transfer and distribution of video content extremely easy. Unimpeded transfer of video and other multimedia content has lead to violation of several antipiracy laws today. Hence, the need to prevent unauthorized distribution and protection of video data is on the rise. This paper demonstrates the lossless video encryption and decryption techniques. For encrypting the frames of the video, column and row shifting method is used, that is transposition cipher is generated. Further a password is used to encrypt the video as well.

System designers need to perform design-space exploration (DSE) to find appropriate number and type of processing elements (PEs) to be present in a Multiprocessor Systems-on-Chip (MPSoC) to support a throughput-constrained application. This paper presents a DSE methodology that provides application to MPSoC architecture mappings, where different PEs get used. The methodology starts from a mapping using only one type of processors and evaluates different mappings by increasing heterogeneity to improve the performance.

The contemporary Internet that we have been using today is based on Best-Effort (BE) service only, where packets are assigned and forwarded with the same priority. The BE service is acceptable only for traditional Internet applications like e-mail, web browsing and file transfer. However, it is not adequate for the applications like video conferencing, voice over IP (VoIP), and Video on Demand (VoD), which require high bandwidth, low delay and delay variation. Obviously, with the emergence of new real-time applications and Quality of Service (QoS) requirements, the Best Effort service becomes insufficient. Therefore, the Internet community has developed a number of new technologies to provide QoS in the Internet such as IntServ, DiffServ and MPLS. The differentiated service (DiffServ) is the most important distinct technology due to its simplicity and scalability benefits. It has been endorsed by Internet Engineering Task Force (IETF) to satisfy the requirements of new real-time applications. Internet Protocol was not designed taking into account mobility of users and terminals. In few years later, the IETF has developed protocols such as Mobile IPv4 (MIP) and Mobile IPv6 (MIPv6) for supporting seamless connectivity to mobile hosts. Mobile IPv6 is considered one of the important host mobility protocols, which was defined more in (RFC 3775 and RFC 6275). Network mobility basic support protocol (RFC 3963) is an extension of Mobile IPv6. It has been endorsed by Internet Engineering Task Force (IETF) to allow every single node in the mobile network to be reachable and connectable to the Internet while the network itself is moving around. Ultimately, this paper aims to propose and develop a new scheme to enhance QoS within NEMO environment.

User mobility in IEEE 802.11 wireless LANs is ever increasing due to wireless technological advances, the recent popularity of portable devices and the desire for voice and multimedia applications. These applications, however, require very fast and secure handoffs among base stations to maintain the quality of the connections. Re-authentication during handoff procedures causes a long handoff latency which affects the fluidity and service quality of interactive real-time multimedia applications such as VoIP. Minimizing the reauthentication latency is crucial in order to support real-time multimedia applications on public wireless IP network. In this paper, we propose two fast re-authentication methods based on the predictive authentication mechanism defined by IEEE 802.11 i security group. We compare our proposed methods to already existing ones. We have implemented these methods in an experimental test-bed using freeware and commodity 802.11 hardware. Conducted measurements show significant latency reductions compared to other proposed solutions.

Recently, user mobility in wireless data networks is increasing because of the popularity of portable devices and the desire for voice and multimedia applications. These applications, however, require fast handoffs among base stations to maintain the quality of the connections. Re-authentication during handoff procedures causes a long handoff latency which affects the flow and service quality especially for multimedia applications. Therefore minimizing re-authentication latency is crucial in order to support real-time multimedia applications on public wireless IP networks. In this paper, we propose two fast re-authentication methods based on the predictive authentication mechanism defined by IEEE 802.11i security group. We have implemented these methods in an experimental test-bed using freeware and commodity 802.11 hardware and we demonstrate that they provide significant latency reductions compared to already proposed solutions. Conducted measurements show a very low latency not exceeding 50 ms under extreme congested network conditions.

We describe the design and implementation of the RIO (Randomized I/O) multimedia object server which manages a set of parallel disks and supports real-time throughput and statistical delay guarantees. The original implementation, on an SMP (Sun Microsystems E4000), has been ported to a cluster of PCs. The new version uses a similar philosophy with respect to allocation of data storage and scheduling of requests. However the parallel "shared nothing" architecture raises all the issues of latency, scalability, etc. that are familiar in parallel and distributed systems. Our requirements are particularly demanding since we expect to support a variety of multimedia applications with varying workload requirements and data reference patterns. 3D interactive applications, video, hypermedia and interactive scientific visualization of terabyte size data sets are among the applications we support. This paper details the design issues we addressed and the results of detailed simulation studies which dictated the design choices made.

