Packet data messaging over TETRA: network performance analysis

In this paper, we address various aspects of packet data transmission in terrestrial trunked radio (TETRA) networks giving particular emphasis on the performance of applications transmitting small messages between a number of radio terminals and a fixed server. The utilization of such applications is constantly increasing in public safety networks and so does the need to dimension and configure TETRA networks to meet their reliability, delay and loss requirements. We present simulation results for a variety of practical scenarios such as loading the packet data channel (PDCH) with different mobile station (MS) populations engaged in transmitting packet data (PD) at various rates. We quantify key performance indicators of the PDCH such as packet delay and packet loss rate. Furthermore, we provide an in-depth analysis of the impact of non-PD MS population—i.e., the loading of main control channel (MCCH)—on the average packet delay. Our results provide an insight of how network loading parameters interact with the protocol performance and may help in dimensioning and planning TETRA networks, and in particular, in determining the number of PD terminals that can be supported in a cell for a given traffic profile and QoS requirements.     

下一代3GPP系统话音呼叫切换机制（上）

演进的3GPP（第三代合作伙伴计划）系统是支持若干无线电接入技术和若干移动机制的混合移动网络结构。本文简要回顾该系统的结构及其关键组成,重点强调若干部署情形中支持话音呼叫移动性的方法。首先介绍称之为单模无线电话音呼叫连续性的机制,该机制能使从E-UTRAN（演进的通用移动电信系统陆地无线接入网）接入到遗留的UTRAN/GERAN（通用移动电信系统陆地无线接入网/增强数据率的全球移动通信系统演进无线接入网）或1xRTT的VoIP呼叫进行中间呼叫切换。然后着重描述不支持E-UTRAN上话音服务的部署情形,并介绍称为回落原地的机制,该机制能在话音呼叫的开始从E-UTRAN到UTRAN/GERAN或1xRTT进行切换。最后介绍由IP多媒体子系统实现的应用层话音呼叫切换机制。本文的结论是,下一代3GPP系统是高度完善的移动通信系统,它支持广泛的话音呼叫移动性机制,并能满足所有的商业部署需要。     

Editorial

Mobile Networks and Applications -     

A survey of autonomic networking architectures: towards a Unified Management Framework

Academic and industrial research initiatives have sought to make fully autonomic networks a reality. Some of these initiatives pursued a holistic approach, while others focused on setting up functionalities for specific networking domains. These efforts did not succeed in being extensively deployed, because the goals of network operators were not satisfactorily met. These goals include unification of management operations, enablement of end‐to‐end management and enhancement of the overall system performance in a trusted way, while reducing management cost. In this paper, we analyse a set of existing autonomic management architectures and frameworks with respect to a selected set of criteria. We then identify missing parts and challenges and propose a framework to unify the most promising attributes towards a novel approach of realization of autonomic networking management. We call this proposal Unified Management Framework (UMF). Copyright © 2013 John Wiley & Sons, Ltd.     

Self-Management for Access Points Coverage Optimization and Mobility Agents Configuration in Future Access Networks

A key challenge for the management systems of future networks is the reduction of human interventions in the fundamental management functions. These include mechanisms that render the networks capable to configure, optimize, heal and protect itself, but also handle the emerging complexity. Demands for the future internet networks mandate the rapid assessment of the feasibility of such cognitive management architectures that shall bridge the gap between conceptual design and practical network deployments. In this paper, a novel architecture is introduced, based on organized distribution of control feedback cycles at locations allocated across network’s operational elements. Two realisations of self-management in the operations of wired and wireless access network segments are presented. The first one is focused on organization of the wireless access regions in networks by the use of compartments of access points for enabling coverage optimization. A compartment-based approach facilitates the more efficient usage of network resources, exploiting local situation awareness and local optimisation features, according to the varying traffic needs. The second realization shows the control of mobility management processes in wired parts of access networks for balancing utilization of network resources. A dynamic deployment and re-configuration of mobility agents permit to tackle the problem of congestion induced by mobility agents in mobile protocols and combined with a dynamic access router assignment, network resources are efficiently balanced within the network. The paper concludes with findings and recommendations on how common principles of self-management evolve from design theory to practice.     

An open financial services architecture based on the use of intelligent mobile devices

The scope of this paper is to explore, analyze and develop a universal architecture that supports mobile payments and mobile banking, taking into consideration the third and the emerging fourth generation communication technologies. Interaction and cooperation between payment and banking systems, integration of existing technologies and exploitation of intelligent procedures provide the prospect to develop an open financial services architecture (OFSA), which satisfies requirements of all involved entities. A unified scenario is designed and a prototype is implemented to demonstrate the feasibility of the proposed architecture.     

A single-step isolation of squalene from olive oil deodorizer distillates by using centrifugal partition chromatography

High added-value squalene (SQ) was purified in one step from olive oil deodorizer distillates (OODD) using preparative centrifugal partition chromatography (CPC) method, operating in the dual mode. The fractionation was performed using a non-aqueous biphasic solvent system consisting of heptane–acetonitrile–butanol (1.8:1.4:0.7, v/v/v), leading to the isolation of the target compound in 4 hours, using a preparative 1L column. Furthermore, a fast UHPLC-DAD method was developed and applied for the identification and quantification of SQ in both OODD and purified form. The content of SQ in the initial material was 23.4%, while the purity of the isolated SQ was 95.5%. The recovery of SQ was calculated at 76.3%. The productivity of the process was calculated at 234 mg/h/L.