Ultra-reliable Communication Research Articles

Reducing computation time of a wireless resource scheduler by exploiting temporal channel characteristics

The long term evolution downlink scheduler must attain a low computation time as it performs scheduling decisions every 1 ms. 5G New Radio introduced mini-slots for the purpose of ultra-reliable and low-latency communications further shrinking the time to make scheduling decisions to 0.125 ms. Many optimal scheduling schemes have such high computation times that they are not suitable for implementation. Previous works generally attack this problem from a computational complexity theory perspective and devise alternative non-optimal problem formulations. Here, we tackle the problem from a practical point of view and propose to reduce the quantity of users and resources in the scheduling problem over a given time. We achieve this by scheduling relatively slow varying signal-to-noise ratio (SNR) users not as frequently but for relatively longer time durations. To evaluate the performance of our idea, we derive a novel correlated bivariate received SNR distribution. The derived distribution can also be applied to a signal-to-interference ratio limited system. We show that the number of operations it takes to make scheduling decisions can be reduced by 33% with confidence probability of 0.7 and by 58% with confidence probability of 0.4. We also evaluate the potential drawbacks of the proposed scheme in terms of efficiency and error rate.

Ultra-Reliable Communications for Industrial Internet of Things: Design Considerations and Channel Modeling

Factory automation is the next industrial revolution. 5G and IIoT are enabling smart factories to seamlessly create a network of wirelessly connected machines and people that can instantaneously collect, analyze, and distribute real-time data. A 5G-enabled communication network for IIOT will boost overall efficiency, launching a new era of market opportunities and economic growth. This article presents the 5G-enabled system architecture and ultra-reliable use cases in smart factories associated with automated warehouses. In particular, for URLLC-based cases, key techniques and their corresponding solutions, including diversity for high reliability, short packets for low latency, and on-the-fly channel estimation and decoding for fast receiver processing, are discussed. Then the channel modeling requirements concerning technologies and systems are also identified in industrial scenarios. Ray tracing channel simulation can meet such requirements well, and based on that, the channel characteristic analysis is presented at 28 and 60 GHz for licensed and unlicensed band frequencies to exploit the available degrees of freedom in the channels.

Massive MIMO is a reality—What is next?: Five promising research directions for antenna arrays

Massive MIMO (multiple-input multiple-output) is no longer a “wild” or “promising” concept for future cellular networks—in 2018 it became a reality. Base stations (BSs) with 64 fully digital transceiver chains were commercially deployed in several countries, the key ingredients of Massive MIMO have made it into the 5G standard, the signal processing methods required to achieve unprecedented spectral efficiency have been developed, and the limitation due to pilot contamination has been resolved. Even the development of fully digital Massive MIMO arrays for mmWave frequencies—once viewed prohibitively complicated and costly—is well underway. In a few years, Massive MIMO with fully digital transceivers will be a mainstream feature at both sub-6GHz and mmWave frequencies.In this paper, we explain how the first chapter of the Massive MIMO research saga has come to an end, while the story has just begun. The coming wide-scale deployment of BSs with massive antenna arrays opens the door to a brand new world where spatial processing capabilities are omnipresent. In addition to mobile broadband services, the antennas can be used for other communication applications, such as low-power machine-type or ultra-reliable communications, as well as non-communication applications such as radar, sensing and positioning. We outline five new Massive MIMO related research directions: Extremely large aperture arrays, Holographic Massive MIMO, Six-dimensional positioning, Large-scale MIMO radar, and Intelligent Massive MIMO.

Availability of Cellular Systems Based on Space Domain

Ultra-Reliable Communication (URC) is one of the promising features in 5G to provide anytime and anywhere services to the end users. Services related to URC require a high level of reliability and availability. Hence, investigation of system’s availability in anytime and anywhere is considered as one of the important topics that would improve the quality and performance of systems. This paper focuses on studying the availability and reliability in the space domain for regular, irregular, and hybrid cell construction schemes. The hybrid construction will be proposed in this work as the more realistic one. The availability analysis for the new model is also studied and results comparison is carried out with those of regular and irregular models. The availability study for static and mobile end-users with different patterns of mobility for individual and multi-cell networks are also considered in this paper. At the end of the paper, the total transmission power for the three schemes considered in case of the homogenous (HomNets) and heterogeneous (HetNet) networks is also considered. Moreover, the power control, path loss, shadowing, Bit Error Rate and Spectral Efficiency are also considered in this work.

