The 5G (fifth generation) mobile communications aim to support a large versatile type of services with different and often diverging requirements, which has posed significant challenges on the design of 5G systems.Modulation and waveforms are one of the key physical layer componentsthat determine the system throughput, reliability, and complexity, therefore their design is critical in meeting the variety requirements of 5G services.A comprehensive overview was presented on the modulation and waveforms that have been considered for their potential application to 5G in the literature, identifying their design requirements, and discussing their advantages to meet such requirements.Additional considerations that extend our view to higher layer aspects and air interface harmonization are provided as the final remarks.As a result of this article, it is hopeful to draw greater attentions from the readers on this important topic, and trigger further studies on the promising modulation and waveform candidates.
Abstract:In HetNets (Heterogeneous Networks),each network is allocated with fixed spectrum resource and provides service to its assigned users using specific RAT (Radio Access Technology).Due to the high dynamics of load distribution among different networks,simply optimizing the performance of individual network can hardly meet the demands from the dramatically increasing access devices,the consequent upsurge of data traffic,and dynamic user QoE(Quality-of-Experience).The deployment of smart networks,which are supported by SRA (Smart Resource Allocation)among different networks and CUA (Cognitive User Access) among different users,is deemed a promising solution to these challenges.In this paper,we propose a framework to transform HetNets to smart networks by leveraging WBD(Wireless Big Data),CR(Cognitive Radio) and NFV (Network Function Virtualization) techniques.CR and NFV support resource slicing in spectrum,physical layers,and network layers,while WBD is used to design intelligent mechanisms for resource mapping and traffic prediction through powerful AI (Artificial Intelligence) methods.We analyze the characteristics of WBD and review possible AI methods to be utilized in smart networks.In particular,the potential of WBD is revealed through high level view on SRA,which intelligently maps radio and network resources to each network for meeting the dynamic traffic demand,as well as CUA,which allows mobile users to access the best available network with manageable cost,yet achieving target QoS(Quality-of-Service)or QoE.
Chandran, et al.introduce the direction of position based cryptography at CRYPTO 2009.In position based cryptography, the position of a party is used to be its unique “credential” in order to realize the cryptographic tasks, such as position based encryption, position based signature, position based key exchange and so on.Position based key exchange, as a basic primitive in position based cryptography, can be used to establish a shared key based on the position of the participant.To begin with, this paper presents the notions of the prover-to-verifier mode and the prover-to-prover mode for position based key exchange.In the prover-to-verifier mode, a secret key can be shared between a prover and the verifiers according to the position of the prover.While in the prover-to-prover mode, two provers located at the valid positions can negotiate a shared key with the help of the verifiers and any other party whose position is illegal cannot obtain the shared key.At the same time, this paper formalizes two security definitions against colluding adversaries: position based prover-to-verifier key exchange and position based prover-to-prover key exchange.Then, this paper introduces the bounded retrieval model and the implementations of position based key exchange in two modes based on the bounded retrieval model.Finally, this paper discusses the position based key exchange protocols in two modes from both security and performance perspectives.
In vehicular networks,the exchange of beacons among neighboring vehicles is a promising solution to guarantee a vehicle’s safety.However,frequent beaconing under high vehicle density conditions will cause beacon collisions,which are harmful to a vehicle’s driving safety and the location tracking accuracy.We propose an ABIwRC (Adaptive Beaconing Interval with Resource Coordination) method for a highway scenario.Each vehicle broadcasts beacon interval requests,including the intervals needed for both the vehicle’s driving safety and location tracking accuracy.The RSU(Road Side Unit) allocates resources for a vehicle’s beaconing according to the requests from all vehicles and the interference relationship between the vehicles in adjacent RSUs.We formulate a resource allocation problem for maximizing the sum utility,which measures the satisfaction of vehicles’requests.We then transform the optimization problem into a maximum weighted independent set problem,and propose an algorithm to solve this efficiently.Simulation results show that the proposed method outperforms the benchmark in terms of beacon reception ratio,vehicle driving safety,and location tracking accuracy.
