## 5 Conclusion: Future Challenges in the Networked Mobile Sensor World  
In light of the above-presented work addressing existing research, there are many significant challenges for the future of networked mobile sensors. In this section, we briefly present some of the key important open research questions and develop a roadmap for the networked robot network area extrapolating into its future.  
The European Robotics Technology Platform (EUROP) published a Strategic Research Agenda (SRA) on 7 July 2009 for robotics researchers to attract attention to key challenging robotic topics and to promote robotic development in Europe [109]. Human-robot interaction is a very challenging research area. Because existing works are still very new and immature, most of the developed systems are not yet able to perform outside simple laboratory experiments. Existing works only focus on single human and single robot problems, so scalable approaches for human-robot interaction is an open research interest to be tackled in the near future. Human-robot learning interfaces, which enable humans and robots to communicate with each other, have to be constructed utilizing cognitive approaches. If many humans interact with networked robots, a distributed learning interface, excited at any different instant of time, at different locations of robot units and human units, will be one of the challenge of cognition.  
Cooperating robots in a distributed manner is another field of research where desired global behavior emerges from the interactions between robots and environments. Distributing and assigning tasks is crucial in order to improve the efficiency of the robot network in real-time and dynamic environments. Thus, scalable and fault tolerant coordination control algorithms with effective local or implicit communication are important to obtain real-time responses by fusing obtained data from reduced communication loads.  
Physical construction of networked robots that can operate under hard and real-time conditions is an opportunity for future robotic research. In particular, reconfigurable robots, in which robot units are connected to each other physically, will inject real-time control to swarms that are mainly exhibiting emergent behaviors nowadays. Wireless communication protocols need to be improved for efficiency in strategic missions such as search and rescue. Reconfigurable heterogeneous robotic systems can adapt their structures to the changing environmental conditions and needs, such as changing the robot configuration from a legged robotic structure to a snake robot and then to a rolling robotic one [110]. Reconfigurable networked robot systems are fault tolerant in the case of robot failures by replacing faulty part autonomously. Self-repairing reconfigurable robots will tend towards self-repairing hybrid networks composed of fixed sensors, computing devices, human operators and robot teams is currently a trendy worldwide research topic. With the help of synergy between these different operation units, the overall performance of the system can be increased in complex and high level tasks. Cooperation between biological and mechanical networks with human beings will present the \"avatarization\" of networked robotics in the long-term future of research.