Advancement of Monitoring Scheme in FTTH-PON Using Access Control System (ACS)

This paper proposes a new developed system named Access Control System (ACS) which is designed to enhance the monitoring, scalability and survivability of Passive Optical Network (PON) toward the implementation of full & Complete edition of Fiber-to-the Network (FTTH) network. The system automatically identifies faults and controls each optical fiber line to provide the restoration against failure in the drop region of PON downwardly from optical line terminal at the central office to the optical network unit of the subscriber. ACS manages the Optical Time Domain Reflectometer (OTDR) troubleshooting wavelength to enable the status of each line which can be displayed onto one single screen in the central office. Our proposed mechanism in this paper is the first reported thus far. Keywords: ACS, monitoring, path routing, experimental, FTTH-PO

A case study of MMO2's Madic: A framework for creating mobile internet systems

Mobile Internet applications on ubiquitous mobile networks allows real-time, anywhere, anytime connectivity to services. Due to its scalability and potential cost savings, mobile communication is being increasingly applied in the business and consumer communities to create innovative data and voice application, which run over the Internet infrastructure. This paper reports on a case study at an organisation that created an innovative approach to developing mobile applications developed by third party independent developers. A conceptual wireless reference model is presented that was used to define the various system components required to create effective mobile applications

Performance evaluation of currently available VLSI implementations satisfying U-interface requirements for an ISDN in South Africa.

A project report submitted to the Faculty of Engineering, University of the Witwatersrand, Johannesburg, in partial fulfilment of the requirements for the degree of Master of Science in Engineering.This project report examines the performance of three VLSI U-interface implementations satisfying the requirements of Basic Access on an ISDN. The systems evaluated are the Intel 89120,Siemens PEB2090 and STC DSP144, operating on 2BIQ, MMS4J and SU32 line codes respectively. Before evaluating the three abovementioned systems, a review of the underlying principles of U-interface technology is presented. Included in the review are aspects of transmission line theory, line coding, echo-cancellation, decision feedback equalisation, and pulse density modulation. The functional specifications of the three systems are then presented followed by a practical evaluation of each system. As an aid to testing the transmission systems, an evaluation board has been designed and built. The latter provides the necessary functionality to correctly activate each system, as well as the appropriate interfacing requirements for the error-rate tester. The U-interface transmission systems are evaluated on a number of test-loops, comprising sections of cable varying in length and gauge. Additionally, impairments are injected into data-carrying cables, in order to test the performance of each system in the presence of noise. The results of each test are recorded and analysed. Finally, a recommendation is made in favour of the 2BIQ U-interface. It is shown to offer superior transmission performance, at the expense of a slightly higher transmit-power level.Andrew Chakane 201

Softswitch Design and Performance Analysis

The increasing number of subscribers’ demands in telecommunication sector has motivated the operators to provide high quality of service in cost effective way. Moreover, operators need to have an open structure system so that they can move their systems to the next generation network architecture. For this purpose, Softswitch is an appropriate technology because it is a safe and cost efficient solution and though it can migrate from traditional circuit-switching based telephone system to internet protocol packet-switching based networking. Softswitch network divides the logical switch into several parts with different functions such as signaling gateway, media gateway, media server, etc. Standard communication protocols are implemented between those parts. Softswitch is software-based system to make connection between devices, and moreover to control voice calls, data and routes calls through different entities of the networks. Softswitch supports management functions such as provisioning, fault handling and reporting, billing, operational support, etc. Softswitch suitable for all types of traffic and services so it is very demanding in the competitive world of mobile operators. In this thesis, Softswitch has been studied and analyzed in details. Softswitch network consisted of different integrated modules such as transportation, calling and signaling, service application and management. Each module provides different services such as call control, routing, billing and network management. Each module is discussed from functional and service point of views. Softswitch based wireless network architecture as well as variety of service solutions is presented. Different protocol interfaces in softswitch network such as signaling system number 7 are explained. Moreover, bearer calls, independent call control protocol, gateway control protocol, IP bearer control protocol are explained as well. Variety of softswitch network architectures analysis has been done based on their performance and the applicability. Three Softswitch network architectures are proposed which are validated through simulations.fi=Opinnäytetyö kokotekstinä PDF-muodossa.|en=Thesis fulltext in PDF format.|sv=Lärdomsprov tillgängligt som fulltext i PDF-format

An Investigation into the testing and commissioning requirements of IEC 61850 Station Bus Substations

