ALBERT

Description: A common-mode (CM) active filter was designed in a compact package to suppress CM conducted emissions at a switching mode power supply (SMPS). Based on the analytical expressions considering both stability and performance, the design and optimization rules for the proposed active filter have been presented. After verifying its performance by measurements using vector network analysis, the proposed filter was installed in a 200-W SMPS board with 64 and 110 kHz switching frequencies, demonstrating its usefulness by experiments. The performance degradation due to the magnetic saturation and the AEF grounding impedance was also analyzed and investigated.

Description: A kind of low-cost electric and magnetic field simulators, which are used to produce simulative lightning electromagnetic pulse (LEMP) with adjustable waveforms and intensity output, are presented. The lightning electric field can be produced within the GTEM cell by feed-in of impulse voltage output by a Marx generator. The lightning magnetic field can be produced within the coil by feed-in of surge current from the lightning surge generator. The simulated magnetic field is measured by a “B-dot” coil. The measured results show that the lightning electric field simulator and magnetic field simulator could provide relatively homogeneous LEMP environment within certain area in the GTEM cell and the coil within 3 dB deviation. The effects of the simulated lightning electric fields on some electronic devices and the influence of the turns and size of the coil on the homogeneity of the simulated magnetic fields are also investigated.

Description: This paper presents a detailed model of devices utilizing many nanotubes and the coupling between them based on the electromagnetic model of a device using one nanotube. Empirical equations are proposed to link the device conductance with the number of nanotubes per device. Then, a circuit model is developed to predict the effect of the number of nanotubes per device on the overall conductance, capacitance, and the frequency response of the device. A prototype structure is fabricated. Its performance is tested and compared with the proposed model, and it shows promising agreements. The model is flexible and can be integrated with quantum transport models.

Description: A full-wave analysis of the fundamental quasi-TEM modes supported by multiple graphene nanoribbons above a ground plane is presented, aimed at characterizing crosstalk in graphene multiconductor lines. A method-of-moments discretization of the relevant electric-field integral equation is performed. Assuming first a local scalar conductivity, an efficient spatial-domain approach with subsectional basis functions is assuming first a local scalar conductivity, a spatial-domain approach with subsectional basis functions is developed. This allows for the efficient treatment of nanoribbons with wide transverse separations, and can be expanded to include in the simulation model spatial nonuniformity of the graphene conductivity. This spatial-domain formulation is then extended to treat the case of weakly nonlocal conductivity, via an original integro-differential approach derived by approximating a recent full spectral graphene conductivity model in the limit of low wavenumbers. Numerical results are provided for propagation constants and characteristic impedances of two identical coupled graphene nanoribbons; on this basis, a crosstalk analysis is performed by means of the modal decomposition method.

Description: Crosstalk within cable bundles can degrade system performance. In aircraft systems that use shielded twisted pairs, the crosstalk occurs primarily in the connector where individual signal wires are not shielded or twisted. In many cases, the parameters which determine crosstalk within the connector are unknown because the connector is closed and wires cannot be easily accessed. Expanding on prior research [14] , a methodology for measuring coupling parameters and modeling crosstalk within aircraft cable connectors at low frequencies (〈400 MHz) was developed. The values of mutual inductance and capacitance were extracted from measurements made with a vector network analyzer (VNA). The characteristics of the individual wires were extracted from VNA-measured TDR response. The accuracy of the model was evaluated through comparison of simulated and measured results. Additionally, a closed-form solution was developed to estimate the worst-case envelope of the differential crosstalk. The calculated results match the measured peak values well. This worst-case crosstalk estimate allows effective evaluation of the impact of crosstalk within different connectors. The developed method can be effective for analyzing complex aircraft cable assemblies and connectors without requiring extensive knowledge of the assembly procedure.

Description: Surface roughness topography of printed circuit boards (PCBs) needs to be included in signal integrity simulations in order to accurately predict the insertion loss of the structure and its delay time. An effective roughness dielectric (ERD) model can be used to substitute an inhomogeneous interface between copper foil and laminate dielectric in a PCB. Herein, this approach is tested for verification using 3-D full-wave numerical simulations. These ERD layers with the appropriate complex permittivity are included in the modeling of stripline examples. The parameters of an ambient laminate dielectric refined from conductor roughness in the stripline are determined using differential extrapolation roughness measurement technique. The agreement of the results of 3-D full-wave modeling simulations and measurements on multiple test structures justifies the proposed approach. Based on the extracted ERD parameters “design curves” can be built and used in numerical simulations of PCB high-speed designs.

Description: A small amount of jitter can quickly eat up timing budgets and create timing issues. Precise characterization of deterministic and crosstalk-induced jitter can help isolate and solve issues within high-speed links. Characterizing deterministic and crosstalk-induced jitter is challenging, however, because many types of jitter work together to create the overall jitter profile. Methods are presented in this paper to characterize the deterministic and crosstalk-induced jitter from measurements of total jitter. An improved tail-fit deconvolution method is proposed for characterizing the impact of deterministic jitter in the presence of random jitter. The contribution of random jitter to total jitter is found first, and then that contribution is accounted for to find deterministic jitter. A Wiener filter deconvolution method is also presented for extracting the characteristics of crosstalk-induced jitter from measurements of total jitter made when the crosstalk sources were and were not present. The Wiener filter allows for accurate deconvolution of the measured histograms for total jitter even in the presence of the measurement noise. The proposed techniques are shown to work well both in simulations and in measurements of a high-speed link.

Description: This paper explored the possibility of building channel emulators by utilizing fused deposition modeling (FDM) three-dimensional (3-D) printing technology. The FDM 3-D printing provides a rapid and economic method to produce parts with different shapes. An optimizing algorithm was developed for obtaining the printing pattern and loss profile. Parts with different dielectric constants and loss tangents can be printed. Those parts will be placed or directly printed on a low-loss transmission line to modify its transmission or reflection. As a result, different channel emulators can be built to emulate the S -parameter and eye diagrams of a target channel with the advantage of avoiding complicated electronic components and only being limited in the frequency range by the transmission line and attached connectors.

Description: In this paper, we present general considerations for the application of the multiconductor transmission-line theory for simulating shielded spacecraft harness cable assemblies. Some of the practical issues that occur in the modeling process of various components of cable assemblies in spacecraft applications, namely connectors, pigtails, and backshells are discussed. The overall transfer impedance of the assembly measured through a current injection with a pseudomicrostrip line is used as a figure of merit to evaluate the total shielding provided by the harness. Some of the parameters of the model were available from the manufacturers’ datasheets, while others were determined either experimentally or empirically. The position of the cables along the cross section was randomly assigned by the simulation tool. In general, the obtained simulation results are found to be in reasonable agreement with the experimental data. It is found that the generally overlooked contact impedances between the cable shields and connectors play a significant role, especially at low frequencies. The presented simulation results also emphasize the importance of the inductance and resistance of the connector backshell interconnection to the spacecraft chassis.

Description: Encryptions are used in almost all standards to ensure the confidentiality of the data. Encryptions can be and indeed are implemented in the different layers of a network protocol stack. Conventional encryption performs the bitwise XOR operation between one message bit and one key stream bit to generate one ciphertext bit. Huo et al. have recently proposed to provide confidentialities on the user data by performing the phase encryption on the time domain OFDM samples in LTE system. Phase encryption is performed on the modulated symbols, different from the bit level of XOR encryption, i.e., stream cipher encryption. In this paper, we extend their study. We first generalize the phase encryption to general communication systems independent of the underlying modulation scheme. Then, we formulate the mathematical models for XOR and phase encryptions. Based on our model, we compare these two encryption methods in terms of their security and encryption efficiency. We also show phase encryption can resist traffic analysis attack when implemented in the physical layer. Finally, we conduct simulations to compare the performance of these two methods in terms of their decoding symbol error rate.

