J. P. Rissen's scientific contributions

Wireless service providers around the world are at a business and technological tipping point. Having made investments in legacy technologies that were designed primarily to support voice traffic they now need to cope with new standards, protocols and business imperatives. In so doing, existing business models and technology platforms will be rendered moot. Consider this: • While the International Telecommunication Union (ITU)-R M.2072 expects voice traffic to account for the lion's share of volume through 2015, a shift is already underway for revenue to be driven by rich multimedia entertainment services like video messaging or all forms of mobile commerce. • This shift will place a premium on technologies that maximize bandwidth and throughput while maximizing spectral efficiency, • Fourth Generation (4G) wireless architectures are rapidly maturing to address these requirements while leveraging the capabilities of Third Generation (3G) technologies, taking advantage of the features associated with an all-IP network system. As a result of these trends, service providers are scrambling to assess, purchase and deploy new wireless service delivery technologies that will address emerging demand, while maximizing the revenue generated from traditional sources. Those organizations that most effectively manage the transition from Second Generation (2G), 3G and ultimately 4G infrastructures will be best positioned to grow through the rest of the decade and into the next. To that end, this article puts these overlapping wireless standards (2G, 3G and 4G) into a context that will explain the evolution of the wireless technology infrastructure and provide a basis for optimizing a company's investment in next generation systems and business models. Public wireless communications have evolved considerably since the emergence of 2G digital wireless cellular technologies in the early '90s. In their earliest incarnation, Groupe Spécial Mobile (GSM) and its North American counterpart Code division multiple access cdmaOne™, primarily were designed for voice services (although they did support some limited data capabilities such as Short Message Service [SMS] and low-speed circuit-switched data).

Digital cellular mobile radio network infrastructure from Alcatel is described. This article gives an overview of the Global system for mobile communications (GSM), the interfaces and protocols. Detailed explanation about the Alcatel 900 way of implementation and network integration is presented.

The Seapso Leg 3 cruise (December, 1985) was carried out in the North Fiji Basin aboard the IFREMER R.V. “Jean Charcot”. The main purpose of the cruise was to carry out a geophysical and geological study of the central part of the basin between 16° S and 22°S. To this end. bathymetric profiles (with the help of the Seabeam multichannel echosounder), single-channel seismic reflection profiles and magnetic and gravimetric profiles were made. Moreover, geological samples were taken (by dredging and piston coring) as well as water samples (with the help of a multiprobe). One of the aims of the cruise was to explore the present-day spreading axis of the North Fiji Basin. We were able to show that accretion (the rate of which is about 7 cm/yr) in the North Fiji Basin has been constrained in a N-S direction for 3 Ma. Very recently, between 0.6 and 0.7 Ma ago, the accretion process changed, resulting in the creation of a ridge-ridge-trench triple junction centered at 173°30′E and 16°40′S. Water samples taken in the vicinity of this triple junction show significant anomalies of methane and manganese, which are probably linked to hydrothermal events.In its morphological characteristics (transversal as well as longitudinal) the ridge of the North Fiji Basin shows striking similarities to the East Pacific Rise. It presents the same differences in level, the same sizes of structures and the same particular features (overlapping spreading centers, offsets, etc.).Another aim of the SEAPSO cruise was to study the complex deformation area located immediately to the west of the Fiji Islands, which we interpret as a distensive type deformation in a strike-slip system.

It has often been remarked that surprisingly few parts of the algorithms which define an operating system require the use of unsafe, low-level language features {1}. Nevertheless, the lack of safety inherent in these parts will propagate to the whole system if an appropriate methodology is not used. It seems desirable to structure programs in such a way that parts with different safety levels are clearly separated and identifiable. The LIS solution to this problem involves the use of two language levels which are used in separate contexts. The general language is a Pascal-like language with the safety that this implies {2, 3}. On the other hand, the use of unsafe features is restricted to so-called implementation parts associated with each declaration level of the program. Several authors {4, 5, 6} have pointed out the advantages of having a two-step data definition, namely, a first step concerned with the semantic properties and a second dealing with the effective realization. In what follows we present the LIS approach to this question and show that the safety levels inherent to these two steps are different. The second step requires implementation specifications which appear in implementation parts.