Same challenges for cable, but on a bigger scale

The big challenge for the European cable industry today is ‘scale’: scaling multi-screen TV services, scaling bandwidth per home, and increasing the amount of narrowcast capacity without blowing the fuses at the headends or hubs. Harmonic Inc. claims it has solutions that enable cable operators to achieve the capex and opex efficiencies that make it viable to keep growing services across all parts of their operations. “There is nothing new in 2012 that the cable industry was not aware of already, in terms of challenges, but what has really changed is the degree of scale they need,” confirmed Gil Katz, VP Cable Solutions & Strategy at Harmonic during ANGA Cable 2012.

Multi-screen remains a priority. “Cable operators have new services and new types of devices and more codecs to work with and for some of our customers it is overwhelming. They are under pressure from competitors and from their own subscribers to offer multi-screen services. One of the issues with scale is the amount of equipment they need because on top of standard-definition and HDTV, multi-screen means multiple bit rates and profiles.”

This is why ‘function collapse’ (meaning that functions previously performed by different devices collapse into the same unit) has been a key part of the Harmonic headend strategy for many years. The Harmonic Electra 9000 is the latest example of this approach, enabling a single video stream to be output into multiple bit rates and formats to cover the needs of STB based services and multi-screen TV from the same encoder. This product enables a unified platform covering anything from 1080p60 HD on the big screen to Apple iPhone streaming.

Bandwidth capacity can be improved by node segmentation and better use of existing fibre. Various transmitter products, such as METROLink with DWDM and the 1550 nm SUPRALink transmitters address this challenge. And without a dramatic increase in the density of edgeQAMs, many cable operators would have been forced already to choose between slower service expansion or larger regional hub sites and higher power costs. QAM demand is being driven by the rapid increase in on-demand services and Harmonic introduced its ultra-dense edgeQAM device, the HectoQAM, two years ago to squeeze more QAMs into the same chassis and so reduce space, cabling, cooling and power requirements. HectoQAM delivers up to 648 QAMs per two-rack unit chassis.

“When you talk about density there are two aspects,” Katz explains. “There is the number of ports and the number of QAMs per port. Ports are important because you need a port for each segment of the network, so if you are segmenting the network [which increases the bandwidth available to each home] you need more ports and if you do not have the necessary port density then the amount of rack space you use will explode. When it comes to the number of QAMs per port, you need more as you introduce more narrowcast [on-demand] services.”

For now, HectoQAM matches the needs of even the most demanding Harmonic cable customers but Katz says the company will have to introduce another generation of QAM product. “We have an MSO customer that is about to consume all the QAMS per port that are available and then they will need the next big thing. That is when CCAP will help.”

CCAP (Converged Cable Access Platform) is the product genre that matches the precise specifications defined by a cooperative industry effort, but which was initially driven by the US cable operator Comcast. It demands minimum levels of performance in terms of QAM density, port density and power consumption, among many other things. Katz says HectoQAM is the foundation for a next-generation CCAP solution from Harmonic. “The interest from European MSOs for a CCAP solution is pretty positive. They are waiting for it to happen,” he reports.