Description: In this paper, an adaptive hierarchical sparse grid collocation (ASGC) method combined with the discontinuous Galerkin time-domain method is leveraged to quantify the impacts of random parameters on the electromagnetics systems. The ASGC method approximates the stochastic observables of interest using interpolation functions over a set of collocation points determined by the Smolyak's algorithm integrated with an adaptive strategy. Instead of resorting to a full-tensor product sense, the Smolyak's algorithm constructs the collocation points in a hierarchical scheme with the interpolation level. Enhanced by an adaptive strategy, the Smolyak's algorithm will sample more points along important dimensions with sharp variations or discontinuities, resulting in a nonuniform sampling scheme. To flexibly handle different stochastic systems, either piecewise linear or Lagrange polynomial basis functions are applied. With these strategies, the number of collocation points is significantly reduced. The statistical knowledge of stochastic observables including the expected value, variance, probability density function, and cumulative distribution function are presented. The accuracy and robustness of the algorithm are demonstrated by various examples.

Description: Signal integrity (SI) analysis based on state-of-the-art measurements can be difficult to perform especially when the structures of interest are on inner layers of multilayer boards or are enclosed by IC packages. To enable an SI analysis in such cases the authors have recently developed a method that is based on the extraction of accurate simulation models from computed tomography (CT) scans. These models can be used in electromagnetic (EM) field simulators for computer-aided SI analyses. Such CT-based models include geometry variations or defects due to the manufacturing process so that computed EM field simulation results have a good correlation with common measurements. In order to identify the potential of the method an analysis of the required voxel resolution for the extraction of single-ended and differential striplines is presented. The analysis is based on the measurement uncertainty of length measurements in CT scans and an analysis of the propagation of uncertainty for the characteristic impedances of single-ended and differential striplines. This analysis shows that the voxel resolution of industrial CT scans is well suited for the extraction of accurate simulation models which can be used for an SI analysis.

Description: In the millimeter wave (mmW) frequency range, the root mean square height of the through silicon via (TSV) sidewall roughness is comparable to the skin depth, and hence, becomes a critical factor for TSV modeling and analysis. In this paper, the impact of the TSV sidewall roughness on electrical performance, such as the loss and impedance alteration in the mmW frequency range, is examined and analyzed. The second-order small analytical perturbation method is applied to obtain a simple closed-form expression for the power absorption enhancement factor of the TSV. In this study, we propose an electrical model of the TSV, which considers the TSV sidewall roughness effect, the skin effect, and the metal oxide semiconductor effect. The parameters of the proposed circuit model can be determined analytically; the accuracy of the model is validated through a comparison of circuit model behavior for full wave electromagnetic field simulations up to 100 GHz.

Description: The following is included in this newsletter: IEEE Young Professionals, Lahore Section Win World Class Award "Hall of Fame 2015"; Distinguished Lecturer Tour of Nei Kato in China, May 2015; Distinguished Lecturer Tour of Tom Hou to Beijing and Nanjing, China; European Wireless 2015 in Budapest; Novel In-Band Full-Duplex Communication Prototype for 5G Systems, Finland, May 2015

Description: Wireless vehicular networks offer the promise of connectivity to vehicles that could provide a myriad of safety and driving-enhancing services to drivers and passengers. With wireless technology available in each car, it is expected that huge amounts of information will be exchanged between vehicles or between vehicles and roadside infrastructure. Due to defective sensors, software viruses, or even malicious intent, legitimate vehicles might inject untrustworthy information into the network. Besides relying on the public key infrastructure, this article proposes a social network approach to study trustworthy information sharing in a vehicular network. We first cover recent research progress in measuring direct trust and modeling indirect trust in online social networks, and then discuss how to apply them to vehicular social networks despite several pressing research challenges.

Description: Presents the front cover for this issue of the publication.

Description: The mobile crowdsourcing network (MCN) is a promising network architecture that applies the principles of crowdsourcing to perform tasks with human involvement and powerful mobile devices. However, it also raises some critical security and privacy issues that impede the application of MCNs. In this article, in order to better understand these critical security and privacy challenges, we first propose a general architecture for a mobile crowdsourcing network comprising both crowdsourcing sensing and crowdsourcing computing. After that, we set forth several critical security and privacy challenges that essentially capture the characteristics of MCNs. We also formulate some research problems leading to possible research directions. We expect this work will bring more attention to further investigation on security and privacy solutions for mobile crowdsourcing networks.

Description: Presents the ComSoc conference calendar of events.

Description: Energy harvesting technologies have gained widespread attention for their perpetual energy supply for sensor nodes. However, the energy resources are still insufficient while the harvesting module is added on the node. To prolong the network lifetime and meet the demand of a green wireless network, a dynamic gradient-aware hierarchical packet forwarding mechanism is designed. According to the relative positions of nodes, gradient-aware clusters are established. Consequently, considering the energy conversion efficiency and relative distance, cluster heads are selected reasonably. Furthermore, by exploiting the available energy and the number of cluster members, packets can be forwarded to the sink in an energy-efficient manner. Results show that the network lifetime can be noticeably improved.

Description: Recently, there has been substantial research interest in the subject of simultaneous wireless information and power transfer (SWIPT) due to its cross-disciplinary appeal and its wide-ranging application potential, which motivates this overview. More explicitly, we provide a brief survey of the state of the art and introduce several practical transceiver architectures that may facilitate its implementation. Moreover, the most important link-level as well as system-level design aspects are elaborated on, along with a variety of potential solutions and research ideas. We envision that the dual interpretation of RF signals creates new opportunities as well as challenges requiring substantial research, innovation and engineering efforts.

Description: The emerging trends of 2014 have continued to dominate the developments in the first half of 2015: 1. The packet optical transport system (P-OTS) concept supports the service provider goal to build a common network infrastructure by integrating Ethernet, IP/MPLS, and DWDM 2. There has been intensifying focus and attention on network functions virtualization (NFV) and softwaredefined networking (SDN) to provide service providers with the tools for more effective operation and management of communications networks in general, and optical communications networks in particular.

Description: In June 2015, the ComSoc Board of Governors approved a revision of ComSoc Constitution. The IEEE approved the revision in July 2015, and ComSoc Membership approval is currently pending.

Description: Power radiation and radiated coupling among different structures represent an important area for research study. The partial element equivalent circuit method (PEEC) is a powerful technique which bridges the gap between the electromagnetic and circuit theories. In this paper, we develop a new approach for PEEC to calculate the distributive power radiation and couplings. With this approach, formulations for both the radiated power and the transferred power can be evaluated. Further, the physical meanings of the power results are interpreted according to the conservation of energy law. We use electric dipoles, magnetic dipoles and patch antennas as well as coupled microstrip lines to benchmark the method. The approach can also be applied to EMC/EMI and other power dissipation computations.

Description: The coupling from electrostatic discharge (ESD) events is effectively calculated using the partial element equivalent circuit (PEEC) method, both in time and frequency domains. The PEEC method has several advantages in predicting dominant coupling sources and waveforms of ESD. Two victim structures were designed so that the inductive or capacitive coupling could be dominant. The calculation of ESD coupling is validated by comparison with measurements and the finite-element method solver in frequency domain. The waveform of the ESD inductive coupling is also validated with measurements and the finite-difference time domain solver in time domain.

