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ITU-R M.1842-1, which is one of the renowned specification for VHF data exchange system (VDES) devoted to maritime mobile applications, has been standardized wireless transmission protocols according to the peculiar characteristics of a maritime communications scenario. Generally, in the Annex-4 of ITU-R M.1842-1, the VHF data link protocols for maritime mobile services are described along with a...
More than half of the mobile backhaul connections are wireless and huge capacity promise of mmW bands is compelling to cope with the increasing data capacity for future 5G system. We reported a backhaul E-band measurement campaign focusing on radio system measurements with the demonstrator developed in the project. The evaluations include the throughput measurement with different modulation coding...
The aim of this paper is to introduce the measurement method for challenging Non-Line of Sight (NLOS) conditions in mobile networks. The need to develop the measurement method appeared LTE (Long Term Evolution) uplink (UL) performance with different antenna technologies when receiving NLOS signal in field tests. Many challenges appeared during the study. This paper introduces the challenges and presents...
In this paper, cognitive machine to machine (CM2M) gateway in e-healthcare systems are presented by accessing several channels via periodic sensing and spectrum handoff. An optimal energy efficient spectrum management mechanism with multiple thresholds is proposed. The developed mechanism aims to reduce energy consumption in the system by optimizing the spectrum sensing and channel switching, while...
Content caching is an efficient technique to reduce delivery latency and system congestion during peak-traffic times by bringing data closer to end users. Existing works consider caching only at higher layers separated from physical layer. In this paper, we study wireless caching networks by taking into account cache capability when designing the signal transmission. In particular, we investigate...
This paper presents field experiments on the downlink throughput performance of a 5G centimeter wave radio access system employing higher rank MIMO in a shopping mall environment and a long corridor environment. The shopping mall has complex reflection paths within its non-line-of-sight areas. The long corridor environment exhibits line-of-sight propagation with many reflection paths. The results...
In this paper, we analyze the performance of the fractional pilot reuse (FPR) scheme with vertical sectorization in massive multiple-input multiple-output (MIMO) system. In this scheme, users are classified into the cell-center ones in inner vertical sector and the cell-edge ones in outer vertical sector according to their signal-to-interference-plus- noise ratios (SINRs) at the receiver side. Then,...
In this paper, we analyze the performance of the fractional pilot reuse (FPR) scheme with pilot contamination mitigation in massive multiple-input multiple-output (MIMO) system. In FPR, users are classified into the cell- center and the cell-edge ones according to their signal-to- interference-plus-noise ratios (SINRs) at the receiver side. Then, the cell- edge users with low SINRs in different cells...
Despite the promising benefits of the cloud-radio access network (C-RAN), the fronthaul (FH) imposes stringent requirements in terms of data rate, latency, jitter and synchronisation. In the classical C-RAN, the FH capacity scales linearly with the number of the transmitting antennas, which has posed severe demands on the FH capacity, especially due to emerging 5G technologies such as massive MIMO...
The objective of this paper is to compare uplink (UL) performance with different antenna technologies when receiving Non-Line of Sight (NLOS) signal in field tests. The antenna configurations in use were a passive antenna system and an active antenna system (AAS). The radiation pattern can be controlled horizontally by changing its azimuth angle and vertically by changing the tilt angle of the antenna...
The downlink coverage of a 5G trial system operating within the 15 GHz frequency band is evaluated in this paper with the help of drive test measurements. Key 5G features, such as beamforming, beam tracking and multi-point transmission have been utilized during the measurements. The results indicate that multi-point transmission provides a clear improvement to the downlink coverage. Received signal...
Large-scale MU-MIMO is a promising technology to scale network capacity and the capacity gain grows linearly with the numbers of antennas and users in theory. However, its practical deployment faces three critical challenges in the state-of-the-art WLANs: i) the demand of a large number of expensive RF chains; ii) the linear growth of feedback overheads with the number of antennas; iii) the lack of...
Millimeter-wave (mm-wave) communication is a promising technology for supporting extremely high data rates in the next generation wireless networks. Mm-wave signals experience high path loss and directional transmission is required to compensate the severe channel attenuation. The special characteristics of the mm-wave propagation arise opportunities as well as challenges for the network resource...
Terahertz band communication is envisioned as a key technology to satisfy the increasing demand for ultra-highspeed wireless links. In this paper, a memory-assisted medium access control (MAC) protocol with angular-division-multiplexing (ADM) is proposed for the service discovery and communications in the THz network. In particular, the efficiency balance is achieved by equipping the nodes with (i)...
High throughput satellites have proven to be an excellent solution to provide Internet services to white spots or to complement other existing infrastructures. With the use of multi-beam antennas, the same frequency may be reused dozens of times across a single satellite coverage area, increasing the system capacity and profitability. Legacy frequency reuse patterns such as uncoordinated 4-color scheme...
the internet and data traffic in Indonesia is still expected to grow [5]. As an archipelagic country this will be a demand for satellite broadband. Next generation satellite system needs to have both higher throughput and availability, whilst trying to reduce the cost per Mbps. To fulfill the demands and performance, a multi beam satellite system has to be implemented over the coverage area. The most...
In this paper, we investigate the energy efficient resource allocation problem for the wireless powered OFDMA multi-cell networks. In the considered system, the users who have data to transmit in the uplink are empowered by the wireless power obtained from multiple base stations (BSs) with a large scale of multiple antennas in the downlink. A time division protocol is considered to divide the time...
In this paper, we study the performance of initial access beamforming schemes in the cases with large but finite number of transmit antennas and users. Particularly, we develop an efficient beamforming scheme using genetic algorithms. Moreover, taking the millimeter wave communication characteristics and different metrics into account, we investigate the effect of various parameters such as number...
This paper presents the performance testing of a train to ground communications network deployed in an underground environment and based on IEEE 802.11ac wireless technology. A fully operational pilot project was deployed in Metro de Madrid facilities for studying the feasibility and performance of the solution. Wireless nodes have been installed in the tunnel and onboard the train. During the testing...
This paper describes the design and simulated performance of a 5G-like spectrum sharing radio that uses both Non-Contiguous-Orthogonal Frequency Domain Modulated (NC-OFDM) waveform and an electrically Reconfigurable Alford Loop Antenna (RALA) to efficiently share spectrum with a co-channel IEEE 802.15.4, or ZigBee, radio link. We present a detailed performance analysis of Monte Carlo simulation trials...
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