Situation-aware Edge Computing

Future wireless networks must cope with an increasing amount of data that needs to be transmitted to or from mobile devices. Furthermore, novel applications, e.g., augmented reality games or autonomous driving, require low latency and high bandwidth at the same time. To address these challenges, the paradigm of edge computing has been proposed. It brings computing closer to the users and takes advantage of the capabilities of telecommunication infrastructures, e.g., cellular base stations or wireless access points, but also of end user devices such as smartphones, wearables, and embedded systems. However, edge computing introduces its own challenges, e.g., economic and business-related questions or device mobility. Being aware of the current situation, i.e., the domain-specific interpretation of environmental information, makes it possible to develop approaches targeting these challenges. In this thesis, the novel concept of situation-aware edge computing is presented. It is divided into three areas: situation-aware infrastructure edge computing, situation-aware device edge computing, and situation-aware embedded edge computing. Therefore, the concepts of situation and situation-awareness are introduced. Furthermore, challenges are identified for each area, and corresponding solutions are presented. In the area of situation-aware infrastructure edge computing, economic and business-related challenges are addressed, since companies offering services and infrastructure edge computing facilities have to find agreements regarding the prices for allowing others to use them. In the area of situation-aware device edge computing, the main challenge is to find suitable nodes that can execute a service and to predict a node’s connection in the near future. Finally, to enable situation-aware embedded edge computing, two novel programming and data analysis approaches are presented that allow programmers to develop situation-aware applications. To show the feasibility, applicability, and importance of situation-aware edge computing, two case studies are presented. The first case study shows how situation-aware edge computing can provide services for emergency response applications, while the second case study presents an approach where network transitions can be implemented in a situation-aware manner

C-Band Airport Surface Communications System Standards Development. Phase II Final Report. Volume 2: Test Bed Performance Evaluation and Final AeroMACS Recommendations

This report is provided as part of ITT s NASA Glenn Research Center Aerospace Communication Systems Technical Support (ACSTS) contract NNC05CA85C, Task 7: New ATM Requirements-Future Communications, C-Band and L-Band Communications Standard Development and was based on direction provided by FAA project-level agreements for New ATM Requirements-Future Communications. Task 7 included two subtasks. Subtask 7-1 addressed C-band (5091- to 5150-MHz) airport surface data communications standards development, systems engineering, test bed and prototype development, and tests and demonstrations to establish operational capability for the Aeronautical Mobile Airport Communications System (AeroMACS). Subtask 7-2 focused on systems engineering and development support of the L-band digital aeronautical communications system (L-DACS). Subtask 7-1 consisted of two phases. Phase I included development of AeroMACS concepts of use, requirements, architecture, and initial high-level safety risk assessment. Phase II builds on Phase I results and is presented in two volumes. Volume I is devoted to concepts of use, system requirements, and architecture, including AeroMACS design considerations. Volume II (this document) describes an AeroMACS prototype evaluation and presents final AeroMACS recommendations. This report also describes airport categorization and channelization methodologies. The purposes of the airport categorization task were (1) to facilitate initial AeroMACS architecture designs and enable budgetary projections by creating a set of airport categories based on common airport characteristics and design objectives, and (2) to offer high-level guidance to potential AeroMACS technology and policy development sponsors and service providers. A channelization plan methodology was developed because a common global methodology is needed to assure seamless interoperability among diverse AeroMACS services potentially supplied by multiple service providers