Networks on Chip (NoC) come along with increased complexity from the implementation and management perspective. This leads to higher energy consumption and programming complexity of NoC architectures. This work introduces communication aware programming to address communication resource management and efficient programming of NoC architectures. A programming interface is introduced to express communication requirements at the language level. These requirements are evaluated by an operating system component, which configures the communication hardware accordingly. The proposed concept enables an intuitive use of NoC features like end-to-end connections and Direct Memory Access (DMA). The presented results show that communication aware programming can improve performance and energy consumption.

This paper describes the process of implementing a complex communications protocol that provides reliable delivery of data in multicast-capable, packet-switching telecommunication networks. The protocol, called the Reliable Multicasting Protocol (RMP), was developed incrementally using a combination of formal and informal techniques in an attempt to ensure the correctness of its implementation. Our development process involved three concurrent activities: (1) the initial construction and incremental enhancement of a formal state model of the protocol machine; (2) the initial coding and incremental enhancement of the implementation; and (3) model-based testing of iterative implementations of the protocol. These activities were carried out by two separate teams: a design team and a V&V team. The design team built the-first version of RMP with limited functionality to handle only nominal requirements of data delivery. This initial version did not handle off-nominal cases such as network partitions or site failures. Meanwhile, the V&V team concurrently developed a formal model of the requirements using a variant of SCR-based state tables. Based on these requirements tables, the V&V team developed test cases to exercise the implementation. In a series of iterative steps, the design team added new functionality to the implementation while the V&V team kept the state model in fidelity with the implementation. This was done by generating test cases based on suspected errant or off-nominal behaviors predicted by the current model. If the execution of a test in the model and implementation agreed, then the test either found a potential problem or verified a required behavior. However, if the execution of a test was different in the model and implementation, then the differences helped identify inconsistencies between the model and implementation. In either case, the dialogue between both teams drove the co-evolution of the model and implementation. We have found that this interactive, iterative approach to development allows software designers to focus on delivery of nominal functionality while the V&V team can focus on analysis of offnominal cases. Testing serves as the vehicle for keeping the model and implementation in fidelity with each other. This paper describes (1) our experiences in developing our process model; "and (2) three example problems found during the development of RMP. Although RMP has provided our research effort with a rich set of test cases, it also has practical applications within NASA. For example, RMP is being considered for use in the NASA EOSDIS project due to its significant performance benefits in applications that need to replicate large amounts of data to many network sites. The RMP source code and documentation are currently available on the WWW via .

We describe a construction of almost universal hash functions suitable for very fast software implementation and applicable to the hashing of variable size data and fast cryptographic message authentication. Our construction uses fast single precision arithmetic which is increasingly supported by modern processors due to the growing needs for fast arithmetic posed by multimedia applications. We report on hand-optimized assembly implementations on a 150 MHz PowerPC 604 and a 150 MHz Pentium-Pro, which achieve hashing speeds of 350 to 820 Mbit/sec, depending on the desired level of security (or collision probability), and a rate of more than 1 Gbit/sec on a 200 MHz Pentium-Pro. This represents a significant speed-up over current software implementations of universal hashing and other message authentication techniques (e.g., MD5-based). Moreover, our construction is specifically designed to take advantage of emerging microprocessor technologies (such as Intel's MMX, 64-bit architectures and others) and then best suited to accommodate the growing performance needs of cryptographic (and other universal hashing) applications. The construction is based on techniques due to Carter and Wegman for universal hashing using modular multilinear functions that we carefully modify to allow for fast software implementation. We prove the resultant construction to retain the necessary mathematical properties required for its use in hashing and message authentication.

Multimedia applications require certain QoS guarantees to be met in order to function properly. QoS requirements for multimedia transmission include bandwidth guarantees and temporal guarantees (delay and jitter). Existing routing protocols on MANeTs are not adequate enough to deal with these necessities imposed by multimedia traffic. In this article, an adaptation of MPLS is proposed for MANeTs. M2PLS and MLDP together are employed in MANeTs to provide QoS and traffic engineering for real time multimedia traffic. These protocols are implemented and tested in the OMNeT++ network simulator. This article describes in detail the design and implementation of M2PLS and MLDP. Keywords: Multimedia traffic, MANeT, QoS, MPLS

TV-2160 128 B.3.3 Placement of the TV-2160 Probe 129 C Tristimulus Measurements 130 C.l Introduction 130 C.l.l Precision 130 C.1.2 Accuracy 131 C.2 Repeatability 132 C.3 Integration Time, Area and Noise C.3.1 Detection of single emissions C.3.2 Integration of several emissions C.3.2.1 Integration of noise C.3.2.2 Synchronization of measurement

