8 research outputs found

    Modeling the NB-IoT transmission process with intermittent network availability

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    Standardized by 3GPP, Narrowband Internet-of-Thing (NB-IoT) technology operating in licensed bands is nowadays widely deployed and utilized for static deployments of IoT communications services. The recent trend to equip large complex inherently nomadic systems such as trains and ships with advanced sensory capabilities call for mobility support in NB-IoT technology. Such systems entering and leaving the NB-IoT coverage periodically could lead to synchronized behavior of sensor nodes resulting in occasional spikes in the number of sensors simultaneously accessing the NB-IoT random access channel. In this study, we develop a model capturing behavior of nomadic systems roaming between coverage of NB-IoT technology. The metrics of interest are mean message transmission delay as well as the message loss probability. Our numerical results illustrate that these metrics are mainly affected by the duration of the outage interval and fraction of time systems spends in outage conditions. At the same time, the loss and delay performance only insignificantly affected by the number of sensors implying that NB-IoT random access procedure may efficiently handle sporadic loads.acceptedVersionPeer reviewe

    Relaying in the Internet of Things (IoT): A Survey

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    The deployment of relays between Internet of Things (IoT) end devices and gateways can improve link quality. In cellular-based IoT, relays have the potential to reduce base station overload. The energy expended in single-hop long-range communication can be reduced if relays listen to transmissions of end devices and forward these observations to gateways. However, incorporating relays into IoT networks faces some challenges. IoT end devices are designed primarily for uplink communication of small-sized observations toward the network; hence, opportunistically using end devices as relays needs a redesign of both the medium access control (MAC) layer protocol of such end devices and possible addition of new communication interfaces. Additionally, the wake-up time of IoT end devices needs to be synchronized with that of the relays. For cellular-based IoT, the possibility of using infrastructure relays exists, and noncellular IoT networks can leverage the presence of mobile devices for relaying, for example, in remote healthcare. However, the latter presents problems of incentivizing relay participation and managing the mobility of relays. Furthermore, although relays can increase the lifetime of IoT networks, deploying relays implies the need for additional batteries to power them. This can erode the energy efficiency gain that relays offer. Therefore, designing relay-assisted IoT networks that provide acceptable trade-offs is key, and this goes beyond adding an extra transmit RF chain to a relay-enabled IoT end device. There has been increasing research interest in IoT relaying, as demonstrated in the available literature. Works that consider these issues are surveyed in this paper to provide insight into the state of the art, provide design insights for network designers and motivate future research directions

    Performance assessment of Narrowband IoT for Intelligent Cargo Transportation

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    Narrow Band Internet of Things (NB-IoT) is the most advanced technology standard for short message services, such as sensor data, developed by 3GPP Release 13 and beyond. The NB-IoT is deployed over Long Term Evolution (LTE) Advanced Pro infrastructure and theoretically, it offers extended coverage up to 40 km from the base station. The objective of this thesis is to analyze the performance of NB-IoT technology in cargo shipment tracking using LTE cellular networks across the coastal line. Currently, about fifty thousand cargo ships use onboard Satellite communication system for all sorts of information exchange with the onshore data centers. The Satellite communication will continue to exist, even after deployment of NB-IoT. Apart from the machine critical data of the cargo ships, the non-emergency periodic short messages for polling meteorological and container metadata such as temperature, humidity, gaseous detection, etc. will be crucial for the quality of the shipment and the traceability. In this thesis, we analyze deployment of NB-IoT sensors for cargo container to track and provide metadata about the condition of goods. We evaluate three implementation methods of NB-IoT for cargo ships, optimize the coverage and enhance the battery life of the sensor equipment. The main idea is to offload non-critical information that would otherwise use expensive Satellite links, thus embrace the NB-IoT technology at offshore and reduce the financial stress on the cargo shipments. In the first method, all the sensors transfer the periodic data directly to the coastal LTE network when the ships sail in close proximity to the shore. In the second method, the sensors transfer data to an LTE base station installed locally on the ship and then accumulated information will be relayed to onshore LTE network over NB-IoT channel. In the third method, an Unmanned Aerial Vehicle (UAV/ Drone) base station will collect the data from the onboard sensors; it then relays the information to the onshore LTE network. For all methods, when there is no LTE coverage, the accumulated data will be sent over the Satellite link, which will be available onboard. The assessment confirms the hypothesis that the packet loss probability reduces when the base station is located close to the sensor, where the number of retransmissions will be reduced, and more uplink resources will be available. For direct access scenario, a large number of users contend for Random Access Channel (RACH) simultaneously after entering into the LTE coverage. The packet will be dropped after reaching the maximum number of attempts for the RACH resources. As per the simulated results, mean lifespan of a sensor is greatly affected by the LTE network availability and random access procedure, during which the sensor spends most of the energy for transmissions. The mean transmit delay will be higher with second and third methods where the ship BS, UAV BS accumulate packets until they find the LTE network or relays the data to the Satellite link if the LTE outage is longer. This performance assessment provides technical insights for the maritime industry to embrace the NB-IoT for tracking and condition monitoring of shipment

    The Internet of Things: A Review of Enabled Technologies and Future Challenges

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    The Internet of Things (IoT) is an emerging classical model, envisioned as a system of billions of small interconnected devices for posing the state-of-the-art findings to real-world glitches. Over the last decade, there has been an increasing research concentration in the IoT as an essential design of the constant convergence between human behaviors and their images on Information Technology. With the development of technologies, the IoT drives the deployment of across-the-board and self-organizing wireless networks. The IoT model is progressing toward the notion of a cyber-physical world, where things can be originated, driven, intermixed, and modernized to facilitate the emergence of any feasible association. This paper provides a summary of the existing IoT research that underlines enabling technologies, such as fog computing, wireless sensor networks, data mining, context awareness, real-time analytics, virtual reality, and cellular communications. Also, we present the lessons learned after acquiring a thorough representation of the subject. Thus, by identifying numerous open research challenges, it is presumed to drag more consideration into this novel paradigm. 2013 IEEE.This work was supported by Institute for Information and communications Technology Promotion (IITP) grant funded by the Korea government(MSIT) (No. 2018-0-01411, A Micro-Service IoTWare Framework Technology Development for Ultra small IoT Device).Scopus2-s2.0-8505888625

    Vehicle-Based Relay Assistance for Opportunistic Crowdsensing over Narrowband IoT (NB-IoT)

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    The Internet of Things (IoT) undergoes a fundamental transformation by augmenting its conventional sensor network deployments with more advanced and mobile devices, such as connected and self-driving cars. This fusion of embedded and automotive domains promises to deliver unprecedented mutual benefits, where vehicles will receive timely updates from their proximate sensors while assisting them in delivering their sensory data to the remote network infrastructure. In this paper, we put forward the vision of opportunistic crowdsensing applications, in which the ubiquitous deployments of low-cost and battery-constrained IoT sensors take advantage of more capable and energy-Abundant vehicle-mounted mobile relays. In particular, we consider the use of the emerging narrowband IoT radio technology recently ratified by 3GPP and offering efficient means for underlying wireless connectivity. Our rigorous mathematical analysis supported with comprehensive system-level evaluations reveals the effects of vehicle-based relays on the important metrics of interest, such as connection reliability, transmission latency, and communication energy efficiency. These systematic findings advocate for an extensive utilization of vehicular relays as part of the next-generation IoT ecosystem. © 2014 IEEE
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