셀룰러 사이드링크 성능 향상을 위한 상위계층 기법

학위논문 (박사) -- 서울대학교 대학원 : 공과대학 전기·정보공학부, 2020. 8. 박세웅.In typical cellular communications, User Equipments (UEs) have always had to go through a Base Station (BS) to communicate with each other, e.g., a UE transmits a packet to a BS via uplink and then the BS transmits the packet to another UE via downlink. Although the communication method can serve UEs efficiently, the communication method can cause latency problems and overload problems in BS. Thus, sidelink has been proposed to overcome these problems in 3GPP release 12. Through sidelink, UEs can communicate directly with each other. There are two representative communications using sidelink, i.e., Device-to-Device (D2D) communication and Vehicle-to-Vehicle (V2V) communication. In this dissertation, we consider three strategies to enhance the performances of D2D and V2V communications: (i) efficient feedback mechanism for D2D communications, (ii) context-aware congestion control scheme for V2V communication, and (iii) In-Device Coexistence (IDC)-aware LTE and NR sidelink resource allocation scheme. Firstly, in the related standard, there is no feedback mechanism for D2D communication because D2D communications only support broadcast-type communications. A feedback mechanism is presented for D2D communications. Through our proposed mechanism, UEs can use the feedback mechanism without the help of BS and UEs do not need additional signals to allocate feedback resources. We also propose a rate adaptation algorithm, which consider in-band emission problem, on top of the proposed feedback mechanism. We find that our rate adaptation achieves higher and stable throughput compared with the legacy scheme that complies to the standard. Secondly, we propose a context-aware congestion control scheme for LTE-V2V communication. Through LTE-V2V communication, UEs transmit Cooperative Awareness Message (CAM), which is a periodic message, and Decentralized Environmental Notification Message (DENM), which is a event-driven message and allows one-hop relay. The above two messages have different characteristics and generation rule. Thus, it is difficult and inefficient to apply the same congestion control scheme to two messages. We propose a congestion control schemes for each message. Through the proposed congestion control schemes, UEs decide whether to transmit according to their situation. Through simulation results, we show that our proposed schemes outperform comparison schemes as well as the legacy scheme. Finally, we propose a NR sidelink resource allocation scheme based on multi-agent reinforcement learning, which awares a IDC problem between LTE and NR in Intelligent Transport System (ITS) band. First, we model a realistic IDC interference based on spectrum emission mask specified at the standard. Then, we formulate the resource allocation as a multi-agent reinforcement learning with fingerprint method. Each UE achieves its local observation and rewards, and learns its policy to increase its rewards through updating Q-network. Through simulation results, we observe that the proposed resource allocation scheme further improves Packet Delivery Ratio (PDR) performances compared to the legacy scheme.전형적인 셀룰러 통신에서는, 단말들은 서로 통신하기 위해 항상 기지국을 거쳐야 한다. 예를 들면, 단말이 uplink를 통해 기지국에게 패킷을 전송한 다음 기지국은 downlink를 통해 해당 패킷을 전송해준다. 이러한 통신방식은 단말들에게 효율적으로 서비스를 제공할 수 있지만, 상황에 따라서는 지연문제와 기지국의 과부하 문제를 야기할 수 있다. 따라서 3GPP release12에서 이러한 문제점들을 극복하기 위해 sidelink가 제안되었다. 덕분에 단말들은 sidelink를 통해서 서로 직접 통신을 할 수 있게 되었다. Sidelink를 사용하는 두 가지 대표적인 통신은 D2D(Device-to-Device) 통신과 V2V(Vehicle-to-Vehicle) 통신이다. 본 논문에서는 D2D 와 V2V 통신 성능을 향상시키기 위한 세가지 전략을 고려한다. (i) D2D 통신을 위한 효율적인 피드백 메커니즘, (ii) V2V 통신을 위한 상황인식기반 혼잡제어 기법, 그리고 (iii) IDC(In-Device Coexistence) 인지 기반 sidelink 자원 할당 방식. 첫째, 관련 표준에는 D2D 통신이 브로드캐스트 유형의 통신만을 지원하기 때문에 D2D 통신에 대한 피드백 메커니즘이 없다. 우리는 이러한 한계점을 극복하고자 D2D 통신을 위한 피드백 메커니즘을 제안한다. 제안된 메커니즘을 통해, 단말은 기지국의 도움없이 피드백 메커니즘을 사용할 수 있으며 피드백 자원을 할당하기 위한 추가 신호를 필요로 하지 않는다. 우리는 또한 제안된 피드백 메커니즘위에서 동작할 수 있는 data rate 조절 기법을 제안하였다. 우리는 시뮬레이션 결과를 통하여, 제안한 data rate 조절 기법이 기존 방식보다 더 높고 안정적인 수율을 제공하는 것을 확인하였다. 둘째, LTE-V2V 통신을 위한 상황 인지 기반 혼잡 제어 기법을 제안한다. LTE-V2V 통신에서 단말들은 주기적인 메시지인 CAM(Cooperative Awareness Message) 및 비주기적 메시지이며 one-hop릴레이를 허용하는 DENM(Decentralized Environmental Notification Message)를 전송한다. 위의 두 메시지는 특성과 생성 규칙이 다르기 때문에 동일한 혼잡 제어 기법을 적용하는 것은 비효율적이다. 따라서 우리는 각 메시지에 적용할 수 있는 혼잡 제어 기법들을 제안한다. 제안된 기법들을 통해서 단말들은 그들의 상황에 따라서 전송 여부를 결정하게 된다. 시뮬레이션 결과를 통해 제안된 기법이 기존 표준 방식 뿐만 아니라 최신의 비교 기법들보다 우수한 성능을 얻는 것을 확인하였다. 마지막으로 ITS(Intelligent Transport System)대역에서 LTE와 NR사이의 IDC문제를 고려하는 NR sidelink 자원할당 기법을 제안한다. 먼저, 표준에 지정된 스펙트럼 방출 마스크를 기반으로 현실적인 IDC 간섭을 모델링한다. 그런 다음 다중 에이전트 강화학습으로 자원할당 기법을 제안한다. 각 단말들은 자신들의 주변 환경을 관측하고 관측된 환경을 기반으로 행동하여 보상을 얻고 Q-network을 자신의 보상을 증가시키도록 정책을 업데이트 및 학습한다. 우리는 시뮬레이션 결과를 통하여 제안된 자원할당 박식이 기존기법 대비하여 PDR(Packet Delivery Ratio) 성능을 향상시키는 것을 확인하였다.Introduction 1 Efficient feedback mechanism for LTE-D2D Communication 8 CoCo: Context-aware congestion control scheme for C-V2X communications 35 IDC-aware resource allocation based on multi-agents reinforcement learning 67 Concluding remarks 84 Abstract(In Korean) 96 감사의 글 99Docto