We consider a multi-rate WLAN using the 802.11 technology. Previous work advocated the use of relay nodes to alleviate the 802.11 anomaly effect, however the role of relay is a thankless one. Here, we propose two relay strategies that aim at giving relay nodes some incentives for their roles, while at the same time enhancing the overall network performances. The first strategy involves the implementation of two LLC queues at each station: one handles 'local' traffic, the other collects relay traffic from other stations. This solution does not require any modification to current 802.11 cards. The second strategy relies on the 802.11e EDCA capabilities. It gives better performance with respect to the previous one, but its implementation depends on the availability of the 802.11e technology. Our strategies apply to infrastructured as well as ad hoc networks. Results show that they significantly improve system performances, both in terms of throughput and fairness.

Component middleware is popular for enterprise distributed systems because it provides effective reuse of the core intellectual property (ie, the “business logic”). Component-based enterprise distributed real-time and embedded (DRE) systems, ...

Nowadays, Wireless Mesh Network is the best solution for extending the coverage of Wireless LAN. Users move to wireless communication networks and expect the same level of performance as their wire line counterparts. Therefore, much research effort has been devoted to investigating how to optimally address the challenges posed by wireless multimedia communications. In this paper, the authors present Wireless Mesh Network and describe the handover schemes, leading to a new method for optimizing handover and a new power control approach.

This paper presents a new technique for implementing a low-power CMOS imager with simultaneous on-chip computation of the difference and sum of two successive frames. Existing difference imagers are susceptible to errors due to collection (by the sense element and in-pixel storage node) of photo-generated charge that diffuses from the photo-active pixel area during integration of the second frame. Our proof-of-concept imager uses a new unbalanced differential signal chain to provide 17 fold reduction in leakage error in the framedifference output. The resulting INL is < 1 % over most of the illumination range. Error reduction is achieved without noticeable increase either of fixed-pattern-noise (FPN) or of read noise, preserving high image quality. Power dissipation in the 256x256 imager is measured to be only 18 mW.

Network-on-chip (NoC) paradigm, which is based on a modular packet-switched mechanism, effectively addresses many of the on-chip communication challenges such as wiring complexity, communication latency, and bandwidth of many-core systems. In designing an efficient NoC, topology and routing algorithm are the most important challenging issues that have significant impact on area, latency and power consumption. The goal of this paper is designing a fuzzy-based routing algorithm for a NoC architecture with honeycomb topology. The proposed algorithm is a livelock and deadlock free routing algorithm based on fuzzy logic for hexagonal zones with flat triple coordinate system. The analysis of simulation results demonstrates that the proposed algorithm, provides higher performance in terms of latency, power consumption, throughput and area than a traditional fuzzy-based routing algorithm for mesh-based NoC architectures. Comparing to a non-fuzzy routing algorithm for honeycomb NoCs, the pro...

Reverse direction transmission and block ACK are effective ways to improve the performance of MAC layer that reduces the overhead and increases the system throughput. As high as 600 Mbps of physical data rate is achieved in IEEE 802.11n where high data rate of the current MAC layer leads to a high performance overhead and low performance throughput. Further,designing the MAC layer is still ongoing to achieve high performance throughput. In this paper, we examine the performance enhancement of the proposed 802.11n MAC layer in terms of reverse direction transmission using a single data frame and multi data frames. We implemented these schemes in the NS2 simulator to show the results for TCP traffic and compared them with the literature.

