Minimum documentation searched (classification system followed by classification symbols):
Documentation searched other than minimum documentation to the extent that such documents are included in the fields searched:
Electronic data base consulted during the international search (name of data base and, where practicable, search terms used):
WPI, EPODOC, CNKI, CNPAT, IEEE, GOOGLE: two, step, random, access, temporary, identifier, resource, PUCCH, uplink