In-building Coverage Research Articles

In-building coverage of millimeter-wave wireless networks from channel measurement and modeling perspectives

To progress cost-effective deployment of millimeter-wave (mmWave) wireless networks for indoor users, the prediction of indoor-to-indoor (I2I) and outdoor-to-indoor (O2I) coverage based on field measurement studies is of great interest to the future generation mobile communication system. First, measurements in I2I and O2I scenarios, which have advantages in terms of achieving a fair comparison of channel characteristics across different mmWave bands and bandwidths, are performed. Next, the developed dual-slope path loss model with a break-point distance is found to well fit omnidirectional and directional measured I2I data, especially at 39.5 GHz, revealing that the transition from lit or shadow regions to totally blocked regions is abrupt. Combined with space-time propagation characteristics, the indoor blockage effect on path loss and angular spread is investigated, therein being essential for the design of beam-steering and tracking algorithms. Double-directional measurement results show that most dominant paths arrive along the line-of-sight path, and only a few in-building reflections can be detected in higher frequency bands. Based on the joint analysis of channel measurement and modeling results, several mmWave network design and in-building coverage enhancement insights are presented.

Architect’s role to improve in-building wireless coverage

This paper investigates the role of architects in improving in-building wireless coverage, a hitherto unexplored and interdisciplinary domain. While architects are still fully focused on built spac...

Multibeam RF Antenna Performance for Indoor Coverage in Stadium

<p>The objective of the proposal is to address the demand on data over the services provided by telecommunication industries during major events held in Malaysia especially in stadiums. Previously, during most of the events, users will experience bad services in both data and voice transactions. It is not only slow or delayed but almost failed to access the network to connect them to the world. Besides a few solutions that have been introduced such as IBC (In-Building Coverage) and Small Cells, this proposed solution Multibeam RF Antenna, is one of them to address the demand. This solution has been chosen as it is fast in deployment, easy to maintain and cost effective even if it may not cover the whole targeted areas.<br />This paper will provide analysis, evaluation and actual Walk Test (WT) to show the effectiveness of the Multibeam RF Antenna</p>

A Review on Monopole and Dipole Antennas for In-Building Coverage Applications

This paper presents a review of several antennas topologies applied for indoor applications. Few requirements are desired for those antennas fo rtheir suitability for indoor applications. Such as antenna size, antenna profile, simple structure, omnidirectional radiations, polarization, and sufficient bandwidth to cover the most wireless communications bands, including GSM, LTE, WLAN ,WiFiand WiMAX. This paper focuses on minimizing the number of antennas needed to cover all these frequencies while offering convenient polarization to mitigate the fading problems and multipath effects losses. To meet these requirements, a monopole antenna with circular polarization is suggested. In addition, various topologies of monopole and dipole antennas are discussed in this paper in terms of their advantages and challenges. Moreover, this review is helpful to understand the current developments in indoor antenna topologies and it proposes a new antenna with a sufficient design for modern indoor applications.

DDAS-DRoF Based a New In-Building Signal Coverage System Supporting Multiple Services

Aiming at the problems of low infrastructure utilization rate, high cost, large power consumption, inconvenient management and maintenance caused by independent in-building signal coverage systems of different operators, this paper puts forward a new in-building signal coverage system supporting multiple services based on digital distributed antenna system (DDAS) and digital radio over fiber (DRoF). The proposed system will not only support existing 2G, 3G and 4G mobile communication services, but also be able to provide access and coverage for future 5G and applications such as the internet of things (IOT) and in-building positioning. Radio frequency (RF) unit and digital signal processing (DSP) unit are designed independently to reduce the correlation and constraints between RF part and DSP part so as to facilitate increase or decrease supported service, dynamic capacity expansion and smooth upgrade. Each service corresponds to a kind of RF card and all RF cards share the same DSP platform. Test results of laboratory, simulation base station and actual mobile network show that proposed system is able to support designed services and performance indexes meet the specified requirements of 3GPP and mobile operators well. This may provide a good platform for co-construction and sharing, saving capital expenditure (CAPEX) and operating expenditure (OPEX) and reducing energy consumption of in-building signal coverage system. It also complies with the development trend of multi-network integration and internet plus.