Description: Time-domain channel characterization (TCC) for de-embedding of an asymmetric fixture is introduced. Two design criteria for the design of a 2x-thru are proposed. Error sensitivity regarding a small error in the S-parameters of the 1x-fixture is analyzed with an insertion loss error-coefficient and a return loss error-coefficient. The TCC procedure, including proposed design criteria and error sensitivity, is also introduced to reduce the error in the TCC application. Three different 2x-thru structures are investigated for the verification of the two proposed design criteria and analyzed for error sensitivity. Test fixtures on a printed circuit boards are fabricated for the experimental verification.

Description: A circuit model of multilayer electromagnetic bandgap (EBG) structure with application on bandgap aggregation design is investigated in this paper. A design concept for bandgap aggregation is merging the lowest two bandgaps into an equivalent wide bandgap by narrowing central passband. This goal could be achieved by optimizing pitch and arrangement of power/ground vias. The theoretical circuit model which only focuses on cutoff frequencies is proposed for efficient bandgap prediction. The accuracy of the proposed model is validated by comparison with full-wave simulation and measurement results. By using the circuit model, mechanism of bandgap aggregation can be explained well, and the influence of structural parameters can also be studied easily. Furthermore, effect on limiting excitation of propagation modes by narrowing central passband is also validated for merging adjacent bandgaps. Test boards with unit cell size 2.03 mm × 3.94 mm are fabricated and measured to validate the design concepts. Both simulation and measurement show the wide bandgap in insertion loss results, which ranges from 1.27 GHz to above 10 GHz by merging even higher bandgaps.

Description: The result of any measurement will only be of significance if the uncertainty of the measurement method can be specified concerning its influence quantities. In the case of CISPR compliant-radiated disturbance measurements, the result of the measurement is usually compared to a given limit line. For established test methods (ETM), this comparison can be done directly if the expanded measurement uncertainty falls below a value stated for a typical test facility by the standard. In this paper, the definitions and the classification the CISPR describes for ETM are applied to transverse electromagnetic (TEM) waveguide measurements. It is shown that the overall uncertainty of a typical TEM waveguide is slightly lower than that of a typical ETM.

Description: A new common-mode filter structure based on planar electromagnetic bandgap (EBG) technologies is designed, fabricated, and measured. It is based on a previously proposed geometry, implementing a sequence of two or more EBGs resonating at a filtering frequency; however, the new filter is placed on the top of the PCB as a standalone component, instead of being included within the PCB stack up. The filter can be easily removed and substituted by another one that is designed to filter a different frequency. The replacement design should maintain the same external size of the component as the original filter, which can be achieved by choosing the permittivity of the dielectric as well as the relationship among the EBG parameters appropriately. The electromagnetic behavior of the filter is simulated and a prototype structure is fabricated and measured. Results are compared to validate the design concept and procedure.

Description: Effects of transmit jitter on lossy clock channel are analyzed analytically by treating the 1010 input clock signal as a sinusoidal wave with a phase modulation that represents jitter. Jitter-to-amplitude-modulation transfer functions are derived for sinusoidal jitter, duty-cycle distortion (DCD), and random jitter (RJ) in terms of the signal transfer function or S-parameters. Input jitter is shown to induce amplitude modulation in the output signal as a result of channel dispersion, leading to voltage noise at the channel output. DCD- and RJ-induced voltage noises are found to scale uniquely with channel loss. To verify the theory, numerical simulations are performed on channels with different losses and at various data rates. The input clock signal is represented with a square wave, and the output signal is calculated by linear superposition of the channel step response. Theoretical and simulation results are found to be in excellent agreement.

Description: The jitter probability density function (PDF) at multistage output buffers due to supply voltage fluctuations is analytically derived. For experimental validation, an integrated circuit (IC) is designed, fabricated, and assembled in a printed circuit board (PCB). The on-chip supply voltage fluctuations are extracted from the simultaneous measurements at the pads on IC and PCB and used to calculate the jitter PDF of the multistage buffers. Also, characteristics of the output channels are measured and modeled with the separately designed channel pattern. Finally, the jitter PDFs for multistage buffers are calculated and compared with the measured jitter histograms.

Description: Presents the President's message for this issue of the publication.

Description: As cloud-assisted WBSNs have become increasingly popular in healthcare applications, security and privacy threats deserve much more attention. In this article, focusing on data privacy and data completeness issues, we propose a VPAA scheme for cloud-assisted WBSNs. Through both simulation and prototype implementation, we confirm that VPAA is energy-efficient and effective in protecting data privacy and completeness.

Description: We review several node architectures for optical slot switching ring networks, which can be used in metropolitan or datacenter applications, and compare them for their networking aspects. The dimensioning, quality of service, latency, and protection issues are discussed for the different approaches. The main devices, i.e. fast wavelength-tunable laser, burst-mode coherent receiver (which is required to enable high data rate transmission at 100 Gb/s and above), and a slot blocker for improved wavelength usage efficiency are described, and available technologies for each key building block are reviewed.

Description: Data center interconnection with elastic optical networks is a promising scenario to meet the high burstiness and high-bandwidth requirements of services. Many data center services require lower delay and higher availability with end-to-end guaranteed QoS, which involves both application and transport network resources. However, in the current mode of operation, the control of elastic optical networks and data centers is separately deployed. Enabling even limited interworking among these separated control systems requires the adoption of complex and inelastic interfaces among the various networks, and this solution is not efficient enough to provide the required QoS. In this article, we present a novel cross stratum optimization (CSO) architecture in elastic data center optical interconnection. The proposed architecture can allow global optimization and control across elastic optical transport network and data center application stratum heterogeneous resources to meet the QoS requirement with the objective of optical as a service (OaaS). The functional modules of CSO architecture, including the core elements of application and transport controllers, are described in detail. The cooperation procedure in CSO-based service provisioning and cross stratum service resilience modes is investigated. The overall feasibility and efficiency of the proposed architecture is also experimentally demonstrated on our OaaS testbed with four OpenFlow-enabled elastic optical nodes, and compared to MFA, ALB, and CSO-DGLB service provisioning schemes in terms of path setup/release/adjustment latency, blocking probability, and resource occupation rate. Numerical results are given and analyzed based on the testbed. Some future discussion and exploration issues are presented in the conclusion.

Description: Unlike most general wireless users enjoying broadband access to the Internet and so on, a number of mission-critical applications such as PPDR are using narrowband systems that are only capable of transmitting voice and low-rate data. Broadband wireless networks with greater reliability are increasingly demanded by these applications including the emerging Smart Grid. With this vision, the IEEE 802.16 Working Group completed two standard amendments recently, IEEE Std 802.16n-2013 and IEEE Std 802.16.1a-2013. 802.16 network reliability is significantly increased by technical developments dealing with failures of network infrastructure stations, radio path and backhaul connectivity, and so on. This article serves to analyze the envisaged typical use cases of greater reliable broadband wireless networks, outline the main technical developments of the two standards, and introduce a recently developed practical system for PPDR applications in Japan.