This paper describes a transport system architecture called ADAPTIVE that we are developing to support multimedia applications utilizing high-speed networks. ADAPTIVE stands for "A Dynamically Assembled Protocol Transformation, Integration, and Validation Environment." It is a transformation-based system with the goal of providing policies and mechanisms for interactively specifying and configuring a flexible and adaptive transport system. In addition, it aims to provide a controlled prototyping environment for monitoring, analyzing, and experimenting with the effects of different transport system designs and implementations on application performance. The performance of distributed applications (such as remote terminal access, network file servers, distributed databases, collaborative work activities, bulk data transfer, computer imaging, audio-and video-conferencing, full-motion video, scientific computation and visualization) is influenced by network factors and transport system 1 factors. Several key network factors include channel speed, bit-error rate, and congestion levels at the intermediate switching nodes (ISNs). Transport system factors include both protocol processing activities (such as connection management, transmission control, and error protection) and general operating system hardware and software factors (such as memory latency, CPU speed, interrupt and context switching overhead, process architecture, and message buffering). Advances in fiber optics and VLSI technology have increased network channel speed by several orders of magnitude [1]. Coupled with the increase in application and network diversity described in Section 2, these changes are shifting performance bottlenecks from the network factors to the transport system factors. Therefore, transport system architectures must be more flexible and adaptive to handle the diversity and dynamism in network characteristics and application communication requirements [2]. However, existing transport systems, which typically offer only a small number of monolithic protocols, are unable to meet these flexible and adaptive requirements adequately [3]. This paper is organized as follows: in Section 2 we define four important research problems involving transport systems and describe how existing systems do not adequately solve these problems, Section 3 introduces the ADAPTIVE system and outlines its design, and Section 4 summarizes the paper and describes future work. 2 Research Problems Our research is investigating solutions to the following four problems involving transport systems: (A) The Throughput Preservation Problem: As noted by [1, 4, 5], only a limited fraction of the available bandwidth in high-speed networks is being delivered to applications. This situation results from transport system overhead not decreasing as rapidly as the network channel-speed is increasing. The overhead results from activities such as memory-to-memory copying and process management operations like interrupt handling, context switching, and scheduling. (B) The Multimedia Application Diversity and Dynamism Problem: Another issue (which is related to the throughput preservation problem) is how to support the communication requirements of distributed multimedia applications 2 that are more demanding and dynamic than those found in traditional data applications such as remote terminal access, file transfer, and electronic mail. For example, multimedia applications involve combinations of requirements such as extremely high throughput (e.g., full-motion video), strict realtime delivery (e.g., manufacturing control systems), low latency (e.g., on-line transaction processing), low delay jitter (e.g., voice conversation), multicast capability (e.g., collaborative work activities), high-reliability (e.g., bulk data transfer), temporal synchronization (e.g., audio-and video-conferencing), and some degree of loss tolerance (e.g., hierarchically-coded voice and video). Moreover, multimedia applications impose different network traffic patterns. For instance, some applications generate highly bursty traffic (e.g., variable bit-rate video applications), some generate continuous traffic (e.g., constant bit-rate video applications), and others generate short, interactive, transaction-oriented traffic (e.g., network file systems using remote Transport Example Average Burst Delay Jitter Order

Memory devices often consume more energy than microprocessors in current portable embedded systems, but their energy consumption changes significantly with the type of transaction, data values, and access timing, as well as depending on the total number of transactions. These variabilities mean that an innovative tool and framework are required to characterize modern memory devices running in embedded system architectures. We introduce an energy measurement and characterization platform for memory devices, and demonstrate an application to multilevel-cell (MLC) flash memories, in which we discover significant value-dependent programming energy variations. We introduce an energy-aware data compression method that minimizes the flash programming energy, rather than the size of the compressed data, which is formulated as an entropy coding with unequal bit-pattern costs. Deploying a probabilistic approach, we derive energy-optimal bit-pattern probabilities and expected values of the bit...

IP Telephony is a potential killer application among the various multimedia applications and services. It is therefore natural to expect support for these services over new network architectures like wireless ad-hoc networks. Despite the proliferation of IP Telephony services in the Internet, the traditional client/server models that have been used are found to be highly inefficient for wireless ad-hoc networks as compared to peer-to-peer (P2P) models. On the other hand, P2P strategies require some tuning to work well in wireless ad-hoc networks. In this paper, we discuss some undesirable situation that may happen if P2P systems are deployed over wireless ad-hoc networks without adaptation. We then define our strategies for positioning Super Nodes in the physical network underlay as well as P2P ID space according to the constraints of these network technologies. We evaluate the efficiency of our approche in reducing the session establishment time and request failure rate as two important criteria for the performance of IP telephony systems.

Because of bursty high data rate and delay sensitive nature of high quality multimedia application, the resource allocation in wireless network to meet its quality of service (QoS) has become the most challenging and interesting issue. Orthogonal Frequency Division Multiple Access (OFDMA) employing adaptive channel allocation technique can support these requirement while increasing the system capacity many fold. Here, an efficient resource allocation method called two stage rate adaptive (TSRA) ...

Search, retrieval, and management of multimedia contents are challenging tasks for users and researchers alike. We introduce a software-hardware system for the global management of the multimedia contents produced by Spanish Civil Courts. The ultimate goal is to obtain an automatic classification of images and segments of the audiovisual records that, coupled with textual semantics, allows an efficient navigation and retrieval of judicial documents and additional legal sources. This paper describes our knowledge acquisition process, sets a typology of Spanish Civil hearings as performed in practice, and a preliminary procedural ontology at its actual stage of development (e-Sentencias ontology). A discussion on procedural, contextual and multimedia ontologies is also provided.

