The Cisco UBR-MC16C cable modem card features one downstream modulator and six upstream demodulators. The UBR-MC16C has the following features and requirements:

• Supports 64 Quadrature Amplitude Modulation (QAM) at approximately 26.97 Mbps and 256 QAM at approximately 38.81 Mbps. The card output is +42 dBmV +/- 2 dB. The card expects nominal receive power level of 0 dBmV.

• Requires Cisco IOS Release 12.0(5)T1 or later version of Cisco IOS Release 12.0 T, Cisco IOS Release 12.1(1a)T1 or later version of Cisco IOS Release 12.1 T, 12.1(2)EC.

The Cisco UBR-MC16C has the following differences with the UBR-MC16B card:

• The power delivered (+42 dBmV) to the Intermediate Frequency (IF)-to-Radio Frequency (RF) upconverter at the Community Antenna Television (CATV) headend is 10 dB greater than the previously released Cisco uBR-MC11 and Cisco uBR-MC16B line cards which deliver +32 dBmV output power. To keep the IF-to-RF upconversion operational, use the optional -10 dB attenuator with your Cisco uBR-MC16C line card.

• The Cisco uBR-MC16B excludes support of 256 quadrature amplitude modulation (QAM) downstream and 16 QAM upstream support at two of the five Data-Over-Cable-Service Interface Specifications (DOCSIS) upstream symbol rates (2560K and 160K), the Cisco uBR-MC16C line card supports the following defaults:
  256 QAM at 40 Mbps downstream and 16 QAM at 5 Mbps upstream. The card supports upstream channel widths of 200 kHz, 400 kHz, 800 kHz, 1.6 MHz, and 3.2 MHz.