Wireless Channel Modeling Perspectives for Ultra-Reliable Communications

Ultra-reliable communication (URC) is one of the distinctive features of the upcoming 5G wireless communication, characterized by packet error rates going down to 10−9. In this paper, we analyze the tail of the cumulative distribution function of block fading channels in the regime of extremely rare events, i.e., the ultra-reliable (UR) regime of operation. Our main contribution consists of providing a unified framework for statistical description of wide range of practically important wireless channel models in the UR regime of operation. Specifically, we show that the wireless channel behavior in this regime can be approximated by a simple power law expression, whose exponent and offset depend on the actual channel model. The unification provides a channel-agnostic tool for analyzing and performance optimization of radio systems that operate in the UR regime. Furthermore, the unified model is particularly useful in the emerging measurement campaigns for empirical characterization of wireless channels in the regime of low outages. Finally, the asymptotic analysis can serve as an underlying building block for designing more elaborate, higher-layer technologies for URC. We showcase this by applying the power law results to analyze the performance of receiver diversity schemes and obtain a new simplified expression for maximum ratio combining.

Reliable Transmission of Short Packets Through Queues and Noisy Channels Under Latency and Peak-Age Violation Guarantees

This paper investigates the probability that the delay and the peak-age of information exceed a desired threshold in a point-to-point communication system with short information packets. The packets are generated according to a stationary memoryless Bernoulli process, placed in a single-server queue and then transmitted over a wireless channel. A variable-length stop-feedback coding scheme—a general strategy that encompasses simple automatic repetition request (ARQ) and more sophisticated hybrid ARQ techniques as special cases—is used by the transmitter to convey the information packets to the receiver. By leveraging finite-blocklength results, the delay violation and the peak-age violation probabilities are characterized without resorting to approximations based on larg-deviation theory as in previous literature. Numerical results illuminate the dependence of delay and peak-age violation probability on system parameters such as the frame size and the undetected error probability, and on the chosen packet-management policy. The guidelines provided by our analysis are particularly useful for the design of low-latency ultra-reliable communication systems.

Micro and Macro Network Slicing: An Experimental Assessment of the Impact of Increasing Numbers of Slices

The fifth generation (5G) telecommunications network aims not only to enhance traffic performance and allow efficient management, but also to enable it to dynamically and flexibly adapt to the traffic demands of different vertical scenarios. In order to support that enablement, the underlying network procedures (i.e., network functions) are being virtualized and deployed in cloud-based environments, allowing for a more optimized usage of the infra-structure resources. In addition, such resources can be sliced, allowing isolated provisioning to specific network functions allocated to disparate vertical deployments. As network slices are envisaged by network operators to fulfill a small number of slices, able to cater towards essential 5G scenario demands (i.e., enhanced mobile broadband, massive machine-type communications and ultra reliable low-latency communications), the total amount of slices existing in a system is currently dictated by the underlying operational overhead placed over the cloud infra-structure. This paper explores the challenges associated to a vision where the network slicing concept is applied with a much greater level of granularity, ultimately allowing it to become a core mechanism of the network’s operation, with large numbers of co-existing slices. In that respect, this paper proposes an architecture framework for instantiation of network slices among network providers, which in turn are able to instantiate sub-slices tailored to use cases and vertical tenants. The evaluation of this concept is done following a two-pronged approach: firstly, different slice dimensions (i.e., from micro to macro) are proposed and discussed, pointing out the benefits and challenges of each proposed slice; secondly, we deployed a mobile network provider (MNO), using OpenAirInterface and FlexRAN frameworks, and experimentally evaluated the its slicing mechanisms. The objective is to provide insight on the challenges and impact associated with the deployment of an increasing amount of slices, using the same available infra-structural resources.

