Heterogeneous LTE/ Wi-Fi architecture for intelligent transportation systems

Intelligent Transportation Systems (ITS) make use of advanced technologies to enhance road safety and improve traffic efficiency. It is anticipated that ITS will play a vital future role in improving traffic efficiency, safety, comfort and emissions. In order to assist the passengers to travel safely, efficiently and conveniently, several application requirements have to be met simultaneously. In addition to the delivery of regular traffic and safety information, vehicular networks have been recently required to support infotainment services. Previous vehicular network designs and architectures do not satisfy this increasing traffic demand as they are setup for either voice or data traffic, which is not suitable for the transfer of vehicular traffic. This new requirement is one of the key drivers behind the need for new mobile wireless broadband architectures and technologies. For this purpose, this thesis proposes and investigates a heterogeneous IEEE 802.11 and LTE vehicular system that supports both infotainment and ITS traffic control data. IEEE 802.11g is used for V2V communications and as an on-board access network while, LTE is used for V2I communications. A performance simulation-based study is conducted to validate the feasibility of the proposed system in an urban vehicular environment. The system performance is evaluated in terms of data loss, data rate, delay and jitter. Several simulation scenarios are performed and evaluated. In the V2I-only scenario, the delay, jitter and data drops for both ITS and video traffic are within the acceptable limits, as defined by vehicular application requirements. Although a tendency of increase in video packet drops during handover from one eNodeB to another is observed yet, the attainable data loss rate is still below the defined benchmarks. In the integrated V2V-V2I scenario, data loss in uplink ITS traffic was initially observed so, Burst communication technique is applied to prevent packet losses in the critical uplink ITS traffic. A quantitative analysis is performed to determine the number of packets per burst, the inter-packet and inter-burst intervals. It is found that a substantial improvement is achieved using a two-packet Burst, where no packets are lost in the uplink direction. The delay, jitter and data drops for both uplink and downlink ITS traffic, and video traffic are below the benchmarks of vehicular applications. Thus, the results indicate that the proposed heterogeneous system offers acceptable performance that meets the requirements of the different vehicular applications. All simulations are conducted on OPNET Network Modeler and results are subjected to a 95% confidence analysis

Hybrid Satellite-Terrestrial Communication Networks for the Maritime Internet of Things: Key Technologies, Opportunities, and Challenges

With the rapid development of marine activities, there has been an increasing number of maritime mobile terminals, as well as a growing demand for high-speed and ultra-reliable maritime communications to keep them connected. Traditionally, the maritime Internet of Things (IoT) is enabled by maritime satellites. However, satellites are seriously restricted by their high latency and relatively low data rate. As an alternative, shore & island-based base stations (BSs) can be built to extend the coverage of terrestrial networks using fourth-generation (4G), fifth-generation (5G), and beyond 5G services. Unmanned aerial vehicles can also be exploited to serve as aerial maritime BSs. Despite of all these approaches, there are still open issues for an efficient maritime communication network (MCN). For example, due to the complicated electromagnetic propagation environment, the limited geometrically available BS sites, and rigorous service demands from mission-critical applications, conventional communication and networking theories and methods should be tailored for maritime scenarios. Towards this end, we provide a survey on the demand for maritime communications, the state-of-the-art MCNs, and key technologies for enhancing transmission efficiency, extending network coverage, and provisioning maritime-specific services. Future challenges in developing an environment-aware, service-driven, and integrated satellite-air-ground MCN to be smart enough to utilize external auxiliary information, e.g., sea state and atmosphere conditions, are also discussed

Towards video streaming in IoT environments: vehicular communication perspective

Multimedia oriented Internet of Things (IoT) enables pervasive and real-time communication of video, audio and image data among devices in an immediate surroundings. Today's vehicles have the capability of supporting real time multimedia acquisition. Vehicles with high illuminating infrared cameras and customized sensors can communicate with other on-road devices using dedicated short-range communication (DSRC) and 5G enabled communication technologies. Real time incidence of both urban and highway vehicular traffic environment can be captured and transmitted using vehicle-to-vehicle and vehicle-to-infrastructure communication modes. Video streaming in vehicular IoT (VSV-IoT) environments is in growing stage with several challenges that need to be addressed ranging from limited resources in IoT devices, intermittent connection in vehicular networks, heterogeneous devices, dynamism and scalability in video encoding, bandwidth underutilization in video delivery, and attaining application-precise quality of service in video streaming. In this context, this paper presents a comprehensive review on video streaming in IoT environments focusing on vehicular communication perspective. Specifically, significance of video streaming in vehicular IoT environments is highlighted focusing on integration of vehicular communication with 5G enabled IoT technologies, and smart city oriented application areas for VSV-IoT. A taxonomy is presented for the classification of related literature on video streaming in vehicular network environments. Following the taxonomy, critical review of literature is performed focusing on major functional model, strengths and weaknesses. Metrics for video streaming in vehicular IoT environments are derived and comparatively analyzed in terms of their usage and evaluation capabilities. Open research challenges in VSV-IoT are identified as future directions of research in the area. The survey would benefit both IoT and vehicle industry practitioners and researchers, in terms of augmenting understanding of vehicular video streaming and its IoT related trends and issues

