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Preben Mogensen

Other affiliations: Nokia, Bell Labs, Aalto University  ...read more
Bio: Preben Mogensen is an academic researcher from Aalborg University. The author has contributed to research in topics: Telecommunications link & Scheduling (computing). The author has an hindex of 64, co-authored 512 publications receiving 16042 citations. Previous affiliations of Preben Mogensen include Nokia & Bell Labs.


Papers
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Journal ArticleDOI
TL;DR: 3GPP (Third Generation Partnership Project), the standardization body responsible for standardizing cellular systems, has specified both Narrowband IoT (NB-IoT) and enhanced Machine-Type Communications (eMTC) in LTE release 13, which both have approximately 20 dB better link budget than LTE, and a modem complexity reduced to about 10% of LTE.
Abstract: Internet of Things (IoT) is expected to dramatically increase the number of connected devices. Multiple forecasts estimate that the number of IoT devices to go beyond 100 billion. The only question is when exactly this will take place. However, there is consensus that it will happen. Over the last approximately three decades, Internet has brought a significant impact on our society. And during last decade, the Internet usage has been dramatically boosted by the availability of powerful smartphones and fast connectivity using Wi-Fi and cellular systems. IoT is expected to become the next big leap of the Internet, where almost anything can be connected. For upcoming 5G systems, the requirements aim to support 1000,000 devices per square kilometers. M2M communications is seen as the nerve system for the Internet of Things (IoT). In the past, M2M communications was typically materialized using wired communication in order to achieve high reliability. Additionally the power consumption of the devices was so high that they required external power supply. With the evolution of wireless communication technologies and further evolution of sensor and actuator technologies, the power consumption and cost of wireless machine-type communications have been reduced significantly; and it is expected that this trend continues during forthcoming years. Applications for M2M communications can be divided into two main categories of massive and mission-critical M2M communications depending on their requirements. With massive M2M communications, we mean that the services typically span a very large numbers of devices that are usually equipped with sensors or actuators. Obviously, the amount of data generated by these devices and sensors is normally very small, and having very low latency is not required. In mission-critical M2M communications, on the other hand, very high reliability and availability as well as very low latency are required. Examples for these systems are traffic safety or control, control of critical infrastructure and wireless connectivity for industrial processes. These systems require different type of communications what it is known as Ultra-Reliable and Low-Latency Communications (URLLC). Wireless has several obvious advantages over wired: ease and reduced cost of installation, higher flexibility, and the support of mobility, to mention a few. M2M communications is often divided into local area and wide area technologies. Local area technologies are providing access from a few meters and up to hundreds of meters, whereas wide area technologies provide a link budget allowing connectivity distances up to tens of kilometers. The GSM system has been the most deployed wide area communication system used for M2M communications. However, many operators have recently announced to decommission GSM systems. This calls for new cellular wide-area M2M connectivity solutions, which can be either standalone or fully embedded into already deployed 4G/ LTE networks by means of software upgrades. 3GPP (Third Generation Partnership Project), the standardization body responsible for standardizing cellular systems, has specified both Narrowband IoT (NB-IoT) and enhanced Machine-Type Communications (eMTC) in LTE release 13, which both have approximately 20 dB better link budget than LTE, and a modem complexity reduced to about 10% of LTE. They are also considered as low power technologies. The approximately 20 dB improved link & Sassan Iraji sassan.iraji@aalto.fi

15 citations

Proceedings ArticleDOI
17 May 2004
TL;DR: The performance of WCDMA uplink systems deploying Node B based scheduling and fast hybrid ARQ (HARQ) retransmission protocols is studied and the potential capacity gain and combined gain obtained are estimated.
Abstract: The performance of WCDMA uplink systems deploying Node B based scheduling and fast hybrid ARQ (HARQ) retransmission protocols is studied With fast Node B scheduling and fast L1 HARQ schemes, both the uplink packet scheduling functionality and the entity controlling the retransmission mechanism are moved from the radio network controller (RNC) to the Node B A Node B scheduling algorithm is proposed to increase the utilisation of the allocated uplink resources; this is achieved by making use of already existing information about the transmitted data rate of the UEs Moreover, fast L1 HARQ schemes make retransmissions less costly from a delay perspective compared to an equivalent RNC controlled ARQ mechanism Therefore, the physical channel can be operated with somewhat higher error probability, which converts directly into enhanced system capacity The potential capacity gain from fast L1 Node B controlled HARQ strategies and fast Node B scheduling operation is estimated by means of an analytical study, as well as system level simulations The combined gain obtained by jointly deploying fast Node B scheduling and fast L1 HARQ retransmission schemes is estimated in the range from 25% to 60%, depending on the mobility scenario Fast Node B scheduling and L1-based HARQ protocols are included in 3GPP's "Feasibility Study for Enhanced Uplink for UTRA FDD" (TR 25896 V112, 2003)

