Catálogo de publicaciones - libros

We propose an admission control approach for IPTV in which decisions to admit new flows are based on effective bandwidth estimates calculated using empirical traffic measurement. We describe our approach to estimate the effective bandwidth required to satisfy given Quality-of-Service constraints on traffic and specify a simple admission control algorithm which uses this estimation to manage flow admissions. We present the results of a simulation study, employing real traffic traces for long-lived flows, which indicate that our algorithm ensures that an adequate, but not overly generous, amount of bandwidth is allocated to ensure that Quality-of-Service targets for accepted flows will be met. We also compare our algorithm with alternative approaches based on analytical estimation of effective bandwidth; we demonstrate that these approaches are weak at taking into account related Quality of Service constraints and thus reserve inappropriate amounts of bandwidth, leading to either increased QoS target violations, or underutilisation of resources.

The integration of multiple network access technologies in the terminal is one of the most important trends in 4G networks. This integration places telecommunications service providers, and in particular operators, under the significant challenge of being able to transform their services in order to adapt them to a great variety of delivery contexts. This paper describes a generic methodology for the adaptation of telecommunications services provided in the context of an operator. A number of scenarios are examined which show how Parlay middleware can be used by trusted service providers to easily access network resources and context information for enhancing location-based and adaptable multimedia telecommunications services.

Naval at sea (maritime tactical) networks are characterised by a dynamic, heterogeneous, and low-bandwidth environment. There is a critical need for Traffic Engineering (TE) mechanisms to support traffic prioritisation and resource optimisation in this environment. A desirable management service in this environment is end-to-end guaranteed bandwidth for critical application flows. Solutions such as RSVP are not appropriate for the maritime environment where links are error prone and easily overloaded. This paper describes the Resource Reservation Service (RRS), a policy-enabled flow-based TE management service developed specifically for the low-bandwidth, high-error rate, and mobility of the maritime environment. This service includes several novel features including multi-path probing, bi-directional reservations, and full policy control. The value of multi-path probing is demonstrated by simulation.

The proliferation of real-time multimedia services has triggered attempts by service providers to seek ways to reduce the cost of managing those services, while satisfying customer demands for the resources involved in the service delivery. A key issue is to avoid costly service interruptions in such real-time multimedia services. In this paper, we propose the use of the inventory control approach from the Operations Research community to remedy to this problem. We show two possible inventory control models to manage the resources involved in real-time multimedia service delivery. We also perform extensive simulations to compare the advantages and disadvantages of the two inventory control models for resource management of real-time multimedia services.

This paper presents the concept and preliminary experiments of a system for assessing on the Quality of Service of multimedia flows. The goal is to devise a mechanism that allows a service provider to take action whenever poor quality of service is detected in the delivery of multimedia flows. Such procedure is fully automatic since it is based on a goodness-of-fit test between source and destination packet interarrival histograms. If the null hypothesis of the test is accepted the flow is marked as in good standing, otherwise it is marked as anomalous and the network management system should take action in response. The proposed technique is analyzed in terms of hardware complexity and bandwidth consumption. The results show this technique is feasible and easily deployable at a minimum hardware and bandwidth expense.

The topology control strategies of wireless sensor networks are very important to reduce the energy consumptions of sensor nodes and prolong the life-span of networks. In this paper, we put forward a minimum-energy path-preserving topology control (MPTC) algorithm. MPTC not only resolves the problem of exceeding energy consumption because of the unclosed region in SMECN[2], but also preserves at least one minimum-energy path between every pair of nodes in a communication network. At last, we demonstrate the performance improvements of our algorithm through simulation.

Currently, several multimedia devices support the UPnP protocol allowing automatic detection of devices, connection of devices and agreement on a certain quality of the communication established between a server of content (Media Server) and a player of content (Media Renderer). The focus of this paper is to add to the UPnP standard quality of service (QoS) some elements to incorporate better performance in the local networks. All these additions are compatible with the current standard.

IP real-time multimedia applications present a challenging environment for network and service management, which requires a new approach. DYSWIS (Do You See What I See), proposed in this paper, is peer-to-peer distributed management architecture for multimedia network and service management, characteristic of active fault probing and identification based on protocol and functional scripting and rules.

The Wireless Multimedia Sensor Networks (WMSN) are a particular case of Wireless Sensors Networks (WSN) as they present a lower density, a limited mobility, require more important resources and need QoS control to transport the multimedia streams. In this paper, we propose, starting from a reference architecture of WMSN, a first approach for hierarchical self-organizing routing ensuring a certain level of QoS.

Due to missing copyright, this chapter was removed from the online version of this volume.