Abstract:Wireless big data describes a wide range of massive data that is generated,collected and stored in wireless networks by wireless devices and users.While these data share some common properties with traditional big data,they have their own unique characteristics and provide numerous advantages for academic research and practical applications.This article reviews the recent advances and trends in the field of wireless big data.Due to space constraints,this survey is not intended to cover all aspects in this field,but to focus on the data aided transmission,data driven network optimization and novel applications.It is expected that the survey will help the readers to understand this exciting and emerging research field better.Moreover,open issues and promising future directions are also identified.
The widespread application of heterogeneous cloud computing has enabled enormous advances in the real-time performance of telehealth systems.A cloud-based telehealth system allows healthcare users to obtain medical data from various data sources supported by heterogeneous cloud providers.Employing data duplications in distributed cloud databases is an alternative approach for achieving data sharing among multiple data users.However, this approach results in additional storage space being used, even though reducing data duplications would lead to a decrease in data acquisitions and realtime performance.To address this issue, this paper focuses on developing a dynamic data deduplication method that uses an intelligent blocker to determine the working mode of data duplications for each data package in heterogeneous cloudbased telehealth systems.The proposed approach is named the SD2M (Smart Data Deduplication Model), in which the main algorithm applies dynamic programming to produce optimal solutions to minimizing the total cost of data usage.We implement experimental evaluations to examine the adaptability of the proposed approach.
Abstract: With the support of the national nature science foundation, the Academy of Space Electronic Information Technology is developing a novel compact spaceborne GNSS receiver, referred to as the HiSGR (High Sensitivity GNSS Receiver). This receiver can operate effectively in the full range of Earth orbiting missions, from LEO (Low Earth Orbit) to geostationary and beyond. Improved signal detection algorithms are used in the signal process section of the HiSGR and an inertial sensor is used for GNSS/INS ultra tight coupled design, which makes the acquisition process fast and provides improved tracking performance for weaker GPS signals in the presence of high dynamics. Extensive tests are performed using the HiSGR to demonstrate the good performance of some crucial specifications, by employing a real GNSS signal received in an open field and through hardware-in-the-loop simulation. Receiver performance is demonstrated for LEO and GEO scenarios. A ground vehicle running test is performed for demonstration of fast acquisition and reacquisition capabilities under conditions of signal loss. The HiSGR showed good performance and it was stable during the simulations and tests, which proved its capability for future space applications.
IoV (Internet of Vehicles) is a promising paradigm to the future of automobiles, which will undoubtedly boost the automobile market as well as accelerate innovation in Internet services and applications.The concept of SD-IoV (Software Defined IoV) is presented, which is capable of improving resource utilization, service quality, and network optimization in the harsh vehicular network environments.First, A generalized SD-IoV architecture as an intuitive big picture is presented.Then, the major functions realized by SD-IoV are elabrated on to illustrate how the current challenges are resolved.As the key enablers of SD-IoV, three possible implementation methods of the wireless control path are described and compared.Finally, the challenges and existing solutions of SD-IoV are disuessed and open issues are pointed out so as to shed light on future research.
In recent years,IoV (Internet of Vehicles) has become one of the most active research fields in network and intelligent transportation system.As an open converged network,IoV plays an important role in solving various driving and traffic problems by advanced information and communications technology.We review the existing notions of IoV from different perspectives.Then,we provide our notion from a network point of view and propose a novel IoV architecture with four layers.Particularly,a novel layer named coordinative computing control layer is separated from the application layer.The novel layer is used for solving the coordinative computing and control problems for human-vehicle-environment.After summarizing the key technologies in IoV architecture,we construct a VV (Virtual Vehicle),which is an integrated image of driver and vehicle in networks.VVs can interact with each other in cyber space by providing traffic service and sharing sensing data coordinately,which can solve the communication bottleneck in physical space.Finally,an extended IoV architecture based on VVs is proposed.
