UDWDM-PON using low-cost coherent transceivers with limited tunability and heuristic DWA

A new Passive Optical Network (PON) for access, making use of Ultra Dense Wavelength Division Multiplexing (UDWDM) by densely spacing channels at few GHz, and introducing the “wavelength-to-the-user” concept, is proposed. The key challenge will be developing low-cost coherent transceivers, providing an excellent selectivity while avoiding filters, and furnishing high sensitivity, which will allow high splitting ratios, large number of users and long distance reach. The Optical Distribution Network (ODN) at the outside plant is based on splitters and kept compatible with legacy systems. Optical Network Unit (ONU) designs realized with coherent transceivers using one or two lasers are presented and the corresponding Optical Line Terminal (OLT) architectures are introduced. The ONUs at customer premises own lasers with limited thermal tunability and their wavelengths are randomly distributed in a band. By using heuristic Dynamic Wavelength Assignment (DWA) schemes and extending the original working band, the required optical band is obtained and optimized. In activation processes, ONU acceptances up to 99.9% are achieved. Furthermore, in operation scenario under indoors and also under outdoors environmental conditions, ONU blocking probabilities below 0.1% and ONU availability ratios (OARs) up to 99.9% are demonstrated. The PON is dimensioned according to the number of deployed users and system reach; moreover, power safety and also fiber nonlinearities constraints are evaluated, illustrating the characteristics of the projected network. Finally, the coexistence with legacy networks is discussed.Peer ReviewedPostprint (author's final draft

Multiuser Communication through Power Talk in DC MicroGrids

Power talk is a novel concept for communication among control units in MicroGrids (MGs), carried out without a dedicated modem, but by using power electronics that interface the common bus. The information is transmitted by modulating the parameters of the primary control, incurring subtle power deviations that can be detected by other units. In this paper, we develop power talk communication strategies for DC MG systems with arbitrary number of control units that carry out all-to-all communication. We investigate two multiple access strategies: 1) TDMA, where only one unit transmits at a time, and 2) full duplex, where all units transmit and receive simultaneously. We introduce the notions of signaling space, where the power talk symbol constellations are constructed, and detection space, where the demodulation of the symbols is performed. The proposed communication technique is challenged by the random changes of the bus parameters due to load variations in the system. To this end, we employ a solution based on training sequences, which re-establishes the signaling and detection spaces and thus enables reliable information exchange. The presented results show that power talk is an effective solution for reliable communication among units in DC MG systems.Comment: Multiuser extension of the power talk concept. Submitted to IEEE JSA

LTE-Advanced - Evolving LTE towards IMT-Advanced

Abstract — This paper provides a high-level overview of some technology components currently considered for the evolution of LTE including complete fulfillment of the IMT-Advanced requirements. These technology components include extended spectrum flexibility, multi-antenna solutions, coordinated multipoint transmission/reception, and the use of advanced repeaters/relaying. A simple performance assessment is also included, indicating potential for significantly increased performance. Keywords-LTE, IMT-Advanced, LTE-Advanced, 4G I

Alternative communication network designs for an operational Plato 4 CAI system

The cost of alternative communications networks for the dissemination of PLATO IV computer-aided instruction (CAI) was studied. Four communication techniques are compared: leased telephone lines, satellite communication, UHF TV, and low-power microwave radio. For each network design, costs per student contact hour are computed. These costs are derived as functions of student population density, a parameter which can be calculated from census data for one potential market for CAI, the public primary and secondary schools. Calculating costs in this way allows one to determine which of the four communications alternatives can serve this market least expensively for any given area in the U.S. The analysis indicates that radio distribution techniques are cost optimum over a wide range of conditions

Artificial Dust Based Attack Modelling: A Threat to the Security of Next Generation WCN

This paper introduces a systematic and novel mechanism for devising a security attack in the WCN (Wireless Communication Network). The proposed model involves the implementation of the AD (Artificial Dust) by the intruder, followed by the execution of the HD (Half-Duplex) attack. The communication network is based on the deployment of urban and rural scenarios with an unknown CSI (Channel State Information). Depending on the achieved path loss based on the distance of the user from the BS, the user with the highest path loss is particularized for the attack. The formulation of AD divulges the increased susceptibilities of the secure network specifically for the selected legitimate user. The parameter of visibility defines the amount of AD present in the communication channel. Based on the enumerated attenuation created by the artificial dust, the parameter of secrecy rate is evaluated with varying distance of the user from the BS and the operating frequency. Furthermore, the proposed scheme of the HD attack is initiated by the intruder at the specified valid user. The strategy of the attack focuses on the continuous monitor of the uplink and attempts the spoofing attack on the downlink wherein the allocation of the resources takes place. The efficacy of the proposed approach is corroborated through the examination of simulation results. The assessment of the proposed mechanism highlights notable characteristics as compared to the conventional methodology of the FD (Full- Duplex) attack

Downlink massive full dimension-multiple input multiple output downlink beamforming analysis at 3.5 GHz using coordinated ON-OFF switching

The long-term evolution and advancement (LTE-A) of the 5G wireless network depends critically on energy consumption. Many existing solutions focus on limiting power constraints and consequently system coverage. So, improving the antenna array elements of the base station (BS) can solve this issue. In this paper, introduce a coordinated ON-OFF switching method in the massive full dimensional multiple input multiple output (massive-FD-MIMO) system. It enhances the radiation pattern of the antenna array element by adjusting the angular power spectra at the BS. By the way, it allows to select the minimum number of antennas for effective beamforming toward specific user equipment’s (UEs). In this context, part of antenna element should be active mode and remining should be sleep mode at the time of signal beamforming. The multipath spatial profiles are decided the beamforming frequency band with minimize energy consumption. As part of the method, we used a conjugated beamforming with power optimization scheme to determine the individual antenna potential and fading channel condition, power optimization is performed. This method quality of service, reliability, energy consumption and data rate can all be evaluated by experimenting with different-sized antenna arrays such as 16×16, 32×32, 64×64 and 128×128

Near-Instantaneously Adaptive HSDPA-Style OFDM Versus MC-CDMA Transceivers for WIFI, WIMAX, and Next-Generation Cellular Systems

Burts-by-burst (BbB) adaptive high-speed downlink packet access (HSDPA) style multicarrier systems are reviewed, identifying their most critical design aspects. These systems exhibit numerous attractive features, rendering them eminently eligible for employment in next-generation wireless systems. It is argued that BbB-adaptive or symbol-by-symbol adaptive orthogonal frequency division multiplex (OFDM) modems counteract the near instantaneous channel quality variations and hence attain an increased throughput or robustness in comparison to their fixed-mode counterparts. Although they act quite differently, various diversity techniques, such as Rake receivers and space-time block coding (STBC) are also capable of mitigating the channel quality variations in their effort to reduce the bit error ratio (BER), provided that the individual antenna elements experience independent fading. By contrast, in the presence of correlated fading imposed by shadowing or time-variant multiuser interference, the benefits of space-time coding erode and it is unrealistic to expect that a fixed-mode space-time coded system remains capable of maintaining a near-constant BER