Towards connecting base stations over metro gigabit ethernets

In this paper, we present a new robust, fast, and accurate deconvolution algorithm for correcting noise disturbed measurements and eliminating the influence of the resolution filter of a spectrum analyzer used for EM-field measurements around a GSM and UMTS base station. Our purpose is to be able to determine immediately the field values at a measurement site. Therefore the algorithm has to be fast and accurate. Furthermore, because of the presence of noise, our algorithm has to be robust. Our algorithm that uses windowing and filtering meets those demands and reduces the present noise by an additional convolution with a square wave function.

Nowadays cellular operators in Indonesia are allocated frequency band for UMTS systems in 2.1 GHz band as well as two channels with each channel allocated at 5 MHz. Bandwidth to meet the 3G service was ranging started from 1920 MHz to 1980 MHz for uplink and 2110 MHz it up to 2170 MHz for the downlink it. The number of channels in both uplink and downlink bandwidth is twelve with each frequency channel has a width band of 5 MHz. Currently the remaining unallocated channel is channel 11 and 12. Along with the traffic growth and RPJP, the allocation of the two channels surely increase the capacity and the throughput of 3G operators. The allocation of these two channels are been realized at least on the first quarter of 2012; with the auction system by BRTI. However, the results of field tests conducted by several operators and BRTI, show that if both channels are allocated to operators for 3G services, the transmitter from CDMA2000 base station which is allocated its downlink frequency at 1983.125 MHz to 1990 MHz will interfere with the receiver base station of 3G GSM, operators which will be allocated in blocks 11 and 12. If interference occurs, the quality of service of 3G GSM operators will significantly decrease. Of course this is a consideration of the relevant institutions and 3G operators who wish to be allocated to one or two channel. This interference can be overcome by manual calculation from link budget and antenna spacing between CDMA2000 antenna Tx to UMTS antenna Rx that operate on blocks 11 and 12. This calculation is based from antenna characteristics equation with assumptions and interference constraints defined by 3GPP and 3GPP2. This solution is specifically performed between CDMA2000's base station and UMTS base station which are located at Hotel Pangrango 2 (Bogor), Infil Limo (Depok), and Cengkareng (Tangerang).

This paper presents a forward scattering UTD method to evaluate GSM signals along the vertical and transverse planes. Reflections and diffractions in forward directions from the base station to the mobile in those two planes are included to determine the power received by the mobile. To find the scattering objects, building exterior geometries are obtained from 1:1000 digital city maps. An efficient method to identify forward propagation paths of multiple reflections and diffractions is developed. Simulations and measurements of the signals from a GSM base station are compared.

Passive radar is a kind of that without its own transmitter and receive the thermal emission energy of an object or its source of microwave energy reflected from the radar to detect targets. The widely distributed GSM base station signals have GMSK frequency modulation characteristics, these signals can be used as a passive radar radiation source for its ambiguity function diagram with axes at a distance and no ambiguity in Doppler shift and the high side-lobe and so on. Multi-base stations passive radar positioning system is one of the important research area. According to the urban low-altitude air defense warning system development, this paper do some researches on line and plane intersection algorithm for passive location and tracking, based on dual-GSM base stations. Meanwhile, probe into the passive tracking technics by utlizing the State-Dependent Riccati Equation Filter tracking algorithm under the dual GSM base stations. Experiments shows that the algorithms have better positioning accuracy, high efficiency and practical value.

In this work a system is proposed that utilizes an unmanned aerial vehicle (UAV) to search and rescue trapped victims using their mobile phones. The systems consists of two parts, a ground station (GS) and an airborne station (AS). The GS provides a downlink to the UAV, a GSM base station along with antenna equipment and a mobile network jamming device. By using a smart approach to block the synchronization sequences of all base stations in range, the mobile phones of the victims to be located are switching to an emergency fallback mode. In this mode the phones connect to the strongest base station in range, thus the one provided by the GS. By initiating a call to the corresponding phone the AS can localize it using direction-of-arrival detection with a 9-channel phase coherent receiver system.

This paper addresses the problem of allocating frequencies in a GSM-based home base station (HBS) system. A novel solution called total frequency hopping (TFH) is presented in order to overcome the frequency allocation and the inter-HBS synchronisation problems. The HBS system will use the same frequency band as the overlaying GSM network and thus creates more interference to it. The simulation results reveal that the negative impact of the underlying HBS system on the GSM network performance is minimal provided that the HBS transmission (TX) power is reasonable low. The TX power cannot be arbitrarily low, however, since the HBS system must be able to function in the presence of the interference from the overlaying high power GSM network. When the power ratio between GSM base station and HBS is around 40 dB, the both networks can co-exist at the same frequency band.