The wide spectrum and propagation characteristics over the air give mmWave communication unique advantages as well as design challenges for 5G applications.To increase the system speed,capacity,and coverage,there is a need for innovation in the RF system architecture,circuit,antenna,and package in terms of implementation opportunities and constraints.The discuss mmWave spectrum characteristics,circuits,RF system architecture,and their implementation issues are discussed.Moreover,the transmitter key components,i.e.,the receiver,antenna,and packaging are reviewed.
Cloud computing facilitates convenient and on-demand network access to a centralized pool of resources.Currently, many users prefer to outsource data to the cloud in order to mitigate the burden of local storage.However, storing sensitive data on remote servers poses privacy challenges and is currently a source of concern.SE (Searchable Encryption) is a positive way to protect users sensitive data, while preserving search ability on the server side.SE allows the server to search encrypted data without leaking information in plaintext data.The two main branches of SE are SSE (Searchable Symmetric Encryption) and PEKS (Public key Encryption with Keyword Search).SSE allows only private key holders to produce ciphertexts and to create trapdoors for search, whereas PEKS enables a number of users who know the public key to produce ciphertexts but allows only the private key holder to create trapdoors.This article surveys the two main techniques of SE: SSE and PEKS.Different SE schemes are categorized and compared in terms of functionality, efficiency, and security.Moreover, we point out some valuable directions for future work on SE schemes.
Satellite networks have many advantages over traditional terrestrial networks.However, it is very difficult to design a satellite network with excellent performance.The paper briefly summarizes some existing satellite network routing technologies from the perspective of both single-layer and multilayer satellite constellations, and focuses on the main ideas, characteristics, and existing problems of these routing technologies.For single-layer satellite networks, two routing strategies are discussed, virtual node strategy and virtual topology strategy.Moreover, considering the deficiency of existing multilayer satellite network routing, we discuss the topic invulnerability.Finally, the challenges and problems faced by the satellite network are analyzed and the trend of future development is predicted.
Recent rapid developments in 4G wireless communication have been motivated by breakthroughs in air interface technology,exemplified by the replacement of WCDMA (Wideband Code Division Multiple Access) with OFDM (Orthogonal Frequency-division Multiplexing).Although the protocol to adopt for 5G HF (High-Frequency) wireless communication—including such matters as waveform,network deployment,and frequency range—has been a controversial issue for a number of years,a common view is that there is a large gap between the rapidly increasing requirements pertaining to traffic capacity and the capabilities of current LTE (Long Term Evolution) networks in terms of spectral and power efficiency.A number of technical challenges need to be overcome in order to bridge this gap.In this paper,by briefly reviewing progress in HF technology,we summarize technical challenges ranging from propagation attenuation and the implementation of circuit devices,to signal processing and the Ka-band to offer feasible reflection on the forthcoming technological revolution.
A fully integrated 60-GHz transceiver for 802.11ad applications with superior performance in a 90-nm CMOS process versus prior arts is proposed and real based on a field-circuit co-design methodology.The reported transceiver monolithically integrates a receiver,transmitter,PLL(Phase-Locked Loop) synthesizer,and LO (Local Oscillator) path based on a sliding-IF architecture.The transceiver supports up to a 16QAM modulation scheme and a data rate of 6 Gbit/s per channel,with an EVM (Error Vector Magnitude) of lower than ?20 dB.The receiver path achieves a configurable conversion gain of 36~64 dB and a noise figure of 7.1 dB over 57~64 GHz,while consuming only 177 mW of power.The transmitter achieves a conversion gain of roughly 26 dB,with an output P1dBof 8 dBm and a saturated output power of over 10 dBm,consuming 252 mW of power from a 1.2-V supply.The LO path is composed of a 24-GHz PLL,doubler,and a divider chain,as well as an LO distribution network.In closed-loop operation mode,the PLL exhibits an integrated phase error of 3.3o rms (from 100 kHz to 100 MHz) over prescribed frequency bands,and a total power dissipation of only 26 mW.All measured results are rigorously loyal to the simulation.
