The AMSC mobile satellite system: Design summary and comparative analysis

Mobile satellite communications will be provided in the United States by the American Mobile Satellite Consortium (AMSC). Telesat Mobile, Inc. (TMI) and AMSC are jointly developing MSAT, the first regional Mobile Satellite Service (MSS) system. MSAT will provide diverse mobile communications services - including voice, data and position location - to mobiles on land, water, and in the air throughout North America. Described here are the institutional relationships between AMSC, TMI and other organizations participating in MSAT, including the Canadian Department of Communications and NASA. The regulatory status of MSAT in the United States and international allocations to MSS are reviewed. The baseline design is described

The Future of Mobile Industry

This paper discusses the future of mobile industry along with some of the background leading to the emergence of wireless technology. First, it gives an overview of today’s telecommunication network and the major differences between fixed wired networks and wireless networks. The discussion then focuses on the challenges facing the wireless industry and the way out through aggressive innovation by employing Wireless Intelligence Network (WIN) technology. The paper also discusses some important trends in wireless industry and the customers expectations which are also part of the challenges for the mobile industry. Finally particular reference is made to the developing nations especially Nigeria in the ongoing trends in mobile communication industry

Regulatory and Policy Implications of Emerging Technologies to Spectrum Management

This paper provides an overview of the policy implications of technological developments, and how these technologies can accommodate an increased level of market competition. It is based on the work carried out in the SPORT VIEWS (Spectrum Policies and Radio Technologies Viable In Emerging Wireless Societies) research project for the European Commission (FP6)spectrum, new radio technologies, UWB, SDR, cognitive radio, Telecommunications, regulation, Networks, Interconnection

Performance Analysis of a Hybrid Cellular Satellite System: Hybrid Cellular Satellite Handoffs

As technological advances are made in the world, communication needs tend to extend with the technology available. Mobile communications has potential for very rapid growth. Many companies are participating in ventures, experiments, and developments that will expand mobile communications services globally. At the University of Maryland, Center for Satellite and Hybrid Communications, a component of Institute for Systems Research, through research these efforts are being facilitated, particularly in the area of Hybrid Cellular-Satellite Communication Networks. This paper discusses progress made in cellular systems, satellite systems, and the networking between them. The functionality of the cellular system and the satellite system is explained, followed by a description of a simulation study involving the hand-off aspect between the cellular and satellite systems. Within the description of the simulation study, the system roles and relationships are described. The simulation study is specifically for monitoring the performance and operation of the Cellular Radio Telecommunication Intersystem Operations IS-41.2-B protocol, used for handoffs in cellular systems, in a hybrid system environment. The main performance issue at hand is the delay to setup a call handoff. The study serves also for developing a model in which a hybrid network intersystem operation can be studied. Final results show the types of analysis that the model can be used to determine

On the modeling of WCDMA system performance with propagation data

The aim of this study was to develop calculation methods for estimating the most important system level performance characteristics of the WCDMA radio network (i.e. network capacity and coverage) in the presence of interference from various sources. The calculation methods described in this work enable the fast design of radio systems with a reasonable degree of accuracy, where different system parameters, propagation conditions and networks as well as frequency scenarios can be easily tested. The work also includes the development and verification of a propagation model for a microcellular environment. Traditionally, system level performance figures have been retrieved using system simulations where the radio network has been modeled as accurately as possible. This has included base stations and mobile stations, propagation models, traffic models and mobility models. Various radio resource management (RRM) algorithms, such as power controls and handovers have also been modeled. However, these system simulations are very complex and time consuming and typically the models are difficult to modify. The idea behind this work is to use the main statistical parameters retrieved from accurate, case specific propagation models and to use these statistics as input for the developed analytical radio network models. When used as output from these analytical models we are able to obtain the performance measures of the network. The specific application area for the developed methods is the evaluation of the effect of the interference from the adjacent frequency channels. Adjacent channel interference decreases the efficiency of the usage of the electromagnetic spectrum i.e. the spectral efficiency. The aim of a radio system design is to ensure that the reduction in the spectral efficiency is as low as possible. This interference may originate from the same or a different radio system and from the same or another operator's network. The strength of this interference is dependent on the system parameters and the network layout. The standard questions regarding adjacent system interference between different operators' network are what guard band is needed between the radio carriers in order to maintain the quality of the network or what are the main mobile and network parameters, such as adjacent channel emission levels or adjacent channel selectivity, required in order to achieve satisfactory network performance. With the developed method proposed here it is possible to answer these questions with reasonable accuracy. One important aspect of network performance is the radio wave propagation environment for which the radio systems are designed. This thesis presents methods evaluating radio wave propagation, especially for cases where the base station antenna is below the rooftops, i.e. in the case of microcellular network environments. The developed microcellular propagation model has been developed for network planning purposes and it has been verified using numerous field propagation measurements. The model can be used in cases where the mobile station is located either indoors or outdoors.reviewe

