## 1 Introduction  
Low-power wide-area network (LPWAN) technologies attract great attention within the academic and industry communities, due to the fact they can wirelessly connect great numbers of geographically dispersed devices at low cost. Internet of Things (IoT) deployments in suburban or rural areas could include a lot of different scenarios for various kinds of data gathering. Depending on the use case, data from sensors at remote locations could be transmitted in big- or small-sized payloads, in short or long intervals, and collected by servers with or without latency. The most important requirements for rural IoT deployments are long-range communication and large network coverage. The network should operate in places with complicated terrain where radio communications are difficult and most times even telecommunication providers are not offering coverage. At the same time, IoT networks deployed in rural areas consist of a huge number of end devices (EDs), especially when we are dealing with smart metering. The communication infrastructure should be scalable in order to connect all the EDs without affecting the performance of the whole network in a non-viable way. In addition, the required maximum lifetime for such IoT deployments may vary from 10 to 15 years, or even more. Therefore, the EDs that will be used for communication should consume minimum energy in order to prolong the lifetime of their batteries, while the total cost of each ED in terms of the annual operating cost should be low. Among these requirements, the range of communication, based on the literature, seems to be the most complicated topic. It is worth mentioning that, during the past years, the world record for the maximum distance that a LoRaWAN data packet can be successfully transmitted has been broken many times. One of these records stands at 832 km (517 miles). However, how can this record help the adoption of the protocol from a network designer? It is commonly accepted that the effective allocation of wireless resources, in order to support a big batch of devices within an area, still remains an open challenge [1]. With LoRa, we have a relatively new technology whose practical limits are not crystal clear yet. In addition, the fact that the theoretical range covers distances of the order of kilometers is creating some difficulties for real-case scenarios, both in laboratory and field tests. In LoRaWAN, the long range of communication is achieved by transmitting with very low data rates to improve the sensitivity of receivers within the sub-GHz industrial, scientific, and medical (ISM) radio bands. LoRaWAN in the EU offers multiple channel availability with different bandwidths within the range of 868-870 MHz in the ISM band, while the orthogonality of spreading factors (SFs) offers simultaneous transmission in the same frequency channel [2]. The protocol consists of the physical layer (LoRa) of the Open Systems Interconnection (OSI) model, which is proprietary, and a medium access and network layer, LoRaWAN, which is an open LPWAN standard. LoRaWAN was initially designed for low data-rate sensor networks, where sensors exchange packets only with the network server [3]. Within the 868 MHz band, LoRaWAN has three common 125 kHz channels by default (868.10, 868.30 and 868.50 MHz). These are the channels that the EDs are using to access the network. The network server can provide extra channels to EDs after the join process. In Europe, which is our case, 10 channels are available and used both for uplinks and downlinks. In addition, apart from LPWANs, a lot of other standardized applications also function on the same spectrum frequencies, such as RFID, alarms, wireless headphones etc. [4]. The ISM bands are license-free, thus can be utilized by almost any ED as long as it transmits based on the spectrum usage regulations. The regulation for ISM bands within Europe are different from other regions (e.g., in the US the band has no duty cycle restrictions) [5].