Mobile PTT Service in Beijing

On the Tian An Men Square and some down town districts in Beijing,peoplecan often come across mobile PTT service buses.These are specially made largebuses which provide mobile postal and telecommunication services for rallies,largeconferences and games,as well as big factories,mines and enterprises which embracegreat number of people.At the same time,they can also be used as command carsfor communication departments,keeping the communication lines open between