Enabling generic wireless coexistence through technology-agnostic dynamic spectrum access

Every year that passes, new standardized and proprietary wireless communication technologies are introduced in the market that seeks to find its place within the already highly congested spectrum. Regulation bodies all around the globe are struggling to keep up with the continuously increasing demand for new bands to offer to specific technologies, some of them requiring by design an exclusive frequency band in order to operate efficiently. Even wireless bands offered for public or scientific usage like the ISM bands are becoming the natural habitat of multiple wireless technologies that seek to use or abuse them in order to provide even more bandwidth to their offered applications. Wireless research teams targeting heterogeneous wireless communication coexistence are developing techniques for enabling one-to-one coexistence between various wireless technologies. Can such an exhaustive approach be the solution for N wireless technologies that wish to operate in the same band? We believe that a one-to-one approach is inefficient and cannot lead to a generic coexistence paradigm, applicable to every existing or new wireless communication technology that will arise in the future. Can another approach provide a more generic solution in terms of frequency reuse and coexistence compared to the one-dimensional frequency separation approach commonly used in commercial deployments today. Can such a generic approach provide a simple and easily adoptable coexistence model for existing technologies? In this paper we present a new generic medium sharing model that solves the huge coexistence problems observed today in a simple and efficient way. Our approach is technology-agnostic and compatible with all existing wireless communication technologies and also has the capability to support emerging ones with minimum overhead

Over-the-air software updates in the internet of things : an overview of key principles

Due to the fast pace at which IoT is evolving, there is an increasing need to support over-theair software updates for security updates, bug fixes, and software extensions. To this end, multiple over-the-air techniques have been proposed, each covering a specific aspect of the update process, such as (partial) code updates, data dissemination, and security. However, each technique introduces overhead, especially in terms of energy consumption, thereby impacting the operational lifetime of the battery constrained devices. Until now, a comprehensive overview describing the different update steps and quantifying the impact of each step is missing in the scientific literature, making it hard to assess the overall feasibility of an over-the-air update. To remedy this, our article analyzes which parts of an IoT operating system are most updated after device deployment, proposes a step-by-step approach to integrate software updates in IoT solutions, and quantifies the energy cost of each of the involved steps. The results show that besides the obvious dissemination cost, other phases such as security also introduce a significant overhead. For instance, a typical firmware update requires 135.026 mJ, of which the main portions are data dissemination (63.11 percent) and encryption (5.29 percent). However, when modular updates are used instead, the energy cost (e.g., for a MAC update) is reduced to 26.743 mJ (48.69 percent for data dissemination and 26.47 percent for encryption)

Portability, compatibility and reuse of MAC protocols across different IoT radio platforms

To cope with the diversity of Internet of Things (loT) requirements, a large number of Medium Access Control (MAC) protocols have been proposed in scientific literature, many of which are designed for specific application domains. However, for most of these MAC protocols, no multi-platform software implementation is available. In fact, the path from conceptual MAC protocol proposed in theoretical papers, towards an actual working implementation is rife with pitfalls. (i) A first problem is the timing bugs, frequently encountered in MAC implementations. (ii) Furthermore, once implemented, many MAC protocols are strongly optimized for specific hardware, thereby limiting the potential of software reuse or modifications. (iii) Finally, in real-life conditions, the performance of the MAC protocol varies strongly depending on the actual underlying radio chip. As a result, the same MAC protocol implementation acts differently per platform, resulting in unpredictable/asymmetrical behavior when multiple platforms are combined in the same network. This paper describes in detail the challenges related to multi-platform MAC development, and experimentally quantifies how the above issues impact the MAC protocol performance when running MAC protocols on multiple radio chips. Finally, an overall methodology is proposed to avoid the previously mentioned cross-platform compatibility issues. (C) 2018 Elsevier B.V. All rights reserved

Cooperation techniques between LTE in unlicensed spectrum and Wi-Fi towards fair spectral efficiency

On the road towards 5G, a proliferation of Heterogeneous Networks (HetNets) is expected. Sensor networks are of great importance in this new wireless era, as they allow interaction with the environment. Additionally, the establishment of the Internet of Things (IoT) has incredibly increased the number of interconnected devices and consequently the already massive wirelessly transmitted traffic. The exponential growth of wireless traffic is pushing the wireless community to investigate solutions that maximally exploit the available spectrum. Recently, 3rd Generation Partnership Project (3GPP) announced standards that permit the operation of Long Term Evolution (LTE) in the unlicensed spectrum in addition to the exclusive use of the licensed spectrum owned by a mobile operator. Alternatively, leading wireless technology developers examine standalone LTE operation in the unlicensed spectrum without any involvement of a mobile operator. In this article, we present a classification of different techniques that can be applied on co-located LTE and Wi-Fi networks. Up to today, Wi-Fi is the most widely-used wireless technology in the unlicensed spectrum. A review of the current state of the art further reveals the lack of cooperation schemes among co-located networks that can lead to more optimal usage of the available spectrum. This article fills this gap in the literature by conceptually describing different classes of cooperation between LTE and Wi-Fi. For each class, we provide a detailed presentation of possible cooperation techniques that can provide spectral efficiency in a fair manner