5,653 research outputs found

    A Review of Interference Reduction in Wireless Networks Using Graph Coloring Methods

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    The interference imposes a significant negative impact on the performance of wireless networks. With the continuous deployment of larger and more sophisticated wireless networks, reducing interference in such networks is quickly being focused upon as a problem in today's world. In this paper we analyze the interference reduction problem from a graph theoretical viewpoint. A graph coloring methods are exploited to model the interference reduction problem. However, additional constraints to graph coloring scenarios that account for various networking conditions result in additional complexity to standard graph coloring. This paper reviews a variety of algorithmic solutions for specific network topologies.Comment: 10 pages, 5 figure

    Transmission of medical messages of patient using control signal of cellular network

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    The healthcare system needs to track and monitor patients’ status and information. One of the most important requirements is that the patient is able to access the service anywhere at any time. Systems are being developed using the Internet to monitor patients’ status, and in some areas, especially rural areas and motorways, the Internet may not be available, even though the mobile network is available. In some cases, the network might be overloaded, so the patient information cannot be delivered to the hospital or medical centre. We propose a new method that uses the spare extension of the random access channel (RACH), which is carried by physical random access channel (PRACH) to send the patient information to the medical centre. We present the mathematical model of the channel and compare the results with another system from 3GPP to evaluate the results. The results show that the proposed method needs less time to transmit the patient’s information

    Satellite provided fixed communications services: A forecast of potential domestic demand through the year 2000: Volume 2: Main text

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    Potential satellite-provided fixed communications services, baseline forecasts, net long haul forecasts, cost analysis, net addressable forecasts, capacity requirements, and satellite system market development are considered

    A Low-latency Collaborative HARQ Scheme for Control/User-plane Decoupled Railway Wireless Networks

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    ArticleThe recently proposed Control/User (C/U) plane decoupled railway wireless network is a promising new network architecture to meet the communication demands of both train control systems and onboard passengers by completely separating the C-plane and U-plane into different network nodes operating at different frequency bands. Although the system capacity of this network architecture can be highly increased, the forwarding latency of X3 interfaces to link the C-plane and U-plane becomes a serious concern, especially for hybrid automatic repeat request (HARQ) protocols which demand frequent interactions between the C-plane and U-plane. This concern becomes more pronounced for latency sensitive train control. To address this challenging problem, in this paper we propose a low-latency collaborative HARQ scheme. Through a newly designed collaborative transmission framework, the possible spare resources on lower frequency bands of macro cells by excluding those used by C-plane transmissions are utilized to help small cells relay erroneously received data. Compared to the conventional HARQ scheme, to reach the same transmission reliability, the proposed scheme requires fewer retransmissions on average, thereby mitigating the latency problem caused by HARQ retransmissions. Correspondingly, the channel mapping is also redesigned to conform to the proposed collaborative transmission framework. In the theoretical analysis, the expression of the average retransmission times related to the sum of independent Gamma variables is developed. Finally, simulation results show that a great decrease in the retransmission latency is gained by the proposed scheme, but at the sacrifice of few average system transmission rate

    Future benefits and applications of intelligent on-board processing to VSAT services

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    The trends and roles of VSAT services in the year 2010 time frame are examined based on an overall network and service model for that period. An estimate of the VSAT traffic is then made and the service and general network requirements are identified. In order to accommodate these traffic needs, four satellite VSAT architectures based on the use of fixed or scanning multibeam antennas in conjunction with IF switching or onboard regeneration and baseband processing are suggested. The performance of each of these architectures is assessed and the key enabling technologies are identified

    Framework for the Integration of Mobile Device Features in PLM

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    Currently, companies have covered their business processes with stationary workstations while mobile business applications have limited relevance. Companies can cover their overall business processes more time-efficiently and cost-effectively when they integrate mobile users in workflows using mobile device features. The objective is a framework that can be used to model and control business applications for PLM processes using mobile device features to allow a totally new user experience

    IDENTIFICATION AND ANALYSIS OF ATTACKS USING RECOVERED RADIO NETWORK TEMPORARY IDENTIFIERS ON 5G USER EQUIPMENT

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    The next cellular network, 5G, will drastically increase the number of devices on a network. The increase in devices will provide a bigger attack surface for potential intruders and offer a pivot point to get inside networks once exploited. Researchers have already discovered how to de-anonymize the messages in the physical downlink control channel to recover Radio Network Temporary Identifiers (RNTI). Analysis of the 5G protocols identified potential vulnerabilities when an RNTI is known. A potential attacker is now able to recover RNTIs, making attacks on 5G devices inevitable. Additional research conducted into protocol vulnerabilities was completed and found possible vulnerabilities in some of the 5G protocols. This thesis examined how the aggregated results of prior work can be utilized to attack individual pieces of user equipment. Cyber security professionals will benefit from this research by understanding how these attacks will be carried out in order to identify defenses against them.Major, United States ArmyApproved for public release. Distribution is unlimited

    Transmission of Disaster Warnings via Control Channels in Cellular Networks, Journal of Telecommunications and Information Technology, 2020, nr 4

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    According to United Nations reports, natural disasters caused, worldwide, approximately 100,000 deaths and affected 175 million people each year between 2004 and 2013. To reduce those numbers, countries around the globe have made specific arrangements enabling them to warn the population about imminent disasters, in order to evacuate the area in due time. But providing such warnings in areas where no Internet access is available poses a great challenge. In this paper, we proposed a method to transmit early warning messages via UMTS cellular networks, while relying on spare extensions of control channels (FACH). The results obtained are validate based on their comparison with theoretical considerations and are also benchmarked against the 3GPP standard. The results show that messages may be sent faster than with the use of the 3GPP standar
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