The emergence of the new IEC 61850 standard generates a potential to deliver a safe, reliable and effective cost reduction in the way substations are designed and constructed. The IEC 61850 Station Bus systems architecture for a substation protection and automation system is based on a horizontal communication concept replicating what conventional copper wiring performed between Intelligent Electronic Devices (IED’s). The protection and control signals that are traditionally sent and received across a network of copper cables within the substation are now communicated over Ethernet based Local Area Networks (LAN) utilising Generic Object Oriented Substation Event (GOOSE) messages. Implementing a station bus system generates a substantial change to existing design and construction practices. With this significant change, it is critical to develop a methodology for testing and commissioning of protection systems using GOOSE messaging. Analysing current design standards and philosophies established a connection between current conventional practices and future practices using GOOSE messaging at a station bus level. A potential design of the GOOSE messaging protection functions was implemented using the new technology hardware and software. Identification of potential deviations from the design intent, examination of their possible causes and assessment of their consequences was achieved using a Hazard and Operability study (HAZOP). This assessment identified the parts of the intended design that required validating or verifying through the testing and commissioning process. The introduction of a test coverage matrix was developed to identify and optimise the relevant elements, settings, parameters, functions, systems and characteristics that will require validating or verifying through inspection, testing, measurement or simulations during the testing and commissioning process. Research conducted identified hardware and software that would be utilised to validate or verify the IEC 61850 system through inspection, testing, measurement or simulations. The Hazard and Operability study (HAZOP) has been identified as an effective, structured and systematic analysing process that will help identify what hardware, configurations, and functions that require testing and commissioning prior to placing a substation using IEC 61850 Station bus GOOSE messaging into service. This process enables power utilities to understand new challenges and develop testing and commissioning philosophies and quality assurance processes, while providing confidence that the IEC 61850 system will operate in a reliable, effective and secure manner

Signaling Security in LTE Roaming

LTE (Long Term Evolution) also known as 4G, is highly in demand for its incomparable levels of experience like high data rates, low latency, good Quality of Services(QoS) and roaming features. LTE uses Diameter protocol, which makes LTE an all IP network, connecting multiple network providers, providing flexibility in adding nodes and flexible mobility management while roaming. Which in turn makes LTE network more vulnerable to malicious actors. Diameter protocol architecture includes many nodes and the communication between the nodes is done through request and answer messages. Diameter manages the control session. Control session includes the signaling traffic which consists of messages to manage the user session. Roaming signaling traffic arises due to subscribers movement out of the geographical range of their home network to any other network. This signaling traffic moves over the roaming interconnection called S9 roaming interface. This thesis project aims to interfere and manipulate traffic from both user-to-network and network-to-network interfaces in order to identify possible security vulnerabilities in LTE roaming. A fake base-station is installed to establish a connection to a subscriber through the air interface. The IMSI (International Mobile Subscription Identity) is captured using this fake station. To explore the network-to-network communication an emulator based LTE testbed is used. The author has investigated how Diameter messages can be manipulated over the S9 interface to perform a fraud or DoS attack using the IMSI number. The consequences of such attacks are discussed and the countermeasures that can be considered by the MNOs (Mobile Network Operators) and Standardization Committees

Towards Developing a Travel Time Forecasting Model for Location-Based Services: a Review

Travel time forecasting models have been studied intensively as a subject of Intelligent Transportation Systems (ITS), particularly in the topics of advanced traffic management systems (ATMS), advanced traveler information systems (ATIS), and commercial vehicle operations (CVO). While the concept of travel time forecasting is relatively simple, it involves a notably complicated task of implementing even a simple model. Thus, existing forecasting models are diverse in their original formulations, including mathematical optimizations, computer simulations, statistics, and artificial intelligence. A comprehensive literature review, therefore, would assist in formulating a more reliable travel time forecasting model. On the other hand, geographic information systems (GIS) technologies primarily provide the capability of spatial and network database management, as well as technology management. Thus, GIS could support travel time forecasting in various ways by providing useful functions to both the managers in transportation management and information centers (TMICs) and the external users. Thus, in developing a travel time forecasting model, GIS could play important roles in the management of real-time and historical traffic data, the integration of multiple subsystems, and the assistance of information management. The purpose of this paper is to review various models and technologies that have been used for developing a travel time forecasting model with geographic information systems (GIS) technologies. Reviewed forecasting models in this paper include historical profile approaches, time series models, nonparametric regression models, traffic simulations, dynamic traffic assignment models, and neural networks. The potential roles and functions of GIS in travel time forecasting are also discussed.