QoS Management and Flexible Traffic Detection Architecture for 5G Mobile Networks.

The next generation of 5G networks is being developed to provide services with the highest Quality of Service (QoS) attributes, such as ultra-low latency, ultra-reliable communication, high data rates, and high user mobility experience. To this end, several new settings must be implemented in the mobile network architecture such as the incorporation of Network Function Virtualization (NFV) and Software-Defined Networking (SDN), along with the shift of processes to the edge of the network. This work proposes an architecture combining the NFV and SDN concepts to provide the logic for Quality of Service (QoS) traffic detection and the logic for QoS management in next-generation mobile networks. It can be applied to the mobile backhaul and the mobile core network to work with both 5G mobile access networks or current 4G access networks, keeping backward compatibility with current mobile devices. In order to manage traffic without QoS and with QoS requirements, this work incorporates Multiprotocol Label Switching (MPLS) in the mobile data plane. A new flexible and programmable method to detect traffic with QoS requirements is also proposed, along with an Evolved Packet System (EPS)-bearer/QoS-flow creation with QoS considering all elements in the path. These goals are achieved by using proactive and reactive path setup methods to route the traffic immediately and simultaneously process it in the search for QoS requirements. Finally, a prototype is presented to prove the benefits and the viability of the proposed concepts.

5G Enabled Technologies for Smart Education

5G technology use cases depicts the prospects of 5G network model to revolutionize Industry and Education is not an exception. The 5G model in general is made up of three main blocks: Enhanced Mobile Broadband, Massive Machine Type Communication and Ultra Reliable and Low Latency Communication. Within these blocks are the services 5G offers to users. In this paper, we focus on Educational users as beneficiaries of 5G technologies. The modern day Educational Institutions can benefit from the deployment of 5G-enabled services adapted to this sector. We proposed frameworks relating 5G and its disruptive technologies in advancing tools that will propel the idea of a Smart Educational System. This paper hence provides a comprehensive discussion on 5G technologies that will facilitate new teaching and learning trends in Educational environment.

Delay Guaranteed Network Association for Mobile Machines in Heterogeneous Cloud Radio Access Network

In the heterogeneous cloud radio access network (H-CRAN), which consists of multiple access points (APs) providing smaller coverage and a high power node (HPN) providing ubiquitous coverage, the mobile machines can connect to multiple APs and HPN by coordinated multi-point transmission (CoMP) concurrently to achieve ultra-reliable and low-latency communication. However, the current network association (or priorly known as handovers), which only focuses on switching between two base stations, may not be an efficient scheme in H-CRAN. In this paper, we innovate a proactive network association mechanism by taking CoMP into consideration under the H-CRAN architecture. We consider two scenarios under the H-CRAN architecture: with and without the assistance of HPN in the network. By regarding APs/HPN in H-CRAN as resources that allocated to mobile machines, a novel proactive network association concept is proposed, and then generalized from one-to-one to multiple-to-multiple case. With the assistance of Lyapunov optimization theory , effective bandwidth, and capacity theory , we can prove that this proactive network association scheme can guarantee that the queueing delay performance and the delay violation probability can be both smaller than a corresponding upper bound. That is, both low-latency and ultra-reliable communication can be guaranteed. We also conduct experiments by using real trace from taxis movement data to verify the analytical results. Our results suggest the guidelines to design the proactive network association scheme in H-CRAN.

Ultra-Reliable IoT Communications with UAVs: A Swarm Use Case

UAVs are powerful IoT components, offering sensing, communications and data analysis in the air. Recently, 3GPP TS 22.261, TR 22.862, and TR 36.777 have specified performance requirements for communications between multiple UAVs in the 5G domain. This article discusses communications reliability challenges in a UAV swarm context. Recommendations for designing an ultra-reliable communications system for UAV swarms are introduced with a focus on the software protocol stack and RF hardware. For the purpose of demonstration, we developed Easy- Swarm, an open-source UAV swarming platform that adopts the LoRa radio at the physical layer and a low-latency channel access protocol at the MAC layer. Real-life testbeds are built consisting of 10 UAVs and 20 robotic cars that produce background traffic. LoRa, WiFi and LTE networks are employed to provide broadband and cellular wireless network support. Results show that using LoRa leads to better reliability, in particular allowing for higher swarm density and longer coverage distance, than when WiFi is used. In addition, LTE provides the best reliability and latency for UAV swarms with good network connectivity.

