784 research outputs found
An Analysis of Packet Fragmentation Impact in LPWAN
Packet fragmentation has mostly been addressed in the literature when
referring to splitting data that does not fit a frame. It has received
attention in the IoT community after the 6LoWPAN working group of IETF started
studying the fragmentation headers to allow IPv6 1280 B MTU to be sent over
IEEE 802.15.4 networks supporting a 127 B MTU. In this paper, and following
some of the recent directions taken by the IETF LPWAN WG, an analysis of packet
fragmentation in LPWANs has been done. We aim to identify the impact of sending
the data in smaller fragments considering the restrictions of industrial
duty-cycled networks. The analyzed parameters were the energy consumption,
throughput, goodput and end to end delay introduced by fragmentation. The
results of our analysis show that packet fragmentation can increase the
reliability of the communication in duty-cycle restricted networks. This is of
especial relevance when densifying the network. We observed relevant impact in
energy consumption and extra latency, and identified the need for
acknowledgements from the gateway/sink to exploit some of the benefits raised
by fragmentation.Comment: paper accepted and presented at IEEE Wireless Communications and
Networking Conference, 15-18 April, Barcelona, Spai
Selective Jamming of LoRaWAN using Commodity Hardware
Long range, low power networks are rapidly gaining acceptance in the Internet
of Things (IoT) due to their ability to economically support long-range sensing
and control applications while providing multi-year battery life. LoRa is a key
example of this new class of network and is being deployed at large scale in
several countries worldwide. As these networks move out of the lab and into the
real world, they expose a large cyber-physical attack surface. Securing these
networks is therefore both critical and urgent. This paper highlights security
issues in LoRa and LoRaWAN that arise due to the choice of a robust but slow
modulation type in the protocol. We exploit these issues to develop a suite of
practical attacks based around selective jamming. These attacks are conducted
and evaluated using commodity hardware. The paper concludes by suggesting a
range of countermeasures that can be used to mitigate the attacks.Comment: Mobiquitous 2017, November 7-10, 2017, Melbourne, VIC, Australi
Cross-layer framework and optimization for efficient use of the energy budget of IoT Nodes
Both physical and MAC-layer need to be jointly optimized to maximize the
autonomy of IoT devices. Therefore, a cross-layer design is imperative to
effectively realize Low Power Wide Area networks (LPWANs). In the present
paper, a cross-layer assessment framework including power modeling is proposed.
Through this simulation framework, the energy consumption of IoT devices,
currently deployed in LoRaWAN networks, is evaluated. We demonstrate that a
cross-layer approach significantly improves energy efficiency and overall
throughput. Two major contributions are made. First, an open-source LPWAN
assessment framework has been conceived. It allows testing and evaluating
hypotheses and schemes. Secondly, as a representative case, the LoRaWAN
protocol is assessed. The findings indicate how a cross-layer approach can
optimize LPWANs in terms of energy efficiency and throughput. For instance, it
is shown that the use of larger payloads can reduce up to three times the
energy consumption on quasi-static channels yet may bring an energy penalty
under adverse dynamic conditions
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Optimal Policy Derivation for Transmission Duty-Cycle Constrained LPWAN
Low-power wide-area network (LPWAN) technologies enable Internet of Things (IoT) devices to efficiently and robustly communicate over long distances, thus making them especially suited for industrial environments. However, the stringent regulations on the usage of certain industrial, scientific, and medical bands in many countries in which LPWAN operate limit the amount of time IoT motes can occupy the shared bands. This is particularly challenging in industrial scenarios, where not being able to report some detected events might result in the failure of critical assets. To alleviate this, and by mathematically modeling LPWAN-based IoT motes, we have derived optimal transmission policies that maximize the number of reported events (prioritized by their importance) while still complying with current regulations. The proposed solution has been customized for two widely known LPWAN technologies: 1) LoRa and 2) Sigfox. Analytical results reveal that our solution is feasible and performs remarkably close to the theoretical limit for a wide range of network activity patterns
Low Power Wide Area Networks (LPWAN): Technology Review And Experimental Study on Mobility Effect
In the past decade, we have witnessed explosive growth in the number of low-power embedded and Internet-connected devices, reinforcing the new paradigm, Internet of Things (IoT). IoT devices like smartphones, home security systems, smart electric meters, garage parking indicators, etc., have penetrated deeply into our daily lives. These IoT devices are increasingly attached and operated in mobile objects like unmanned vehicles, trains, airplanes, etc. The low power wide area network (LPWAN), due to its long-range, low-power and low-cost communication capability, is actively considered by academia and industry as the future wireless communication standard for IoT. However, despite the increasing popularity of mobile IoT, little is known about the suitability of LPWAN for those mobile IoT applications in which nodes have varying degrees of mobility. To fill this knowledge gap, in this thesis:1. We present a thorough review on LPWAN technology focusing on the mobility effect. 2. We conduct an experimental study to evaluate, analyze, and characterize LPWAN in both indoor and outdoor mobile environments.Our experimental results indicate that the performance of LPWAN is surprisingly susceptible to mobility, even to minor human mobility, and the effect of mobility significantly escalates as the distance to the gateway increases. These results call for development of new mobility-aware LPWAN protocols to support mobile IoT
Long-Range Communications in Unlicensed Bands: the Rising Stars in the IoT and Smart City Scenarios
Connectivity is probably the most basic building block of the Internet of
Things (IoT) paradigm. Up to know, the two main approaches to provide data
access to the \emph{things} have been based either on multi-hop mesh networks
using short-range communication technologies in the unlicensed spectrum, or on
long-range, legacy cellular technologies, mainly 2G/GSM, operating in the
corresponding licensed frequency bands. Recently, these reference models have
been challenged by a new type of wireless connectivity, characterized by
low-rate, long-range transmission technologies in the unlicensed sub-GHz
frequency bands, used to realize access networks with star topology which are
referred to a \emph{Low-Power Wide Area Networks} (LPWANs). In this paper, we
introduce this new approach to provide connectivity in the IoT scenario,
discussing its advantages over the established paradigms in terms of
efficiency, effectiveness, and architectural design, in particular for the
typical Smart Cities applications
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