Mobile Radio Access Networks Research Articles

Measurement of Electromagnetic Field Attenuation by Building Walls in the Mobile Phone and Satellite Navigation Frequency Bands

The electromagnetic (EM) wave attenuation by building walls is experimentally investigated, focusing on the frequency range 700 MHz-5 GHz. The results of this research can be used in the planning of the indoor radio coverage of wireless access networks like 2G, 3G, 4G, WiFi, and future 5G mobile phone systems, in the study of satellite navigation applications, and in the evaluation of the resident population exposure to electromagnetic fields emitted by the radio base stations (RBSs) of the mobile phone radio access network (RAN). Measurements are obtained using a portable vector network analyzer (VNA) connected to two light Vivaldi antennas. Time-domain methods are used to reduce errors caused by multiple paths. Measurements of EM building wall attenuation have been carried out in the city of Rome, Italy, in different buildings topologies: historical buildings from the Roman Empire up to middle 19th-century and modern reinforced concrete buildings. Measurements of EM shielding effectiveness (SE) show values even greater than 80 dB.

Measurements of the Outdoor-To-Indoor Attenuation of Mobile Phone Signal

This work reports a series of measurements of the attenuation of UMTS and GSM mobile phone signal by buildings structures in the city of Rome. The context of the research is the concern about the exposure of the population resident in the buildings to electromagnetic fields emitted by the radio base stations of the mobile phone radio access network. The aim of the research is to analyze a conservative method of measurement for the outdoor-to-indoor attenuation. The measurement method takes intrinsically into account the presence of apertures like doors and windows on the wall of the buildings, the materials around the apertures and within the buildings. The measurements of attenuation are carried out by instrumentations able to demodulate the radio base station antennas RF carriers. Four different topologies of urban buildings are considered: reinforced concrete buildings, buildings between late 1800 and early 1900th century, historical buildings in the inner Rome and steel and glass buildings structures. Measurements of electromagnetic attenuation are in the range 6 - 27 dB. A numerical analysis of the attenuation of apertures like door/windows has been computed and the results discussed. The results show that the attenuation depends on the material of the walls and by the objects indoor located.

Electromagnetic characterization and shielding effectiveness of concrete composite reinforced with carbon nanotubes in the mobile phones frequency band

The electromagnetic properties of carbon nanotube powder reinforced concretes are numerically and experimentally characterized. This typology of composite material is built by following the simple procedure usually adopted for the on-site concrete production. The dielectric parameters are investigated by means of waveguide measurements in the frequency band 0.75–1.12 GHz that is currently exploited in mobile phone radio access networks. The obtained results are used to compute the electromagnetic shielding effectiveness of large wall-shaped concrete structures. A shielding effectiveness up to 50 dB is obtained for a 15 cm thick wall when the carbon nanotube inclusion is raised up to 3 wt%.

A coral‐reef optimization algorithm for the optimal service distribution problem in mobile radio access networks

ABSTRACTMobile technology is currently one of the main pillars of worldwide economy. The constant evolution that mobile communications have undergone in the last decades, due to the appearance of new services and new technologies such as Universal Mobile Telecommunication Systems/High Speed Data Access and Long Term Evolution, has contributed to achieve this position in global economy. However, because of the crisis of the sector in the last 5 years, mobile operator's revenues and investments have been reduced. Thus, mobile network operators tend to exploit the existing infrastructure at maximum possible, trying to use the existing network in the most efficient way. In this paper, a novel bio‐inspired algorithm, the coral reef optimization algorithm (CRO) is introduced to minimise a network deployment investment cost problem. This is carried out by means of optimising the user demand of different services offered by mobile operators over the available technologies in the market, namely the optimal service distribution problem. The CRO is a recently proposed meta‐heuristic based on the computer simulation of corals reproduction and reefs’ formation. In this paper, this algorithm has been tested on several optimal service distribution problem scenarios in Spain, observing a significant reduction (up to 400 M€) on the total investment costs associated to the radio access network deployment. We compare the performance of the CRO approach with that of a classical (experience‐based) services distribution, and with alternative meta‐heuristics techniques, obtaining good results in all cases. Copyright © 2013 John Wiley & Sons, Ltd.