Cyber-physical systems are being confronted with an ever-increasing number of security threats from the complicated interactions and fusions between cyberspace and physical space.Integrating security-related activities into the early phases of the development life cycle is a monolithic and cost-effective solution for the development of security-critical cyber-physical systems.These activities often incorporate security mechanisms from different realms.We present a fine-grained design flow paradigm for security-critical and software-intensive cyber-physical systems.We provide a comprehensive survey on the domain-specific architectures, countermeasure techniques and security standards involved in the development life cycle of security-critical cyber-physical systems, and adapt these elements to the newly designed flow paradigm.Finally, we provide prospectives and future directions for improving the usability and security level of this design flow paradigm.
Modern mobile devices provide a wide variety of services.Users are able to access these services for many sensitive tasks relating to their everyday lives (e.g., finance, home, or contacts).However, these services also provide new attack surfaces to attackers.Many efforts have been devoted to protecting mobile users from privacy leakage.In this work, we study state-ofthe-art techniques for the detection and protection of privacy leakage and discuss the evolving trends of privacy research.
Applications of VANETs (Vehicular Ad hoc Networks) have their own requirements and challenges in wireless communication technology.Although regarded as the first standard for VANETs,IEEE 802.11p is still in the field-trial stage.Recently,LTE V2X(Long-Term Evolution Vehicular to X)appeared as a systematic V2X solution based on TD-LTE(Time Division Long-Term Evolution)4G.It is regarded as the most powerful competitor to 802.11p.We conduct link level simulations of LTE V2X and DSRC (Dedicated Short-Range Communication)for several different types of scenarios.Simulation results show that LTE V2X can achieve the same BLER(Block Error Ratio)with a lower SNR(Signal Noise Ratio)than DSRC.A more reliable link can be guaranteed by LTE V2X,which can achieve the same BLER with lower receiving power than DSRC.The coverage area of LTE V2X is larger than that of DSRC.
Cloud-based video communication and networking has emerged as a promising new research paradigm to significantly improve the quality of experience for video consumers.An architectural overview of this promising research area was presented.This overview with an end-to-end partition of the cloud-based video system into major blocks with respect to their locations from the center of the cloud to the edge of the cloud was started.Following this partition, existing research efforts on how the principles of cloud computing can provide unprecedented support to 1) video servers, 2) content delivery networks, and 3) edge networks within the global cloud video ecosystems were examined.Moreover, a case study was exemplfied on an edge cloud assisted HTTP adaptive video streaming to demonstrate the effectiveness of cloud computing support.Finally, by envisioning a list of future research topics in cloud-based video communication and networking a coclusion is made.
To meet the ever growing traffic in mobile communication,mmWave (millimeter-Wave) frequency bands have gained considerable attention for having a greater amount of bandwidth available than the current cellular spectrum below 3 GHz.Several test systems have been reported on recently to validate the possibility of mmWave links in mobile scenarios.However,there still exist practical issues to enable the application of mmWave in mobile communication,including reliability and cost.In this article,we present some new designs that address these issues,where system architecture,transceiver architecture,and related issues such as circuits and antenna arrays are considered.Hypercellular architecture is applied in mmWave mobile networks to overcome blockage problems,and a Butler-matrix-based HBF (Hybrid Beamforming) architecture is considered in an mmWave link.Simulations and experimental results are presented to validate the effectiveness of the Butler-matrix-based system.
Abstract:Future communication systems will include different types of messages requiring different transmission rates,packet lengths,and service qualities.We address the power-optimization issues of communication systems conveying multiple message types based on finite-delay information theory.Given both the normalized transmission rate and the packet length of a system,the actual residual decoding error rate is a function of the transmission power.We propose a generalized power allocation framework for multiple message types.Two different optimization cost functions are adopted:the number of service-quality violations encountered and the sum log ratio of the residual decoding error rate.We provide the optimal analytical solution for the former cost function and a heuristic solution based on a genetic algorithm for the latter one.Finally,the performance of the proposed solutions are evaluated numerically.