Pure-Exploration Bandits for Channel Selection in Mission-Critical Wireless Communications

In emergency communications, guaranteeing ultrareliable and low-latency communication is challenging yet crucial to save human lives and to coordinate the operations of first responders. To address this problem, we introduce a general approach for channel selection in mission-critical communications, i.e., choose channels with the best quality timely and accurately via channel probing. Since the channel conditions are dynamic and initially unknown to wireless users, choosing channels with the best conditions is nontrivial. Thus, we adopt online learning methods to let users probe channels and predict the channel conditions by a restricted time interval of observation. We formulate this problem as an emerging branch of the classic multiarmed bandit (MAB) problem, namely the pure-exploration bandit problem, to achieve a tradeoff between sampling time/resource budget and the channel selection accuracy (i.e., the probability of selecting optimal channels). The goal of the learning process is to choose the “optimal subset” of channels after a limited time period of channel probing. We propose and evaluate one learning policy for the single-user case and three learning policies for the distributed multiuser cases. We take communication costs and interference costs into account, and analyze the tradeoff between these costs and the accuracy of channel selection. Extensive simulations are conducted and the results show that the proposed algorithms can achieve considerably higher channel selection accuracy than previous exploration bandit approaches and classic MAB methods.

Sparse Vector Coding for Ultra Reliable and Low Latency Communications

Ultra reliable and low latency communication (URLLC) is a newly introduced service category in 5G to support delay-sensitive applications. In order to support this new service category, the 3rd Generation Partnership Project (3GPP) sets an aggressive requirement that a packet should be delivered with 10−5 packet error rate within 1-ms transmission period. Since the current wireless transmission scheme, which is designed to maximize the coding gain by transmitting the capacity achieving long codeblock, is not relevant for this purpose, and a new transmission scheme to support URLLC is required. In this paper, we propose a new approach to support the short packet transmission, called sparse vector coding (SVC). The key idea behind the proposed SVC technique is to transmit the information after the sparse vector transformation. By mapping the information into the position of nonzero elements and then transmitting it after random spreading, we obtain an underdetermined sparse system for which the principle of compressed sensing can be applied. From the numerical evaluations and performance analysis, we demonstrate that the proposed SVC technique is very effective in URLLC transmission and outperforms the 4G LTE and LTE-Advanced scheme.

Diversity Enhancing Multiple-Mode OFDM With Index Modulation

As an emerging multi-carrier transmission scheme, multiple-mode orthogonal frequency division multiplexing with index modulation (MM-OFDM-IM) conveys information through multiple distinguishable constellations (or modes, alternatively) and their full permutations, increasing the spectral efficiency of OFDM-IM and classical OFDM. However, both MM-OFDM-IM and its extension, that is, MM-OFDM with in-phase/quadrature index modulation (MM-OFDM-IM-IQ), cannot provide any transmit diversity gain, which may be critical for ultra-reliable communications. In this paper, aiming at enhancing the diversity gain of MM-OFDM-IM(-IQ) schemes, coordinate interleaved (CI-)MM-OFDM-IM and linear constellation precoded (LCP-) MM-OFDM-IM-IQ are proposed, both of which achieve a diversity order of two without loss of spectral efficiency. The optimal rotation angle for CI-MM-OFDM-IM and the optimal precoding matrix for LCP-MM-OFDM-IM-IQ, in the sense of maximizing their coding gains, are derived in closed form. Computer simulations corroborate the advantages of the proposed schemes in terms of diversity and bit error rate performance toward next-generation wireless networks.