Optimizing the Cellular Network Planning Process for In-Building Coverage using Simulation

The global scenario of mobile telecommunications networks suggests that the next years the number of mobile users will continue growing as well as the services demand. The biggest growth is expected mainly in Asiatic and developing countries. Particularly, the Mexican telecommunications market suggests that if the number of mobile users will continue growing in Mexico as in the last years, then the mobile networks operators should increment the network capacity and the in-building coverage in order to maximize the quality of service. Also, network operators should offer attractive plans to users in order to maximize their economic benefits. Therefore, this research study aims to develop a simulation model to analyze the services transmission in a Third Generation mobile network and maximize the network coverage and the theoretical economic benefit of network operators. The delivered services included are voice, data and video. Using this simulation model we obtained the optimal cost-effective network design in a scenario of a Mexican airport. This design consisted of six cells, each one configured with an Omni-directional antenna and capacity of seven traffic channels. Through the traffic channels were delivered the services: sound, multimedia, narrow band and wide band, with a data rate of 12 kb/s, 128kb/s, 384 kb/s, and 1920 kb/s, respectively. The maximum economic benefit was 46.6% using the optimal network design. We propose this simulation model as a tool for decision-making support of mobile network operators in Mexico.

Enabling the Femtocells: A Cooperation Framework for Mobile and Fixed-Line Operators

Femtocells' ability to improve the in-building coverage and capacity in a cost-efficient way has drawn significant attention from mobile operators. However, a mobile operator may lack a fixed-line network infrastructure, which is indispensable for enabling femtocell service. In this paper, we propose a hybrid cooperation framework where a mobile operator can collaborate with a fixed-line operator (as a virtual integrated operator) to provide femtocell service to indoor users. The framework consists of sequential game and Nash bargaining. The sequential game models the interactions of the operator and users. Specifically, the operator announces the price for wireless services first and then the users decide their spectrum demands in response to the given price. Then the two operators divide the cooperation benefit according to the Nash bargaining model, which makes the profit sharing fair and cooperation framework amenable to operators. We theoretically derive the unique closed-form equilibrium for the framework as well as the conditions that promote the cooperation. The simulation results verify that the cooperation framework can make more revenue for the operators and the spectrum efficiency is significantly improved.

In Building Penetration Loss in Office and Residential Building Structures in Palestine at GSM 900 MHz Frequency

Cellular operators often design their cellular infra- structures for outdoor coverage not paying much attention to in-building coverage as part of the necessary grade of service, they must meet. One of the reasons is that operators tend to act when customer complaints rise, leading to customer migration to other operators, with a consequence of threatening annual profit returns. Another reason is the lack of quality research in signal degradation through different building structures and their utilization in modeling. We propose a new comprehensive standard for in-building penetration loss for most building structure classes in Palestine and vast areas in the Middle East. The model incorporates penetration loss of twelve types of different external wall classes and two types of internal walls that represent over 90 % of building structures in the country. The twelve types are different and widespread stone and concrete building structures.

Distortion Mechanisms Originating From Modal Noise in Radio Over Multimode Fiber Links

Harmonic and intermodulation distortion contributions generated by modal noise in radio over multimode fiber (RoMMF) systems for in-building wireless coverage are reviewed. The role played by the launching technique and by the optical transmitter and receiver in an intensity-modulated direct-detection RoMMF system is described theoretically and experimentally. The presented results constitute a basis for the design of multiband RoMMF systems, where spurious emission due to distortions should be compliant with wireless standards both in downlink and uplink.

The Use of Mobile Devices To Improve Alarm Systems

The Joint Commission 2007 Annual Report stated, “Inadequate communication between care providers, or between care providers and patients/families, is consistently the main root cause of sentinel events.”1 Critical components of communication regarding the health status of a patient are the alerts and notifications originating from the various patient monitors; yet according to the American Journal of Emergency Medicine, as many as 99.4% of alarms are false and less than 1% result in change to patient management.2 Looking to 2011, alarm hazards remain an ongoing challenge, listed at number two on the ECRI Institute’s Top 10 Health Technology Hazards for this year.3 This paper addresses how the use of mobile devices such as the iPhone, the Android smart phone, and the Blackberry with intuitive interfaces and messaging coupled with an integrated alarm management platform will improve clinical satisfaction and operational workflow and decrease risk at the point of care.

Macro-femto heterogeneous network deployment and management: from business models to technical solutions

The femtocell technique can address the poor in-building coverage problem and increase network capacity cost efficiently. At present, some wireless service providers have launched their femtocell services, although there are still plenty of challenges unsettled. In this article we discuss the business mode in macro-femto heterogeneous networks. We propose three frameworks according to the deployment types of femtocells, which are joint deployment, WSP deployment, and user deployment frameworks. Their unique characteristics, corresponding challenges, and potential solutions are further investigated to provide deeper insight systematically. We also present two schemes for WSP revenue maximization under the WSP deployment framework. The first scheme jointly handles the interference and users’ demand satisfaction via cross-tier channel allocation, and the second scheme further considers the optimal pricing selection for accessing different networks.

