A high-occupancy toll lane (HOT lane) is a type of or that is available to and other exempt vehicles without charge; other vehicles are required to pay a that is adjusted in response to demand. Unlike, drivers have an option to use general purpose lanes, on which a fee is not charged. Express toll lanes, which are less common, operate along similar lines, but.
[pdf] This guide provides a practical, standards-based approach to selecting managed industrial Ethernet switches and designing robust OT networks. Industrial fiber optic Ethernet switches are designed to deliver stable, long-distance, and interference-resistant network connectivity in harsh industrial environments where copper Ethernet is limited by distance or electromagnetic noise. Unmanaged switches are the simplest active network. To overcome the barriers caused by different protocols, the International Electrotechnical Commission (IEC) developed IEC 61850, which provides a standard communication protocol for electrical substations and power grid automation.
[pdf] 
