Flat Cellular (UMTS) Networks

Traditionally, cellular systems have been built in a hierarchical manner: many specialized cellular access network elements that collectively form a hierarchical cellular system. When 2G and later 3G systems were designed there was a good reason to make system hierarchical: from a cost-perspective it was better to concentrate traffic and to share the cost of processing equipment over a large set of users while keeping the base stations relatively cheap. However, we believe the economic reasons for designing cellular systems in a hierarchical manner have disappeared: in fact, hierarchical architectures hinder future efficient deployments. In this paper, we argue for completely flat cellular wireless systems, which need just one type of specialized network element to provide radio access network (RAN) functionality, supplemented by standard IP-based network elements to form a cellular network. While the reason for building a cellular system in a hierarchical fashion has disappeared, there are other good reasons to make the system architecture flat: (1) as wireless transmission techniques evolve into hybrid ARQ systems, there is less need for a hierarchical cellular system to support spatial diversity; (2) we foresee that future cellular networks are part of the Internet, while hierarchical systems typically use interfaces between network elements that are specific to cellular standards or proprietary. At best such systems use IP as a transport medium, not as a core component; (3) a flat cellular system can be self scaling while a hierarchical system has inherent scaling issues; (4) moving all access technologies to the edge of the network enables ease of converging access technologies into a common packet core; and (5) using an IP common core makes the cellular network part of the Internet

Telecommunications Networks

This book guides readers through the basics of rapidly emerging networks to more advanced concepts and future expectations of Telecommunications Networks. It identifies and examines the most pressing research issues in Telecommunications and it contains chapters written by leading researchers, academics and industry professionals. Telecommunications Networks - Current Status and Future Trends covers surveys of recent publications that investigate key areas of interest such as: IMS, eTOM, 3G/4G, optimization problems, modeling, simulation, quality of service, etc. This book, that is suitable for both PhD and master students, is organized into six sections: New Generation Networks, Quality of Services, Sensor Networks, Telecommunications, Traffic Engineering and Routing

Designing and optimization of VOIP PBX infrastructure

In the recent decade, communication has stirred from the old wired medium such as public switched telephone network (PSTN) to the Internet. Present, Voice over Internet Protocol (VoIP) Technology used for communication on internet by means of packet switching technique. Several years ago, an internet protocol (IP) based organism was launched, which is known as Private Branch Exchange "PBX", as a substitute of common PSTN systems. For free communication, probably you must have to be pleased with starting of domestic calls. Although, fairly in few cases, VoIP services can considerably condense our periodical phone bills. For instance, if someone makes frequent global phone calls, VoIP talk service is the actual savings treat which cannot achieve by using regular switched phone. VoIP talk services strength help to trim down your phone bills if you deal with a lot of long-distance (international) and as well as domestic phone calls. However, with the VoIP success, threats and challenges also stay behind. In this dissertation, by penetration testing one will know that how to find network vulnerabilities how to attack them to exploit the network for unhealthy activities and also will know about some security techniques to secure a network. And the results will be achieved by penetration testing will indicate of proven of artefact and would be helpful to enhance the level of network security to build a more secure network in future

The detection and tracking of portable GSM handset using a 5-element circular array

Includes bibliographical references (leaves 130-131)Direction Finding (OF) is a process that involves estimating the directions of the arrival for propagating wavefronts impinging on an antenna array from arbitrary directions relative to that antenna array. By understanding how the signals captured relate to the geometry of the OF antenna, one can separate out these signals spatially, and provide their directions of arrival with some degree of certainty. GSM, the Global System for Mobile Communications is a mobile digital communications system which has rapidly gained acceptance on a global scale since the early 1990s. Because the communications standard is made use of throughout the world today, it would be desirable to investigate the feasibility of the detection and tracking of such signals as an extension for OF platforms that are used by monitoring authorities such as the police or service providers. This thesis presents and discusses the implications of detecting and tracking GSM mobile handsets. Because the thesis was commissioned by a company that already manufactures broadband surveillance equipment with a particular OF implementation, the thesis approaches the problem with their specific implementation in mind assessing its competency in detecting and tracking GSM mobile phones. To understand the nature of GSM, a simulator was developed to convey information about the structure of the datasets that would be recorded in the field, and is compared to datasets captured with the OF equipment. Conclusions are drawn from the recordings, and recommendations for future work in this field are discussed

