With mobile operators kicking the tires on hybrid fiber-coax (HFC) networks for delivering backhaul for their small cell densification efforts, CableLabs has established its Mobile Backhaul R&D Lab.
The new lab was touted yesterday in a blog post from Jennifer Andreoli-Fang, distinguished technologist for wireless technologies at the cable technology consortium. (The lab's first effort is a white paper, prepared by Andreoli-Fang and Belal Hamzeh, VP of research & development, wireless technologies at CableLabs.)
“The growth in mobile data consumption has required Mobile Network Operators (MNOs) to deploy small cell networks in order to meet the demand,” reads the white paper’s executive summary. “Although small cells provide a robust solution for increasing capacity, they also increase deployment complexity due to the need for a pervasive backhaul network that can support the mobile network requirements.”
HFC networks have, of course, traditionally been used to deliver video and high-speed internet services using DOCSIS technologies. But CableLabs sees these networks as ideal for backhaul.
“There are three fundamental requirements needed from any network to provide mobile backhaul or fronthaul services: bandwidth, latency and timing,” the white paper said.
According to the NCTA, 93% of U.S. households are reachable via HFC networks.
In April, Andreoli-Fang blogged about a test she jointly performed with John Chapman, Cisco fellow and CTO of cable access, showing off a solution that consistently reduces the DOCSIS upstream latency to 1-2 milliseconds.
“Looking closely, LTE and DOCSIS are two independent systems—their operations occur in serial,” Andreoli-Fang wrote. “The overall latency is the sum of the two system latencies. The two technologies have similar mechanisms to access the channel, and that is through a request-grant-data transfer loop.
“The LTE loop is much longer than DOCSIS, resulting in much higher latency than DOCSIS,” she added. “This presents a hidden opportunity for DOCSIS. Rather than waiting for the LTE transaction to complete and then start the request process on the DOCSIS side as it is today, we proposed that LTE tell DOCSIS about the data that is on its way so that the DOCSIS request process can start earlier and in parallel with the LTE transaction. This will lead to much lower overall system latency.”