Mobile video optimization at the base station: Adaptive guaranteed bit rate for HTTP adaptive streaming

Video is expected to be the dominant application by traffic volume over mobile networks in the near future. Mobile network operators are deploying video optimization techniques to enhance the user experience and network utilization for video delivery. Video optimization is typically “out-of-network” and includes techniques such as transcoding, transrating, time shifting and pacing that are implemented outside of mobile radio access and core networks. However, such techniques cannot easily exploit information about real time cell congestion and radio conditions for the video terminals because it is difficult to obtain such information from the radio access network. We propose a novel “in-network” video optimization technique, named Adaptive Guaranteed Bit Rate (AGBR), for HTTP-based Adaptive Streaming (HAS) video. This optimization technique is implemented at the base station and can thus exploit knowledge of the radio and congestion conditions. With only limited knowledge of the video stream properties or content, AGBR works by adjusting the throughput delivered to the different HAS clients that in turn adjust the video quality they request. The optimization algorithm maximizes aggregate quality across multiple video flows served by the base station without starving data clients, thereby improving the overall quality of experience. We demonstrate through extensive analytical modeling and simulations that AGBR can adapt to changing network conditions to support more video sessions at an acceptable quality than alternative algorithms, while enforcing fairness among all users competing for resources within a sector.

Adaptive neuro-fuzzy inference models for speech and video quality prediction in real-world mobile communication networks

This article presents a unified Quality of Service (QoS) prediction methodology based on neuro-fuzzy inference systems that can be used in contemporary rollout mobile communication networks. Our work is concentrated on radio key performance indicators of mobile radio access networks that affect speech and video quality of wireless multimedia communications, and on how we can estimate Quality of end-user Experience (QoE) using fuzzy-based techniques. We propose a methodology that is based on modern experimental drive-test equipment with which a measurement campaign is configured and conducted in various environments. Afterwards, ANFIS models are developed based on real network measurements and numerical results are presented.

무선접속망에서 IP 전송 방식과 ATM 전송 방식간의 상호연동을 위한 IP 버전 처리

이 논문에서는 이동통신망의 무선접속망(RAN . Radio Access Network)에서 ATM 전송 방식과 IP<TEX>$_v$</TEX>4 전송 방식 그리고 IP<TEX>$_v$</TEX>6전송 방식이 혼재하여 존재할 때, 다른 전송 방식들간의 연동을 지원하는 방법을 제시한다. 제시된 연동 방법은 하나의 노드안에 세 가지 전송 방식에 대한 각각의 기능모듈을 모두 구현하는 Triple Capable 노드 방법으로 다양한 전송 방식을 가진 노드들과 직접 연동할 수 있도록 설계되었다. 그리고 제시된 Triple Capable 노드 방법과 같이 하나의 노드가 다수의 전송 방식중에서 하나의 전송 방식을 선택하여 사용하는 것이 가능할 때, 네트워크 통신 상황에 따라서 통신 성능을 향상시킬 수 있도록 전송 방식을 동적으로 선택하여 사용하는 알고리즘을 제시한다. In this paper, we investigate the interworking method between three transport mechanisms, that is, ATM transport, IP<TEX>$_v$</TEX>4 transport and Ip<TEX>$_v$</TEX>6transport, where these mechanisms are wholly used in a Mobile RAN (Radio Access Network). The proposed interworking method, called Triple Capable Node, is to implement three transport mechanisms simultaneously in a single node so that the node can communicate directly to other nodes having various transport mechanisms by using one of three transport mechanisms. In addition, we propose a dynamic algorithm which selects one among multiple transport mechanisms at run time in order to achieve better communication performance.

The Future of Radio Access in 3G

In the last two years, UMTS has progressed from the drawing board to prototypes and pre-release trials. Through the concentrated efforts of manufacturers and operators in the standards bodies, the 3GPP specifications for UMTS, including W-CDMA, TD/CDMA and TD/SCDMA, are currently being developed into deployable equipment for the first UMTS networks. However, human nature dictates that there is always room for improvement, with a constant drive for better performance and higher efficiency. UMTS is by no means the ultimate mobile radio access network, and, even before the first equipment rolls off the production lines, the work of the standards bodies is already looking at enhancements to the system. This paper considers some of these improvements, the evolution of W-CDMA, and the role of TDD in the ongoing developments of third generation mobile radio access.

Emerging wireless broadband networks

The rapid evolution of mobile wireless access networks toward multimedia support with QoS provision forces the development of advanced wireless broadband systems with high reliability and high data rate. To achieve this goal, new system design concepts with increased system capacity will be required. In that context, ATM is becoming a major infrastructure, receiving a lot of attention for telecommunication systems since ATM networks can most effectively support wireless access systems. Wireless ATM systems have low transmission cost, flexible functionality, mobile ATM protocol, and radio access layer protocols. This article overviews the various wireless broadband systems studied at 5, 19.37, 40, and 60 GHz by European Union funded projects within the ACTS program. Moreover, related standardization activities and network evolution are also addressed.