5,823 research outputs found
Scalability analysis of large-scale LoRaWAN networks in ns-3
As LoRaWAN networks are actively being deployed in the field, it is important
to comprehend the limitations of this Low Power Wide Area Network technology.
Previous work has raised questions in terms of the scalability and capacity of
LoRaWAN networks as the number of end devices grows to hundreds or thousands
per gateway. Some works have modeled LoRaWAN networks as pure ALOHA networks,
which fails to capture important characteristics such as the capture effect and
the effects of interference. Other works provide a more comprehensive model by
relying on empirical and stochastic techniques. This work uses a different
approach where a LoRa error model is constructed from extensive complex
baseband bit error rate simulations and used as an interference model. The
error model is combined with the LoRaWAN MAC protocol in an ns-3 module that
enables to study multi channel, multi spreading factor, multi gateway,
bi-directional LoRaWAN networks with thousands of end devices. Using the
lorawan ns-3 module, a scalability analysis of LoRaWAN shows the detrimental
impact of downstream traffic on the delivery ratio of confirmed upstream
traffic. The analysis shows that increasing gateway density can ameliorate but
not eliminate this effect, as stringent duty cycle requirements for gateways
continue to limit downstream opportunities.Comment: 12 pages, submitted to the IEEE Internet of Things Journa
Understanding the limits of LoRaWAN
The quick proliferation of LPWAN networks, being LoRaWAN one of the most
adopted, raised the interest of the industry, network operators and facilitated
the development of novel services based on large scale and simple network
structures. LoRaWAN brings the desired ubiquitous connectivity to enable most
of the outdoor IoT applications and its growth and quick adoption are real
proofs of that. Yet the technology has some limitations that need to be
understood in order to avoid over-use of the technology. In this article we aim
to provide an impartial overview of what are the limitations of such
technology, and in a comprehensive manner bring use case examples to show where
the limits are
Slotted ALOHA Overlay on LoRaWAN: a Distributed Synchronization Approach
LoRaWAN is one of the most promising standards for IoT applications.
Nevertheless, the high density of end-devices expected for each gateway, the
absence of an effective synchronization scheme between gateway and end-devices,
challenge the scalability of these networks. In this article, we propose to
regulate the communication of LoRaWAN networks using a Slotted-ALOHA (S-ALOHA)
instead of the classic ALOHA approach used by LoRa. The implementation is an
overlay on top of the standard LoRaWAN; thus no modification in pre-existing
LoRaWAN firmware and libraries is necessary. Our method is based on a novel
distributed synchronization service that is suitable for low-cost IoT
end-nodes. S-ALOHA supported by our synchronization service significantly
improves the performance of traditional LoRaWAN networks regarding packet loss
rate and network throughput.Comment: 4 pages, 8 figure
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