Abstract:Wireless big data is attracting extensive attention from operators,vendors and academia,which provides new freedoms in improving the performance from various levels of wireless networks.One possible way to leverage big data analysis is predictive resource allocation,which has been reported to increase spectrum and energy resource utilization efficiency with the predicted user behavior including user mobility.However,few works address how the traffic load prediction can be exploited to optimize the data-driven radio access.We show how to translate the predicted traffic load into the essential information used for resource optimization by taking energy-saving transmission for non-real-time user as an example.By formulating and solving an energy minimizing resource allocation problem with future instantaneous bandwidth information,we not only provide a performance upper bound,but also reveal that only two key parameters are related to the future information.By exploiting the residual bandwidth probability derived from the traffic volume prediction,the two parameters can be estimated accurately when the transmission delay allowed by the user is large,and the closed-form solution of global optimal resource allocation can be obtained when the delay approaches infinity.We provide a heuristic resource allocation policy to guarantee a target transmission completion probability when the delay is no-so-large.Simulation results validate our analysis,show remarkable energy-saving gain of the proposed predictive policy over non-predictive policies,and illustrate that the time granularity in predicting traffic load should be identical to the delay allowed by the user.
A virtual machine placement optimization model based on optimized ant colony algorithm is proposed.The model is able to determine the physical machines suitable for hosting migrated virtual machines.Thus, it solves the problem of redundant power consumption resulting from idle resource waste of physical machines.First, based on the utilization parameters of the virtual machine, idle resources and energy consumption models are proposed.The models are dedicated to quantifying the features of virtual resource utilization and energy consumption of physical machines.Next, a multi-objective optimization strategy is derived for virtual machine placement in cloud environments.Finally, an optimal virtual machines placement scheme is determined based on feature metrics, multi-objective optimization, and the ant colony algorithm.Experimental results indicate that compared with the traditional genetic algorithms-based MGGA model, the convergence rate is increased by 16%, and the optimized highest average energy consumption is reduced by 18%.The model exhibits advantages in terms of algorithm efficiency and efficacy.
Abstract:Atmospheric ducts are horizontal layers that occur under certain weather conditions in the lower atmosphere.Radio signals guided in atmospheric ducts tend to experience less attenuation and spread much farther,i.e,hundreds of kilometers.In a large-scale deployed TD-LTE(Time Division Long Term Evolution) network,atmospheric ducts cause faraway downlink wireless signals to propagate beyond the designed protection distance and interfere with local uplink signals,thus resulting in a large outage probability.In this paper,we analyze the characteristics of ADI atmospheric duct interference (Atmospheric Duct Interference) by the use of real network-side big data from the current operated TD-LTE network owned by China Mobile.The analysis results yield the time varying and directional characteristics of ADI.In addition,we proposed an SVM (Support Vector Machine)-classifier based spacial prediction method of ADI by machine learning over combination of real network-side big data and real meteorological data.Furthermore,an implementation of ADMM (Alternating Direction Methods of Multipliers) framework is proposed to implement a distributed SVM prediction scheme,which reduces data exchange among different regions/cities,maintains similar prediction accuracy and is thus of a more practical use to operators.
Mobile devices such as smartphones and tablets have continued to grow in recent years.Nowadays, people rely on these ubiquitous smart devices and carry them everywhere in their daily lives.Acoustic signal, as a simple and prevalent transmitting vector for end-to-end communication, shows unique characteristics comparing with another popular communication method, i.e., optical signal, especially on the applications performed over smart devices.Acoustic signal does not require lineof-sight when transmission, the computational power of most smart devices are sufficient to modulate/demodulate acoustic signal using software acoustic modem only, which can be easily deployed on current off-the-shelf smart devices.Therefore, many acoustics-based short range communication systems have been developed and are used in sensitive applications such as building access control and mobile payment system.However, past work shows that an acoustic eavesdropper snooping on the communication between a transmitter and its legitimate receiver can easily break their communication protocol and decode the transmitted information.To solve this problem, many solutions have been proposed to protect the acoustic signal against eavesdroppers.In this overview, we explore the designs of existing solutions, the corresponding implementations, and their methodologies to protect acoustic signal communication.For each dependable and secure acoustics-based short range communication system, we present the major technical hurdles to be overcome, the state-of-the-art, and also offer a vision of the future research issues on this promising technology.