Description: The continuously increasing consumption of power to access the Internet has been a major concern for network operators and equipment vendors. Passive optical network (PON) systems are widely seen as the future of broadband access. In 2010, ITU-T standardized a protocol-based PON energy efficiency mechanism that is comprised of two main modes, the doze mode and the cyclic sleep mode, which promise to save significant amounts of energy. However, the use of these two standardized alternative modes requires extra signaling and wastes energy. In this article we present the watchful sleep mode, a new mode that unifies the doze and cyclic sleep modes into a single power management mode. The new mode eliminates the extra control signaling and maximizes the amount of energy saved by keeping only the necessary hardware ON. Recently, the watchful sleep mode has been included in the ITU-T G.984 (G-PON) and ITUT G.987 (XG-PON) recommendations. It is expected to be operated as the only power management mode in future PON systems.

Description: Over the last decade, energy harvesting has emerged as a promising approach to enable self-sufficient and self-sustaining operation for devices in energy-constrained networks by scavenging energy from the ambient environment to power up devices.

Description: The city of Trento, the educational, scientific, financial and political centre of Northern Italy, served as the ideal launching point for the first IEEE Communications Society (ComSoc) Summer School. With a population of more than 100,000 residing in this noted university city, Trento is recognized throughout the country for its high quality of life, prosperous business opportunities, advanced research centers and renowned international cultural institutions. It also boasts a rich heritage of cultural and social lifestyles; enriched international conferences, meetings and exhibitions; traditional costume festivals and market fares; historical events; and global festivals highlighted with theatre, music and dance.

Description: Energy harvesting technology has become a promising solution to enhance the energy efficiency and reduce carbon emissions in future wireless systems. In future wireless systems, most of the data throughput will come from delay-sensitive applications. To ensure a good experience for an end user, we target the optimization of the delay performance of an EH wireless system with finite energy storage. As such, it is necessary to adapt the resource allocation to the channel fading information, data queue length, and energy queue length information. The channel fading information provides the channel quality, the data queue length information provides the dynamic urgency of the transmitted data flows, and the energy queue length information provides the information on how much available energy is left in the energy buffer. Such a problem is quite challenging because it belongs to an infinite dimensional stochastic optimization. In this article, we review the existing works on the resource allocation problem in EH wireless systems. We also propose a low-complexity delay-sensitive resource control scheme and discuss valuable design insights.

Description: The concept of energy harvesting cooperative networks is an emerging technology that has very high potential for a large variety of applications. However, energy transfer capability may lead to unprecedented security challenges. In this article, we study energy security issues and the solutions in energy harvesting networks. We first identify typical energy related attacks and then propose defense solutions against these attacks. We also carry out security analysis and performance analysis to evaluate our proposed solutions. Simulation results have shown that the proposed defense solutions are effective and efficient.

Description: Information-centric networking (ICN) is an emerging networking paradigm that places content identifiers rather than host identifiers at the core of the mechanisms and protocols used to deliver content to end users. Such a paradigm allows routers enhanced with content-awareness to play a direct role in the routing and resolution of content requests from users, without any knowledge of the specific locations of hosted content. However, to facilitate good network traffic engineering and satisfactory user QoS, content routers need to exchange advanced network knowledge to assist them with their resolution decisions. In order to maintain the location-independency tenet of ICNs, such knowledge (known as context information) needs to be independent of the locations of servers. To this end, we propose CAINE — Context-Aware Information-centric Network Ecosystem — which enables context-based operations to be intrinsically supported by the underlying ICN routing and resolution functions. Our approach has been designed to maintain the location-independence philosophy of ICNs by associating context information directly to content rather than to the physical entities such as servers and network elements in the content ecosystem, while ensuring scalability. Through simulation, we show that based on such location-independent context information, CAINE is able to facilitate traffic engineering in the network, while not posing a significant control signalling burden on the network.

Description: The growing popularity of cloud and multimedia services is dramatically increasing the traffic volume that each data center needs to handle. This is driving the demand for highly scalable, flexible, and energy-efficient networks inside data centers, in particular for the edge tier, which requires a large number of interconnects and consumes the dominant part of the overall power. Optical fiber communication is widely recognized as the highest energy- and cost-efficient technique to offer ultra-large capacity for telecommunication networks. It has also been considered as a promising transmission technology for future data center applications. Taking into account the characteristics of the traffic generated by the servers, such as locality, multicast, dynamicity, and burstiness, the emphasis of the research on data center networks has to be put on architectures that leverage optical transport to the greatest possible extent. However, no feasible solution based on optical switching is available so far for handling the data center traffic at the edge tier. Therefore, apart from conventional optical switching, we investigate a completely different paradigm, passive optical interconnects, and aim to explore the possibility for optical interconnects at the top of the rack. In this article, we present three major types of passive optical interconnects and carry out a performance assessment with respect to the ability to host data center traffic, scalability, optical power budget, complexity of the required interface, cost, and energy consumption. Our results have verified that the investigated passive optical interconnects can achieve a significant reduction of power consumption and maintain cost at a similar level compared to its electronic counterpart. Furthermore, several research directions on passive optical interconnects have been pointed out for future green data centers.

Description: Space information networks were proposed to broaden the observation area and realize continuous information acquisition using satellites and high altitude platform stations. Space information networks are able to enhance detection and transmission capabilities compared to the current single Earth observation satellite. Although lots of technical work has been done concerning the space network architecture and protocols, the security issues have not been investigated well. In this article, we focus on the security problems in space information networks from four perspectives, that is, secure handoff, secure transmission control, key management, and secure routing. Existing works, together with their challenges and open problems, are discussed, and our proposed scheme is introduced. Overall, this article aims to help readers understand the motivation, problem formulation, and solutions regarding security issues on space information networks.

Description: This article addresses the use of REMs to support interference management optimization in heterogeneous networks composed of cells of different sizes and including both cellular and non-cellular (e.g. WiFi) technologies. After presenting a general architecture for including REM databases in different network entities, the article analyzes the achievable benefits in relation to specific interference management techniques, including a discussion on practical considerations such as information exchange requirements, REM ownership, and security aspects. Finally, several research directions derived from the proposed framework are identified.

Description: Presents the index of advertisers in this issue of the publication.

Description: Knowledge of end-to-end network distances is essential to many service-oriented applications such as distributed content delivery and overlay network multicast, in which the clients have the flexibility to select their servers from among a set of available ones based on network distance. However, due to the high cost of global measurements in large-scale networks, it is infeasible to actively probe end-to-end network distances for all pairs. In order to address this issue, network distance prediction has been proposed by measuring a few pairs and then predicting the other ones without direct measurements, or splicing the path segments between each pair via observation. It is considered important to improve network performance, and enables service- oriented applications over large-scale networks. In this article, we first illustrate the basic ideas behind network distance prediction, and then categorize the current research work based on different criteria. We illustrate how different protocols work, and discuss their merits and drawbacks. Finally, we summarize our findings, and point out potential issues and future directions for further research.

Description: The analysis of electromagnetic coupling in nonlinear circuit simulations requires a bidirectional, fully consistent approach. Nonlinear responses of semiconductor devices in electronic circuit components can change the impedances seen at circuit nodes, changing the boundary conditions encountered by impressed electromagnetic fields and, thus, changing the characteristics of the energy coupled from these external fields into that circuit. It is important to include the coupling in the circuit simulation self-consistently because this allows us to accurately predict the responses to various EMI/EMC problems of interest. It is also important to predict circuit responses efficiently because that opens the door to statistical applications for the technique being used. In this paper, we review a technique that we have developed called A Thevenin Equivalent Network Approach. This approach is shown to be quite robust in that it is computationally efficient; it can be implemented in a variety of commonly available circuit solving codes; it already includes a few additional techniques required to enhance its implementation in those codes; and it is quite accurate.

