Fire and Smoke, Morning Bell and Twilight Drum, Sticking Plum Blossoms and Biography of Hongyan are described respectively.

Fire, Wolf, Smoke, Morning Bell, Twilight Drum, Plum Blossom and Hongyan Chuanshu respectively describe the ancient media in China, and talk about the advantages and disadvantages of these media in the use process.

A beacon tower is a beacon tower used to resist the invasion of foreign enemies. Morning bell and dusk drum first refers to the bell and drum used by monks in Chang 'an Big Wild Goose Pagoda, and Meihua Post refers to the official post office.

The advantage of bonfire is that it can transmit information quickly, but the distance is limited.

The advantage of morning bell and late drum is faster transmission speed, but the disadvantage is inaccurate.

The advantage of the post station is that it is suitable for long-distance information transmission, and it was the fastest and most perfect in the past.