Drones are winning widespread popularity in China. We're not talking about the ones used in wars, but small, low altitude ones used commercially or personally. Just this month three Unmanned Aerial Vehicle (UAV) exhibitions were held in China.

"Smaller and more functional", that's what manufacturers say of their star products at this drone expo.

Aside from usage in the military and police, UAVs are swooping into various commercial industries. These days, the small, buzzing aircraft can be used for aerial photography, deliveries, and farming.

And looking at the large number of visitors at this expo, you can see just how many people are attracted by the possibilities of consumer drones.

This exhibition follows two similar ones which took place last week in Shanghai and Shenzhen. As small drones become more and more popular, concerns are rising over how they should be used.

That's why a debate on drone regulations is on agenda of the three-day exhibition.

Reports on small drone crashes due to unskilled handling, and the possibility of unlicensed usage has shifted attention to safety, privacy, and even national security.

"Regulations on small drones are weak links. Though the air traffic control departments, civil aviation administration and the police are all working on this, the small, low-altitude and relatively slow-speed aircraft is certainly a major challenge now," said Sun Boyuan, secretary-general of China Association for Unmanned Vehicles Systems.

Chinese authorities say they would ban drone delivery in crowded cities, and they have issued regulations to categorize the drones into seven types, according to their weight class, and local restrictions.

Guidelines are set around a threshold of 7 kilograms. Currently, users who operate drones which are no heavier than that and fly within 120 meters in height do not have to register their aircraft.

But with the industry burgeoning, wider-covering regulations are needed.

"Regulations are needed in drone production, sales, and application. Producers should follow certain standards, and business should know of the regulations and make sure their customers are aware of the rules before selling. And operator should understand safety specifications and restrictions before flying a drone. It is only when each of these links are streamlined, then can the industry thrive in the long term," Sun said.

Worldwide spending on drones is expected to more than double over the next decade - and China is one of the major markets.

But the future of it in China hinges on these guidelines.