# LoRa 2.4 GHz Communication Link and Range  
[PERSON]  
1 IDLab-Faculty of Applied Engineering, University of Antwerp-imec, Sint-Pietersvliet 7, 2000 Antwerp, Belgium; [EMAIL_ADDRESS] (T.J.); [EMAIL_ADDRESS] (N.B.); [EMAIL_ADDRESS] (M.A.); [EMAIL_ADDRESS] (R.B.)  
[PERSON]  
1 IDLab-Faculty of Applied Engineering, University of Antwerp-imec, Sint-Pietersvliet 7, 2000 Antwerp, Belgium; [EMAIL_ADDRESS] (T.J.); [EMAIL_ADDRESS] (N.B.); [EMAIL_ADDRESS] (M.A.); [EMAIL_ADDRESS] (R.B.)  
[PERSON]  
222  
[PERSON]  
In general, the range of sub-GHz LPWAN varies from a few kilometers in urban environments to more than 10 km in rural environments. Obviously, the maximum communication range between the transmitter and receiver also depends on the used frequency band. The goal of this research is to study the inverse relationship between the maximum communication range and the corresponding data rate of LoRa in the 2.4 GHz band.  
Since sub-GHz LoRa devices are very limited in terms of their number of possible transmissions--i.e., to comply with duty cycle regulations--they are typically used for applications that do not require frequent communication. For example, [PERSON] et al. proposed a LoRa-based forest fire detection system that transmits sensor measurements every 28 min [1]. Besides this, the long-range communication benefit of sub-GHz LoRa has been exploited to provide emergency services in GPS-less environments [2]. Other application examples with sub-GHz LoRa include smart meter reading, environmental monitoring, smart farming and smart building applications [3; 4]. On the other hand, LoRa devices that operate at 2.4 GHz are able to transmit at higher data rates because of the higher available bandwidth [5]. Consequently, this technology can offer a balance for applications that require a higher data rate than LPWANs and a longer communication range than classic 2.4 GHz technologies such as Wi-Fi and Bluetooth. Additionally, a higher bandwidth also allows for more accurate time-based localization [6]. Thus, LoRa at 2.4 GHz represents an interesting solution for a variety of applications that involve indoor localization, such as warehouse management, but also for applications that require outdoor localization, such as construction site monitoring, livestock tracking, etc. Moreover, the adoption of this technology can add flexibility to applications that require consistent asset tracking in both indoor and harsh outdoor environments; e.g., smart ports.  
The main contributions of this work are the following:  
* We provide an overview of the physical layer of LoRa operating at 2.4 GHz.
* We discuss the maximum communication range and data rate in three different scenarios: free space, indoor and urban environments.
* We discuss the impact of moving from LoRa at sub-GHz bands to 2.4 GHz on communication and localization applications.  
The remainder of this paper is structured as follows. Section 2 contains related work regarding LoRa in both sub-GHz bands and the 2.4 GHz band. Subsequently, a mathematical background of LoRa at 2.4 GHz is provided in Section 3. Next, three path loss models are presented in Section 4 in order to estimate the maximum communication range and corresponding data rate in a free space and in indoor and urban environments. The results of these estimations are shown in Section 5 and compared to other technologies operating in the 2.4 GHz band in Section 6, which also discusses the impact on the application potential of LoRa at 2.4 GHz. Finally, general conclusions are drawn in Section 7.