15 citations

Proceedings ArticleDOI
01 Sep 2013
TL;DR: This work proposes a solution that avoids the starvation of the lowest priority Access Categories (AC), taking into account the priority defined by the 802.11e amendment and at negligible or extremely low cost for the high priority ones.
Abstract: The 802.11e and subsequently the 802.11n amendments brought Quality of Service (QoS) into the Wireless Local Area Network (WLAN) arena, in order to provide higher access priority to certain types of traffic such as video and voice. Unfortunately these improvements are not enough, since in very dense and highly loaded network conditions they can provide more harm than benefits, by making the lower priority traffic starve and increasing the average collision rate. This lack of performance in the Medium Access Control (MAC) layer is where we focused our work. We propose a solution that avoids the starvation of the lowest priority Access Categories (AC), taking into account the priority defined by the 802.11e amendment and at negligible or extremely low cost for the high priority ones. Simulation results presented in this paper prove the effectiveness of the method by showing delay improvements up to 92% in overcrowded and overloaded networks.

15 citations

Proceedings Article
11 Oct 2015
TL;DR: The proposed numerology options enable low latency with tolerable overhead, while maintaining a common clock with the Long Term Evolution (LTE) radio technology and robustness to hardware impairments.
Abstract: A 5 th Generation (5G) radio access technology is expected to cope with the relentless increase of the data traffic demand and is meant to accommodate a plethora of services with different requirements. In this paper, we elaborate on the design of the radio numerology for a 5G wide area system operating at carrier frequencies below 6 GHz. The main requirements are identified, and their inevitable conflicts are addressed. The proposed numerology options enable low latency with tolerable overhead, while maintaining a common clock with the Long Term Evolution (LTE) radio technology and robustness to hardware impairments.

15 citations

Journal ArticleDOI
TL;DR: The performance of an uplink-synchronous wide-band code-division multiple-access (WCDMA) system is evaluated for radio environments with low temporal dispersion and suggests that the capacity gain of synchronous WCDMA decreases when other capacity-enhancing techniques are deployed.
Abstract: The performance of an uplink-synchronous wide-band code-division multiple-access (WCDMA) system is evaluated for radio environments with low temporal dispersion. The capacity gain of synchronous WCDMA is evaluated theoretically under certain constraints and by means of extensive dynamic system level simulations for more advanced scenarios. The effect of channelization code shortage, the impact of the dispersive radio channel on the orthogonality of received signals, and soft handover are some of the considered effects. The potential capacity gain is found to equal 35.8% in a multicell scenario, conditioned on an infinite number of channelization codes per cell. For a more realistic scenario with channelization code constraints, the capacity gain is reduced to 9.6%. The absolute number of users per cell, relative to the available number of channelization codes within each scrambling code group, is therefore found to be an important metric. This further suggests that the capacity gain of synchronous WCDMA decreases when other capacity-enhancing techniques are deployed, such as uplink antenna diversity, soft handover, voice activity detection, etc. The presented simulation results in the case where soft handover is not considered accurately match the analytical findings.

15 citations


Cited by
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Journal Article
TL;DR: This book by a teacher of statistics (as well as a consultant for "experimenters") is a comprehensive study of the philosophical background for the statistical design of experiment.
Abstract: THE DESIGN AND ANALYSIS OF EXPERIMENTS. By Oscar Kempthorne. New York, John Wiley and Sons, Inc., 1952. 631 pp. $8.50. This book by a teacher of statistics (as well as a consultant for \"experimenters\") is a comprehensive study of the philosophical background for the statistical design of experiment. It is necessary to have some facility with algebraic notation and manipulation to be able to use the volume intelligently. The problems are presented from the theoretical point of view, without such practical examples as would be helpful for those not acquainted with mathematics. The mathematical justification for the techniques is given. As a somewhat advanced treatment of the design and analysis of experiments, this volume will be interesting and helpful for many who approach statistics theoretically as well as practically. With emphasis on the \"why,\" and with description given broadly, the author relates the subject matter to the general theory of statistics and to the general problem of experimental inference. MARGARET J. ROBERTSON

