5G Mobile Wireless Networks Research Articles

Adaptive Handover Decision Using Fuzzy Logic for 5G Ultra-Dense Networks

With the explosive increase in traffic volume in fifth-generation (5G) mobile wireless networks, an ultra-dense network (UDN) architecture, composed of highly concentrated millimeter-wave base stations within the fourth-generation (4G) system, has been developed. User equipment (UE) may encounter more frequent handover opportunities when moving in a UDN. Conventional handover schemes are too simple to adapt to the diverse handover scenarios encountered in 5G UDNs because they consider only UE signal strength. Unnecessary handovers aggravate the ping-pong effect and degrade the quality of service of cellular networks. Fuzzy logic (FL) is considered the best technique to unravel the handover problem in a high-density scenario of small cells for 4G/5G networks. In this paper, we propose an FL-based handover scheme to dynamically adjust the values of two handover parameters, namely handover margin (HOM) and time to trigger (TTT), with respect to each UE. The proposed scheme, abbreviated as FLDHDT, has dynamic adjustment of TTT in addition to HOM by using the signal to interference plus noise ratio and horizontal moving speed of the UE as inputs to the FL controller. To demonstrate the effectiveness and superiority of FLDHDT, we perform simulations using the well-known ns-3 simulator. The performance measures include the number of handovers, overall system throughput, and ping-pong ratio. The simulation results demonstrate that FLDHDT improves the handover performance of 5G UDNs in terms of the number of handovers, ping-pong ratio, and overall system throughput compared to a conventional handover scheme, namely Event A3, and an FL-based handover scheme with dynamic adjustment of only HOM.

Network Slicing for mMTC and URLLC Using Software-Defined Networking with P4 Switches

Massive machine-type communication (mMTC) and ultra-reliable low-latency communication (URLLC) are two key services in fifth-generation (5G) mobile wireless networks. These networks have been developed with extremely high service quality requirements: scalability for mMTC and reliability with low latency for URLLC. Fifth-generation network slicing will play a key role in supporting the distinct requirements of various services. Software-defined networking (SDN), a promising technology for network softwarization, physically separates the network control plane from the data plane by centrally controlling switches with an SDN controller. However, control channel bottleneck and processing delays due to this centralized control may reduce the scalability, reliability, and security of SDN. This paper proposes an SDN framework with programming protocol–independent packet processor (P4) switches (SDNPS), and defines a packet format containing in-band network telemetry data to simultaneously support heavy Internet of Things and URLLC traffic in 5G network slices. The method both satisfies the requirements of mMTC and URLLC and alleviates the load on the SDN controller. P4 is an advanced switch interface technology that provides enhanced stateful forwarding and reveals a persistent state on the SDN data plane. To demonstrate the superiority of SDNPS, simulations are performed on conventional SDNs and SDNPS. SDNPS outperforms the other schemes in terms of average throughput, packet loss ratio, and packet delay for both the mMTC and URLLC network slices.

Authentication for 5G Mobile Wireless Networks

Discussions regarding 5G mobile wireless networks frequently involve the impact they will create to our daily lives. Some view 5G as a disruption while some are questioning the need to deploy the network when conventional mobile networks are still performing optimally. The economic and lifestyle impact of 5G is rather subjective, but it is definite that there will be consequences to the security and privacy discussion sphere with an emphasis on authentication. As it arrives with new mechanisms, there is certainly a whole new attacking avenues to be capitalised. This paper surveys the state of 5G mobile wireless networks in terms of authentication. It further discusses the security features and challenges in the 5G mobile wireless networks, and future directions will also be charted.

A full-duplex MAC technique to improve spectrum-efficiency on 5G mobile wireless networks

