EXHIBIT 21.1 DOMESTIC SUBSIDIARIES--CELLNET BCN Data Systems, L.L.C. (Delaware) CellNet Data Retrofit Services, Inc. (Delaware) CellNet Data Services, Inc. (Delaware) CellNet Data Services (AZ), Inc. (Delaware) CellNet Data Services (CA), Inc. (Delaware) CellNet Data Services (IS), Inc. (Delaware) CellNet Data Services (KC), Inc. (Delaware) CellNet Data Services (ME), Inc. (Delaware) CellNet Data Services (MSP), Inc. (Delaware) CellNet Data Services (NH), Inc. (Delaware) CellNet Data Services (PA), Inc. (Delaware) CellNet Data Services (SE), Inc. (Delaware) CellNet Data Services (SF), Inc. (Delaware) CellNet Data Services (SL), Inc. (Delaware) CellNet Data Services (TX), Inc. (Delaware) CellNet Funding, LLC (Delaware) CN Frequency (IS), Inc. (Delaware) CN Frequency (KC), Inc. (Delaware) CN Frequency (MSP), Inc. (Delaware) CN Frequency (SE), Inc. (Delaware) CN Frequency (SF), Inc. (Delaware) CN Frequency (SL), Inc. (Delaware) CN Holdings, Inc. (Delaware) CN Holdings (TX), Inc. (Delaware) CN Partners (TX), L.P. (Texas) CN WAN Corp. (Delaware) FOREIGN SUBSIDIARIES--CELLNET BCN Data Systems Limited (England/Wales)