Jodra Luque, Jose Luis

ABSTRACT
This chapter introduces the principal characteristics of MANETs and shows how these particularities may affect both QoS conditions and QoS management/provisioning systems, and therefore the capabilities of MANETs for properly providing multimedia services. After a deep analysis of different QoS mechanisms at different layers, the authors claim that QoS management cannot be handled only at the network layer or by applying some QoS-aware routing protocols. In fact, any end-to-end QoS provision architecture will demand QoS control mechanisms and information exchange among all the layers. A clear understanding of different proposals aimed at coping with QoS requirements at different layers will not only provide researchers with valuable information for designing better multimedia capable MANETs, but will also assist them in evaluating the need for a unified cross-layer approach in order to optimize the performance of analyzed protocols.

ABSTRACT
This paper proposes a service discovery protocol for discovering and advertising services in a proactive ad hoc network. The protocol we have defined is piggybacked into the OLSR protocol. We define a new message type into OLSR called Service Discovery Message (SDM) for both advertisement and discovery of services. The advertisement frequency and advertisement lifetime are user-controlled parameters, so that they can be modified depending on the user requirements. Each node maintains a service cache to store information about its own services, and the services each device discovers in the network. We also present simulation results of our protocol and show that the service discovery protocol defined here achieves much efficiency in discovering services, while it introduces practically no packet overhead compared to the basic OLSR protocol.

ABSTRACT
This paper proposes the deployment of a network software platform for experimentation called LabQoS that will allow the scientific community to establish scientific experiments relating to measure the performance of applications and services on the Internet and other network environments. Previous experiences have already deployed measurement systems, but they don’t incorporate the concept of control of the scenario to enable the performing of experiments. This LabQoS capacity makes it an innovative platform unique in its approach. A module called Test Environment Builder has been designed in order to monitor the operating parameters, and to propose adaptation strategies to handle the scenario control variables. We define an experimental data model that identifies the entities to be considered in the management of the platform. Assessment mechanisms are proposed to study the dynamic sensitivity of the control variables with respect to the parameters. LabQoS is based on QoSMETER architecture that addresses technological aspects such as user management, deployment tools, data collection, reporting, security, etc.

ABSTRACT
This paper presents the design of a centralized system responsible for the management of remote procedures execution in a distributed scenario. The architecture proposed will be able to unify the information provided by several services with different types of managing interfaces. In these terms, the application will catch, organize and execute procedure queries from clients in order to achieve the information by means of a common interface that will be supported by a structure of plug-ins. On the other hand, one of the objectives of the design is to describe a model for the generic definition of tasks, so that the developed system could arrange them regardless of the type of service to which they belong.

ABSTRACT
Data network services have been developed since their begining and nowadays they are showing a great expansion. This is the case of the streaming services such as voice transmision over IP (VoIP). The technology is in an advanced state, however, the Quality of Service (QoS) measurement and evaluation are still being studied. This paper analyzes the relationship between the user's perceived quality and the impairment factors of the network, as well as, the methodology followed to measure the required parameters. The results are expected to be interesting not only for the users but also for the Internet providers, so that it gives them the oportunity to improve the service offered in an optimal way.

ABSTRACT
Data network Quality of Service (QoS) measurement and evaluation is a challenge being deeply studied nowadays. Measurement techniques and methodologies are broad available, but they are not connected among them, this is, the evaluation is based on raw parameters. In this paper we present a proposal of an integrating architecture which can evaluate user's perceived QoS, merging results obtained by different measurement tools in order to acquire a better knowledge of the communication link than using a single parameter. Extra effort is made to develop a set of easy to use and understand measurement tools.

ABSTRACT
This paper considers the subject of provisioning services in ad-hoc networks. Service discovery in these networks is challenging due to the lack of central infrastructure, limited resources and high mobility. We propose integrating this mechanism on the proactive OLSR (Optimized Link State Routing) protocol. A new message type, called Service Discovery Message (SDM), is added. This message will announce (servers) and request (clients) for services. Available local services will only be advertised once, with a specific lifetime, in order to avoid increasing the network overhead. These services will be stored in a local service cache that is maintained on each node. When a node wants to make use of a service, it will look on the cache. If it is not yet stored, it will send a query message. Simulation results are presented to demonstrate that the introduced packet overhead is insignificant compared with the standard OLSR protocol.

These mechanisms must be efficient: every node should know the maximum number of services as possible. In networks with few nodes, the percentage of discovered services is around 90%. On the other hand, in bigger networks, was higher than the 80%. We believe that due to the obtained results, the following step consists on proving the protocol here presented in real scenarios using prototypes.

ABSTRACT
This paper presents a comprehensive model intended to analyze quality of service in telecommunications services and its causes. Although many works have been published in this area, both from a technical viewpoint as well as taking into consideration subjective concerns, they have not resulted in a unique methodology to assess the experienced quality. While most of the studies consider the quality of service only from a technical and end-to-end point of view, we try to analyze quality of service as a general gauge of final users' satisfaction. The proposed model allows us to estimate the quality experienced by end users, while offering detailed results regarding the responsibility of the different agents involved in the service provision. Once we overview the most significant elements of the model, an in-depth analytical study is detailed. Finally, we illustrate a practical study for web browsing service in order to validate the theoretical model.