We describe the software implementation of a GSM base station and consider the performance of each of its radio interface components. The performance of each software module is evaluated using both a % CPU metric and a processor-independent metric based on SPEC benchmarks. These results can be used to dimension systems, e.g., to estimate the number of GSM channels that can be supported by a given processor configuration, and to predict the impact of future processor enhancements on base station capacity.

This paper aims to provide an alternative green energy source for a remote GSM base station. To achieve this, a hybrid renewable energy (RE) plant is proposed, comprising a wind turbine, photovoltaic panels, and a fuel cell (incorporated with an electrolyzer and a hydrogen tank for the production and uniform supply of hydrogen). The system will be controlled logically by a power flow controller which will help to provide continuous power to the base station by application of economic optimization of power generation. The hybrid system and the associated load (GSM base Station) are simulated using the HOMER software and required analyses carried out. The simulation results show that renewable energy sources are feasible solutions to reducing air contaminants and pollutants (such as SO 2 & CO 2 ) produced by sources like diesel generators which also serve as an alternate source of energy for a remote GSM base station.

A GSM 900 MHz vertically polarised multibeam antenna testbed is presented incorporating a thin 4 beam microstrip planar antenna, a GSM mobile, a GSM base station (BS) a DSP and a personal computer (PC) to control the measurement procedure. The multibeam antenna covers 120/spl deg/ in azimuth with 4 beams offering an impedance bandwidth >10%, a minimum gain of 15.8 dBi for each beam and has dimensions of 710/spl times/800/spl times/12 mm. The static beamforming is performed at the radio frequency (RF). The results demonstrate a carrier to interference (C/I) improvement together with increased received signal strength indication (RSSI).

The deployment of Gigabit Ethernet in corporate and ISP networks makes the transmission over WDM networks necessary to provide for the interconnection over metropolitan and wide area WDM networks. As the specifications of the optical signal between Gigabit Ethernet and the WDM-network mismatch, a transponder is needed. We propose an architecture for a Gigabit Ethernet over WDM transponder and report on a transponder prototype implementation. We further show how to use the transponder for Gigabit Ethernet networks over WDM rings.

The power density in electronic equipment and thus the overall power consumption are increasing continuously. This is especially true for the new technologies in telecommunication systems like the UMTS base stations, where full control over thermal management at any point inside the enclosures is mandatory. Since an improved cooling normally is based on higher air flow rates, acoustic noise becomes more and more relevant, because the installed systems are not accepted if they do not fulfil low noise specifications. For a given forced convection cooled equipment - typically using fans or blowers - a CFD based numerical analysis provides design information which allows sophisticated flow control inside the enclosure. The next step is to use CFD based optimisation of the fans and blowers themselves in order to optimise these building blocks for maximum performance at low noise. This paper shows how the performance of equipment fans and blowers can be optimised by using computer simulation during the design phase. Besides the correlation between flow rate and pressure the simulation results provide additional information about the sources for aerodynamic acoustic noise generated by the rotating blades. The target is to integrate fan and blower optimisation into a customised thermal management on system level. Thus concurrent use of modern CFD tools enables sophisticated cooling solutions with control over flow, temperatures and noise simultaneously

It is important for ubiquitous networks to survey a wireless area with required communication quality, i.e., communication quality required by an application. However, communication quality of wireless networks dynamically changes depending on various invisible factors. Nor can their influence be accurately estimated beforehand. Thus, actual wireless measurement is unavoidable. Existing wireless measurement methods are mainly based on the effort of network engineers. If wireless networks become larger in scale, like a metropolitan area, how do they carry out an accurate and effortless survey of the whole wireless network? When can they complete such a laborious task? Furthermore, the invisible factors chiefly depend on a propagation path between a user and a base station (BS), i.e., they depend on a user's location. Hence, we need to perform a wireless measurement at each point in wireless networks. In our research, we will attempt to effortlessly, and continuously conduct detailed wireless measurement over wireless networks. The difficulty of achieving such wireless measurement is continuously conducting detailed wireless measurement of the whole wireless network without burdening engineers. As a first step, in this paper, we focus on the measurement framework of each BS. In our framework, a BS measures communication quality of multiple layers at each position from users' active traffic. Since users are distributed over a wireless area, a BS can obtain communication quality in its own wireless area by making a map between communication quality and geographical location, called a quality map. Then, we evaluate the accuracy of the quality map and investigate the characteristics of the quality map depending on configurable parameters through simulation experiments.

