The Federal Communications Commission (FCC) has ruled that all radio communications equipment in the United States, operating in the VHF (150-174 MHz) and UHF (421-512 MHz) frequency bands, must conform to new narrowband requirements from the 1st of January 2013 or cease operations.
To meet these requirements, radio communications equipment in operation on, or after, this date must provide at a minimum:

These regulations will affect all United States' governmental, commercial, public safety, transport and utilities organisations deploying UHF and VHF radio communications equipment. MiMOMax Wireless Ltd assures existing and prospective users in the United States that the complete MiMOMax narrowband UHF (420 MHz-470 MHz) product family complies with these requirements.
The MiMOMax narrowband UHF product family spectral efficiencies are as follows:

MORE INFORMATION ON THE FCC & 2013 NARROWBAND REQUIREMENTS CAN BE FOUND BELOW:
http://www.fcc.gov/pshs/public-safety-spectrum/narrowbanding.html
MORE INFORMATION ON THE SPECTRAL EFFICIENCY OF THE MiMOMAX NARROWBAND UHF FAMILY CAN BE FOUND BELOW:
MiMOMax Network Digital Link (NDL)
MiMOMax Multi-point Digital Link (MDL)
MiMOMax Optimised Protection Variant (OPV)