ABSTRACT
This paper presents a comprehensive model intended to analyse quality of service in telecommunications services. Many works have been published in this area, both from a technical viewpoint as well as taking into consideration subjective concerns. However, these works have not resulted in a unique methodology to assess the experienced quality. While most of the studies consider the quality of service from biased perspectives, we try to analyse quality of service as a general gauge of final users’ satisfaction. The proposed model allows us to estimate the quality experienced by end users, while offering detailed analysis regarding the different agents involved in the service provision. Once we overview the most significant elements of the model, an in-depth analytical study is detailed. Finally, we illustrate a practical study for HTTP service in order to validate the theoretical model.

ABSTRACT
This paper proposes a service descovery protocol for discovering and advertising services in a proactive ad hoc network. The protocol we have defined is piggybacked into the OLSR (Optimized Link State Routing) routing protocol. We have defined a new message type into OLSR, called Service Discovery Message (SDM), for both advertisement and discovery of services. The advertisement frequency and advertisement lifetime are user-controlled parameters, so that they can be modified depending on the user requirements. Each node mantains a service cache to store information about its own services, and the services each device discovers in the network. We also present simulation results of our protocol and show that the service discovery protocol defined here, achieves much efficiency in discovering services, while it introduces practically no packet overhead compared to the basis OLSR protocol.

ABSTRACT
This paper proposes a service discovery protocol for discovering and advertising services in a proactive ad hoc network. The protocol we have defined is piggybacked into the OLSR (Optimized Link State Routing) protocol. We define a new message type into OLSR called Service Discovery Message (SDM) for both advertisement and discovery of services. The advertisement frequency and advertisement lifetime are usercontrolled parameters, so that they can be modified depending on the user requirements. Each node maintains a service cache to store information about its own services, and the services each device discovers in the network. We also present simulation results of our protocol and show that the service discovery protocol defined here achieves much efficiency in discovering services, while it introduces practically no packet overhead compared to the basis OLSR protocol.

ABSTRACT
This paper considers the problem of provisioning services in proactive ad hoc networks. Our proposal consists in a service discovery mechanism, integrated on the proactive OLSR (Optimized Link State Routing) protocol. We define a new message type into OLSR called Service Discovery Message (SDM) for advertising and discovering services. The advertisement frequency and advertisement lifetime are usercontrolled parameters, so that they can be modified depending on the user requirements. Each node maintains a service cache to store information about services discovered via advertisements. We also present simulation results that demonstrate that the service discovery mechanism defined here, introduces insignificant packet overhead compared to the basis OLSR protocol.

ABSTRACT
This paper presents an overview of the research activities accomplished in the 'Telematics Engineering Group' (UPV/EHU) in the area of perceived QoS. We go over the achieved works until the current day and we present as well the scheduled research tasks regarding the measurement of QoS from an end user perspective. The proposed theoretical model is intended to analyse the performance experimented in every agent involved in the provision o f Internet services. Furthermore, we state several in-progress enhancements to the model and introduce an approach to empirically validate the model.

ABSTRACT
The current expansion of new services, which require high bandwidth rates, has enforced an increase of network throughput hindering network monitoring. Conventional network traffic analysis tools like tcpdump or ethereal were not designed to keep up with new rates so loss rates are very high. Consequently, we have developed a sensor that exploits multiprocessor features in order to reduce loss rates in high speed networks. Most network traffic analysis require communication among instances yielding synchronization troubles that must be solved. As the sensor splits traffic analysis loads among different processes, they will concurrently access to shared memory areas. Conventional synchronization mechanisms like semaphores are not a good approach because they harm sensor’s performance highly. Hence, in this paper we introduce a number of mechanisms that improve the overall performance of the sensor as a result of an effective communication among instances.

ABSTRACT
This paper presents an overview of the research activities accomplished in the N-QaS (Networking, Quality and Security Group) in the area of quality of service (QoS) in wireless environments and concretely in Ad HOC networks. After studying the different objective parameters that can be used to guarantee a minimum of QoS (such as: bandwidth, delay, jitter and rate of errors), and with the later study of different signalling systems for the reservation of resources (such as INSIGNIA and dRSVP), the possibility has been identified of using the period of discovery of routes from the origin to the destination (in search of the road that better responds to our necessities from the point of view of the QoS) only not thinking of the shortest road (the one that less hops offers from the origin to the destination, habitual operation from the point of view of the most routing protocols, it is not the most effective parameters in the QoS) also keeping in mind that we are allowed to be able to give priority to other parameters of QoS (objective parameters) and that they can be reserved for the whole session of communication in the same way that the route is reserved. And what is more important, this whole process would be made in parallel (at the same time), winning this way in functionality (we are fusing two necessary processes in one).