## 1 Introduction
We comparatively analyze existing detection and alert solutions and define the design objectives of a WSN platform that can overcome most of their weaknesses. Then, we present the main design phases, the effort spent, the major pitfalls building the first prototype and the lessons learned from its field test. We also show how the resulting WSN platform can support a large class of environmental monitoring applications, increasing its value and reducing its return on investment. Platform specifications were defined in collaboration with an industrial beneficiary and respond to pragmatic and stringent requirements for pervasive wildfire detection and alerting. For this purpose, the company consulted several actors in areas subject to wildfires, such as firefighters, state forestry corps, civil protection and forest rangers. The main contributions of the paper can be summarized as follows:  
1. A methodical holistic analysis of the effects of the application requirements and of the available design options for the platform hardware, software, communication protocols and field deployment procedures on the overall platform performance, the cost and the reliability of its nodes, of the platform commissioning and exploitation. This method can be applied for the analysis of other WSN platforms in the context of different application requirements. 2. Design criteria, optimization and field validation of cost-effective sensor nodes and gateways that use much lower resources and energy than the typical nodes in the literature based on off-the-shelf components. 3. Analysis, definition and field test of a cost-effective and reliable field deployment procedure for the network nodes that minimizes human-introduced errors. 4. Design, optimization and field test of a simple, yet effective field communication protocol that matches application requirements well, significantly contributes to the reduction of node energy consumption and cost and supports an effective field deployment procedure for the nodes. It can also scale up to support networks with a very large number of nodes. 5. Analysis and selection of the hardware and software features to implement on node prototypes designed for laboratory testing in order to adapt them, in a short time and with reduced effort, for a relatively long, unattended field experiment with two equally important purposes: to check and demonstrate the autonomous operation of the platform and to acquire sufficient visibility of node and system behavior that can be used to improve the design of the platform. The rest of the paper is organized as follows. Section 2 reviews related published works and defines the specifications of the system through comparative analysis of the strengths and weaknesses of existing methods. Section 3 outlines the design criteria, which drive the platform design decisions. Section 4 explores the most important design decisions made for the implementation of the WSN platform components. Section 5 presents how the prototype platform was prepared for a field test, on short notice. Section 6 presents the unfolding of the field test, the major issues during its various phases and the most important lessons learned to improve the WSN platform. Section 7 presents a summary of the future work and concludes the paper.