Latency Analysis of Systems with Multiple Interfaces for Ultra-Reliable M2M Communication

One of the ways to satisfy the requirements of ultra-reliable low latency communication for mission critical Machine-type Communications (MTC) applications is to integrate multiple communication interfaces. In order to estimate the performance in terms of latency and reliability of such an integrated communication system, we propose an analysis framework that combines traditional reliability models with technology-specific latency probability distributions. In our proposed model we demonstrate how failure correlation between technologies can be taken into account. We show for the considered scenario with fiber and different cellular technologies how up to 5-nines reliability can be achieved and how packet splitting can be used to reduce latency substantially while keeping 4-nines reliability. The model has been validated through simulation.Comment: Accepted for IEEE SPAWC'1

Ultra-Reliable Low Latency Communication (URLLC) using Interface Diversity

An important ingredient of the future 5G systems will be Ultra-Reliable Low-Latency Communication (URLLC). A way to offer URLLC without intervention in the baseband/PHY layer design is to use interface diversity and integrate multiple communication interfaces, each interface based on a different technology. In this work, we propose to use coding to seamlessly distribute coded payload and redundancy data across multiple available communication interfaces. We formulate an optimization problem to find the payload allocation weights that maximize the reliability at specific target latency values. In order to estimate the performance in terms of latency and reliability of such an integrated communication system, we propose an analysis framework that combines traditional reliability models with technology-specific latency probability distributions. Our model is capable to account for failure correlation among interfaces/technologies. By considering different scenarios, we find that optimized strategies can in some cases significantly outperform strategies based on $k$-out-of-$n$ erasure codes, where the latter do not account for the characteristics of the different interfaces. The model has been validated through simulation and is supported by experimental results.Comment: Accepted for IEEE Transactions on Communication

A Framework for Ultra Reliable Low Latency Mission Critical Communication

Title from PDF of title page viewed June 22, 2017Thesis advisor: Cory BeardVitaIncludes bibliographical references (pages 26-29)Thesis (M.S.)--School of Computing and Engineering. University of Missouri--Kansas City, 2017Mission-critical communication is one of the central design aspects of 5G communications. But there are numerous challenges and explicit requirements for development of a successful mission-critical communication system. Reliability and delay optimization are the two most crucial among them. Achieving reliability is influenced by several difficulties, including but not limited to fading, mobility, interference, and inefficient resource utilization. Achieving reliability may cost one of the most critical features of mission critical communication, which is delay. This thesis discusses possible strategies to achieve reliability in a mission-critical network. Based on the strategies, a framework for a reliable mission-critical system has also been proposed. A simulation study of the effects of different pivotal factors that affect communication channel is described. This study provides a better understanding of the requirements for improving the reliability of a practical communication system.Introduction -- Related works -- Case studies for mission critical communication -- Strategies to achieve ultra-reliable M2M -- Adaptive mimo system with OSTBC -- Simulation results -- Conclusions and future aspect

Reliability-Oriented Intra-Frequency Dual Connectivity for 5G Systems: Configuration Algorithms and Performance Evaluation

User association in wireless networks has historically been done on the basis of single connectivity, i.e. the user equipment (UE) being connected to a single serving access point (AP). Such a design was quite efficient for conventional homogeneous networks with mostly voice-centric applications. However, as networks become more heterogeneous and services become diverse with different performance requirements, connecting to a single AP has proven to be quite inefficientThe 5th Generation (5G) New Radio (NR) interface is expected to continue utilising the existing homogenous networks for some time in the near future serving a wide range of use cases, one of those cases is Ultra-Reliable Low Latency Communications (URLLC) services. For URLLC, short data packets must be correctly transmitted and received within very short latency up to 1ms with a reliability of 99.999%. There are several options being proposed to meet this difficult design target. One very promising suggested solution is the dual connectivity with data duplication, where the same packet is duplicated and independently transmitted via two different nodes. This work uses a system-level simulation to study how the data duplication at PDCP level for dual connectivity is functioning, where every copy of the designated packet is sent via the two connections that a certain User Equipment (UE) is connected. The studied scenario is a homogeneous network of 21 macro cells of 500m inter-site distance. The scenario is first optimized for the single connectivity mode, which supports less than 1Mbps URLLC offered load while meeting the IMT2020 latency requirements. As we enable dual connectivity, in a URLLC traffic only scenario, it is shown that dual connectivity provides some noticeable gain by enabling the support of up to 1.5Mbps URLLC load within the URLLC requirements but not improving the low load criteria in comparison to single connectivity results due to the low interference condition in single connectivity. As a second stage, the gain of DC is studied when the URLLC traffic coexist with a heavy full buffer background eMBB traffic. Results show that a latency gain as well as higher load support than the single connectivity case can be obtained by dual connectivity, however the sensitivity of this gain on the scenario conditions is very high. Finally, an enhanced duplication configuration is added, that is if a packet is successfully sent through one of the links and correctly decoded at the UE, the duplicated copy transmission on the other link is cancelled (i.e. the packet is dropped at the network side). This results in a significant performance improvement in terms of the latency and supported URLLC load especially at relatively high load because it avoids the queuing delay

Multiterminal Source-Channel Coding

Cooperative communication is seen as a key concept to achieve ultra-reliable communication in upcoming fifth-generation mobile networks (5G). A promising cooperative communication concept is multiterminal source-channel coding, which attracted recent attention in the research community. This thesis lays theoretical foundations for understanding the performance of multiterminal source-channel codes in a vast variety of cooperative communication networks. To this end, we decouple the multiterminal source-channel code into a multiterminal source code and multiple point-to-point channel codes. This way, we are able to adjust the multiterminal source code to any cooperative communication network without modification of the channel codes. We analyse the performance in terms of the outage probability in two steps: at first, we evaluate the instantaneous performance of the multiterminal source-channel codes for fixed channel realizations; and secondly, we average the instantaneous performance over the fading process. Based on the performance analysis, we evaluate the performance of multiterminal source-channel codes in three cooperative communication networks, namely relay, wireless sensor, and multi-connectivity networks. For all three networks, we identify the corresponding multiterminal source code and analyse its performance by the rate region for binary memoryless sources. Based on the rate region, we derive the outage probability for additive white Gaussian noise channels with quasi-static Rayleigh fading. We find results for the exact outage probability in integral form and closed-form solutions for the asymptotic outage probability at high signal-to-noise ratio. The importance of our results is fourfold: (i) we give the ultimate performance limits of the cooperative communication networks under investigation; (ii) the optimality of practical schemes can be evaluated with respect to our results, (iii) our results are suitable for link-level abstraction which reduces complexity in network-level simulation; and (iv) our results demonstrate that all three cooperative communication networks are key technologies to enable 5G applications, such as device to device and machine to machine communications, internet of things, and internet of vehicles. In addition, we evaluate the performance improvement of multiterminal source-channel codes over other (non-)cooperative communications concepts in terms of the transmit power reduction given a certain outage probability level. Moreover, we compare our theoretical results to simulated frame-error-rates of practical coding schemes. Our results manifest the superiority of multiterminal source-channel codes over other (non-)cooperative communications concepts