# Performance Evaluation of LoRa Considering Scenario Conditions
## 1 Introduction  
Low Power - Wide Area Networks (LP-WAN) have emerged as one of the most promising Internet of Things (IoT) enabling technologies due to their advantages over other solutions such as short-range transmission technologies (e.g., WiFi, Bluetooth, IEEE 802.15.4-based protocols, etc.) or cellular communications [1, 2]. This fact is motivated by the different requirements that current and future IoT systems present in comparison with traditional Wireless Sensor Networks (WSN) or cellular systems. These conceptual differences between the IoT, WSN, and cellular-network paradigms are presented in Table 1. Observe that, basically, the main characteristics and requirements that an IoT system presents are: (i) a reduced use of bandwidth; (ii) a limited number of messages per node per day; (iii) huge number of simultaneously-connected end-devices; (iv) long-range links; and (v) low-cost end-devices. The majority of these features are satisfied by the different LP-WAN platforms in the market [3]; however, they present important differences mostly related to their network architecture and the adopted business model. In this work, the focus is on LoRaWAN (Long-RangeWide Area Network) [4], which is a platform promoted by the LoRa Alliance (IBM, Semtech, and Cisco, among others), positioned together with Sigfox [5] at the top of the rank of platforms receiving more attention from both the academia and the industry [1]. Although both of them offer similar features to their users, each one takes different technological approaches. On the one hand, Sigfox presents a highly closed and limited transmission scheme with very few adaptation capabilities as it employs a proprietary ultra-narrow band technology with a maximum uplink data-rate of 100 bps and a maximum packet-payload of 12 Bytes. As the majority of the LP-WAN platforms, Sigfox uses the Industrial, Scientific, and Medical (ISM) sub-GHz frequency bands so, due to the strict duty-cycle limitations imposed by worldwide regulations, the number of transmissions is highly restricted; for example, in Europe, a maximum of 140 messages per end-node per day are allowed. Nevertheless, despite these technological limitations, Sigfox is having great success due to its business and architecture model that consists of a wide network of base-stations covering great part of some European territories and a backhaul network that permits to deliver the collected data from the edge-network to the cloud almost with reduced latency. Therefore, the end-users are only in charge of acquiring and installing the end-devices, because data-transport and its presentation is in Sigfox hands, which notably eases the management tasks from the user side. In turn, LoRaWAN [4] presents a more advanced solution that permits the end-user to adapt the system to her needs. Specifically, LoRaWAN defines the OSI's (Open Systems Interconnection) Physical (PHY) and Medium Access Control (MAC) layers (please, see Figure 1). In the PHY layer, LoRaWAN employs their own-developed modulation scheme, so-called LoRa (Long Range), which is a proprietary technology based on a Chirp Spread Spectrum (CSS) modulation that permits low-power long-range transmissions. On the MAC layer, LoRaWAN defines the communication protocol, the system architecture, and other services and interfaces for higher-layer applications. Both layers present some customizable settings that provide the system with a valuable flexibility to adapt it to different use cases. Further insights about LoRa and LoRaWAN are provided in subsequent sections.