Automotive Cognitive Access: Towards customized vehicular communication system

The evolution of Software Defined Networking (SDN) and Virtualization of mobile Network Functions (NFV) have enabled the new ways of managing mobile access systems and are seen as a major technological foundation of the Fifth Generation (5G) of mobile networks. With the appearance of 5G specifications, the mobile system architecture has the transition from a network of entities to a network of functions. This paradigm shift led to new possibilities and challenges. Existing mobile communication systems rely on closed and inflexible hardware-based architectures both at the access and core network. It implies significant challenges in implementing new techniques to maximize the network capacity, scalability and increasing performance for diverse data services. This work focuses preliminary on the architectural evolutions needed to solve challenges perceived for the next generation of mobile networks. I consider Software defined plus Virtualization featured Mobile Network (S+ MN) architecture as a baseline reference model, aiming at the further improvements to support the access requirements for diverse user groups. I consider an important class of things, vehicles, which needs efficient mobile internet access at both the system and application levels. I identify and describe key requirements of emerging vehicular communications and assess existing standards to determine their limitations. To provide optimized wireless communications for the specific user group, the 5G systems come up with network slicing as a potential solution to create customized networks. Network slicing has the capability to facilitates dynamic and efficient allocation of network resources and support diverse service scenarios and services. A network slice can be broadly defined as an end-to-end logically isolated network that includes end devices as well as access and core network functions. To this effect, I describe the enhanced behaviour of S+ MN architecture for the collection of network resources and details the potential functional grouping provided by S+ MN architecture that paves the way to support automotive slicing. The proposed enhancements support seamless connection mobility addressing the automotive access use case highly mobile environment. I follow the distribution of gateway functions to solve the problem of unnecessary long routes and delays. Exploiting the open SDN capabilities, the proposed S+ NC is able to parallelize the execution of certain control plane messages thus enabling the signalling optimisation. Furthermore, it enables the (Re)selection of efficient data plane paths with implied upper-layer service continuity mechanisms that remove the chains of IP address preservation for session continuity during IP anchor relocation. An implementation setup validates the proposed evolutions, including its core functionalities implemented using the ns-3 network simulator. The proposed slicing scheme has been evaluated through a number of scenarios such as numbers of signalling messages processed by control entities for an intersystem handover procedure relative to current mobile network architecture. I also perform the performance improvement analysis based on simulation results. Furthermore, I experimentally prove the feasibility of using Multipath TCP for connection mobility in intersystem handover scenario. The experiments run over the Linux Kernel implementation of Multipath TCP developed over the last years. I extend the Multipath TCP path management to delegates the management of the data paths according to the application needs. The implementation results have shown that the proposed S+ MN slicing architecture and enhancements achieve benefits in multiple areas, for example improving the mobility control and management, maintaining QoS, smooth handover, session continuity and efficient slice management and orchestration

An adaptive network coding scheme for multipath transmission in cellular-based vehicular networks

With the emergence of vehicular Internet-of-Things (IoT) applications, it is a significant challenge for vehicular IoT systems to obtain higher throughput in vehicle-to-cloud multipath transmission. Network Coding (NC) has been recognized as a promising paradigm for improving vehicular wireless network throughput by reducing packet loss in transmission. However, existing researches on NC do not consider the influence of the rapid quality change of wireless links on NC schemes, which poses a great challenge to dynamically adjust the coding rate according to the variation of link quality in vehicle-to-cloud multipath transmission in order to avoid consuming unnecessary bandwidth resources and to increase network throughput. Therefore, we propose an Adaptive Network Coding (ANC) scheme brought by the novel integration of the Hidden Markov Model (HMM) into the NC scheme to efficiently adjust the coding rate according to the estimated packet loss rate (PLR). The ANC scheme conquers the rapid change of wireless link quality to obtain the utmost throughput and reduce the packet loss in transmission. In terms of the throughput performance, the simulations and real experiment results show that the ANC scheme outperforms state-of-the-art NC schemes for vehicular wireless multipath transmission in vehicular IoT systems.This work was supported in part by the Fundamental Research Funds for the Central Universities under Grant No.2019YJS015, in part by the National Natural Science Foundation of China (NSFC) under Grant 61872029, and in part by the Beijing Municipal Natural Science Foundation under Grant 4182048