A Priority Rate-Based Routing Protocol for wireless multimedia sensor networks

The development of affordable hardware has made it possible to transmit multimedia data over a wireless medium using sensor devices. Deployed sensors span larger geographical areas, generating different kinds of traffic that need to be communicated either in real-time or non-real-time mode to the sink. The tiny sized design of sensor nodes has made them even more attractive in various environments as they can be left unattended for longer periods. Since sensor nodes are equipped with limited resources, newer energy-efficient protocols and architectures are required in order to meet requirements within their limited capabilities when dealing with multimedia data. This is because multimedia applications are characterized by strict quality of service requirements that distinctively differentiate them from other data types during transmission. However, the large volume of data produced by the sensor nodes can easily cause traffic congestion making it difficult to meet these requirements. Congestion has negative impacts on the data transmitted as well as the sensor network at large. Failure to control congestion will affect the quality of multimedia data received at the sink and further shorten the system lifetime. Next generation wireless sensor networks are predicted to deploy a different model where service is allocated to multimedia while bearing congestion in mind. Applying traditional wireless sensor routing algorithms to wireless multimedia sensor networks may lead to high delay and poor visual quality for multimedia applications. In this research, a Priority Rate-Based Routing Protocol (PRRP) that assigns priorities to traffic depending on their service requirements is proposed. PRRP detects congestion by using adaptive random early detection (A-RED) and a priority rate-based adjustment technique to control congestion. We study the performance of our proposed multi-path routing algorithm for real-time traffic when mixed with three non real-time traffic each with a different priority: high, medium or low. Simulation results show that the proposed algorithm performs better when compared to two existing algorithms, PCCP and PBRC-SD, in terms of queueing delay, packet loss and throughput

Towards Autonomic Service Provisioning Systems

This paper discusses our experience in building SPIRE, an autonomic system for service provision. The architecture consists of a set of hosted Web Services subject to QoS constraints, and a certain number of servers used to run session-based traffic. Customers pay for having their jobs run, but require in turn certain quality guarantees: there are different SLAs specifying charges for running jobs and penalties for failing to meet promised performance metrics. The system is driven by an utility function, aiming at optimizing the average earned revenue per unit time. Demand and performance statistics are collected, while traffic parameters are estimated in order to make dynamic decisions concerning server allocation and admission control. Different utility functions are introduced and a number of experiments aiming at testing their performance are discussed. Results show that revenues can be dramatically improved by imposing suitable conditions for accepting incoming traffic; the proposed system performs well under different traffic settings, and it successfully adapts to changes in the operating environment.Comment: 11 pages, 9 Figures, http://www.wipo.int/pctdb/en/wo.jsp?WO=201002636

SLAng: A language for defining service level agreements

Application or web services are increasingly being used across organisational boundaries. Moreover, new services are being introduced at the network and storage level. Languages to specify interfaces for such services have been researched and transferred into industrial practice. We investigate end-to-end quality of service (QoS) and highlight that QoS provision has multiple facets and requires complex agreements between network services, storage services and middleware services. We introduce SLAng, a language for defining Service Level Agreements (SLAs) that accommodates these needs. We illustrate how SLAng is used to specify QoS in a case study that uses a web services specification to support the processing of images across multiple domains and we evaluate our language based on it

Vertical sub-contracting relationships strategy, the Airbus First-tier suppliers\' coordination

This paper analyzes the transformations of industrial vertical relationships, and more particularly the duality of the coordination modes within new industrial architectures. The paper aims to characterize relationship between the architect and the first-tier suppliers according to the strategic degree of their competence. Two models of coordination arm\'s length and systems integration coexist within the same industrial architecture. The recourse to one or the other varies according to the policy of purchase and the strategic degree of the sub-contracted subsystems. Thus we will analyze the system of subcontracting of Airbus by focusing to the importance of the purchasing policy. The argumentation articulates in two parts. The first one considers the vertical subcontracting relationships in the framework of complex productions, by insisting on organizational aspects. The second one analyses the transformation of the \"Airbus\" productive system by focusing on purchasing process and the emergence of new First-tier supplier’s coordination modes.NAModularity – Systems Integration – Strategic competences – Purchasing Strategy – First Tier Suppliers – Airbus

A Framework for the Design of Service Maps

The concept of service-oriented architecture (SOA) is recognized as an important enabler for business transformation and application integration. Service maps emerge when individual services are (pre)configured on various architectural levels. For example, business-oriented service maps sustain the communication and coordination among participants within and between businesses. Difficulties occur when, based on different service design strategies, heterogeneous service maps are created which need to be aligned. A methodological approach to establish a systematic design process for such service maps within companies or business networks is needed