Group cornet (also called cluster network) is a mobile virtual private network cornet tailored by China Mobile Yunnan Company for government, corporate customers and campus customers. It uses public mobile communication network and intelligent service platform, and on the basis of keeping the original mobile phone number 1 1 unchanged, it uniformly distributes 3-6 short numbers to group customers to form a cluster network. Members of the cluster network can directly call customers in the same group network through cornet to enjoy preferential tariffs, and choose to join the group according to their own needs. Trumpets can be coded freely. The rate is subject to the explanation of the group account manager. '