Description: This paper presents a novel approach to minimize the radio frequency (RF)-induced heating from external fixation devices under magnetic resonance imaging (MRI) procedure. With proper placement and selection of absorption material, one can alter the electromagnetic field and current distributions around and/or on medical devices so that the MRI RF field-induced heating can be reduced. The absorption-material-based RF heating reduction schemes are analyzed and validated. Numerical and experimental studies are conducted to illustrate the potentials of reducing the RF heating for external fixation devices. A design strategy based on response surface methodology is presented for material selection, and it is shown that absorption materials can significantly reduce the RF heating effects from 645 to 172 W/kg in terms of 1-g spatial-averaged SAR for the device under this investigation.

Description: In this paper, two models for the calculation of geomagnetically induced electric fields near the shoreline are compared. The first is an analytic model which requires the solution of an integral equation at each frequency, and the second is a simplified model that only requires Fourier transforms. The mechanism responsible for the differing results is determined, and it is suggested that one of the features of the analytic model should be included in the simplified model. This modification can be made without reducing the computational advantages of the second model. We also show the relative effect of the shoreline enhancement on the voltage impressed on cables for two different ground conductivities.

Description: For radiation source locating above a ground plane, its far field can be predicted by only the magnetic near field through the method proposed in this paper. This method applies the finite element method to get the equivalent current sources from the tangential magnetic near fields. With the equivalent current sources, the far-field radiation can be calculated based on Huygens's principle and image theory. The magnetic near field is scanned on a Huygens's surface that encloses the source with its ground. In this paper, this Huygens's surface was first proposed as a five-surface cube on the ground. Then, the Huygens's surface was further simplified by using four lines instead of four side walls to make the proposed method easier in regards to practical near-field scanning. Several numerical examples were tested to validate the proposed method. In addition, the proposed method was validated experimentally by using a patch antenna. The performance of using only the top plane near fields was also investigated and discussed. By using only the magnetic near fields on the simplified Huygens's surface, the proposed method significantly saves measurement time and cost while also retaining good far-field prediction.

Description: The difference of the partial self-inductance of a single conductor is determined between two extremes of the frequency range: at dc and at HF (infinite frequency). They are first calculated separately for a finite large length. Both contain the same logarithm(length) singularity, but this disappears in their difference, which only involves the logarithm of the ratio of the equivalent radius and the geometrical mean distance. We have applied this to some common conductor cross sections: circle, ellipse, rectangle, and diamond and to the limit of zero thickness of these cross sections. In the latter case, a general expression is derived.

Description: In a power inverter configuration with pull-up and pull-down transistors, ringing that occurs on the high-to-low and low-to-high transitions can be used to track aging or degradation of the transistors and potentially predict failures. Changes in a transistor's equivalent resistance and capacitance can affect the frequency and damping factor of the characteristic ringing detected on the inverter's output. In this paper, the matrix pencil method is used to locate the poles associated with this ringing, and detect shifts in position that indicate transistor degradation.

Description: In this paper, a quick and efficient approach is proposed to estimate in vivo RF-induced heating from small medical implants under MRI procedure. An efficient methodology is developed to correlate the incident electric field to the induced temperature rise for stents of arbitrary shapes. A 10-cm-long titanium rod and a 6-cm-long intestine stent are used as examples to validate the approach under in vitro testing conditions. In vivo temperature rise estimations are then performed on an anatomically corrected adult male model. Numerical and experimental studies demonstrate the efficiency and accuracy of the proposed method.

Description: As the ESD stress is becoming more and more important for integrated circuits (ICs), the ability to predict IC failures becomes critical. In this paper, an 18-MHz D flip-flop IC is characterized and its behavioral model is presented. The resulting IC model is validated in the setup according to the ISO 10605 standard. A complete model of the setup combining the IC behavioral model and the passive parts of the setup, including parallel and twisted pair harnesses, is built to estimate the failure prediction accuracy in a totally simulated environment. The results show that the model can predict the failure level with the error of less than 20% in parallel harness case and around 30% in the twisted pair case.

Description: A hybrid approach is proposed to signal integrity analysis of trace and vias in plate pair with an infinitely large dimension. By using the domain decomposition method, trace domain and via domain are divided from the plate domain. Each individual domain of via and trace structure is modeled by the 3-D full-wave tool HFSS as a multimode network composed of TEM mode waveguide ports at top/bottom antipad interfaces and vertical lumped ports on the segmentation interfaces. The plate domain is dominated by TM Z0 modes and network parameters are solved by boundary integral method. Connection of network of each domain enforces the field continuity conditions along the segmentation interfaces and yields the final S parameter of trace and via as well as trace/via to trace/via coupling. Once the via pattern and trace routing are determined, the coupling can be efficiently modeled by the proposed hybrid approach and the layouts of via structures and trace routing in a plate pair are efficiently optimized.

Description: A fully operational 4G long-term evolution (LTE) base station is tested in a reverberation chamber to analyze its performance in the presence of a multipath environment, typical of wireless and vehicular communications. Transmission quality parameters are measured ranging from the empty chamber situation (very rich multipath channel) to a very high loading condition to mitigate multipath. In that way, both outdoor and indoor propagation are accounted for. A large attenuation is inserted between the transmitter and the antenna to reduce the signal received by the user to real-life values encountered in both outdoor and indoor environments. In these scenarios, operators may choose to transmit a constant power spectral density throughout all LTE spectrum, or to increase the energy of control channels at the expense of data channels in order to enforce transmission and provide better quality to the user, especially in poor radio conditions. This is called “power boosting,” and its effect is analyzed in this paper.

Description: Cage connectors for optical subassembly I/O modules have been identified as one of the main coupling paths in an optical link at the front-end of switches and routers. In the study presented herein, the simulation model used to study electromagnetic interference coupling physics and mitigation of the optical cage connector was corroborated by comparing the measured and simulated results for the total radiated power (TRP). Currents on the adjacent ground references to the differential signal conductors caused half-wave resonant peaks in the TRP response in the frequency range of 4–18 GHz. At frequencies from 18 to 28 GHz, both full-wave simulation and analytical formulas indicate that the radiation results primarily from the currents on the signal traces. The radiation from the optical cage connector was suppressed with absorbing materials, and the coupling path was verified, together with the optical cage and module enclosure.

Description: Electromagnetic radiation at a production printed circuit board (PCB) midplane connector is studied in this paper. A highly detailed simulation model is constructed and corroborated by comparing measured and simulated results, for both mixed-mode S-parameters and total radiated power, which is measured in a reverberation chamber and over-the-air anechoic chamber. The radiation loss in the production connector is a small fraction of the total loss. Common-mode antenna current is used to understand the radiation physics.

Description: The advanced fifth generation (5G) infrastructure is expected to become the ???nervous system??? of the digital society, digital economy, and silver economy. New service paradigms such as ???immersive experience??? and ???anything as a service??? (XaaS) everywhere are envisioned as among the primary drivers for global adoption and market uptake of new 5G technology components. Above all, 5G networks will support mission-critical machine communications and massive machine type of traffic. As a result, the key performance metrics that 5G is expected to improve are in terms of, but not limited to, latency, reliability, capacity, and spectrum and network agility. This calls for a complete rethinking of all functional domains, including access stratum (AS), non-access stratum (NAS), and transport network layer (TNL), in terms of protocols and procedures. New emerging technologies, such as software defined networking (SDN), network functions virtualization (NFV), mobile edge computing (MEC), and high-performance computing (HPC), provide momentum for new design principles toward software (service) defined 5G networks, targeting a software defined air interface (SDAI) for available bands (spectrum); sliced "networks on demand" for multiple industries, especially for vertical markets (new architecture); and flexibility and spectral efficiency for mobile broadband and machine type communications (new air interface).