Full-duplex (FD) communications shall play an important role on the next generation (5G) mobile wireless networks as they are expected to enhance spectrum usage and throughput. Unleashing the benefits of FD communications, however, requires a fitted design of medium access control (MAC) schemes. In spite of that, existing full-duplex MAC schemes are build upon the IEEE 802.11 which is designed to operate on half-duplex radios. The main contribution of this work is to propose a full-duplex communication mechanism devised to improve spectrum usage and throughput in the context of FD communications. The proposed scheme, named Full-Duplex Dynamic Scheduling MAC (FDDS-MAC), uses a novel strategy to select a communicating pair that maximizes the probability of establishing a full-duplex communication between sending and receiving nodes. A mathematical analysis of the proposed strategy is presented to show the potential improvement that can be achieved using FDDS-MAC. Moreover, in order to compare FDDS-MAC throughput with state-of-art full-duplex communications mechanisms, an analytical model addressing the details of a FD communication is proposed. Analytical evaluation shows that the proposed scheme provides throughput gain up to 50% as compared to the state-of-art full-duplex communications mechanisms. Furthermore, an enhanced version of FDDS-MAC (termed FDDS-MAC*) is proposed to further reduce the time spent selecting the receiver node that maximizes the probability of establishing a full-duplex communication. Numerical results reveals that FDDS-MAC* achieved an improvement over existing full-duplex MAC schemes up to 59% in terms of throughput, thus showing the positive impact of FDDS-MAC* deployment.

Electrical Vehicles: Current State of the Art, Future Challenges, and Perspectives

The goal of the study presented in this article is to provide a general overview of the various aspects related to electric vehicles (EVs), along with all associated emerging challenges and perspectives. In this context, the basic types of EVs and the corresponding charging technologies are analyzed. Since EVs are expected to be a key component of future smart electrical grids (SEG), connection to the grid issues, along with advanced charging techniques (i.e., wireless power transfer), are analyzed as well. To this end, the main features, the requirements of vehicle to grid (V2G) communications, as well as future developments and scenarios of electrification, are also presented and analyzed. Moreover, integration issues with currently deployed fifth generation (5G) mobile wireless networks are also outlined, in order to ensure optimum transmission and reception quality in V2G communications and improved user experience. This integration is also expanded in autonomous vehicles (AVs) technology (self-driving objects), since optimized information processing from various diverse sources is required in order to ensure advanced traffic management aspects.

Heterogeneous Statistical-QoS Driven Resource Allocation Over mmWave Massive-MIMO Based 5G Mobile Wireless Networks in the Non-Asymptotic Regime

The statistical delay-bounded quality-of-service (QoS) theory has been developed to efficiently support multimedia transmissions over 5G wireless networks. On the other hand, unlike in Shannon’s information-theoretic formalism requiring infinite blocklength, finite blocklength coding (FBC) has recently emerged for error control in the non-asymptotic regime, guaranteeing stringent statistical QoS requirements in terms of both latency and reliability for ultra-reliable low-latency communications (URLLC) in 5G services. Moreover, integrated with FBC, millimeter wave (mmWave) massive multi-input multi-output (m-MIMO) schemes have been designed to significantly improve the performance in guaranteeing delay/error-rate bounded QoS. However, due to the complexity of modeling and solving the optimization problems over mmWave m-MIMO fading channels in the non-asymptotic error-control regime, it is challenging to derive an optimal resource allocation policy for maximizing $\epsilon$ -effective capacity to guarantee statistical delay/error-rate bounded QoS. To overcome the above problems, in this paper we propose heterogeneous statistical-QoS driven resource allocation policies for mmWave m-MIMO based 5G wireless networks in both asymptotic and non-asymptotic regimes. In particular, we develop an mmWave m-MIMO based 5G wireless networks model to optimize the effective capacity for our proposed schemes. Our simulations show that our proposed schemes outperform the existing schemes in guaranteeing heterogeneous statistical delay/error-rate bounded QoS.

COMPREHENSIVE SURVEY OF WIRELESS COGNITIVE AND 5G NETWORKS

The tremendous progress in the wireless mobile communication devices and the continuous growth in the data rates and the usage with the entailment of enhanced performance in the network in the terms of the throughput, delay, energy utilization, data capacity, bandwidth utilization and the cost have led to the emergence of the 5G networks. The flexible transmission empowered by the cognitive radio networks make them prominent in the transmission of the applications that are significant and sensitive to latency. The paper surveys the details of the 5G network, the cognitive radio networks and the impacts in the network by having the cognitive radio in the 5G mobile wireless networks.

Low Complexity GFDM Receiver for Frequency-Selective Channels

Generalized frequency division multiplexing (GFDM) is a new waveform that can play an important role in some 5th generation (5G) mobile wireless networks scenarios, such as 5G for remote areas. It offers low out-of-band emission, good spectral efficiency and has the flexibility to cover the 5G requirements in remote areas applications. The GFDM receiver implementation complexity poses restrictions to the use of this powerful waveform in constrained resources devices such as the ones used in the Internet of Things (IoT). This letter proposes, an innovative frequency-domain equalizer showing complexity close to the zero-forcing (ZF) receiver while achieving performance close to the Minimum Mean Square Error (MMSE) receiver. The study also evaluates the proposed equalizer performance under frequency selective fading channel for the single-input/single-output (SISO) and multiple-input/multiple-output (MIMO) cases. The results show that with a small increment in complexity a performance gain can be obtained.

