where do we use cross and standard cable
Ethernet crossover cable Intentionally crossed wiring in the crossover cable connects the transmit signals at one end to the receive signals at the other end. Many devices today support Auto MDI-X capability, wherein a patch cable can be used in place of a crossover cable, or vice versa, and the receive and transmit signals are reconfigured automatically within the devices to yield this desired result.
Shortwave radio Shortwave communications began to grow rapidly in the 1920s,[10] similar to the internet in the late 20th century. By 1928, more than half of long distance communications had moved from transoceanic cables and longwave wireless services to shortwave and the overall volume of transoceanic shortwave communications had vastly increased. Shortwave stations had cost and efficiency advantages over massive longwave wireless installations,[11] however some commercial longwave communications stations remained in use until the 1960s. Long distance radio circuits also reduced the load on the existing transoceanic telegraph cables and hence the need for new cables, although the cables maintained their advantages of high security and a much more reliable and better quality signal than shortwave.