Analytical Study of a Dual Pointer Based Strategy for Location Update Using Node B Sojourn Time in UMTS Networks

This article describes how Universal Mobile Telecommunications System (UMTS) is a 3G cellular network standard that uses location update (LU) and location search (LS) for mobility management. LU requires update in two location registers (LRs) - home LR (HLR) and visiting LR (VLR) - where one HLR controls multiple VLRs. HLR updates (HLRUs) are costlier, and hence should be less frequent. To achieve it, VLRs maintain a forward pointer chain among themselves, instead of updating HLR. But a lengthy chain increases LS cost considerably. So, we propose to restrict the chain length to unity by introducing an additional backward pointer, and using the concept of root-VLR similar to the home agent concept of mobile IP. We derive a closed form solution to approximate the average HLRUs per call, and substantiate it by simulation in cases of both random and diurnal mobilities. Results reveal substantial reduction in HLRUs per call, even when call-to-mobility ratio is high. UMTS operators will find the analysis worth considering, while managing their 3G networks.

Functional development of a New Zealand weather station network to improve plant production

For over 25 years The New Zealand Institute for Plant Food Research Ltd (PFR) and its antecedents have operated a network of weather stations in the main New Zealand horticultural regions Data from these stations have been applied to the analysis of trials and surveys and used for the development of disease models and horticultural software Access to the data has evolved from direct links between each weather stations dialup modem and the users computer to standalone MetWatch software to the webbased MetWatch Online and finally to the current Internet Protocol (IP)based system allowing directaccess via smartphones The most recent network upgrade to provide near realtime data via the 3G cellular network provides the focus for this review of the network and its applications We discuss opportunities for future development of equipment within the weather station network

New Technologies for Information and Communication, PWM Remote Experimenting and 3G Networks as Teaching Support

<p class="Abstract" style="margin: 0cm 0cm 10pt;"><span style="layout-grid-mode: line;" lang="EN-US"><strong><span style="font-family: Times New Roman; font-size: x-small;">Remote experiments may be an important tool to implement new technologies in the teaching/learning process, since it enables experimenting with real plants, essential to consolidate the concepts acquired in the theoretical classes, especially in technical and scientific disciplines.<span style="mso-spacerun: yes;">&nbsp; </span>This article presents the &ldquo;modulator PWM&rdquo; remote experiment, its operational architecture and construction. It seeks to demonstrate its integration with theory and the use of the 3G cellular network as a communications channel for remote experimenting. The PWM modulators are often used in disciplines of higher education courses in electrical engineering, telecommunications and electronics. This article shows that it is possible to perform the practical activity completely remotely, via 3G cellular networks or through the internet to access the experiment and perform the experiments needed to fully understand the theories of the PWM modulator.<span style="mso-spacerun: yes;">&nbsp; </span>.This article is a further initiative for remote experiments in the world of different engineering specialties, involving the cellular networks that are rapidly expanding at this time.</span></strong></span></p>