13,333 citations

Journal ArticleDOI
TL;DR: Machine learning addresses many of the same research questions as the fields of statistics, data mining, and psychology, but with differences of emphasis.
Abstract: Machine Learning is the study of methods for programming computers to learn. Computers are applied to a wide range of tasks, and for most of these it is relatively easy for programmers to design and implement the necessary software. However, there are many tasks for which this is difficult or impossible. These can be divided into four general categories. First, there are problems for which there exist no human experts. For example, in modern automated manufacturing facilities, there is a need to predict machine failures before they occur by analyzing sensor readings. Because the machines are new, there are no human experts who can be interviewed by a programmer to provide the knowledge necessary to build a computer system. A machine learning system can study recorded data and subsequent machine failures and learn prediction rules. Second, there are problems where human experts exist, but where they are unable to explain their expertise. This is the case in many perceptual tasks, such as speech recognition, hand-writing recognition, and natural language understanding. Virtually all humans exhibit expert-level abilities on these tasks, but none of them can describe the detailed steps that they follow as they perform them. Fortunately, humans can provide machines with examples of the inputs and correct outputs for these tasks, so machine learning algorithms can learn to map the inputs to the outputs. Third, there are problems where phenomena are changing rapidly. In finance, for example, people would like to predict the future behavior of the stock market, of consumer purchases, or of exchange rates. These behaviors change frequently, so that even if a programmer could construct a good predictive computer program, it would need to be rewritten frequently. A learning program can relieve the programmer of this burden by constantly modifying and tuning a set of learned prediction rules. Fourth, there are applications that need to be customized for each computer user separately. Consider, for example, a program to filter unwanted electronic mail messages. Different users will need different filters. It is unreasonable to expect each user to program his or her own rules, and it is infeasible to provide every user with a software engineer to keep the rules up-to-date. A machine learning system can learn which mail messages the user rejects and maintain the filtering rules automatically. Machine learning addresses many of the same research questions as the fields of statistics, data mining, and psychology, but with differences of emphasis. Statistics focuses on understanding the phenomena that have generated the data, often with the goal of testing different hypotheses about those phenomena. Data mining seeks to find patterns in the data that are understandable by people. Psychological studies of human learning aspire to understand the mechanisms underlying the various learning behaviors exhibited by people (concept learning, skill acquisition, strategy change, etc.).

13,246 citations

Book
01 Jan 2005

9,038 citations

Journal ArticleDOI
TL;DR: The gains in multiuser systems are even more impressive, because such systems offer the possibility to transmit simultaneously to several users and the flexibility to select what users to schedule for reception at any given point in time.
Abstract: Multiple-input multiple-output (MIMO) technology is maturing and is being incorporated into emerging wireless broadband standards like long-term evolution (LTE) [1]. For example, the LTE standard allows for up to eight antenna ports at the base station. Basically, the more antennas the transmitter/receiver is equipped with, and the more degrees of freedom that the propagation channel can provide, the better the performance in terms of data rate or link reliability. More precisely, on a quasi static channel where a code word spans across only one time and frequency coherence interval, the reliability of a point-to-point MIMO link scales according to Prob(link outage) ` SNR-ntnr where nt and nr are the numbers of transmit and receive antennas, respectively, and signal-to-noise ratio is denoted by SNR. On a channel that varies rapidly as a function of time and frequency, and where circumstances permit coding across many channel coherence intervals, the achievable rate scales as min(nt, nr) log(1 + SNR). The gains in multiuser systems are even more impressive, because such systems offer the possibility to transmit simultaneously to several users and the flexibility to select what users to schedule for reception at any given point in time [2].

5,158 citations

01 Jan 2000
TL;DR: This article briefly reviews the basic concepts about cognitive radio CR, and the need for software-defined radios is underlined and the most important notions used for such.
Abstract: An Integrated Agent Architecture for Software Defined Radio. Rapid-prototype cognitive radio, CR1, was developed to apply these.The modern software defined radio has been called the heart of a cognitive radio. Cognitive radio: an integrated agent architecture for software defined radio. Http:bwrc.eecs.berkeley.eduResearchMCMACR White paper final1.pdf. The cognitive radio, built on a software-defined radio, assumes. Radio: An Integrated Agent Architecture for Software Defined Radio, Ph.D. The need for software-defined radios is underlined and the most important notions used for such. Mitola III, Cognitive radio: an integrated agent architecture for software defined radio, Ph.D. This results in the set-theoretic ontology of radio knowledge defined in the. Cognitive Radio An Integrated Agent Architecture for Software.This article first briefly reviews the basic concepts about cognitive radio CR. Cognitive Radio-An Integrated Agent Architecture for Software Defined Radio. Cognitive Radio RHMZ 2007. Software-defined radio SDR idea 1. Cognitive radio: An integrated agent architecture for software.Cognitive Radio SOFTWARE DEFINED RADIO, AND ADAPTIVE WIRELESS SYSTEMS2 Cognitive Networks. 3 Joseph Mitola III, Cognitive Radio: An Integrated Agent Architecture for Software Defined Radio Stockholm.

3,814 citations