Ultra-Reliable Communication in 5G mmWave Networks: A Risk-Sensitive Approach

This letter investigates the problem of providing gigabit wireless access with reliable communication in 5G millimeter-Wave (mmWave) massive multiple-input multiple-output (MIMO) networks. In contrast to the classical network design based on average metrics, a distributed risk-sensitive reinforcement learning-based framework is proposed to jointly optimize the beamwidth and transmit power, while taking into account the sensitivity of mmWave links due to blockage. Numerical results show that our proposed algorithm achieves more than 9 Gbps of user throughput with a guaranteed probability of 90%, whereas the baselines guarantee less than 7.5 Gbps. More importantly, there exists a rate-reliability-network density tradeoff, in which as the user density increases from 16 to 96 per km2, the fraction of users that achieve 4 Gbps are reduced by 11.61% and 39.11% in the proposed and the baseline models, respectively.

Ultra-Reliable Cooperative Short-Packet Communications With Wireless Energy Transfer

We analyze a cooperative wireless communication system with finite block length and finite battery energy, under quasi-static Rayleigh fading. Source and relay nodes are powered by a wireless energy transfer process, while using the harvested energy to feed their circuits, send pilot signals to estimate channels at receivers, and for wireless information transmission. Other power consumption sources beyond data transmission power are considered. The error probability is investigated under perfect/imperfect channel state information, while reaching accurate closed-form approximations in ideal direct communication system setups. We consider ultra-reliable communication (URC) scenarios under discussion for the next fifth-generation (5G) of wireless systems. The numerical results show the existence of an optimum pilot transmit power for channel estimation, which increases with the harvested energy. We also show the importance of cooperation, even taking into account the multiplexing loss, in order to meet the error and latency constraints of the URC systems.

Rate‐compatible ARACA codes

A design method for rate-compatible (RC) accumulate repeat accumulate check accumulate (ARACA) codes as protograph-based RC low-density parity-check codes is presented. The proposed RC-ARACA codes provide not only good iterative decoding thresholds with the linear minimum distance growth property but also efficient encoder/decoder structures with low complexities, so that they are appropriate to ultra-reliable and low latency communication services for fifth generation.

Achieving Ultra Reliable Communication in 5G Networks: A Dependability Perspective Availability Analysis in the Space Domain

As part of the 5G communication paradigm, ultra reliable communication (URC) is envisaged as an important technology pillar for providing anywhere and anytime services to end users. While most existing studies on reliable communication do not investigate this problem from a dependability theory perspective, those dependability-based studies tend to define reliability merely in the time domain. In this letter, we advocate extending the concept of URC from the dependability perspective also in the space domain . We initiate definitions on cell availability and system availability. The availability and the probability of providing a guaranteed level of availability in a network are analyzed both/either cell-wise and/or system-wise. Poisson point process and Voronoi tessellation are adopted to model the spatial characteristics of cell deployment in both homogeneous and heterogeneous networks.

Upcoming 5-G Wireless technology and its security concept

Abstract: The abbreviation of 5G technology is fifth generation technology. Today globalization in telecommunication has seen lots of improvements like 0G, 1G to 2.5G and from 3G to 5G. 5G is a major phase of mobile telecommunication beyond 4G standard. 5G technology is not currently commercially used for any country of the world. 5G supported voice over IP (VOIP) enabled devices. The advantages of 5G technology are that users can simultaneously connect to the multiple wireless devices. The aim of 5G planning is to provide the higher density of mobile broadband users and supporting device-to-device ultra-reliable and massive machine communications and lower latency than 4G and lower battery consumption for better implementation of the internet of things.5G wireless technology is depend on IEEE 802.11 wireless technology. Wireless local area network (WLAN) wireless metropolitan area (WLAN) and AD-hoc wireless technology are included in 5G wireless technology. This paper cover the security of 5G wireless technology. The main aim is to provide protection of 5G wireless technology

Ultrareliable Short-Packet Communications With Wireless Energy Transfer

We analyze and optimize a wireless system with energy transfer in the downlink and information transfer in the uplink, under quasi-static Nakagami-m fading. We consider ultrareliable communication scenarios representative of the fifth generation of wireless systems, with strict error and latency requirements. The error probability and delay are investigated, and an approximation for the former is given and validated through simulations. The numerical results demonstrate that there are optimum numbers of channels uses for both energy and information transfer for a given message length.