It's not using the glass itself as an antenna though: >NTT Docomo reports that it uses transparent conductive materials as the basis for its antenna, sandwichi

It's not using the glass itself as an antenna though: >NTT Docomo reports that it uses transparent conductive materials as the basis for its antenna, sandwiching the conductive material along with a transparent resin, the kind used in laminated windshields, in between two sheets of glass.