Future wireless applications for a networked city: services for visitors and residents

Future wireless networks will offer near-ubiquitous high-bandwidth communications to mobile users. In addition, the accurate position of users will be known, either through network services or via additional sensing devices such as GPS. These characteristics of future mobile environments will enable the development of location-aware and, more generally, context-sensitive applications. In an attempt to explore the system, application, and user issues associated with the development and deployment of such applications, we began to develop the Lancaster GUIDE system in early 1997, finishing the first phase of the project in 1999. In its entirety, GUIDE comprises a citywide wireless network based on 802.11, a context-sensitive tour guide application with, crucially, significant content, and a set of supporting distributed systems services. Uniquely in the field, GUIDE has been evaluated using members of the general public, and we have gained significant experience in the design of usable context-sensitive applications. We focus on the applications and supporting infrastructure that will form part of GUIDE II, the successor to the GUIDE system. These developments are designed to expand GUIDE outside the tour guide domain, and to provide applications and services for residents of the city of Lancaster, offering a vision of the future mobile environments that will emerge once ubiquitous high-bandwidth coverage is available in most cities

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

Quality of Service over Specific Link Layers: state of the art report

The Integrated Services concept is proposed as an enhancement to the current Internet architecture, to provide a better Quality of Service (QoS) than that provided by the traditional Best-Effort service. The features of the Integrated Services are explained in this report. To support Integrated Services, certain requirements are posed on the underlying link layer. These requirements are studied by the Integrated Services over Specific Link Layers (ISSLL) IETF working group. The status of this ongoing research is reported in this document. To be more specific, the solutions to provide Integrated Services over ATM, IEEE 802 LAN technologies and low-bitrate links are evaluated in detail. The ISSLL working group has not yet studied the requirements, that are posed on the underlying link layer, when this link layer is wireless. Therefore, this state of the art report is extended with an identification of the requirements that are posed on the underlying wireless link, to provide differentiated Quality of Service

Internet Accounting

This article provides an introduction to Internet accounting and discusses the status of related work within the IETF and IRTF, as well as certain research projects. Internet accounting is different from accounting in POTS. To understand Internet accounting, it is important to answer questions like "what is being paid for" and "who is being paid". With respect to the question "what is being paid for" a distinction can be made between transport accounting and content accounting. Transport accounting is interesting since techniques like DiffServ enable the provision of different quality of service classes; each class will be charged differently to avoid all users selecting the same top-level class. The interest in content accounting finds its roots in the fast growth of commercial offerings over the Internet; examples of such offerings include remote video and software distribution. The question "who is being paid" has two possible answers: the network provider or the owner of the content. The case in which the network provider issues the bill is called provider-based accounting. Since this case will become more and more important, this article introduces a new architecture for provider-based accounting

Description and Experience of the Clinical Testbeds

This deliverable describes the up-to-date technical environment at three clinical testbed demonstrator sites of the 6WINIT Project, including the adapted clinical applications, project components and network transition technologies in use at these sites after 18 months of the Project. It also provides an interim description of early experiences with deployment and usage of these applications, components and technologies, and their clinical service impact