We propose a new architecture for broadcasting an enormous amount of information over a large population of users in a typical urban area via multiple base stations for delay tolerant applications. The core idea is that each base station partially broadcasts the information instead of transmitting the whole information. In particular, the large target file is broken into M smaller chunks and is provided to N base stations. Each base station i independently generates M <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">i</sub> <; M linear combinations of the chunks using random linear network coding (RLNC) techniques and broadcasts it to the users in its coverage area. Users then code and exchange packets in their possession via their short range communication links (e.g. bluetooth). Thanks to the random nature of human mobility patterns, it is expected that after a while, the placement of the users would be mixed enough so that users can obtain sufficient number of chunks to decode the entire file. The proposed architecture provides a fundamentally bandwidth efficient scheme for delay tolerant broadcast applications and has the potential to be implemented in practice. In particular, the proposed approach is completely opportunistic i.e. it does not require any routing algorithm. We evaluate the performance of the proposed architecture via extensive simulations using a well known human mobility patterns simulator.

software-defined vehicles (SDVs) employ zonal architectures whose zones exchange periodic real-time traffic over a high-speed Time-Sensitive Ethernet (IEEE 802.1Q) backbone. Existing research has produced many deterministic routing schemes for such backbone Ethernet networks, yet has largely ignored the complementary problem of payload-level frame minimization: multiplexing dozens of small zonal messages—whether CAN, LIN, or any other in-zone protocol—into the fewest possible Ethernet frames so that bandwidth, switch buffers and latency budgets are not squandered. This letter concentrates on that neglected frame-minimization facet and presents an optimization flow dedicated to reducing the number of Ethernet frames. We first formulate an exact Satisfiability Modulo Theories (SMTs) model that finds the minimal set of multiplexed frames required across an entire hyper-period. Because SMT becomes intractable on large vehicle topologies, we then introduce a matrix-based heuristic aggregation (MaHA) algorithm that reproduces the SMT’s frame-minimization decisions to within a few percent while executing in milliseconds. Experiments on synthetic SDV workloads show that naive one zonal message per Ethernet frame policies waste significant available payload capacity; our SMT eliminates this waste completely, and the heuristic achieves closely similar savings with up to three orders of magnitude less run-time, making it a practical drop-in solution for next-generation SDV networks.

The purpose of this study was to obtain information regarding single and multi channel VHF and UHF radio signal booster systems which have been constructed in subway and highway tunnels in Europe and to disseminate this information in the U.S.A. Early in 1977, while the author was engaged in designing a UHF radio system for a subway, he learned that low power radio signal booster systems using a daisy chain of amplifiers (similar to a CATV trunk line) were being used in coal mines in the United Kingdom and that London Transport was installing a signal booster system in the Bakerloo Tube to replace a conventional system that had used a base station to feed a tee section of leaky coaxial cable. This new system used low power signal booster amplifiers spaced 500 meters apart to compensate for the attenuation in the leaky coaxial cable antenna system. The design was based upon similar systems which were used in coal mines in the United Kingdom and it afforded a number of advantages over conventional multiple base station systems used in the U.S.A. such as: • Signal strengths throughout the tunnel system are uniform. • Only one base station per radio channel is needed for a typical subway; this substantially reduces costs for renovating space for radio systems in existing subways and also eliminates hetrodyne interference that occurs at transitions between the ends of adjacent antennas. • If wide band class A linear signal booster amplifiers (similar to CATV line amplifiers) are used, a number of channels can be readily and more economically provided for train communications, maintenance, security, fire, police and para-medical services. • Fewer control circuits are needed and central control facilities and operations are simpler. • Equipment, installation and operating costs are lower. In August, 1977, the author visited Dr. D.J.R. Martin, co-inventor of the daisy chain concept and London Transport and obtained information regarding the VHF radio system in the Bakerloo Tube which was summarized in a paper that he presented at the 28th IEEE Vehicular Technology Conference at Denver, Colorado, in March, 1978. A somewhat similar VHF signal booster system was designed for the new U-1 subway in Vienna by German and Austrian engineers who evidently were not aware of the work that had been done in England. The Vienna system was visited in 1978 shortly after the subway was commissioned and its performance was superior to conventional systems used on other subway lines. The subways in Munich and Milan also were visited, but they used conventional base stations to feed tee sections of leaky coaxial cable antenna. A unique multi-channel radio signal booster system for extending AM and FM broadcasting and seven two way VHF public safety channels into two 395 meter highway tunnels in Brussels was visited in 1979 and the designers of the system were interviewed. A single discone antenna constructed of meta½ rods is used for both transmitting and receiving. The Swiss Posts, Telephone and Telegraphs (PTT) authority in Switzerland has developed an eleven channel VHF two way signal booster system for their long highway tunnels. FM broadcasting (87.6 - 104 MHz) as well as two way VHF radio telephone, police, fire and maintenance services will be accommodated. A list of persons in Europe who are engaged in development research or operation of radio systems using signal boosters (in-line repeater amplifiers) in tunnels is included in Appendix 1.