Because the IP Internet is a connectionless system, gateways and hosts route datagrams without coordinating with the original sender. This works fine except when a problem delivering a datagram occurs. Problems occur when nodes or whole networks become disconnected, the time-to-live counter expires, or gateways become too congested to process more traffic. (Warthman Associates)

These autonomous devices, or nodes, combine with routers and a gateway to create a typical WSN system. The distributed measurement nodes communicate wirelessly to a central gateway, which provides a connection to the wired world where you can collect, process, analyze, and present your measurement data. (National Instruments Corporation)

A gateway repackages information to match the requirements of the destination system. Gateways can change the format of a message so that it will conform to the application program at the receiving end of the transfer. A gateway links two systems that might not use the same Communication protocols and Data formatting structures. (HMS Industrial Networks)