Introduction to Mobile Communication: history and evolution of mobileradiosystems, types of mobile wireless services/systems - cellular, WLL, paging, satellitesystems, standards, and future trends in personal wireless systems. Cellular concepts and system design fundamentals/frequency management and channel Assignment: Cellular concept and frequency reuse, Multiple Access Schemes, fixed Channel assignment, non-fixed channel assignment and handoff. Interference and system capacity, Trunking and Erlang capacity calculations. Mobileradio propagation Radio wave propagation issues in personal wireless systems, Propagation models, Multipath fading and base band impulse response models, Parameters of mobile multipath channels, Antenna systems in mobileradio.
per timeslot than GSM, which attains a maximum d ata rate of 9.6 kbps as discussed earlier. Considering also the fact th a t several timeslots can be used by the same user for data transmission, one can conclude th a t very high d a ta rates can be achieved with GPRS. There is of course a trade off between the high coding rates and the total delay caused by the retransmissions of erroneous blocks, and the scheme th at provides the most balanced solution must be adopted for each different radio en vironment. USFs provide the user with information th a t has to be decoded a lot faster than the rest of the block in order to enable him /her to prepare the data transmission in the next block time. Therefore, in schemes CS2-CS4 a 12-bit USF codeword is created. In schemes CS2 and CSS a 6-bit USF block is created, and then convolutional coding is applied to the whole block without puncturing the first 12 bits.
Early studies on multi-satellite transmission were carried out in 1992. Based on circular scans of ﬁsheye-camera pictures in diﬀerent environments an empirical model was developed describing the correlation coeﬃcient between two satellite signals depending on their azimuth separation . In 1996 a statistical channel model for two correlated satellites based on ﬁrst-order Markov chains was developed . The state sequence generation is based on state transition probabilities of two independent satel- lites. Both satellites are combined by a state correlation parameter which can be taken from empirical models. Due to its simplicity this modelling approach is frequently used today. However, ﬁrst-order Markov chains have limi- tations in state duration modelling, as their state durations follow an exponential distribution. Studies in [8-10] found that this condition does not hold for the LMS channel. Nevertheless, a correct state duration modelling is of high interest for the optimal conﬁguration of physical layer and link layer parameters for modern broadcasting stan- dards with long time interleaving (e.g. for physical layer interleaver size, link layer protection time). Therefore, diﬀerent concepts improving the state duration modelling were introduced: semi-Markov chains  and dynamic Markov chains . For these approaches some exemplary parameters for the single-satellite reception are pub- lished. However, an intense study for multi-satellite state duration modelling and a corresponding channel model including parameters for diﬀerent environments and orbital positions does not exist so far. In this sense, a new channel model for two or more satellites was developed in the context of the project MiLADY (Mobilesatellite channeL with Angle DiversitY) . This project covered two measurement campaigns in the U.S. and in Europe: In the ﬁrst campaign the power levels of the Satellite Digital Audio Radio Services (SDARS) satellites (S-Band) were recorded synchronously with a sample rate of 2.1 kHz. The signals allow to study slow and fast fading eﬀects in combination with angle diversity for a limited set of elevation and azimuth angle combinations. A second measurement campaign was carried out in the area of Erlangen in Germany to record the carrier-to-noise spec- tral density ratio (C/N 0 ) from Global Navigation Satellite
Space-Time Codes (STCs) have been implemented in cellular communications as well as in wireless local area networks. Space time coding is performed in both spatial and temporal domain introducing redundancy between signals transmitted from various antennas at various time periods. It can achieve transmit diversity and antenna gain over spatially uncoded systems without sacrificing bandwidth. The research on STC focuses on improving the system performance by employing extra transmit antennas. In general, the design of STC amounts to finding transmit matrices that satisfy certain optimality criteria. Constructing STC, researcher have to trade-off between three goals: simple decoding, minimizing the error probabilty, and maximizing the information rate. The essential question is: How can we maximize the transmitted date rate using a simple coding and decoding algorithm at the same time as the bit error probability is minimized
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The conducted measurements show a very good performance and a rather similar performance of the measured phones. This is as expected, since the radio chips used are of a few types and all comply fully with the required performance. This shows very clearly that only the antenna cause the phones to have very different coverage performance.
