August 22, 2012

Video quality and the OTT dilemma

Assuming responsibility for the quality of video that traverses relatively unmanaged networks to unmanaged endpoints poses new challenges for Pay TV operators. Accustomed to spotting problems within managed networks, traditional test and monitoring systems accordingly are shifting into new territory.

Quality needs to be excellent when people start installing 4k 84" screens in to their homes

The Sentry product from Tektronix, for instance, monitors compressed video for linear broadcast streams, checking the output from master encoders for audio and video defects that could impact QoE. But Sentries are also being used to test OTT apps from headend to set-top box. “The two areas are testing the output from encoders into transcoders, which generate the various bit rates,” said Paul Robinson, CTO Video, Tektronix. “Then the same monitoring probes are used for those transcoded outputs.”

Tektronix’s Certify family is a software-based product designed for a similar range of tests, but on file-based assets, and using a decoder of the playing device. Could such technology scale to millions of end devices? “As time moves forward, the likelihood is that the paying applications will have some form of built-in statistics that are able to report back to the operator that things are going correctly at the receiving device,” Robinson said.

Whether the receiving device is a set-top or connected TV or tablet, operators do well to connect with it. “The endpoint becomes more and more important as you have less control over your distribution network,” said Mikael Dahlgren, CEO of Agama Technology, another digital TV and video services monitoring company.

Agama has just announced its plans to launch of a Microsoft Mediaroom edition of its end-to-end IPTV quality assurance at IBC2012. (See here for more.) But in March, at the IP&TV World Forum 2012, Agama revealed that its DTV monitoring technology had evolved to cover OTT services, as well. At one end, the Agama solution touches the OTT “head-end” and CDN, and at the other, it provides service quality assurance at every endpoint. To do so, Agama integrates its embedded in-device monitoring client into set-top boxes and other CPE devices. At the backend, it features reporting and APIs for operations and business support services (OSS/BSS) integration.

Also in March, Agama also announced that Finish service provider Maxisat was using its test technology to monitor the delivery of OTT video to connected Samsung TVs. Maxisat primarily delivers video via Motorola set-top boxes. While a small deployment—Maxisat was approaching 10,000 OTT total customers in September 2011—it is an example of how monitoring tools and stateful record-keeping can help operators gain control in an OTT scenario.

How Agama interacts with end devices sheds further light on network management options. Two conventional protocols are SNMP and TR-069. “We can use any protocol, really, for collecting information into our aggregation infrastructure,” Dahlgren said. “We also have a protocol of our own, a little more compact, to be used if you have real-time monitoring of large amounts of devices.”

Dahlgren said the Agama protocol uses only one IP packet for each interaction instead of multiple packets, as with TR-069. Given that the Agama sends back one-second snapshots every two minutes, that extra overhead could overburden a central collection location. Nonetheless, these technologies coexist. “It’s not unusual that you have all of these protocols at the same time: TR-069 to configure the gateway, and our high-efficiency protocol for real-time monitoring,” he said.

For more on this topic, see the latest Videonet special report, “QoE and the New Pay TV Home,” from which this article was adapted.