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公开(公告)号:US2644932A
公开(公告)日:1953-07-07
申请号:US6387248
申请日:1948-12-07
Applicant: ERICSSON TELEFON AB L M
IPC: H04Q3/42
CPC classification number: H04Q3/42
公开(公告)号:US2644932A
公开(公告)日:1953-07-07
申请号:US6387248
申请日:1948-12-07
Applicant: ERICSSON TELEFON AB L M
IPC: H04Q3/42
CPC classification number: H04Q3/42