電気通信システムと管理

The purpose of this article is to summarize the current state of understanding the smart city concept and to present a proposed communication platform for the development of city services. The first part of the article is an introduction and definition of a smart city concept. This introduction gives an overview of various aspects - city services, smart infrastructure and facilities, using information and communication technologies, interconnection, feedback, and electronic and digital applications. The next part addresses individual challenges for the planning, development, and operation of cities. New solutions allow for use of different data on cities and meet the request for better city services. An overview of smart cities applications and services is given in the next section of the article. The deployment, implementation and approval of innovative internet based services and applications have to be made in order to permit facing the challenges of advanced cities. An overview of some aspects related to the technological solution of services is discussed in the summary section.

The world becoming a global village comes with its challenges. One of such challenge is that both local and international manufacturing firms are engaged in fierce competition of winning customer’s loyalty through Total Quality Management (TQM). The methodology of this paper used both questionnaire and statistical tools like t-test, F-test, ANOVA, regression and correlation analysis to study the components of TQM and how they affect effective delivery of manufacturing projects. The result of analysis indicates that staff training, staff empowerment, genuine quality culture, top management support, quality-based custom design and product improvement are critical to effective delivery of manufacturing projects. It is therefore very important that for the transformation of the nation, manufacturing sector of the Nation must imbibe the culture and practice of Total Quality Management in their product development and delivery.

A number of key management challenges are encountered when operating tactical communication systems using a group-wide shared key. A large portion of such communications occurs over low bit-rate channels, and all communication channels must be available at any moment for mission action. Current over-the-air rekeying protocols consume too much channel bit-rate to be practical for large tactical radio networks. This caused an off-line pre-placed key (PPK) approach to become most commonly used key distribution method in these environments. Unfortunately, with this key management scheme, revoking group membership requires a full intra-mission rekey, which can be dangerous in a battlefield situation. This paper introduces a new group key distribution method called Viral Electronic Key Exchange (VEKE). This paper examines the protocol as an extension to the Internet Key Exchange (IKE) protocol, but any electronic key exchange protocol can be used (Ex. IKE v2). A feature of this protocol is a parallel key distribution scheme enabled by propagating the key management role to authenticated nodes while establishing security associations across the network. We performed a comprehensive stochastic analysis to develop a model for computing the expected rekey time across the entire group, taking into account the likelihood of node jamming, channel failures, and message corruption. This model was verified with a Monte-Carlo simulation. Our results confirmed that the VEKE protocol can accomplish an over-the-air rekey in a short period of time, even over low bit-rate systems, while preserving rigid security and channel availability properties of the network. It also allows for the amount of pre-placed public-key material and other preparations necessary in tactical networks to be minimized.

In this paper, we describe our vision of the advanced 5G infrastructure, a ubiquitous mobile ultra-broadband network supporting the Future Internet (FI). It is argued that 5G should not be simply seen as an evolution of current 4G networks, but, rather a revolution in the ICT field towards the “nervous system” of the Digital Society and Digital Economy. In fact, 5G will efficiently enable new ultra reliable, dependable, secure, privacy preserving, and delay critical services to everyone and everything, such as machines, vehicles, smart things, robots, etc. Adoption of new service models, such as “Full Immersive Experience”, enriched by “Context Information”, and “Anything as a Service” will create the conditions for the socio-economic sustainability of 5G infrastructures. In particular, “Anything as a Service” is a paradigm where devices, machines, smart things or robots will become “tools” to produce and consume applications, services and data, both for business and pleasure. This will dramatically contribute to the development of the Digital Economy centered on robots working alongside humans, thus freeing up people from many cognitive tasks and creating new jobs. As of today, for 5G many challenges are still to be addressed to meet the target performance indicators, especially, in terms of latency, reliability and spectrum usage. This paper gives a comprehensive analysis of said challenges, including recommendations on target network architectures and related enabling technologies. An exploitation scenario for Europe is presented and, eventually, a survey about main RT&D and innovation activities on 5G ongoing globally is provided.

Network Functions Virtualization (NFV) is an emerging technology approach, which refers to the migration of certain network functionalities, traditionally performed by hardware elements, to virtualized IT infrastructures, where they are deployed as software components. NFV leverages commodity servers and storage, including cloud platforms, to enable rapid deployment, reconfiguration and elastic scaling of network functionalities. This introduces a new framework, enabling providers not only to deploy Virtualized Network Functions (VNFs) for their own needs, but also to offer them as value added services to their customers. Virtual network appliances can be provided on-demand asa- Service, eliminating the need to acquire, install and maintain specialized hardware like gateways, proxies, firewalls, transcoders and analyzers at customers’ premises. The main goals of paper are the definition of basic use cases and the identification of the key system requirements for the design and deployment of ‘Network Functions as-a-Service (NFaaS) over virtualized infrastructures’.

This work depicts a proposal of possible and feasible method for reduction of prepaid credit control and update requests in real time, within the ‘Policy and Charging Control’ (PCC) architecture. Consideration is relating to IMS (IP Multimedia Subsystem) environment, on condition where QoS can be dynamic changed and different feasible service configurations affect the charging process.