A new internal CDMA cellular modem option for the GR-3 family of receivers has been announced by Topcon Positioning Systems. The CDMA option allows the use of signals from Verizon and Sprint, two major cell phone providers. The new receiver kits are available with both single- and dual-mode GR-3 UHF receivers. Topcon announced the GR-3 fully integrated system (GNSS receiver, batteries, antenna and communications system) last year.