A Multi-Technology Communication Platform for Urban Mobile Sensing

Rodrigo Almeida, Rui Oliveira, Miguel Luís, Carlos Senna, Susana Sargento
2018 Sensors  
A common concern in smart cities is the focus on sensing procedures to provide city-wide information to city managers and citizens. To meet the growing demands of smart cities, the network must provide the ability to handle a large number of mobile sensors/devices, with high heterogeneity and unpredictable mobility, by collecting and delivering the sensed information for future treatment. This work proposes a multi-wireless technology communication platform for opportunistic data gathering and
more » ... ata exchange with respect to smart cities. Through the implementation of a proprietary long-range (LoRa) network and an urban sensor network, our platform addresses the heterogeneity of Internet of Things (IoT) devices while conferring communications in an opportunistic manner, increasing the interoperability of our platform. It implements and evaluates a medium access communication (MAC) protocol for LoRa networks with multiple gateways. It also implements mobile Opportunistic VEhicular (mOVE), a delay-tolerant network (DTN)-based architecture to address the mobility dimension. The platform provides vehicle-to-everything (V2X) communication with support for highly reliable and actionable information flows. Moreover, taking into account the high mobility pattern that a smart city scenario presents, we propose and evaluate two forwarding strategies for the opportunistic sensor network. of energy efficiency, poor usage of the natural resources, environmental pollution, and sustainable resource management, among others. A typical smart city scenario has to deal with an extensive number of sensors and data generators (some of which are placed in high mobile devices), deployed to collect and generate all types of information, which will increase the numbers of communicating machines, modifying the current scenario of human-centric communications. The consequence is an avalanche of mobile and wireless traffic information. The high heterogeneity and volatility of the network carries connectivity issues, such as long and variable delays, sparse and intermittent connectivity, high error rate, high latency, highly asymmetric data rate, or even a non-existent end-to-end connectivity [6] . Along with the necessity to have a low-cost infrastructure, and to overcome the issues associated with the network disruption, the concept of the delay-tolerant network [7] is usually adopted in these scenarios. Moreover, in a smart city environment, a large number of devices are battery-powered and located in remote areas where wired connectivity is hard to guarantee. However, these devices need to be connected to cloud applications that offer a broad vision of city management. Low-Power Wide-Area Network (LPWAN) technology can be a good option to meet these requirements [8] . The long-range (LoRa) network is also a relevant form of LPWAN technology due to its unique modulation [9] , which makes it a very versatile form of technology that can be easily adapted to different types of environments and applications [10] . Besides, it is seen as an attractive solution for IoT and machine-to-machine (M2M) platforms since it operates in unlicensed bands. In this context, this work implemented and evaluated, through a real environment, a multi-technology opportunistic platform for environmental data gathering with respect to smart cities, considering both static and moving sensing elements, and both long-and short-range communication. The main contributions of this work can be summarized as follows: A brief description about the distinct software modules that assemble the platform architecture is now detailed: Sensor Controller: Module responsible for establishing and managing all the direct interactions between the controller board and the element's inner sensors. Multi-technology Communication Manager: Module responsible for establishing the behavior of each communication interface, WiFi, and LoRa. It has the authority of defining the most suitable technology to deliver its stored data packets (built-in Sensor Controller), according to the information type and the interface availability, until they reach a LoRa gateway or are transfered to a mobile node. LoRa Communication Manager: Module responsible for handling all the behavior regarding the LoRa communication interface. Unlike what happens in a DCU, where we have the Multi-technology Communication Manager, this software module only has to deal with the LoRa technology, since the WiFi is managed under the DTN operating processes. DTN: Module responsible for implementing the disrupted and delay-tolerant network architecture. Multi-Technology Communication Multi-technology exploitation has the purpose of providing a more resourceful and flexible architecture, since it allows for covering some technology inconsistencies with another form of
doi:10.3390/s18041184 pmid:29649175 pmcid:PMC5948508 fatcat:shlyuyfqwbh4nck6ghagcqacri