1, the development process of network communication
(1), single stage
(2), local area network stage
(3), wide area network Internet stage
(4), mobile Internet stage
(5), the stage things
2, the three major networks
(1), telecommunications networks, television networks, Internet
3, the network communication transmission medium
(1), the wireless transmission: WIFI, Bluetooth, zigbee, 4G / 5G / GPRS (2.5G) and the like
(2), a wired communication: twisted pair, coaxial cable, optical fiber,