Using the Motorola DOCSIS 3.0 RX48 return path receiver module operating within a Motorola BSR 64000 CMTS edge router, the record of 356 Mbps for a 5-85 MHz return path was set by transmitting across 12 return path channels, of which six channels employed 256-QAM. Typical HFC networks today have two or three upstream channels delivering an aggregate of 40-70 Mbps.
In addition to establishing the world record at 5-85 MHz, a maximum transmission rate of 141 Mbps was also achieved over a 5-42 MHz return path using six return path channels. Three of the channels were able to operate using 256-QAM, as opposed to the typical 64-QAM maximum in use today.
All tests were conducted across Cox's Las Vegas HFC network employing multiple DOCSIS 3.0 and DOCSIS 2.0 modems. It feeds a three-amplifier cascade followed by an HFC optical link consisting of a standard Motorola DFB return path laser transmitting over 7 dB of fiber to the optical receiver. The output of the receiver was linked to the RX48 card in the BSR 64000. Measurements were made in accordance with standard cable industry practices. At the CableLabs conference, Motorola and Cox demonstrated the new record of 400 Mbps on a 5-85 MHz return path, which broke the previous record of 356 Mbps.