Demo: Using LoRa Communications and Epidemic Routing in Disaster Rescue Operations Electronic Communications of the EASST Volume 080 (2021) Conference on Networked Systems 2021 (NetSys 2021) Demo: Using LoRa Communications and Epidemic Routing in Disaster Rescue Operations Yamani Dalpathadu 1, Showry Thumma †, Asanga Udugama, Anna Förster 4 pages Guest Editors: Andreas Blenk, Mathias Fischer, Stefan Fischer, Horst Hellbrueck, Oliver Hohlfeld, Andreas Kassler, Koojana Kuladinithi, Winfried Lamersdorf, Olaf Landsiedel, Andreas Timm-Giel, Alexey Vinel ECEASST Home Page: http://www.easst.org/eceasst/ ISSN 1863-2122 1 The authors performed the primary work and contributed equally. http://www.easst.org/eceasst/ ECEASST Demo: Using LoRa Communications and Epidemic Routing in Disaster Rescue Operations Yamani Dalpathadu1 †, Showry Thumma1 †, Asanga Udugama2, Anna Förster3 1 sachitha@uni-bremen.de, 1 thumma@uni-bremen.de University of Bremen, Bremen, Germany. 2 adu@comnets.uni-bremen.de 3 anna.foerster@uni-bremen.de University of Bremen, Bremen, Germany. Abstract: A casualty of disasters is the communication infrastructure. Rescuers, in the aftermath of the disaster, require solutions to maintain communications in order to communicate critical information gathered by them. Despite the numerous solu- tions proposed, a drawback is the communication range. In this work, we propose a communication system based on LoRa, a long-range, low-power communication technology. We use the commercially available, off-the-shelf LoRa based PyCom LoPy4 platform with opportunistic networking to demonstrate the viability of using LoRa for post-disaster recovery operations. Keywords: Epidemic Forwarding, LoRa, Pycom LoPy4, Disaster Rescue Opera- tions 1 Introduction The job of emergency first responders is important in saving as many lives as possible and assist- ing the affected in the aftermath of disasters. Since disasters destroy communication infrastruc- ture, satellite communications are widely used to provide broadband point-to-point connectivity for devices carried by rescuers. But, satellite communications are expensive due to costly equip- ment and subscriptions. Since almost every mobile device these days is equipped with Device-to-Device (D2D) com- munication technologies (e.g., WiFi, Bluetooth), they are considered a viable solution during rescue operations [GW14, MTN18]. However, the short range of these communication methods makes them inefficient when rescuers are dispersed and operating in debris. LoRa is a low-power wide-area networking (LPWAN) technology with a low data rate and a long range (usually 3 to 30 kilometers), making it an excellent alternative. Some of the crucial data exchanged during rescue operations are short messages consist- ing of environmental information such as position coordinates or detected dangers (gas leaks, etc.).Therefore, we propose a solution for rescuers based on a low-cost, commercially avail- able microcontroller platform equipped with LoRa and multiple sensors. This platform, called PyCom LoPy41, carried by each rescuer, is configured to sense environmental information and † The authors performed the primary work and contributed equally. 1 https://pycom.io 1 / 4 Volume 080 (2021) mailto:sachitha@uni-bremen.de mailto:thumma@uni-bremen.de mailto:adu@comnets.uni-bremen.de mailto:anna.foerster@uni-bremen.de Demo: Using LoRa Communications and Epidemic Routing in Disaster Rescue Operations use Opportunistic Networking (OppNets) with Epidemic Forwarding [VB00] and the LoRaMAC mode to disseminate data between rescuers and a disaster management center. In this work, we demonstrate the operation of our solution using a scenario mimicking communication during rescue operations. This work has been evaluated with multiple scenarios previously2 and the architecture and the performance evaluation have been accepted for publication [DTK+21]. 2 Related Work There are a number of work focusing on using LoRa in disaster communications. An IoT frame- work based on LoRaWAN and WiFi technology for disaster management has been presented in [DDZ+19]. The authors of [CFM+19] suggest a communication scheme for disaster commu- nications. The authors of [HBK+20] describe a firmware that enables users to use LoRaWAN technology via smartphones in post-disaster conditions. Considering these works, our work is unique in that it is the first time LoRaMAC has been de- ployed in emergency communication applications. LoRaMAC refers to the mode of operation in LoRa for direct, device-to-device (D2D) communications with other devices in a wireless neigh- borhood. In the LoRaWAN mode, the communications are performed over a deployed gateway. In contrast to [DDZ+19], [HBK+20], and [SFTD18], we employ LoRaMAC and an enhanced version of Epidemic Forwarding [VB00] to disseminate data. Our approach is closely related to the work described in [SFTD18], but the authors propose the use of the LoRaMAC interface as an attachment to a smartphone, thereby limiting their solution to the sensing capabilities offered by the smartphone. 