## 1 Introduction  
Despite technical improvements, the work of firefighters still remains dangerous. Research into firefighter support systems is intensely motivated as it has the potential to save lives.  
In a reconnaissance mission, a firefighting team must enter the site of the incident, and conduct a systematic inspection under extremely rough physical conditions. Because of the fumes and heat, firefighters have to wear equipment that severely limits their range of motion. Work in such conditions is very complex, during which training and intuition play an important role [1]. Getting lost in a mission inside an unknown building is a common cause of accidents in firefighting [2]. Currently, very limited pervasive technology, if any, comes into play for preventing this kind of accident. Thus, our research into the field began by developing a wireless sensor network (WSN) infrastructure to support way-finding for firefighters performing missions in indoor fires [3].  
Our investigation followed a human-centered approach based on leveraging ambient intelligence technologies to develop new practices of navigation [4]. The approach involved a professional fire brigade, a firefighting institute and training center, a leading company for firefighting equipment, two companies focused on the creation of mobile and wearable solutions and three academic research institutes. The goal of this structure was to create an environment to test ideas and establish a dialog around the potential of technology to support navigation [5, 6]. As an important result, we showed the feasibility of a deployable ad-hoc wireless sensor system compatible with the complexities of firefighting work [7].  
However, this system primarily provides assistance in unexpected emergency situations but falls short in assisting firefighters in typical routine missions. Here we analyze the experience from that work and extract requirements for a system that would assist firefighters in the course of every-day activities as well. Communication technology presents an important aspect of firefighting front-line work and currently has a range of shortcomings. Most importantly these are the high propabality of radio failure and the disruptive nature of communication queries on a firefighters' concentration. Both may lead to reduced efficiency, delayed communication reactions or worse. We present a system sketch that complements the current communication technology by combining ad-hoc networking, implicit interaction and a reduced explicit messaging interface. The system could reduce communication induced stress in the firefighters on-site while at the same time improving the incident commanders' knowledge of the scene.  
In this paper, we analyze an approach for automating a large portion of the firefighters' standard communication, making feedback implicit instead of explicit responses. We first present a brief description of current firefighting practice in Germany. We then present and analyze these interviews, which constitute a major contribution of this work, and derive a range of high level requirements for a possible support system. Finally we present and discuss a conceptual sketch of a novel firefighter system based on pervasive computing technology.