Description: In this article, we present a real-time full duplex radio system for 5G wireless networks. Full duplex radios are capable of opening new possibilities in contexts of high traffic demand where there are limited radio resources. A critical issue, however, in implementing full duplex radios in real wireless environments is being able to cancel self-interference. To overcome the selfinterference challenge, we prototype our design on a software-defined radio platform. This design combines a dual-polarization antenna-based analog part with a digital self-interference canceler that operates in real time. Prototype test results confirm that the proposed full duplex system achieves about 1.9 times higher throughput than a half duplex system. This article concludes with a discussion of implementation challenges that remain for researchers seeking the most viable solution for full duplex communications.

Description: The Internet of Things (IoT) is the result of many different enabling technologies such as embedded systems, wireless sensor networks, cloud computing, big-data, etc., which are used to gather, process, infer, and transmit data. Combining all these technologies requires a research effort to address all the challenges of these technologies, especially for sensing and delivering information from the physical world to cloud-hosted services. In this article we outline the most important issues related to standardization efforts, mobility of objects, networking and gateway access, and QoS support. In particular, we describe a novel IoT network architecture that integrates software defined networking (SDN) and data distribution service (DDS) middleware. The proposed architecture will improve service delivery of IoT systems and will bring flexibility to the network.

Description: As one of the fastest growing technologies, machine-to-machine (M2M) communications are expected to provide ubiquitous connectivity. M2M devices can be used for a wide range of emerging applications that have various communications requirements. While M2M communications have been developed for many years, major challenges still remain with their efficient implementation from the perspective of low energy consumption and wide coverage. To address these challenges, low power wide area (LPWA) technology is investigated as one of the potential candidate solutions. In this article, we first introduce some typical LPWA M2M application scenarios. Given their requirements, we highlight key techniques and standards that are explicitly designed for LPWA M2M communications. Finally, we present an LPWA prototype system to evaluate its performance and demonstrate its potential in bridging a technological gap for future Internet-of-Things (IoT) applications.

Description: The introduction of smart electricity meters with cellular radio interfaces has placed an additional load on wireless cellular networks. Currently, these meters are designed for low duty cycle billing and occasional system check, which generates low-rate sporadic traffic. As the number of distributed energy resources increases, household power will become more variable and thus unpredictable from the viewpoint of the distribution system operator (DSO). Therefore, it is expected that in the near future there will be an increase in the number of wide area measurement system (WAMS) devices with phasor measurement unit (PMU)-like capabilities in the distribution grid, thus allowing utilities to monitor the low voltage grid quality while providing information required for tighter grid control. From a communication standpoint, the traffic profile will change drastically toward higher data volumes and higher rates per device. In this paper we characterize the current traffic generated by smart electricity meters, and we discuss the potential traffic requirements resulting from the introduction of enhanced smart meters, i.e. meters with PMUlike capabilities. Our study shows how GSM/ GPRS and LTE cellular system performance behaves with current generation and next generation smart meter traffic, where it is clearly seen that the PMU data will seriously challenge these wireless systems. We conclude by highlighting the possible solutions for upgrading the cellular standards, in order to cope with the upcoming smart metering traffic.

Description: The ongoing paradigm shift from classical centralized wireless technologies toward distributed large-scale networks such as the Internet of Things has introduced new security challenges that cannot be fully handled via traditional cryptgraphic means. In such emerging wireless environments, devices have limited capabilities and are not controlled by a central control center; thus, the implementation of computationally expensive cryptographic techniques can be challenging. Motivated by these considerations, substantial recent research has been investigating the use of the physical layer as a means to develop low-complexity and effective wireless security mechanisms. Such techniques are grouped under the umbrella of physical layer security . These techniques range from information-theoretic security, which exploits channel advantages to thwart eavesdropping, to physical layer fingerprinting techniques that exploit physical layer features for device identification. In this context, providing state-of-the-art tutorials on the various approaches to physical layer security is of considerable interest. This Feature Topic gathers together such tutorial-style and overview articles that provide an in-depth overview of the broad spectrum of security opportunities brought forward by physical layer security.

Description: Including: (1) IEEE ComSoc Iraq Chapter Activities Continue Despite the Severity of the Situation Inside Iraq (2) Effectiveness of ComSoc DLT Program and Workshops in New Zealand (3) Tutorial Sessions on Quantum and Optical Wireless Communications and Exhibition at IEEE TENCON 2014, Bangkok, Thailand

Description: Physical layer key generation that exploits reciprocity and randomness of wireless fading channels has attracted considerable research attention in recent years. Although theoretical study has shown its potential to generate information- theoretic secure keys, great challenges remain when transforming the theory into practice. This article provides an overview of the physical layer key generation process and discusses its practical challenges. Different passive and active attacks are analyzed and evaluated through numerical study. A new key generation scheme using random probing signals, and combining user generated randomness and channel randomness, is introduced as a countermeasure against active attacks. The numerical results show that the proposed scheme achieves higher security strength than existing schemes using constant probing signals under active attacks. Future research topics on physical layer key generation are discussed.

Description: There has recently been significant interest in applying the principles of information-theoretical security and signal processing to secure physical layer systems. Although the community has made progress in understanding how the physical layer can support confidentiality and authentication, it is important to realize that there are many important issues that must be addressed if physical layer security is ever to be adopted by real and practical security systems. In this article, I briefly review several different flavors of physical layer security (at least for wireless systems), and then identify aspects (a.k.a. weaknesses) where the foundation for physical layer security needs to be strengthened. I then highlight that the opportunities for applying physical layer security to real systems will be quite rich if the community can overcome these challenges. In the course of the article, I note new directions for the community to investigate, with the objective of keeping physical layer security research targeted at having a practical impact on real systems.

Description: This month???s President???s Page is devoted to the IEEE Green Information and Communications Technology (ICT) initiative. By its very nature, Green ICT is a theme, not only of interest but also offering numerous opportunities, for virtually every IEEE Society and Council. Through this initiative, ComSoc seeks an IEEE-wide outreach to achieve even greater recognition for IEEE???s mission of advancing technology for humanity.

Description: Wireless energy harvesting (WEH) is becoming one of the key techniques in energy harvesting in wireless networks. On the other hand, interference alignment (IA) is a promising solution for interference management in wireless networks. Although plenty of effort has been conducted on WEH and IA, these two important areas have been addressed separately in most of the existing literature. In this article we provide an overview of WEH in IA networks, and present a unified framework to jointly study WEH and IA. To simultaneously optimize both information transmission (IT) and WEH performance in IA networks, we propose a power splitting optimization (PSO) algorithm. In addition, we study the power allocation problem in the proposed PSO algorithm. Simulation results are presented to compare the performance of the proposed schemes for WEH in IA networks. Some interesting research challenges are also presented for the WEH in IA networks.