Design Of Wireless Communication Sensing Networks For Tunnels, Trains And Buildings

Abstract This paper deals with the various assumptions used in the design and analysis of distributed antenna system (DAS) for trains, tunnels and in-building wireless radio coverage. The design includes handover overlap design, base station connectivity, signal reticulation using splitters, couplers, bidirectional amplifiers, attenuators, discrete antennas, radiating cables and opto-electric couplers etc. It is found that signal strength, noise, intermodulation calculated for the up and down links are in compliance with the given specifications and satisfy the required system margin. Our system specifications based on TETRA (Terrestrial Trunked Radio) ensures that the received signal is at least 5 dB higher than the TETRA dynamic sensitivity level and yields 95% coverage of all the used areas

On predicting in-building WiFi coverage with a fast discrete approach

A new approach for predicting coverage of wireless LAN at 2.4 GHz is presented. Coverage prediction is one of the core parts of indoor wireless LAN planning tools. The main concern it has to deal with is providing a good trade-off between prediction accuracy and computational load. Usual approaches belong to either empirical or deterministic methods. A new perspective has recently been offered that exploits a discrete formalism based on the TLM formulation. It is referred to as Multi-Resolution Frequency Domain ParFlow (MR-FDPF). While ray-tracing handles computational load by restricting the number of considered paths, the proposed approach acts by adapting the spatial resolution. This paper presents the straight lines of MR-FDPF and details the conditions for efficient in-building coverage prediction at 2.4 GHz. In a second part this paper tackles the calibration problem and claims for an automatic calibration process to improve the fit between predictions and measurements. A couple of experiments are presented.

Broadband access using wireless-over-fibre technologies

This paper describes a number of wireless-over-fibre technologies for broadband access which are being investigated in the Photonics Group at University College London (UCL). In particular, the paper will report the asymmetric Fabry-Perot modulator/detector (AFPM), functioning not only as an optical modulator in the uplink direction, but also as a conventional photodetector in the downlink direction in a single device. Compared to the existing waveguide type electro-absorption modulator, the AFPM is polarisation-insensitive to light, simpler to fabricate and uses only a single optical fibre for both uplink and downlink transmissions, and therefore has the potential to lower the costs of future picocell deployments. Direct modulation of a semiconductor laser is the simplest way to generate modulated optical signals. In the presence of multiple large modulation signals, however, intermodulation or inter-channel distortion can easily be generated in the semiconductor laser and affect other lower power neighbouring channels. A feed-forward linearisation technique for directly modulated semiconductor lasers, capable of operating at frequencies above 5 GHz, has been developed and will be described in detail in this paper. Most modern commercial buildings already have a multimode optical fibre (MMF) infrastructure for carrying the Ethernet data. To provide cost-effective and reliable indoor cellular and wireless local area network (WLAN) coverage without dependence on the radio penetration from outside base-stations, it is highly desirable that the same MMF infrastructure be used to carry these additional services between the equipment room and the remote antenna units around the building. Although not previously regarded as having sufficient bandwidth, it has now been shown that MMF can successfully carry microwave modulated optical signals, including GSM1800 and UMTS cellular radio. Use of MMF for multiservice, multioperator in-building radio coverage has been demonstrated in a collaboration between UCL and the University of Cambridge and will be described in this paper. As the number of cellular and broadband WLAN devices increases, the lower parts of the radio spectrum are becoming more and more congested. To meet the demand for ever higher data transmission rates, other parts of the radio spectrum are being considered for these applications, particularly the millimetre-wave region (30 GHz and above). One of the challenges facing such systems is the generation and delivery of a low phase noise precisely synchronised local oscillator signal. In this paper, a simple optical heterodyne source with two injection locked slave lasers and a more environmentally robust source using an optical injection phase lock loop will be described, together with signal distribution using a bidirectional semiconductor optical amplifier in a coarse wavelength division multiplex fibre ring architecture. Finally it will be argued in the conclusions that future broadband wireless-over-fibre access networks will be required to provide multiservice and multi-operator coverage for buildings, and having the required technologies at sufficiently low cost will be the key factor to success.

Characteristics of radio transmission over polymer optical fiber for indoor wireless coverage

The characteristics of radio over polymer optical fiber (RoPOF) are evaluated for indoor or in-building wireless coverage. The frequency responses and the third order intermodulation distortion products of the RoPOF link are investigated. The eye diagrams and EVM values of signals carrying quadrature-phase-shift-keyed (QPSK) data and global system for mobile (GSM) signals are measured to evaluate the transmission performance. The interference measurements with FDM are also carried out. The results show that although the nonlinear distortion and power loss deteriorate the system to some extent, making use of passband transmission, RoPOF can provide fairly good transmission performance for wireless applications.