3 System Architecture The architecture of the system deployed in each PyCom LoPy4 device consists of a 3-layer pro- tocol stack with an additional shim-layer for neighborhood management. The primary purpose of this protocol stack is to exchange sensed data between the devices of the rescuers. The fig- ure 1a shows the Micro-Python programmed protocol stack of a device. Following is a brief description of the protocol stack. • Application Layer is for applications that sense environmental information (e.g., position co- ordinates) and to use the received data of other rescuers. Currently, we use the PyTrack and PySense extensions of the PyCom LoPy4 to retrieve the last available localized GPS coordi- nates, ambient light, pressure, and humidity. This traffic is transmitted periodically and the period of transmitting packets is configurable. • Forwarding Layer is the OppNets forwarding layer where an extended version of Epidemic Forwarding [VB00] is implemented. The extended version consists of anti-entropy sessions based on timeouts to overcome the effects of deadlocks that arise due to the packet losses during transmissions. 2 https://github.com/ComNets-Bremen/Epidemic-on-PyCom/tree/master/results NetSys 2021 2 / 4 ECEASST Application Epidemic Forwarding Sensed Data Collector and Transmitter LoRa Neighbour Management Forwarding Link (a) The 3-layer protocol stack includ- ing the shim-layer X XX X X X Path of mobile nodes X Stationary node X Mobile node Building (b) The view of the 6-node scenario demonstrated Figure 1: Node Architecture and Demonstrated Scenario • Link Layer is realized through LoRa where the LoRaMAC mode is configured at initializa- tion to perform D2D communications. Because LoRa only offers broadcast communications, this module manages unicast operations internally by considering packets that are destined to themselves. The addressing is realized through the unique MAC-like address provided by the LoRa network interface. • Neighbor Management shim-layer is responsible for maintaining the neighbor list of a node using a beaconing mechanism. There are four different packet types used: HELLO message is used by neighbor management to beacon the presence and to know about other devices in its wireless vicinity, DATA message carries the sensed data, REQUEST and SUMMARY-VECTOR messages are used by Epidemic Forwarding to perform the anti-entropy operation [VB00]. 4 Demonstration The focus of our demonstration is to show the dissemination of data to the different devices of rescuers. The figure 1b shows a view of the placement of devices during the demonstration. The demonstration consists of six devices (nodes), three moving (mobile), and three stationary. We have chosen three initial nodes that are responsible for sensing data while all nodes spread the sensed data throughout the network. In this demonstration, we visually show the spread of data throughout the network and at the end, convey how successfully the Epidemic routing protocol disseminated the data throughout the network, and how LoRa enabled this spread to occur. 5 Summary and Future Work The work presented here for the demonstration focuses on disseminating sensed data of res- cuers in the aftermath of a disaster when usual networking infrastructure-based communications 3 / 4 Volume 080 (2021) Demo: Using LoRa Communications and Epidemic Routing in Disaster Rescue Operations are unavailable. The solution we propose uses LoRa and OppNets with Epidemic Forwarding for communications. The solution uses the commercially available off-the-shelf PyCom LoPy4 platform with Micro-Python to implement the functionality. The code and the performance eval- uation is available at GitHub3 and published at [DTK+21]. Though we have an operational version, the performance results show us a number of challenges to address in the future. The primary challenge is the identification of optimal configuration parameters (e.g., the spreading factor). Additionally, we plan to undertake an extensive performance analysis to include eval- uations based on realistic post-disaster rescue operations that take into account factors such as node velocity, the distance between nodes, and weather conditions. Bibliography [CFM+19] R. P. Centelles, F. Freitag, R. Meseguer, L. Navarro, S. F. Ochoa, R. M. Santos. A LoRa-Based Communication System for Coordinated Response in an Earthquake Aftermath. Proceedings 31(1), 2019. [DDZ+19] A.-M. Dragulinescu, A. Dragulinescu, C. Zamfirescu, S. Halunga, G. Suciu. Smart Neighbourhood: LoRa-based environmental monitoring and emergency manage- ment collaborative IoT platform. In 2019 22nd International Symposium on Wireless Personal Multimedia Communications (WPMC). Pp. 1–6. 2019. [DTK+21] Y. Dalpathadu, S. Thumma, V. Kuppusamy, A. Udugama, A. Förster. Disseminat- ing Data using LoRa and Epidemic Forwarding in Disaster Rescue Operations. In ACM International Conference on Information Technology for Social Good (GoodIT 2021). 09 2021. [GW14] B. P. Gautam, K. Wasaki. Using a redundant Wi-Fi network as an emergency detour route to proactively reduce disaster risk in Wakkanai, Hokkaido. In 2014 Interna- tional Conference on Information Science, Electronics and Electrical Engineering. Volume 3, pp. 1830–1837. 2014. [HBK+20] J. Höchst, L. Baumgärtner, F. Kuntke, A. Penning, A. Sterz, B. Freisleben. LoRa- based Device-to-Device Smartphone Communication for Crisis Scenarios. 05 2020. [MTN18] M. Murase, K. Tanaka, K. Naito. Prototype implementation of human management system with BLE beacon devices in natural disasters. 2018 15th IEEE Annual Con- sumer Communications and Networking Conference (CCNC), pp. 1–2, 2018. [SFTD18] L. Sciullo, F. Fossemo, A. Trotta, M. Di Felice. LOCATE: A LoRa-based mObile emergenCy mAnagement sysTEm. In 2018 IEEE Global Communications Confer- ence (GLOBECOM). Pp. 1–7. 2018. [VB00] A. Vahdat, D. Becker. Epidemic Routing for Partially-Connected Ad Hoc Networks. Technical Report, 06 2000. 3 https://github.com/ComNets-Bremen/Epidemic-on-PyCom.git NetSys 2021 4 / 4 Introduction Related Work System Architecture Demonstration Summary and Future Work