A reference voltage generating circuit is described. The AAA service is selected based upon a set of rules applied to information which has been received dynamically from the plurality of AAA services and is indicative of load and status of the plurality of AAA services. Routing information is embedded at the periphery of the network CPE’s rather than at the satellite. The hole section is opened in a manner so as to enter the wiring inward from an edge of the surface of the wiring by a first predetermined distance. The above-mentioned method can realize mutation breeding including among plants on same edge, near edge or far edge, is suitable for most of plants and has the advantages of high success rate of breeding, high mutation probability, favorable comprehensive mutation performance, diversified mutation performance, quick stability and the like.