3Gbps: A Missing Piece for Multiviewers

3Gbps—the transmission format that can carry 1080p/60 video—is becoming integral to the use of multi-image displays (aka multiviewers), according to manufacturers who produce these devices.

"3Gbps has become a standard offering for multi-image viewers today," said Mike Garrido. Harris' multiviewer product manager. "People buying multiviewers expect 3Gbps functionality in everything we design."

"We support 3Gbps on all of our platforms," echoed Jamie Horner, senior product manager for Evertz in Burlington, Ontario. Evertz's multiviewer software "has the ability to support two 3Gbps 1080p/60 video signals; allowing the users to send them where they will in Master Control."

Evertz supplied the monitoring equipment for Rainbow's Media Center (TOC). Apantac's 3Gbps multiviewer can support anywhere from four to 32 inputs, according to Thomas Tang, president of the Portland, Ore.-based developer of multiviewers. "Our systems can even autodetect what kinds of signals are coming into the router, from composite all the way up to 3 Gig."

Miranda, which launched its Kaleido X-3D multiviewer at the 2009 NAB Show, offers 3Gbps to handle not just 1080p, but also stereoscopic 1080i, according to Marco Lopez, Miranda's senior vice president of Control & Monitoring. "Sports broadcasters are very interested in stereoscopic 3D HDTV, because of how attractive it will be to viewers."

Barco also supports 3Gbps. "This sort of 'futureproofness' is now expected by our customers," said Steven Luys, Barco's Broadcast and Telecom marketing director. "They might not use it today, but one day they will."


There is no doubt that 1080p/60 images, which need 3Gbps signal paths with the television plant, provide crisper pictures with fewer artifacts than 1080i. Meanwhile, 1080p provides more screen area than 720p; making 1080p superior in terms of overall viewing quality.

This said, broadcasters are still paying the bills for converting to DTV. So why would they would care about 1080p when the U.S. ATSC system cannot broadcast such signals?

In the case of multiviewers, the answer is clarity. When a large screen is being called upon to show multiple images, using the highest resolution possible helps anyone who has to monitor the display. Since multiviewers are becoming common in TV master control rooms and production trucks, delivering 1080p images to these screens makes good sense. "It's just a better viewing experience," said Evertz's Horner.

Of course, such a system requires stations to upconvert their 1080i video to 1080p; that is, unless the video is already in this format. Right now, this isn't the case, but times are changing: "Broadcasters who want to 'futureproof' their productions are considering shooting in 1080p, simply because it provides film-like quality that will stand up to higher resolution viewing formats," said Miranda's Lopez. "If your program is in 1080p, it is easy to downconvert it to 1080i or 720p for ATSC broadcast, while using the original 1080p resolution for Blu-ray disks. And should broadcasters eventually migrate to 1080p, your program will still look good enough to run in this resolution. Either way, you are covered."

In either instance, it makes sense to install 3Gbps multiviewers; especially when today's technology offers 3Gbps capability either as a standard feature, or an upgrade option that can be implemented at minimal extra cost in the future.

"Whether you produce in 1080i, 720p, 1080p, stereoscopic 1080i or 4:4:4 today or tomorrow, 3Gbps HD-SDI will carry your content," said Barco's Luys. "No customer wants to lock him or herself out of these possibilities when making core infrastructure decisions like routers, multiviewers, monitors or glueware."


The makers of 3Gbps multiviewer equipment believe that there's a strong case for 3Gbps equipment. But are broadcasters buying it?

Yes and no: "There is a lot of interest in 3Gbps technology, including the 3 Gig 24-inch and 32-inch monitors we sell," said David Hartmann, the U.S. Master Distributor for the German firm Tamuz, which makes HDTV monitors. "However, the market for selling this equipment is crummy, due to the recession."

"Judging from discussions with customers, project specifications and tenders, they are largely buying it," said Luys. "Customers might not produce in 1080p/60 today, but they have no doubt that tomorrow they will."

Horner at Evertz acknowledges "moderate acceptance" among broadcasters when it comes to 3Gbps. "We are seeing it being implemented by Tier One broadcasters; especially when they build new facilities," he said. "But I wouldn't say that there is a rush to 3 Gig. The changeover is akin to what we saw when people were moving from SD to HD in their plants."

Harris' Garrido says none of their current customers is using a full 3Gbps plant, but "we have a large number of people that are capable with most of the product in their facilities. It seems that everyone is waiting for 'a couple more components'."

Garrido cited Toronto broadcaster CanWest Global as a typical example. "Global has almost all the equipment for 3G except there are a few components missing; cameras being the big one," he said. "They have our multiviewer and router that are 3G ready, and they also have the 3G fiber distribution, the displays and the switcher. Now they just need the sources."

The 2008 Beijing Olympics was a boon for HDTV broadcasting. So could the 2010 Winter Games in Vancouver provide the same kick start for 1080p?

Yes, according to Miranda's Marco Lopez. "Several broadcasters are considering offering 3D HDTV coverage of at least part of the 2010 games," he said. "For this to happen, they will need to use a complete 3Gbps production chain—including 3 Gig multiviewers. Even without 3D, 1080p does provide better quality viewing."

Certainly 1080p Olympics coverage would play well with the Dish Network, which is already offering 1080p delivery of select programs. In this regard, broadcasters would be hard-pressed to compete with Dish; at least over the air.

Olympic speculation aside, it is clear that 3Gbps is a de facto standard for today's multi-image displays. Broadcasters considering such purchases would do well to bear this in mind—whether they buy 3Gbps as a feature, or as an option to be added later.

James Careless

James Careless is an award-winning journalist who has written for TV Technology since the 1990s. He has covered HDTV from the days of the six competing HDTV formats that led to the 1993 Grand Alliance, and onwards through ATSC 3.0 and OTT. He also writes for Radio World, along with other publications in aerospace, defense, public safety, streaming media, plus the amusement park industry for something different.