Description: The advancements in microwave power transfer (MPT) over recent decades have enabled wireless power transfer over long distances. The latest breakthroughs in wireless communication ??? massive MIMO, small cells, and millimeterwave communication ??? make wireless networks suitable platforms for implementing MPT. This can lead to the elimination of the ???last wires??? connecting mobile devices to the grid for recharging, thereby tackling a huge long-standing ICT challenge. Furthermore, the seamless integration between MPT and wireless communication opens up a new area called wirelessly powered communications (WPC) where many new research directions arise, such as simultaneous information and power transfer, WPC network architectures, and techniques for safe and efficient WPC. This article provides an introduction to WPC by describing the key features of WPC, shedding light on a set of frequently asked questions, and identifying the key design issues and discussing possible solutions.

Description: Cooperative relaying has been recognized as a promising technique to exploit spatial diversity gain using simple hardware, but it may barely fall in the class of green communications because extra power is consumed for information relaying. Recent advances in energy harvesting devices have paved the way for self-sustainable relays that power themselves by replenishing ambient energy without wires. This article examines the current progress of EH relays with special emphasis on wireless power transfer through RF signals that carry both information and energy at the same time. In this context, information relaying and EH are two tightly coupled processes, and practical constraints of EH devices pose new challenges to self-sustainable relays. This article addresses these issues and points out future research directions.

Description: In mobile communications, two potentially ground-breaking ideas have emerged in recent years: massive MIMO antenna technology, which delivers enormous information rates, and wireless energy transfer (WET), which makes remote charging of mobile users possible. This article realizes the huge potential of combining the two for high wireless information transfer (WIT) and WET. In particular, to maximize the synergy, the distributed version of massive MIMO (known as massive distributed antenna system, MDAS) is advocated to go with the joint wireless information and energy transfer (JWIET) system capable of both WIT and WET. We present the opportunities in MDAS-JWIET, and discuss research trends in MDAS with several architectures involving WET and WIT.

Description: In this article, we cover eco-friendly cellular networks, discussing the benefits that ambient energy harvesting offers in terms of energy consumption and profit. We advocate for future networks where energy harvesting will be massively employed to power network elements; even further, communication networks will seamlessly blend with future power grids. This vision entails the fact that future base stations may trade some of the excess energy they harvest so as to make a profit and provide ancillary services to the electricity grid. We start by discussing recent developments in the energy harvesting field, and then deliberate on the way future energy markets are expected to evolve and the new fundamental trade-offs that arise when energy can be traded. Performance estimates are given throughout to support our arguments, and open research issues in this emerging field are discussed.

Description: Coding has long been fundamental to communication systems, even as far back as the advent of telegraphy in the 1840s: Samuel F. B. Morse created the Morse code as a means of efficiently encoding and transmitting messages in the English language. Channel coding has advanced considerably since the inauguration of information theory by Claude Shannon in 1948, followed by the seminal work by Richard Hamming on practical error correcting codes in 1949. Many crucial algorithms utilized in radio communications today, including convolutional and block codes, the Viterbi algorithm, BCH and Reed- Solomon codes, soft decoding, and so on, date back to the 1960s. Much of the interest in channel coding was driven by space research, to solve the formidable problem of communicating with space probes millions or even billions of kilometers from Earth.

Description: OFDM has been regarded as a promising candidate for use in cognitive radio systems with dynamic spectrum reuse capability. However, conventional OFDM has significant OOBE, which can cause severe interference to systems operating in adjacent frequency bands. In addition to conventional techniques such as spectral shaping filtering, guard band insertion, and time domain windowing, new OOBE reduction techniques, including cancellation carrier and spectral precoding, have been proposed in recent years. This article reviews various OOBE reduction techniques and proposes a generalized lowcomplexity OOBE reduction framework for discrete Fourier transform precoded OFDM. With the allocation of explicit frequency domain cancellation subcarriers and data domain cancellation symbols, the proposed framework enables various configurations to achieve significant OOBE reduction with low implementation complexity, and provides flexibility in balancing OOBE reduction and other performance metrics such as peak-to-average power ratio.

Description: Presents the front cover to the supplemental issue of this publication.

Description: The importance of standards to the work and careers of communications practitioners is the basis of this publication. It is a platform for presenting and discussing standards-related topics in the areas of communications, networking, research, and related disciplines.

Description: Presents summaries of new communications standards.

Description: The Internet of Things (IoT) is an emerging computing concept that describes a structure in which everyday physical objects, each provided with unique identifiers, are connected to the Internet without requiring human interaction. Long-term and self-sustainable operation are key components for realization of such a complex network, and entail energy-aware devices that are potentially capable of harvesting their required energy from ambient sources. Among different energy harvesting methods, such as vibration, light, and thermal energy extraction, wireless energy harvesting (WEH) has proven to be one of the most promising solutions by virtue of its simplicity, ease of implementation, and availability. In this article, we present an overview of enabling technologies for efficient WEH, analyze the lifetime of WEH-enabled IoT devices, and briefly study the future trends in the design of efficient WEH systems and research challenges that lie ahead.

Description: In order to deal with the challenges and opportunities presented by the mobile Internet, this paper proposes a new Internet-oriented mobile network architecture, dubbed i-Net, for fifth generation (5G) mobile communication systems. Based on direct communications established between the base stations (BSs), i-Net can implement local data routing for mobile data traffic, which adapts to increased service localization for the mobile Internet. We first present the network architecture and main technical features, i.e., inter-connection, integration, and intelligence. Then the key techniques are discussed to show their potential in improving the network efficiency of i-Net. Field trials for inter-BS direct communications to implement cooperative multipoint oPeration (CoMP) in i-Net are carried out to demonstrate the feasibility of i-Net. It is expected that i-Net can provide a good quality of experience for end users through the efficient integration of the multi-BS, multi-band, and multi-radio-access-technology (RAT) radio resources in 5G.

Description: Small cell networks have attracted a great deal of attention in recent years due to their potential to meet the exponential growth of mobile data traffic, and the increasing demand for better quality of service and user experience in mobile applications. Nevertheless, wide deployment of small cell networks has not happened yet because of the complexity in the network planning and optimization, as well as the high expenditure involved in deployment and operation. In particular, it is difficult to provide grid power supply to all the small cell base stations in a cost-effective way. Moreover, a dense deployment of small cell base stations, which is needed to meet the capacity and coverage of next generation wireless networks, will increase operators??? electricity bills and lead to significant carbon emission. Thus, it is crucial to exploit offgrid and green energy sources to power small cell networks, for which energy harvesting technology is a viable solution. In this article, we conduct a comprehensive study of energy harvesting small cell networks, and investigate important aspects, including a feasibility analysis, network deployment, and network operation issues. The advantages as well as unique challenges of energy harvesting small cell networks are highlighted, together with potential solutions and effective design methodologies.

Description: Provides a listing of the editors, board members, and current staff for this issue of the publication.

Description: This paper provides qualitative and quantitative values for the received interference power at the antenna ports of automotive radars as well as the probability of their occurrence for actual and future, not yet measurable traffic scenarios on main roads. The influence of the environment, the road traffic behavior, and the radar penetration rate for a defined antenna configuration can be observed. The basis for the analyses are ray-tracing based simulations in order to achieve adequate predictions for the received power levels due to multipaths. The results show that for a radar penetration rate of 100%, the difference between the strongest overall incoherent received interference power level and the level that is received in 90% of the time is up to 7 dB, dependent on the antenna placement and the environment.

