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Anticipating ACE

Working out the bugs in the first installation of the PBS automation system

AMES, IOWA: Readers of this column should be aware by now that IPTV (Iowa Public Television) was selected to be the first statewide PBS network in the United States to install the new PBS ACE automation system, which is scheduled to be operational by this summer.

Conceptually, ACE is a total program ingest and playout system for the multichannel broadcast environment. In IPTV's case the system will operate a four-SD, one-HD master control environment. Depending on the time of day, IPTV will operate either a single HD stream and SD stream for children's programming or four SD multicast streams.

The primary components of ACE are the Broadview traffic systems, the OmniBus automation system, an Omneon media server, Miranda master control switching and monitoring, as well as a Masstech archive management system controlling a SpectraLogic tape archive system. This system will then feed content to the nine digital and nine analog transmitters operated by IPTV throughout the state.


In essence, three critical software components operate as a team in the ACE environment. The leader is the BroadView traffic system. In addition to controlling local traffic, the Broadview system at IPTV will talk directly to the BroadView system at PBS in Virginia.

The communication between the two systems is bidirectional and close to real time, so that changes made in programming from the network are rippled to the ACE station and vice versa. BroadView generates logs not only for playback but for ingesting as well. The librarian is Masstech which has access to our library of content, much of it local material.

OmniBus functions as the system operator coordinating schedules and assets--both physical and virtual--to ensure that all material is processed correctly.

No small feat, this requires a considerable amount of processing power. In the last set of documentation that I received, there were 11 servers in use by OmniBus for command and control of all the systems. The entire ACE system, not including the SpectraLogic library, occupies six full equipment racks that are fairly tightly packed, and it is the job of OmniBus to make sure that everything works in harmony.

Of course, software is never finished and the features that you want will always be in the next version. On our latest conference call with the integrator, we discovered that OmniBus had released a new driver for the Miranda Presmaster switcher that evidently had some issues with switching and drop frame timecode. According to Marilyn Pierce, senior director of digital asset management for PBS, it turns out that 20:00:00:00 is the same frame count in drop frame NTSC as 23:59:59:29+1 frame in non-drop PAL.

The challenge of releasing products into the world market is that problems come from the most unexpected areas. It is critical that all the systems involved be operationally stable and reliable. Given the scope and complexity of the system, failures have to be few and far between and when they do occur, have to be automatically healed.


My colleague André Mendes at PBS is one of the chief proponents of the ACE system, and although he and I agree that the concept is a good one, there are some fine issues that we differ on.

The system uses exception monitoring for normal operation, so it essentially runs without any operator intervention. With that in mind, the system was proposed without any video monitoring associated with it. We had an interesting discussion on why anyone would want to waste money on monitoring since it was just going to show that everything was fine.

André believes that there should be no monitors and locked doors on the front of the ACE system and no one should have the key. I couldn't find too many broadcasters that were of that opinion; André comes from the world of IT. For me, there is always some comfort in walking by the MC operation and seeing the program on the monitor. It keeps us focused on what we're supposed to be doing even when everything is going well.

A few weeks ago we had a meeting with the IPTV staff members who will be taking on leadership roles on the ACE implementation from the various departments. A number of them were asking questions and looking for detailed information so that when the system was installed it would be flawless from the start.

I don't think I scared them, but I did give them pause when I said that I did not expect that ACE would work out of the box. I also told them that we would spend some considerable time debugging and massaging the system to make it function. Expecting a flawless performance out of serial number one is not reasonable. What I expect is that the basic system will work but that we're going on a shake-down cruise and we'll find some leaks along the way. I don't have a problem with that as long as the vendors and PBS are willing to step in and make the needed corrections. I look at this as a partnership and its success benefits us all.