LightCon: Simplify line-of-sight connection with visible symbols in industrial wireless networks

To establish data connection in industrial wireless networks, the engineer has to enter the address of the target machine or manually select it from a list. Since the machines are densely deployed in the plant, the manual data connection becomes a non-trivial issue which may lead to connection error and waste of time. The existing technologies, such as QR code scanning and proximity estimation, simplify the process of data connection to the closest node. However, they can not be used to connect with any node located in line-of-sight of the engineer, and thus limits their application. In this paper, we propose a scheme called LightCon which controls the display module (LCD screen or LED light) of nodes to display different visible symbols such as colors and numbers, thus the engineer can select the corresponding symbol on the mobile device to establish connection. Moreover, symbol assignment algorithms are proposed to reduce the complexity of symbol selection when the number of nodes are greater than the number of symbols. The theoretical and experimental results prove that LightCon reduces the complexity of line-of-sight connection with guaranteed accuracy.