Full-Duplex Secure Relay Beamforming Design for Systems With Perfect and Partial CSI

Considering that wireless unidirectional full-duplex (FD) transmission is one of the FD transmissions over 5G mobile wireless networks, this paper proposes a joint receive and transmit relay beamformer design for systems consisting of a source, a FD relay, an intended destination, and an eavesdropper. The source and destination are single-antenna nodes, whereas the FD relay is a multi-antenna node. Assuming that full channel state information (CSI) is available and the eavesdropper processes two blocks of received data at a time, the joint optimization problem is reformulated as a semidefinite relaxation (SDR) problem (in terms of relay transmit beamformer), which is tight in the sense that the rank-one beamformer can always be recovered from the SDR solution. In order to significantly minimize the computational cost of the SDR implementation, a novel semi-analytical approach based on dual optimization is proposed to obtain the optimum transmit beamformer. When the number of data blocks is arbitrary, we propose a successive convex approximation approach for solving the original non-convex optimization problem and show that a stationary solution can be efficiently obtained. We then propose a distributionally robust beamformer design for the case of an arbitrary number of blocks, assuming that the means and covariance matrices of the eavesdropper's channels are known. Computer simulations show that the proposed semi-analytical solution matches with that obtained from numerical optimization of the SDR problem, the FD scheme significantly outperforms its half-duplex counterpart, and the proposed robust design provides robustness against CSI uncertainty.

Scalable Virtualization and Offloading-Based Software-Defined Architecture for Heterogeneous Statistical QoS Provisioning Over 5G Multimedia Mobile Wireless Networks

As a crucial step moving towards the next generation of super-fast wireless networks, recently the fifth-generation (5G) mobile wireless networks have received a plethora of research attention and efforts from both the academia and industry. The 5G mobile wireless networks are expected to provision distinct delay-bounded quality of service (QoS) guarantees for a wide range of multimedia services, applications, and users with extremely diverse requirements. However, how to efficiently support multimedia services over 5G wireless networks has imposed many new challenging issues not encountered before in the fourth-generation wireless networks. To overcome these new challenges, we propose a novel network-function virtualization and mobile-traffic offloading based software-defined network (SDN) architecture for heterogeneous statistical QoS provisioning over 5G multimedia mobile wireless networks. Specifically, we develop the novel SDN architecture to scalably virtualize wireless resources and physical infrastructures, based on user’s locations and requests, into three types of virtual wireless networks: virtual networks without offloading, virtual networks with WiFi offloading, and virtual networks with device-to-device offloading. We derive the optimal transmit power allocation schemes to maximize the aggregate effective capacity, overall spectrum efficiency, and other related performances for these three types of virtual wireless networks. We also derive the scalability improvements of our proposed three integrated virtual networks. Finally, we validate and evaluate our developed schemes through numerical analyses, showing significant performance improvements as compared with other existing schemes.

Hierarchical Caching for Statistical QoS Guaranteed Multimedia Transmissions over 5G Edge Computing Mobile Wireless Networks

The 5G mobile wireless networks are expected to provision distinct delay-bounded QoS guarantees for a wide range of multimedia services, applications, and users with extremely diverse requirements. On the other hand, how to efficiently support multimedia services over 5G wireless networks has imposed many new challenging issues not encountered before in 4G wireless networks. Bringing data contents closer to mobile users, the caching-based content- centric edge computing network is a promising candidate network architecture and technique to efficiently guarantee QoS for time-sensitive multimedia transmissions over 5G mobile wireless networks. However, how to collaboratively integrate in-network caching and edge computing for multimedia transmissions over 5G wireless networks has been neither well understood nor thoroughly studied. To remedy these difficulties, in this article we propose hierarchical-caching-based content-centric network architectures and their three different implementation/ control mechanisms over 5G edge computing mobile multimedia wireless networks, where popular multimedia data contents can be cached at different network tiers (e.g., routers, base stations, and mobile devices) to guarantee the statistical delay-bounded QoS for multimedia transmissions while minimizing redundant transmissions. We propose three hierarchical edge caching mechanisms: random hierarchical caching, which maximizes the average effective capacity based on the users' request frequency (i.e., data popularity); proactive hierarchical caching, which maximizes the cache hitting rate by predicting the popularity of data contents and caching the data contents with high popularity nearby mobile users; and game-theory-based hierarchical caching, where three network caching tiers are formulated as three game players in a cooperative game to maximize their aggregate effective capacity under the constraints of caching expenses at each tier. We develop three concrete algorithms to implement and control the three hierarchical caching mechanisms, respectively, for statistical delay-bounded QoS guaranteed multimedia transmissions. Using simulations and numerical analyses, we show that our proposed three hierarchical caching mechanisms significantly outperform other existing schemes in supporting the statistical delay-bounded QoS provisioning over 5G edge computing mobile wireless networks.