Lajos Hanzo received his degree in electronics in 1976 and his doc- torate in 1983. During his career in telecommunications he has held various research and academic posts in Hungary, Germany and the UK. Since 1986 he has been with the Department of Electronics and Com- puter Science, University of Southampton, UK, where he holds the chair in telecommunications. He has co-authored 10 books on mobileradio communications, published about 400 research papers, organised and chaired conference sessions, presented overview lectures and has been awarded a number of distinctions. Currently he heads an academic re- search team, working on a range of research projects in the field of wireless multimedia com- munications sponsored by industry, the Engineering and Physical Sciences Research Council (EPSRC) UK, the European IST Programme and the Mobile Virtual Centre of Excellence (VCE), UK. He is an enthusiastic supporter of industrial and academic liaison and he of- fers a range of industrial courses. He is also an IEEE Distinguished Lecturer. For further information on research in progress and associated publications please refer to http://www- mobile.ecs.soton.ac.uk
communication systems. Compared with the related schemes, the proposed scheme achieves the following three main advantages: (1) It is just based on a secure one-way hash function for avoiding complex computations for both mobile users and network control center (NCC), (2) it does not require sensitive verification table which may cause NCC to become an attractive target for numerous attacks (e.g., insertion attacks and stolen-verifier attacks), and (3) it provides higher security level (e.g., secure mutual authentication and key establishment, confidential communication, user ’ s privacy, simple key management, and session key independence). As a result, the proposed scheme is very suitable for lightweight-device environments because of very low computation overload on the part of both mobile user and NCC.
The realized mobile unit has been used for the first time in operating activities following the “Youth Meeting” with the Pope in September 2007 in Loreto. The system has ensured, 24h to 24h, the radio and telephone links with all the operational centers involved in the control and safety of the meeting. The Unit attracted great interest and appreciation from other Italian Department for the full operational autonomy and the immediacy of radio and wire communications implemented with the transponder. We report some pictures of meeting’s place:
Observation is done by draw a line for every 2 0 of azimuth angle from radar station to mobile unit. Calculate altitude, h and from there find elevation angle for every azimuthal scanning. Observed rain attenuation path for every 1 km of volumetric inside a range bin from radar station. Observation is done under the rain height or melting layer is about 5 km. In this project n of range bin that rainfall were intersecting must be also considered.
The methodology is as outlined in Fig. 1. Firstly, all equipment was prepared to conduct an observation. According to , site selection is very important for decision makers to propose where to determine the observation site. It was decided to perform the data collection at KUSZA Observatory, East Coast Environmental Research Institute (ESERI), UniSZA which is situated in Merang, Terengganu. KUSZA Observatory is located near the beach at 5 ° 32' 10" N and 102 ° 56' 55" E on top of the hill with low population density and tropical wet climate. Both RFI pattern and temperature were observed on 26th of August 2015. Statistical analysis was performed from 3600 data to determine the correlation between temperature change and the radio signal pattern.
Our research interests are focused on smart sensing systems based on CMOS/MEMS technology. Multimodal sensing systems integrated with different kind of sensors such as physical sensors, chemical sensors, and biosensors, attract attention as a key element of new generation society based on IoT and big data analysis. This concept is proposed in the 5th Science and Technology Basic Plan of Japan as “Society 5.0”. In our laboratory, design and fabrication technologies of the multi-modal sensors are studied. Novel application of sensors in the harsh environment that can be realized using robust packaging technology is also investigated.
In the standardization forum, WCDMA technology has emerged as the most widely adopted third generation air interface. Its specification has been created in 3GPP (the 3 rd Generation Partnership Project), which is the joint standardization project of the standardization bodies from Europe, Japan, Korea, the USA and China. Within 3GPP, WCDMA is called UTRA (Universal Terrestrial Radio Access), FDD (Frequency Division Duplex) and TDD (Time Division Duplex). The name of WCDMA being used to cover both FDD and TDD operation.
Backbone or back haul systems have been built for mobile operators who want to be independent from Telcos and fixed wire operators. It saves cost for leasing a fixed line and allows a simple upgrade of the network if higher capacity is required. In addition traditional and new telcom's, utilities as well as broadcast organizations are upgrading their networks to offer higher capacities to clients or to upgrade their system from analogue to digital service. Backbone systems usually use large size antennas in frequency bands below 10 GHz.
Communication systems have introduced plethora of technological advancements in infor- mation sharing. Every innovation in communication has propounded yet another revolu- tionary idea in the field of technology. Similarly, the birth of Internet can be accredited to contributions from communication systems. With the advent of Internet, many other technologies in communications are born. One such technologies is wireless-local-area- network (Wi-Fi) . And not just Wi-Fi, but cellular technologies have evolved as well. These profound technologies use wireless media to transmit information to longer distances using electromagnetic waves and are entitled to mathematical models for wave-propagation proposed by many renowned scientists and mathematicians such as Maxwell, Hertz, Mar- coni, Tesla, and many more .