MidSHM: A flexible middleware for SHM application based on service-oriented architecture

Wireless Sensor Network (WSN) is often used for developing Structural Health Monitoring (SHM) application by civil researchers but they do not have much expertise on hardware and network related issues. By providing programming abstractions and hiding low level network issues middleware layer makes it easier to develop an efficient WSN-based SHM application. Service-oriented architecture (SOA) is a popular approach for designing middleware for WSN as it provides flexibility in developing WSN applications by using loosely coupled services. SOA can overcome issues like adaptation, reliability which are usually difficult to deal using other middleware approaches applied for WSN. This paper surveys various middleware approaches for WSN focusing mainly on SOA-based approach. It discusses drawbacks in various middleware approaches and points out design issues that not completely addressed by existing middleware architectures designed for SHM application. An easy-to-use SOA-based middleware, named MidSHM, has been proposed to deal with various SHM application issues such as resource optimization, in-network processing, quality of service, and fault tolerance. Two different application examples enabled by MidSHM are also shown to illustrate its flexibility and usability.