MEC Coordinated Future 5G Mobile Wireless Networks

MEC Coordinated Future 5G Mobile Wireless Networks

Security for 5G Mobile Wireless Networks

The advanced features of 5G mobile wireless network systems yield new security requirements and challenges. This paper presents a comprehensive study on the security of 5G wireless network systems compared with the traditional cellular networks. The paper starts with a review on 5G wireless networks particularities as well as on the new requirements and motivations of 5G wireless security. The potential attacks and security services are summarized with the consideration of new service requirements and new use cases in 5G wireless networks. The recent development and the existing schemes for the 5G wireless security are presented based on the corresponding security services, including authentication, availability, data confidentiality, key management, and privacy. This paper further discusses the new security features involving different technologies applied to 5G, such as heterogeneous networks, device-to-device communications, massive multiple-input multiple-output, software-defined networks, and Internet of Things. Motivated by these security research and development activities, we propose a new 5G wireless security architecture, based on which the analysis of identity management and flexible authentication is provided. As a case study, we explore a handover procedure as well as a signaling load scheme to show the advantages of the proposed security architecture. The challenges and future directions of 5G wireless security are finally summarized.

Outage Performance for IDF Relaying Mobile Cooperative Networks

Cooperative communication has emerged as a key technique in fifth generation (5G) mobile wireless networks. In this paper, with incremental decode-and-forward (IDF) relaying and transmit antenna selection (TAS), we investigate the outage probability (OP) performance of mobile cooperative networks. Exact closed-form expressions for OP with optimal TAS are derived. These expressions are used to evaluate the impact of power allocation on OP performance. Then we verify the mathematical derivations using Monte Carlo simulations. The OP performance is influenced by power-allocation parameter.

5G

Explosive growth in data traffic for mobile networks — fueled by applications such as ultra-high-definition video or augmented reality — is driving the industry toward fifth-generation (5G) mobile wireless networks. Many advances are underway, covering wireless access and network technologies. This special issue discusses TCP/multipath-TCP with new mmWave radio bands, network slicing, and dynamic botnet detection in 5G.

Crowd-Funding: A New Resource Cooperation Mode for Mobile Cloud Computing.

Mobile cloud computing, which integrates the cloud computing techniques into the mobile environment, is regarded as one of the enabler technologies for 5G mobile wireless networks. There are many sporadic spare resources distributed within various devices in the networks, which can be used to support mobile cloud applications. However, these devices, with only a few spare resources, cannot support some resource-intensive mobile applications alone. If some of them cooperate with each other and share their resources, then they can support many applications. In this paper, we propose a resource cooperative provision mode referred to as "Crowd-funding", which is designed to aggregate the distributed devices together as the resource provider of mobile applications. Moreover, to facilitate high-efficiency resource management via dynamic resource allocation, different resource providers should be selected to form a stable resource coalition for different requirements. Thus, considering different requirements, we propose two different resource aggregation models for coalition formation. Finally, we may allocate the revenues based on their attributions according to the concept of the "Shapley value" to enable a more impartial revenue share among the cooperators. It is shown that a dynamic and flexible resource-management method can be developed based on the proposed Crowd-funding model, relying on the spare resources in the network.