Codes Cross-Correlation Impact on S-curve Bias and Data-Pilot Code Pairs Optimization for CBOC Signals

The aim of this paper is to analyze the impact of spreading codes cross-correlation on code tracking performance, and to optimize the data-pilot code pairs of Galileo E1 Open Service (OS) Composite Binary Offset Carrier (CBOC) signals. The distortion of the discriminator function (i.e., S-curve), due to data and pilot spreading codes cross-correlation properties, is evaluated when only the data or pilot components of CBOC signals are tracked, considering the features of the modulation schemes. Analyses show that the S-curve bias also depends on the receiver configuration (e.g., the tracking algorithm and correlator spacing). In this paper, two methods are proposed to optimize the data-pilot code pairs of Galileo E1 OS. The optimization goal is to obtain minimum average S-curve biases when tracking only the pilot components of CBOC signals for the specific correlator spacing. The S-curve biases after optimization processes are analyzed and compared with the un-optimized results. It is shown that the optimized data-pilot code pairs could significantly mitigate the intra-channel (i.e., data and pilot) codes cross-correlation，and then improve the code tracking performance of CBOC signals

Mobility and Handoff Management in Wireless Networks

With the increasing demands for new data and real-time services, wireless networks should support calls with different traffic characteristics and different Quality of Service (QoS)guarantees. In addition, various wireless technologies and networks exist currently that can satisfy different needs and requirements of mobile users. Since these different wireless networks act as complementary to each other in terms of their capabilities and suitability for different applications, integration of these networks will enable the mobile users to be always connected to the best available access network depending on their requirements. This integration of heterogeneous networks will, however, lead to heterogeneities in access technologies and network protocols. To meet the requirements of mobile users under this heterogeneous environment, a common infrastructure to interconnect multiple access networks will be needed. In this chapter, the design issues of a number of mobility management schemes have been presented. Each of these schemes utilizes IP-based technologies to enable efficient roaming in heterogeneous network. Efficient handoff mechanisms are essential for ensuring seamless connectivity and uninterrupted service delivery. A number of handoff schemes in a heterogeneous networking environment are also presented in this chapter.Comment: 28 pages, 11 figure

Recursive Model Selection for GNSS-Combined Precise Point Positioning Algorithms

The accuracy of Global Positioning algorithms can be improved by incorporating observations from the satellites of multiple Global Navigation Satellite Systems (GNSS). To best utilize these observations, inter-system biases must be modeled. A unified observational model is proposed which accounts for these factors for an arbitrary number of GNSS. The Bayesian Information Criterion (BIC) may be imposed upon the unified model to balance data-fitting degree with model complexity among candidate models for a given satellite configuration scenario. A simple formulation is derived for the change to the Weighted Sum Squared Residuals (WSSR) outcome caused by modifying the least-squares design matrix to accomodate additional ISB parameters. The process of updating WSSR is shown to be $O(n^2)$, allowing a low-cost determination of the information entropy between any two candidate models. With this computationally cheap parameter selection process and a set of GNSS-heterogeneous observations, the form of the unified model with the highest expected accuracy may be efficiently selected, at a stage before matrix inversion is performed

VOICE CALLS BETWEEN WIRELESS (ANDROID) PHONES AND A COOPERATIVE APPLICATION FOR SENDING SMS OVER WI-FI NETWORKS

Wi-Fi technology is a form of telecommunication that allows data and voice transmissions to be sent across a wide range of interconnected networks. The success in deploying services and applications based on this concept needs the development of applications that allows intermediate users the reception and forwarding of information to destination users. The user may take the maximum benefit from the technology acquired inside the mobile phone for instance, since it is possible extend the radio coverage by several hops, and enjoy similar mobile2018;s operator services free of charge. In this work we are going to present the development of an integrated Java application to send SMS and Voice among user mobile phones through its WIFI interface. A software application is developed using Android which allows free and secured communication between selected phones in the Wi-Fi network. The base idea is unifying voice and data onto a single network infrastructure by digitizing success of wireless and mobile communications has resulted in the creation of a large variety of technologies. Expanding services through the use and coordination of these diverse networks will provide user mobility between different types of systems