Real-Time Radio Signal Mapping using an Autonomous Robot

International audience—A measurement technique for an indoor/outdoor radio signal mapping based on remote sensing through a mobile robot is provided. The robot is autonomous and able to provide its actual location in relation to its initial position. The data are sent in real time to the base station using wireless transmission and the electromagnetic mapping is obtained in real time as well. A real case scenario is considered by measuring the electromagnetic field from our department network. The automated system gives consistent results since it shows highest energy levels next to the sources. This papers shows that a robot can remotely make a precise radio signal mapping of an unknown environment. I. INTRODUCTION Radio signal strength mapping is generally realized in wireless site surveys in order to monitor the coverage of a wireless network. Systems and methods for surveying a wireless network site are presented in [1]. The radio frequency (RF) coverage is generally based on measurement done by a mobile human user. The measurements consist of repetitive tasks which are time consuming and can lead to measuring errors regarding the coordinate information. Other measurement campaigns are done with sensor nodes placed on transport vehicles such as [2], however this method does not enable a controllable path by the sensor node itself. This article proposes a measurement technique to avoid these disadvantages by using an autonomous mobile robot. Besides, measurements are done for different positions since the robot can move inside an environment and record its path. The data are transferred in real-time to the base station (BS) using a wireless transmission. Then the user can watch in real time the actual position of the robot and the data exploitation. The advantages of this method are the fact that measurements are done in an autonomous way and the mapping is done in real time. The user's presence on the site is only needed at the beginning of the measurement process. Moreover, electromagnetic mapping can be used to find and identify the different electromagnetic sources available in the environment. This automated system can then be exploited for other projects which aim at harvesting RF energy. Jabbar presents the overview and progress achieved in RF energy harvesting field in [3]. The automated system can also produce RSSI fingerprinting of an area, which is used for WiFi localisation in some studies [4],[5]. Our main contribution is the automation of the RF mapping by a robot and the RF distribution can be viewed in real time