A Sleep-Scheduling-Based Cross-Layer Design Approach for Application-Specific Wireless Sensor Networks

The pervasiveness and operational autonomy of mesh-based wireless sensor networks (WSNs) make them an ideal candidate in offering sustained monitoring functions at reasonable cost over a wide area. To extend the functional lifetime of battery-operated sensor nodes, stringent sleep scheduling strategies with communication duty cycles running at sub-1% range are expected to be adopted. Although ultra-low communication duty cycles can cast a detrimental impact on sensing coverage and network connectivity, its effects can be mitigated with adaptive sleep scheduling, node deployment redundancy and multipath routing within the mesh WSN topology. This work proposes a cross-layer organizational approach based on sleep scheduling, called Sense-Sleep Trees (SS-Trees), that aims to harmonize the various engineering issues and provides a method to extend monitoring capabilities and operational lifetime of mesh-based WSNs engaged in wide-area surveillance applications. Various practical considerations such as sensing coverage requirements, duty cycling, transmission range assignment, data messaging, and protocol signalling are incorporated to demonstrate and evaluate the feasibility of the proposed design approach

DESIGN OF MOBILE DATA COLLECTOR BASED CLUSTERING ROUTING PROTOCOL FOR WIRELESS SENSOR NETWORKS

Wireless Sensor Networks (WSNs) consisting of hundreds or even thousands of nodes, canbe used for a multitude of applications such as warfare intelligence or to monitor the environment. A typical WSN node has a limited and usually an irreplaceable power source and the efficient use of the available power is of utmost importance to ensure maximum lifetime of eachWSNapplication. Each of the nodes needs to transmit and communicate sensed data to an aggregation point for use by higher layer systems. Data and message transmission among nodes collectively consume the largest amount of energy available in WSNs. The network routing protocols ensure that every message reaches thedestination and has a direct impact on the amount of transmissions to deliver messages successfully. To this end, the transmission protocol within the WSNs should be scalable, adaptable and optimized to consume the least possible amount of energy to suite different network architectures and application domains. The inclusion of mobile nodes in the WSNs deployment proves to be detrimental to protocol performance in terms of nodes energy efficiency and reliable message delivery. This thesis which proposes a novel Mobile Data Collector based clustering routing protocol for WSNs is designed that combines cluster based hierarchical architecture and utilizes three-tier multi-hop routing strategy between cluster heads to base station by the help of Mobile Data Collector (MDC) for inter-cluster communication. In addition, a Mobile Data Collector based routing protocol is compared with Low Energy Adaptive Clustering Hierarchy and A Novel Application Specific Network Protocol for Wireless Sensor Networks routing protocol. The protocol is designed with the following in mind: minimize the energy consumption of sensor nodes, resolve communication holes issues, maintain data reliability, finally reach tradeoff between energy efficiency and latency in terms of End-to-End, and channel access delays. Simulation results have shown that the Mobile Data Collector based clustering routing protocol for WSNs could be easily implemented in environmental applications where energy efficiency of sensor nodes, network lifetime and data reliability are major concerns

High-Performance Modelling and Simulation for Big Data Applications

This open access book was prepared as a Final Publication of the COST Action IC1406 “High-Performance Modelling and Simulation for Big Data Applications (cHiPSet)“ project. Long considered important pillars of the scientific method, Modelling and Simulation have evolved from traditional discrete numerical methods to complex data-intensive continuous analytical optimisations. Resolution, scale, and accuracy have become essential to predict and analyse natural and complex systems in science and engineering. When their level of abstraction raises to have a better discernment of the domain at hand, their representation gets increasingly demanding for computational and data resources. On the other hand, High Performance Computing typically entails the effective use of parallel and distributed processing units coupled with efficient storage, communication and visualisation systems to underpin complex data-intensive applications in distinct scientific and technical domains. It is then arguably required to have a seamless interaction of High Performance Computing with Modelling and Simulation in order to store, compute, analyse, and visualise large data sets in science and engineering. Funded by the European Commission, cHiPSet has provided a dynamic trans-European forum for their members and distinguished guests to openly discuss novel perspectives and topics of interests for these two communities. This cHiPSet compendium presents a set of selected case studies related to healthcare, biological data, computational advertising, multimedia, finance, bioinformatics, and telecommunications