Towards Massive Machine Type Communications in Ultra-Dense Cellular IoT Networks: Current Issues and Machine Learning-Assisted Solutions

The ever-increasing number of resource-constrained Machine-Type Communication (MTC) devices is leading to the critical challenge of fulfilling diverse communication requirements in dynamic and ultra-dense wireless environments. Among different application scenarios that the upcoming 5G and beyond cellular networks are expected to support, such as eMBB, mMTC and URLLC, mMTC brings the unique technical challenge of supporting a huge number of MTC devices, which is the main focus of this paper. The related challenges include QoS provisioning, handling highly dynamic and sporadic MTC traffic, huge signalling overhead and Radio Access Network (RAN) congestion. In this regard, this paper aims to identify and analyze the involved technical issues, to review recent advances, to highlight potential solutions and to propose new research directions. First, starting with an overview of mMTC features and QoS provisioning issues, we present the key enablers for mMTC in cellular networks. Along with the highlights on the inefficiency of the legacy Random Access (RA) procedure in the mMTC scenario, we then present the key features and channel access mechanisms in the emerging cellular IoT standards, namely, LTE-M and NB-IoT. Subsequently, we present a framework for the performance analysis of transmission scheduling with the QoS support along with the issues involved in short data packet transmission. Next, we provide a detailed overview of the existing and emerging solutions towards addressing RAN congestion problem, and then identify potential advantages, challenges and use cases for the applications of emerging Machine Learning (ML) techniques in ultra-dense cellular networks. Out of several ML techniques, we focus on the application of low-complexity Q-learning approach in the mMTC scenarios. Finally, we discuss some open research challenges and promising future research directions.Comment: 37 pages, 8 figures, 7 tables, submitted for a possible future publication in IEEE Communications Surveys and Tutorial

Evolução da telefonia na web

Mestrado em Sistemas de InformaçãoCom a ameaça imposta às operadoras por aplicações OTT como WhatsApp ou Skype, diversas iniciativas coordenadas pela GSMA foram criadas para tentar responder a este fenómeno. Paralelamente, com a evolução de tecnologias como HTML5 e WebRTC, novos serviços como o Twilio têm surgido, oferecendo APIs para o desenvolvimento de novas aplicações Web. No entanto, a integração destas tecnologias em tradicionais redes de telecomunicações não faz parte das actuais especificações. Sendo assim, o objectivo desta dissertação consiste na especificação e implementação de um protótipo baseado nestas tecnologias emergentes, integrado com uma rede IMS. Primeiramente, foi feito um estudo do estado de arte, definindo requisitos e casos de uso a serem explorados. De seguida, o desenho da solução foi feito e implementado, tendo sido criado uma plataforma que alia WebRTC e a OneAPI da GSMA (que define funcionalidades básicas para operadores), oferecendo interoperabilidade entre ambos os mundos. A solução é composta por um servidor aplicacional que expõe a API e gateway WebRTC, tendo sido testada e considerada adaptada às necessidades estabelecidas.With the threat to operators by OTT applications such as Skype or WhatsApp, several initiatives coordinated by GSMA were created in an effort to respond to this phenomenon. In parallel, with the evolution of technologies such as HTML5 and WebRTC, new services such as Twilio are now available, offering APIs for web application development. However, the integration of these technologies and traditional telecommunication networks is not a part of the current standards. As such, the objective of this dissertation is the specification and implementation of a prototype based on these emerging technologies, integrated in an IMS network. First, a state-of-the-art analysis was made, defining requirements and use-cases to be explored. Secondly, the design and implementation of the solution was done, creating a platform that unites WebRTC and GSMA’s OneAPI (which exposes basic operator features), offering interoperability between both worlds. The solution is composed by an application server that exposes the API and a WebRTC gateway, having been successfully tested and adapted to the established needs