Internet worms can propagate across networks at terrifying speeds, reduce network security to a remarkable extent, and cause heavy economic losses.Thus, the rapid elimination of Internet worms using partial immunization becomes a significant matter for sustaining Internet infrastructure.This paper addresses this issue by presenting a novel worm susceptiblevaccinated-exposed-infectious-recovered model, named the SVEIR model.The SVEIR model extends the classical susceptibleexposed-infectious-recovered model (refer to SEIR model) through incorporating a saturated incidence rate and a partial immunization rate.The basic reproduction number in the SVEIR model is obtained.By virtue of the basic reproduction number, we prove the global stabilities of an infection-free equilibrium point and a unique endemic equilibrium point.Numerical methods are used to verify the proposed SVEIR model.Simulation results show that partial immunization is highly effective for eliminating worms, and the SVEIR model is viable for controlling and forecasting Internet worms.
Nowadays,the increase amounts of mobile data has resulted in great demand on existing communication networks.The millimeter-wave band offers large bandwidths to be exploited,which eases the spectrum crunch for bands below 3 GHz.In order to mitigate the path loss from high frequencies,a large antenna array and beamforming technology are adopted to increase the link gain.However,a challenge arises from the new band.Given the order of gigahertz bandwidth and the high sampling rate,the high-resolution ADC (Analog-to-Digital Converter) used in the large array creates a power consumption bottleneck.One solution is to use a low-resolution ADC to replace the full-precision ADC.In this paper,we propose a mixed LMS (Least Mean Square) receiver beamforming method for a millimeter-wave one-bit antenna array.We first use a grid-based approach to roughly estimate the DOA (Direction of Arrival) of the incoming signal.Then,we use the steering vector for the DOA as an initial value for the LMS method.A simulation shows that our proposed mixed LMS receiver beamforming method for the onebit antenna array attains a performance level near the optimal one that obtained with an accurate DOA.The radiation pattern of the mixed LMS method almost overlaps the pattern for the accurate DOA,and the spectral efficiency of the mixed LMS method reach up with that obtained from accurate DOA.Furthermore,owing to the use of initial values from rough DOA estimation,the mixed LMS method has a fast convergence.
User targeting via behavioral analysis is becoming increasingly prevalent in online messaging services.By taking into account users' behavior information such as geographic locations, purchase behaviors, and search histories, vendors can deliver messages to users who are more likely to have a strong preference.For example, advertisers can rely on some ad-network for distributing ads to targeted users.However, collecting such personal information for accurate targeting raises severe privacy concerns.In order to incentivize users to participate in such behavioral targeting systems, addressing the privacy concerns becomes of paramount importance.We provide a survey of privacy-preserving user targeting.We present the architectures of user targeting, the security threats faced by user targeting, and existing approaches to privacy-preserving user targeting.Some future research directions are also identified.
Connected vehicles are promoted with the use of different communication technologies for diverse applications and services.There is an ongoing debate in the research and industry communities whether short range communications based on IEEE 802.11p or cellular based on 3GPP LTE should be used for vehicular communications.We propose a mechanism to utilise both short range and cellular communications simultaneously in a cost efficient way while providing the required quality of service to the users.A host connected to multiple networks is referred to as a multi-homed node and SCTP (Stream Control Transmission Protocol)is an IETF standard which supports multi-homing.We propose an extension to SCTP that takes into account not only path quality but also the cost of using each network.It is shown that the combination of QoS and cost information increases economic benefits for provider and end-users,while providing increased packet throughput.
Test results for a 10-Gbps prototype demonstrator working at 71~76 GHz frequency band with a 2-bit/s/Hz spectral efficiency are reported.To overcome the speed limitation of the commercial DA/ADs,a two-channel analog IF multiplexing and demultiplexing topology is adopted as a trade-off between cost and spectrum efficiency.The same approach is also used to achieve up to 20 Gbps with a full 10-GHz bandwidth of the allocated commercial bands (71~76 GHz and 81~86 GHz).