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Author

Sassan Iraji

Other affiliations: Nokia Networks, Intel
Bio: Sassan Iraji is an academic researcher from Aalto University. The author has contributed to research in topics: Control channel & Wireless. The author has an hindex of 15, co-authored 24 publications receiving 1178 citations. Previous affiliations of Sassan Iraji include Nokia Networks & Intel.

Papers
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Journal ArticleDOI
TL;DR: This study presents a roadmap from the current cellular technologies toward fully MTC-capable 5G mobile systems, and provides a clear mapping between the main MTC service requirements and their associated challenges.
Abstract: Machine-type communications (MTC) enables a broad range of applications from mission- critical services to massive deployment of autonomous devices. To spread these applications widely, cellular systems are considered as a potential candidate to provide connectivity for MTC devices. The ubiquitous deployment of these systems reduces network installation cost and provides mobility support. However, based on the service functions, there are key challenges that currently hinder the broad use of cellular systems for MTC. This article provides a clear mapping between the main MTC service requirements and their associated challenges. The goal is to develop a comprehensive understanding of these challenges and the potential solutions. This study presents, in part, a roadmap from the current cellular technologies toward fully MTC-capable 5G mobile systems.

425 citations

Proceedings ArticleDOI
07 Apr 2013
TL;DR: The system performance analysis of 3GPP Long-Term Evolution (LTE) and IEEE 802.11 Wireless Local Area Networks (WLAN) in a situation where LTE downlink has been expanded over to unlicensed frequency band usually used by WLAN is presented.
Abstract: This paper presents the system performance analysis of 3GPP Long-Term Evolution (LTE) and IEEE 802.11 Wireless Local Area Networks (WLAN) in a situation where LTE downlink (DL) has been expanded over to unlicensed frequency band usually used by WLAN. Simple fractional bandwidth sharing mechanism is used to allow both technologies to transmit. The system performance is evaluated by means of fully dynamic network simulations.

188 citations

Journal ArticleDOI
TL;DR: The experiments were carried out using an early-standard-compliant prototype based on a software defined radio partial implementation of NB-IoT that runs on a desktop computer connected to the network and it is found that a cloud radio access network is a good candidate for NB- IoT implementation.
Abstract: The 3GPP has introduced a new narrowband radio technology called narrowband Internet of Things (NB-IoT) in Release 13. NB-IoT was designed to support very low power consumption and low-cost devices in extreme coverage conditions. NB-IoT operates in very small bandwidth and will provide connectivity to a large number of low-data-rate devices. This article highlights some of the key features introduced in NB-IoT and presents performance results from real-life experiments. The experiments were carried out using an early-standard-compliant prototype based on a software defined radio partial implementation of NB-IoT that runs on a desktop computer connected to the network. It is found that a cloud radio access network is a good candidate for NB-IoT implementation.

116 citations

Patent
21 Jun 2012
TL;DR: In this article, power control for LTE transmissions in unlicensed bands is discussed, where a first device (such as a LTE UE or LTE eNB) determines a scheduled transmission window for a LTE transmission in an unlicensed band.
Abstract: Methods of power control for LTE transmissions in unlicensed bands are described. One method includes determining, at a first device (such as a LTE UE or LTE eNB), a scheduled transmission window for a LTE transmission in an unlicensed band. The transmission window indicates a time for sending the transmission in the unlicensed band. Prior to the scheduled transmission window, the method also includes determining whether a WiFi transmitter is transmitting a signal in the unlicensed band. The method also includes, in response to determining that the transmitter is transmitting in the unlicensed band, determining an adjusted transmission power for the transmission and sending the transmission (such as from an LTE UE to an LTE eNB or from an LTE eNB to an LTE UE) in the transmission window at the adjusted transmission power. Apparatus and computer readable media are also described.

104 citations

Proceedings ArticleDOI
10 May 2017
TL;DR: It is reported how the NB-IoT coverage improvement is limited by the channel estimation quality and coherence time of the channel.
Abstract: Narrow-Band Internet of Things (NB-IoT) is 3GPP's cellular technology designed for narrow-band and Low-Power Wide Area Network (LPWN). NB-IoT provides deep indoor coverage for thousands of low-data-rate and low-powered devices. Coverage enhancement for devices in weak coverage condition is enabled by having signal repetitions over extended period of time in order to boost the signal quality. Performance gain from repetitions of signals is limited by channel estimation quality. In this paper we analyze impact of channel coherence time on the uplink coverage. In addition to analytical performance bound and simulation results, we also present coverage performance results from practical measurements using a NB-IoT prototype. It is reported how the NB-IoT coverage improvement is limited by the channel estimation quality and coherence time of the channel.

86 citations


Cited by
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Journal ArticleDOI
TL;DR: The concepts of IoT, Industrial IoT, and Industry 4.0 are clarified and the challenges associated with the need of energy efficiency, real-time performance, coexistence, interoperability, and security and privacy are focused on.
Abstract: Internet of Things (IoT) is an emerging domain that promises ubiquitous connection to the Internet, turning common objects into connected devices. The IoT paradigm is changing the way people interact with things around them. It paves the way for creating pervasively connected infrastructures to support innovative services and promises better flexibility and efficiency. Such advantages are attractive not only for consumer applications, but also for the industrial domain. Over the last few years, we have been witnessing the IoT paradigm making its way into the industry marketplace with purposely designed solutions. In this paper, we clarify the concepts of IoT, Industrial IoT, and Industry 4.0. We highlight the opportunities brought in by this paradigm shift as well as the challenges for its realization. In particular, we focus on the challenges associated with the need of energy efficiency, real-time performance, coexistence, interoperability, and security and privacy. We also provide a systematic overview of the state-of-the-art research efforts and potential research directions to solve Industrial IoT challenges.

