Recent escalating efforts to realize the vision of smart cities have become a global trend. Within such efforts, the setup of relevant infrastructure is necessary to enable scalable sensing and sense-making in urban environments. In this paper, we discuss the design and implementation of MOON – Massive Open Online Networks – to interconnect large-scale and diverse IoT devices to enable the acquisition of real-time sensing data. We describe the system architecture and software protocols that form the components of MOON. In addition, we highlight the challenges in the deployment and management of such networks. These are derived through experiences gleaned from our extensive deployments of wireless infrastructure for large-scale, real-time sensing in both indoor and outdoor urban environments.
Efforts to realize the smart city vision is now a global phenomenon, whereby information and communications technology is harnessed to enhance the quality of lives of citizens. Such technology can be applied in various domains-such as healthcare, transport and education. With the availability of real-time sensing data provided by the integration of sensor and communications technologies, informed decision-making and appropriate response protocols can then take place among citizens, governments and other stakeholders.
SYSTEM ARCHITECTURE AND DESIGN
A generic system architecture is illustrated in Figure 1. The sensor frontend comprises a tiered mesh networking platform, whereby sensor nodes are connected via single or multiple hops to one or more gateways. Each sensor node may have one or more sensing modalities – such as passive infrared (PIR), temperature, noise, humidity and dust. Each gateway is connected to the backend via backhaul communications such as WiFi, Ethernet or cellular communications.
DEPLOYMENT AND MANAGEMENT CHALLENGES
Sensor nodes may be equipped with multi-modal sensing components. The use of off-the-shelf hardware may require the physical interconnection of the hardware components via auxiliary components such as USB hubs and cables. These physical interconnections are generally not resilient to movements and high operating temperatures. Various sensing components may also require dedicated power sources.
The SHINE Seniors project aims to provide Smart Homes and Intelligent Neighbors to Enable Seniors and support ageing-in-place. Through the use of open and always online networks, multi-modal sensors can be installed in the homes of the elderly, to provide real-time passive monitoring of the elderly and to detect anomalies in their living patterns. This enables volunteers and caregivers to provide timely intervention through a response protocol.
Many networks have been deployed for urban sensing worldwide; however, many of these deployments are small-scale, use proprietary hardware and software platforms that limit the heterogenity of the network, and may have intermittent network connectivity. Through our extensive deployment experiences, we have identiﬁed the three key criteria of sensing infrastructure for smart cities as massive, open and online.
Source: Singapore Management University
Authors: Hwee Xian Tan | Hwee-Pink Tan