Description: Electric drive systems are going to be the future of the automotive industry. Electromagnetic compatibility (EMC) issues and challenges arise with its growing entry into modern cars. This contribution provides an overview of the field dominating disturbance currents of an automotive high-voltage (HV) power inverter within an electric drive system. In order to minimize the cost and time needed for EMC measurements and engineering, a precompliance measurement method is introduced and applied to the inverter's setup. The method presented allows the calculation of radiated emissions, according to CISPR 25, needed during the development process without the need for an expensive anechoic chamber. Transfer functions in combination with measured disturbance currents on the attached HV harnesses are used to obtain a cost-efficient estimation of the radiated emissions occurring during a component test. Its theory is discussed and demonstrated using a derived model. The method is verified using a rudimentary test setup, which represents a distributed system, and is later validated by the active electric drive system test setup introduced. Examinations of repeatability and reproducibility of disturbance current measurements as well as applied EMC counter measures complete the contribution.

Description: In this paper, a coplanar symmetrical meander line structure is presented, and an equivalent circuit model is proposed to allow estimation of its electrical characteristics based on numerical modeling. The parasitic couplings in the proposed structure are considerably different from those of a simple meander line with a ground structure below it. Analysis and derivation of inductive and capacitive couplings and of resistance in the effective frequency band are addressed in detail, and the effects of geometrical parameters on the electrical characteristics are also demonstrated. The validity of the proposed equivalent circuit model is verified by both commercial electromagnetic simulator and measurement of the scattering parameters in the frequency domain, as well as of the reflected and transmitted waveforms in the time domain. Because the proposed model is easily coded, and takes little time to compute the parameters, it is very useful in the design of inductance and capacitance in circuits on substrate, which can be used for the design of time-delay elements and stop band filters in power delivery lines.

Description: In this paper, a new formulation in the time domain of the Cooray–Rubinstein expression is presented. This new formulation overcomes the problems related to the previous formulation: The Dirac pulse contained in the kernel of the previous formulation is extracted, making the numerical treatment easier and more accurate.

Description: Lightning electromagnetic pulse (LEMP) is a severe threat to sensitive electronic devices installed in buildings. To protect these devices from LEMP effects, the evaluation of the electromagnetic fields inside of the building is required. Although numerous studies have been devoted to the analysis of these fields stemming from direct and indirect lightning strikes, no thorough study on the analysis of the electromagnetic environment inside a building with layered reinforcing bars has been presented in the past. In this paper, using the 3-D finite-difference time-domain method, we present a systematic analysis of the electromagnetic field inside a full-scale building associated with direct and nearby lightning strikes, taking into account the presence of reinforced concrete, to evaluate the effect of the structure of the reinforced concrete on the lightning electromagnetic fields.

Description: In this paper, lightning-induced voltages on multiconductor lines with surge arresters and pole transformers have been computed using the 3-D finite-difference time-domain method. This method uses a subgrid model, in which spatial discretization is fine (cell side length is 0.5 m) in the vicinity of overhead wires and coarse (cell side length is 5 m) in the rest of the computational domain. In the simulations, four-conductor lines with surge arresters and pole transformers are considered. The 1-cm-radius overhead conductors are represented by placing a wire having an equivalent radius of about 0.12 m (≈ 0.23 × 0.5 m) in the center of an artificial rectangular prism having a cross-sectional area of 1 m × 1 m (2 cells × 2 cells) and the modified (relative to air) constitutive parameters: lower electric permittivity and higher magnetic permeability. The computed lightning-induced voltage waveforms agree reasonably well with the corresponding ones measured in the small-scale experiment of Piantini et al. (2007).

Description: The random coupling model (RCM) and Baum–Liu–Tesche EM topology have been well developed to describe the statistical fluctuation of the scattering and impedance matrices of wave-chaotic metallic-enclosed cavity, and the interaction of interconnected networks of complicated enclosures, respectively. In this paper, a stochastic approach that combines these two methods is tested and verified on a network of wave-chaotic metallic cavities, and induced voltage derived by this method is also compared with other methods.

Description: Presents upcoming conference events pertaining to the Communications Society.

Description: Authentication is a fundamental requirement for secure communications. In this article, we describe a general framework for fingerprint embedding at the physical layer in order to provide message authentication that is secure and bandwidth-efficient. Rather than depending on channel or device characteristics that are outside of our control, deliberate fingerprint embedding for message authentication enables control over performance trade-offs by design. Furthermore, low-power fingerprint designs enhance security by making the authentication tags less accessible to adversaries. We define metrics for communications and authentication performance, and discuss the trade-offs in system design. Results from our wireless software-defined radio experiments validate the theory and demonstrate the low complexity, practicality, and enhanced security of the approach.

Description: This paper introduces an equivalent circuit model for through silicon vias including the nonlinear effect of metal–oxide–semiconductor capacitance. This nonlinear effect is combined to the frequency-dependent via resistance and inductance, as well as capacitance and conductance of the silicon substrate for a transient analysis. The impact of frequency-dependent RLCG parameters and the nonlinear depletion capacitance on signal propagation, crosstalk and eye diagram is studied using the proposed equivalent circuit model.

Description: The design of robust receivers in environments with strong impulsive noise may be challenging due to their high-amplitude events and their rare but nonnegligible occurrence. In substation environments, these impulsive noises are predominant. They are induced by corona discharges such as electrical arcs or partial discharges in the air. The emitted radiations can occupy a wide range of frequencies typically reaching a few gigahertz with very high amplitude. In this paper, we develop a generalized model of impulsive electromagnetic interference induced by corona discharges for wireless channels. Radiations emitted by these sources are generally transient impulses, their occurrences follow cyclostationary process, due to their generation by an alternative current. In this model, we both take into account the physical mechanism of these discharges and the induced electromagnetic radiations. Experimental results validate the approach in terms of first- and second-order statistics such as amplitudes, interarrival time, occurrences, and power spectrum densities of impulsive transient noise.

Description: A simple and efficient analytical method has been developed for predicting the electromagnetic field coupling with a lossless transmission line (TL) located in a rectangular enclosure. The metallic enclosure is excited by an internal electrical short dipole or monopole source. The electric fields generated inside the rectangular enclosure and excited by some simple sources are calculated by using the electric-type dyadic Green's function. Our approach combines, on one hand, a lumped-pi circuit model of TL and, on the other hand, the Agrawal coupling model. A simple equivalent circuit has been derived which can give prediction for the coupling between the cavity field and the TL. This method is computationally less intensive compared to other numerical methods to solve such a problem. The analytical results have been successfully compared over a wide frequency band with the finite-difference time domain and experimental results carried out in different combinations of source and line position.

Description: A SPICE model for the twisted-wire pair with uniform twists in free space is proposed in this paper, which is capable of calculating the transient terminal response of the twisted-wire pair terminated with nonlinear loads in the presence of a transient plane wave illumination. The model differs from its counterpart for a straight-wire pair in that an extra convolution is included in the source terms, which can be calculated efficiently by the recursive convolution method. For the sake of convenience, the derivation of the model is made in the frequency domain on the basis of the transmission-line theory. The resultant expressions are compared with the outcome of the method of moments, showing that the transmission-line model can be applied to the twisted-wire pair with loose twists. Furthermore, the low-frequency coupling properties and resonant peak of the twisted-wire pairs are investigated according to the derived approximate formulae. Based on the frequency-domain results, a SPICE model for the twisted-wire pair is proposed in the time domain before it is verified and applied to the twisted-wire pair terminated with nonlinear loads.