1,402 citations

Journal ArticleDOI
TL;DR: This article provides a comprehensive review on emerging and enabling technologies related to the 5G system that enables IoT, such as 5G new radio, multiple-input–multiple-output antenna with the beamformation technology, mm-wave commutation technology, heterogeneous networks (HetNets), the role of augmented reality (AR) in IoT, which are discussed in detail.
Abstract: Recently, wireless technologies have been growing actively all around the world. In the context of wireless technology, fifth-generation (5G) technology has become a most challenging and interesting topic in wireless research. This article provides an overview of the Internet of Things (IoT) in 5G wireless systems. IoT in the 5G system will be a game changer in the future generation. It will open a door for new wireless architecture and smart services. Recent cellular network LTE (4G) will not be sufficient and efficient to meet the demands of multiple device connectivity and high data rate, more bandwidth, low-latency quality of service (QoS), and low interference. To address these challenges, we consider 5G as the most promising technology. We provide a detailed overview of challenges and vision of various communication industries in 5G IoT systems. The different layers in 5G IoT systems are discussed in detail. This article provides a comprehensive review on emerging and enabling technologies related to the 5G system that enables IoT. We consider the technology drivers for 5G wireless technology, such as 5G new radio (NR), multiple-input–multiple-output antenna with the beamformation technology, mm-wave commutation technology, heterogeneous networks (HetNets), the role of augmented reality (AR) in IoT, which are discussed in detail. We also provide a review on low-power wide-area networks (LPWANs), security challenges, and its control measure in the 5G IoT scenario. This article introduces the role of AR in the 5G IoT scenario. This article also discusses the research gaps and future directions. The focus is also on application areas of IoT in 5G systems. We, therefore, outline some of the important research directions in 5G IoT.

896 citations

Journal ArticleDOI
TL;DR: The IoT ecosystem is presented and how the combination of IoT and DA is enabling smart agriculture, and future trends and opportunities are provided which are categorized into technological innovations, application scenarios, business, and marketability.
Abstract: The surge in global population is compelling a shift toward smart agriculture practices. This coupled with the diminishing natural resources, limited availability of arable land, increase in unpredictable weather conditions makes food security a major concern for most countries. As a result, the use of Internet of Things (IoT) and data analytics (DA) are employed to enhance the operational efficiency and productivity in the agriculture sector. There is a paradigm shift from use of wireless sensor network (WSN) as a major driver of smart agriculture to the use of IoT and DA. The IoT integrates several existing technologies, such as WSN, radio frequency identification, cloud computing, middleware systems, and end-user applications. In this paper, several benefits and challenges of IoT have been identified. We present the IoT ecosystem and how the combination of IoT and DA is enabling smart agriculture. Furthermore, we provide future trends and opportunities which are categorized into technological innovations, application scenarios, business, and marketability.

814 citations

Journal ArticleDOI
TL;DR: This survey makes an exhaustive review on the state-of-the-art research efforts on mobile edge networks, including definition, architecture, and advantages, and presents a comprehensive survey of issues on computing, caching, and communication techniques at the network edge.
Abstract: As the explosive growth of smart devices and the advent of many new applications, traffic volume has been growing exponentially. The traditional centralized network architecture cannot accommodate such user demands due to heavy burden on the backhaul links and long latency. Therefore, new architectures, which bring network functions and contents to the network edge, are proposed, i.e., mobile edge computing and caching. Mobile edge networks provide cloud computing and caching capabilities at the edge of cellular networks. In this survey, we make an exhaustive review on the state-of-the-art research efforts on mobile edge networks. We first give an overview of mobile edge networks, including definition, architecture, and advantages. Next, a comprehensive survey of issues on computing, caching, and communication techniques at the network edge is presented. The applications and use cases of mobile edge networks are discussed. Subsequently, the key enablers of mobile edge networks, such as cloud technology, SDN/NFV, and smart devices are discussed. Finally, open research challenges and future directions are presented as well.

782 citations

Journal ArticleDOI
TL;DR: A comprehensive survey on the UAVs and the related issues will be introduced, the envisioned UAV-based architecture for the delivery of Uav-based value-added IoT services from the sky will be introduction, and the relevant key challenges and requirements will be presented.
Abstract: Recently, unmanned aerial vehicles (UAVs), or drones, have attracted a lot of attention, since they represent a new potential market. Along with the maturity of the technology and relevant regulations, a worldwide deployment of these UAVs is expected. Thanks to the high mobility of drones, they can be used to provide a lot of applications, such as service delivery, pollution mitigation, farming, and in the rescue operations. Due to its ubiquitous usability, the UAV will play an important role in the Internet of Things (IoT) vision, and it may become the main key enabler of this vision. While these UAVs would be deployed for specific objectives (e.g., service delivery), they can be, at the same time, used to offer new IoT value-added services when they are equipped with suitable and remotely controllable machine type communications (MTCs) devices (i.e., sensors, cameras, and actuators). However, deploying UAVs for the envisioned purposes cannot be done before overcoming the relevant challenging issues. These challenges comprise not only technical issues, such as physical collision, but also regulation issues as this nascent technology could be associated with problems like breaking the privacy of people or even use it for illegal operations like drug smuggling. Providing the communication to UAVs is another challenging issue facing the deployment of this technology. In this paper, a comprehensive survey on the UAVs and the related issues will be introduced. In addition, our envisioned UAV-based architecture for the delivery of UAV-based value-added IoT services from the sky will be introduced, and the relevant key challenges and requirements will be presented.

693 citations