Antonio Bueno

Multicast Extension of Unicast Charging for QoS Services

In order to successfully deploy multicast services in QoS-aware networks, pricing architectures must take into account the particular characteristics of multicast sessions. With this objective, we propose a charging scheme for QoS multicast services, assuming that the unicast cost of each interconnecting link is determined and that such cost is expressed in terms of quality of service (QoS) parameters. Our scheme allows determining the cost distribution of a multicast session along a cost distribution tree (CDT), and basing such distribution in those pre-existing unicast cost functions. The paper discusses in detail the main characteristics of the problem in a realistic interdomain scenario and how the proposed scheme would contribute to its solution

A quality-based cost distribution charging scheme for QoS multicast networks

This paper presents a new charging scheme for cost distribution along a point-to-multipoint connection when destination nodes are responsible for the cost. The scheme focus on QoS considerations and a complete range of choices is presented. These choices go from a safe scheme for the network operator to a fair scheme to the customer. The in-between cases are also covered. Specific and general problems, like the incidence of users disconnecting dynamically is also discussed. The aim of this scheme is to encourage the users to disperse the resource demand instead of having a large number of direct connections to the source of the data, which would result in a higher than necessary bandwidth use from the source. This would benefit the overall performance of the network. The implementation of this task must balance between the necessity to offer a competitive service and the risk of not recovering such service cost for the network operator. Throughout this paper reference to multicast charging is made without making any reference to any specific category of service. The proposed scheme is also evaluated with the criteria set proposed in the European ATM charging project CANCAN.

On the use of QoS requirements as base of multicast charging

We propose a charging scheme for cost distribution along a multicast tree when cost is the responsibility of the receivers. This scheme focuses on QoS considerations and it does not depend on any specific type of service. The scheme has been designed to be used as a bridge between unicast and multicast services, solving the problem of charging multicast services by means of unicast charging and existing QoS routing mechanisms. We also include a numerical comparison and discussions of the case of non-numerical or relative QoS and on the application to some service examples in order to give a better understanding of the proposal.

AXARM: An Extensible Remote Assistance and Monitoring Tool for ND Telerehabilitation

AXARM is a multimedia tool for rehabilitation specialists that allow remote assistance and monitoring of patients activities. This tool is the evolution of the work done in 2005-06 between the BCDS research group of UdG and the Multiple Sclerosis Foundation (FEM in Spanish) in Girona under the TRiEM project. Multiple Sclerosis (MS) is a neurodegenerative disease (ND) that can provoke significant exhaustion in patients even just by going to the medical centre for rehabilitation or regular checking visits. The tool presented in this paper allows the medical staff to remotely carry on patient consults and activities from their home, minimizing the displacements to medical consulting. AXARM has a hybrid P2P architecture and consists essentially of a cross-platform videoconference system, with audio/video recording capabilities. The system can easily be extended to include new capabilities like, among others, asynchronous activities whose result can later be analyzed by the medical personnel.

Automatic self-configuration of the logical network using distributed software agents

We present a system for dynamic network resource configuration in environments with bandwidth reservation. The proposed system is completely distributed and automates the mechanisms for adapting the logical network to the offered load. The system is able to manage dynamically a logical network such as a virtual path network in ATM or a label switched path network in MPLS or GMPLS. The system design and implementation is based on a multi-agent system (MAS) which make the decisions of when and how to change a logical path. Despite the lack of a centralised global network view, results show that MAS manages the network resources effectively, reducing the connection blocking probability and, therefore, achieving better utilisation of network resources. We also include details of its architecture and implementation.

CITS 2017 general chairs' message

Welcome to the 2017 International Conference on Computer, Information and Telecommunication Systems (CITS 2017). This years conference marks the sixth CITS, which is being held on annual basis.

Charging Multicast Services: A Cost Distribution Scheme Comparative Study

In this article we examine the problem of cost distribution in a real-time multicast service across network domains. Current solutions like content distribution networks may not be adequate when real-time (or almost real-time) services are considered. Multicast is a well-known technology that, although requiring significant involvements of all participants, provides a scalable method to offer such services. Assuming each domain that participates in the service can express their cost in terms of QoS parameters, we study the application of charging schemes that combine such unicast cost functions. We implement and compare several charging schemes, one of them our own MXUCS, and show how they reflect the use of resources, their fairness among participants, as well as how are they influenced by content distribution tree topologies.

Qualitative Reasoning for Admission Control in ATM Networks

Asynchronous Transfer Mode (ATM) provides transport functionality to the future Broadband Integrated Service Digital Network, ATM networks are connection oriented and Connection Admission Control (CAC) is a preventive control procedure responsible for determining whether a connection request is admitted or denied. There is a trade-off between the accuracy and the evaluation time on the CAC schemes. Most accurate methods spend excessive time on evaluations and consequently the request is rejected due to time-out. A possible approach is to evaluate some possible future situations (pre-evaluation). These results would be previously evaluated and saved on a table. Between consecutive connection requests, the evaluation system evaluates in advance the future response for each class of traffic.