In this paper routing and wavelength assignment for supporting multicast traffic is investigated in WDM mesh networks under sparse splitting constrain. This problem is generally solved in two phases respectively with the purpose of minimizing the number of wavelengths required. Alternative routing is first proposed to route each session by pre-computing a set of candidate light-forests. Then wavelength assignment is formulated as a coloring problem by constructing a conflict graph. Potential heuristic algorithms are proposed.

The success of mobile and ubiquitous computing, coupled with the increasing demand for applications with high Quality of Service (QoS) and Quality of Experience (QoE) requirements, has brought great challenges to the future access networks. Thus, wireless mesh networks distinguish due to its flexibility, redundancy, low-cost and broadband capacity. However, aspects as scalability, availability and reliability, are still challenging. Following the limitations of existing proposals, this paper proposes the Multi-Service ...

The analysis of video data targeting the identification of relevant objects and the extraction of associated descriptive characteristics will be the enabling factor for a number of multimedia applications. This process has intrinsic difficulties, and since semantic criteria are difficult to express, usually only a part of the desired analysis results can be automatically achieved. For many applications, the automatic tools can be complemented with user guidance to improve performance. This paper proposes an integrated framework for video analysis, addressing the video segmentation and feature extraction problems. The framework includes a set of modules that can be combined following specific application needs. It includes both automatic (more objective) and user interaction (more semantic) analysis modules. The paper also proposes a specific segmentation solution to one of the most relevant application scenarios considered -off-line applications requiring precise segmentation.

The most complete, focused guide to MPEG-4--the breakthrough standard for interactive multimedia. The comprehensive, focused, up-to-the-minute guide to MPEG-4 Practical solutions for next-generation multimedia applications In-depth coverage of natural and synthetic audiovisual object coding, description, composition and synchronization Binary and textual scene description Transport and storage of MPEG-4 content MPEG-4 profiles and levels; verification tests MPEG-4 represents a breakthrough in multimedia, delivering ...

This paper presents a study addressed to evaluate the variation in perceived QoS experienced by a user running multimedia applications in a heterogeneous wireless network. To perform this evaluation, a real-time testbed emulating an all-IP B3G network that includes UMTS Terrestrial Radio Access Network (UTRAN), GSM/EDGE Radio Access Network (GERAN), and Wireless Local Area Network (WLAN); and the corresponding common core network (CN) based on DiffServ technology and Multiprotocol Label Switching (MPLS) has been used. Results for videostreaming and video conference applications when running under interruptions due to a vertical handover (VHO) are included in this paper, pointing out the variations in behaviour of different applications.

The goal of this research is to provide a framing structure for a sequence of ATM cells which carry multimedia traffic. We will redefine the concept of a connection in the context of cell streams, show how to identify the starting and ending points of connections, and investigate the signaling and hardware support. A new Multimedia Application Adaptation Layer (MAAL) protocol is proposed as an application of this concept. The resolution technique being proposed may reduce the processing overhead when cells travel through the switches. Furthermore, it may simplify the traffic scheduling at the application level and re-synchronize the multimedia traffics through the Asynchronous Transfer Mode network interface.

There is an emerging class of computationally demanding multimedia applications involving vision, speech and interaction with the real world (e.g., CRL's Smart Kiosk). These applications are highly parallel and require low latencies for good performance. They are well-suited for implementation on clusters of SMP's, but they require efficient scheduling of application tasks. General purpose schedulers produce high latencies because they lack knowledge of the dependencies between tasks. Previous research in optimal scheduling has been limited to static problems. In contrast, our application is highly dynamic as the optimal schedule depends upon the behavior of the kiosk's customers. We observe that the dynamism of our application class is constrained, in that there are a small number of operating regimes which are determined by the state of the application. We present a framework for optimal scheduling of constrained dynamic applications. The results of an experimental comparison with a hand-tuned schedule are promising.

Quality of Service (QoS) based routing provides QoS guarantees to multimedia applications and an efficient utilization of the network resources. Nevertheless, QoS routing is likely to be a costly process that does not scale when the number of nodes increases. Thus, the routing algorithm must be simple and a class-of-service routing is an alternative to provide QoS guarantees instead of per-flow routing. This paper proposes and analyzes the performance of a distance-vector QoS routing algorithm that takes into account three metrics: propagation delay, available bandwidth, and loss probability. Classes of service and metriccombination are used to turn the algorithm scalable and as complex as a two-metric one. The processing requirements of the proposed algorithm and those of an optimal approach are compared and the results show an improvement up to 50%.