Evolution Toward 5G Mobile Networks – A Survey on Enabling Technologies

In this paper, an extensive review has been carried out on the trends of existing as well as proposed potential enabling technologies that are expected to shape the fifth generation (5G) mobile wireless networks. Based on the classification of the trends, we develop a 5G network architectural evolution framework that comprises three evolutionary directions, namely, (1) radio access network node and performance enabler, (2) network control programming platform, and (3) backhaul network platform and synchronization. In (1), we discuss node classification including low power nodes in emerging machine-type communications, and network capacity enablers, e.g., millimeter wave communications and massive multiple-input multiple-output. In (2), both logically distributed cell/device-centric platforms, and logically centralized conventional/wireless software defined networking control programming approaches are discussed. In (3), backhaul networks and network synchronization are discussed. A comparative analysis for each direction as well as future evolutionary directions and challenges toward 5G networks are discussed. This survey will be helpful for further research exploitations and network operators for a smooth evolution of their existing networks toward 5G networks.

Statistical-QoS Driven Energy-Efficiency Optimization Over Green 5G Mobile Wireless Networks

Since the Information and Communications Technologies (ICT) were designed without taking the energy-saving into account, the unexpected excessive energy consumption of the fourth-generation (4G) and pre-4G wireless networks causes serious carbon dioxide emissions. To achieve green wireless networks, the fifth-generation (5G) wireless networks are expected to significantly increase the network energy efficiency while guaranteeing the quality of service (QoS) for time-sensitive multimedia wireless traffics. In this paper, we develop the statistical delay-bounded QoS driven green power allocation schemes to maximize the effective power efficiency (EPE), which is defined as the statistical-QoS-guaranteed throughput (effective capacity) per unit power, over single-input single-output (SISO) and multipleinput multiple-output (MIMO)-channels based 5G mobile wireless networks. For the SISO-channel based 5G wireless networks, our developed QoS-driven green power allocation scheme converges to the despicking water-filling scheme (despicking channel inversion scheme) when the QoS constraint becomes very loose (stringent). We further develop and analyze the statistical-QoS-driven green power allocation scheme to maximize the EPE over the multiplexing-MIMO based 5G mobile wireless networks. The obtained numerical results show that our developed statistical QoS-driven green power allocation schemes can optimize the EPE over 5G mobile wireless networks, thus enabling the effective implementation of green 5G wireless networks.

Full-duplex transmission in phy and mac layers for 5G mobile wireless networks

As the fourth-generation (4G) standards have been successfully deployed in all 4G-based wireless communication industries and mobile devices, research attention and the efforts of academia and industry have already moved onto fifth-generation (5G) technologies. While the frequency-division duplexing (FDD) and timedivision duplexing (TDD) are widely used in 4G mobile wireless networks, they have their inherent deficiencies of low spectrum efficiency because FDD and TDD are both based on the half-duplex transmission mode. To overcome these problems existing in 4G systems, in this article we propose novel wireless full-duplex transmission schemes in both the PHY and MAC layers for 5G mobile wireless networks to significantly increase the spectrum efficiency. In particular, we first develop the wireless fullduplex model for both bidirectional transmission and unidirectional transmission, respectively, taking into account self-interference mitigation. Then we analyze the traditional half-duplex FDD and TDD modes and show the superiority of the wireless full-duplex mode over the halfduplex FDD and TDD modes, respectively. Using our developed wireless full-duplex model, we develop and evaluate the efficient full-duplex power allocation scheme at the PHY layer. Corresponding to full-duplex transmission at the PHY layer, we also develop and analyze the fullduplex MAC protocol at the MAC layer to implement full-duplex transmission over the entire 5G mobile wireless network architecture. Through simulation experiments we show that our proposed schemes can significantly enhance spectrum efficiency for 5G mobile wireless networks.

Information-centric network function virtualization over 5g mobile wireless networks

Wireless network virtualization and information-centric networking (ICN) are two promising techniques in software-defined 5G mobile wireless networks. Traditionally, these two technologies have been addressed separately. In this paper we show that integrating wireless network virtualization with ICN techniques can significantly improve the end-to-end network performance. In particular, we propose an information- centric wireless network virtualization architecture for integrating wireless network virtualization with ICN. We develop the key components of this architecture: radio spectrum resource, wireless network infrastructure, virtual resources (including content-level slicing, network-level slicing, and flow-level slicing), and informationcentric wireless virtualization controller. Then we formulate the virtual resource allocation and in-network caching strategy as an optimization problem, considering the gain of not only virtualization but also in-network caching in our proposed information-centric wireless network virtualization architecture. The obtained simulation results show that our proposed information-centric wireless network virtualization architecture and the related schemes significantly outperform the other existing schemes.