Motorola, Cox Achieve Record in Upstream Data Transmission

Motorola Mobility has announced the achievement of a new world record for return path data transmission by using technology from Motorola on Cox Communications’ Las Vegas network infrastructure.

Using the ultra low noise 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 twelve return path channels of which six channels employed 256QAM modulation. Typical HFC networks today have two or three upstream channels delivering an aggregate of 40-70 Mbps.

“The RX48 and these tests demonstrate that Cox’s HFC networks are much more future proof than many have believed,” said Jay Rolls, senior vice president of technology, Cox Communications, in a statement. “We also increasingly need to be able to segment our business and residential customers, visibility into which is provided by the 5-85 MHz return spectrum utilizing 256QAM. Our networks have the capability to support much higher data speeds than today without the need to replace any of the amplifiers, taps or cables.”

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 these channels were able to operate using 256 QAM modulation, as opposed to 64 QAM maximum in use today, which is also believed to be a record. Cable operators can now use the 5-42 return path to provide 100 Mbps dedicated to business customers and simultaneously provide residential customers with the return path bandwidth necessary to meet their growing needs.

All tests were conducted across Cox’s Las Vegas hybrid fiber coaxial (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 this 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 356Mbps.