The Challenges of Using Wireless Mesh Networks for Earthquake Early Warning Systems

Abstract

The total cost of an Earthquake Early Warning System (EEWS) can be substantially decreased by using Wireless Mesh Networks (WMNs), which are inexpensive computer networks whose nodes communicate wirelessly using a license-free spectrum in a self-organized manner. The Early Warning System triggers on the small-amplitude, but fast P-wave in order to shutdown critical infrastructures before the destructive, but slow S-waves arrive only a few seconds later. It demands low-latency communications of high robustness. We conducted shakeboardbased measurements using IEEE 802.11a/b. Innovatively, our tests show that already for the slight shaking related to Pwaves representative for strong (Mw > 6) and nearby (epicentral distance < 40 km) earthquakes, the performance of the wireless communications can be considerably affected at the very moment when the Early Warning system is supposed to be used. We observed swift link quality oscillations of up to 10 dB within only half a second. The more an environment is vulnerable to multi-path interference and shadow fading, e.g. no line of sight (NLOS), the more erratic are the wireless links between nodes. However, for clear line of sight (LOS) the influence of the vibrations is negligible. We recommend several measures that should be applied in order to make the unique use case of Earthquake Early Warning, nonetheless, well-functioning on top of a Wireless Mesh Network. A higher fade margin, in our setup at least an additional 5 dB, should be included to cope with sudden link fading. Moreover, antenna diversity should be enabled as it strongly mitigates the adverse effects of shaking.

Processing and Communication Delays in EWS: On the Performance of the Earthcloud Prototype

“…For instance, Uga et al [4] test these sensors specifically for SASs applications and study how to separate false positives from real ground motion, although tests are performed against artificial data obtained with a shakeboard, and smartphones are positioned on horizontal flat surfaces for the entire duration of the experiments. Shakeboards are also employed to test prototypes designed to form an IEEE 802.11 (WiFi) Wireless Mesh Network [5,6]. In these cases, however, authors focus specifically on the performance of wireless communications.…”

A Novel Technique for Automatic Detection of Earthquake and Landslide Using Iot

“…In [3], Heindl proposes an innovated idea tries to use the threeaxis acceleration information in smart phones or hard disk as a collaborative sensor system. The other researches [4,5,6] focus on connection organization by using wireless mesh network, wireless sensor network P2P technology to collect the data rapidly. The Japan Meteorological Agency (JMA) started providing the Earthquake Early Warning by several means such as TV and radio on Oct 2007.…”

Application of Laplace Approximation Formula in Performance Analysis of Wireless Relay Communication System in Multipath Fading Environment

“…In environments susceptible to earthquakes, floods etc. improvement of wireless system performances using reliable transmission techniques can be of crucial importance [5]. Further, multi-hop amplify-andforward (AF) relay system signal envelope can be modeled as the product of two or more random variables where the first random variable is the signal envelope at the first section, the second variable is the signal envelope at the second section while the last random variable is the signal envelope at the last section [6,7].…”