by Meghan Fuller Hanna
The folks behind this month�s NXTcomm08 Conference are rightly touting IPTV as one of the industry�s bigger trends, but that doesn�t mean tried-and-true RF broadcast will be cast aside. In fact, some say the technology is experiencing a resurgence of sorts, with several formerly all-IP service providers now adding a basic RF broadcast tier to complement their existing IPTV offerings.
RF broadcast or RF video overlay refers to television programming that is aggregated and transported, via an RF carrier, on the downstream 1,550-nm wavelength of a GPON or EPON system. (The 1,310- and 1,490-nm wavelengths are reserved for upstream and downstream data, respectively.) The IPTV or switched digital video approach, by contrast, transports television programming as data packets in a data network, using Internet Protocol. Video is delivered in-band, over the same wavelengths (1,310 and 1,490 nm) that carry both the voice and data services.
As promising as IPTV is and will continue to be, it does have its share of issues, including challenges at the chipset level for the set-top boxes and the delivery of HDTV; problems associated with the middleware; the absence of industry standards for IPTV delivery; and, in particular, a lack of interoperability among the disparate vendors who provide the various components. In the broadcast world, one vendor supplies everything�the hardware, software, digital rights management, etc. In the IPTV world, different vendors supply each piece of the puzzle, and they don�t always work together.
Jim Farmer, CTO of Wave7 Optics, which was recently purchased by Enablence (www.enablence.com), says there are few if any practical applications that can�t be accomplished either on broadcast or on IPTV. �You can do essentially the same set of services both ways,� he says, citing video-on-demand (VoD), HDTV, and on-screen caller ID as three advanced applications that can be supported in both RF and IPTV environments.
�What I tell people now is if you�re not in an environment with a strong broadcast competitor, you could probably make it with IPTV�but be prepared for some extra pain,� cautions Farmer. �But if you�re in an area with a strong broadcast competitor, you�re liable to find yourself at a disadvantage if you don�t have at least a basic broadcast tier, and you may want to consider having more than just a basic tier. We�re still seeing quite a bit of interest in the RF tier,� he reports.
Geoff Burke, director of marketing at Calix (www.calix.com), agrees. As an example, he cites one North American Calix customer, which he describes as �a leader in providing IPTV services over GPON,� that recently turned up RF overlay services in its existing FTTH network. The customer did not migrate from RF to IPTV; it started with IPTV and added RF video.
This particular customer found certain niche markets, say Burke, where it is more appropriate to deliver RF video. There are several potential reasons why this may be the case. �One is if it is a market that, by definition, does not have a strong ARPU upside in terms of the opportunity to sell a lot of high-end services into it,� he explains. Or it has a population that might be averse socioeconomically. Often, there are even generational differences among the customer base; elderly subscribers may not be accustomed to a set-top box, which is required in IPTV delivery. As such, RF broadcast tends to play very well in nursing homes and hospitals, Burke says.
Kevin Bourg, director of international sales support for Enablence, has also seen operators in Europe add an RF broadcast tier to complement their existing IPTV offerings. �We�re seeing customers now saying, �I�m losing a lot of my market share because I can�t deliver a simple RF broadcast tier cost-effectively on IPTV.� In other words, the installation requirements, the cost that it takes to install that service, the set-top box, etc. for a basic-tier service, is a little expensive in an IPTV environment,� he admits.
Bourg reports that a number of 100% all-IPTV service providers in Europe are now looking to deliver a simple 12- to 15-channel RF broadcast tier over their FTTH networks. Offering lower tier RF video would enable them to increase their penetration while still offering a broadband connection and voice connectivity into those markets.
These new RF deployments would seem to run counter to the prevailing wisdom, which held that RF broadcast would help telcos get a jumpstart on their video service delivery but that IPTV, ultimately, was the endgame.
Certainly, this was the rationale behind Verizon�s (www.verizon.com) decision to deploy a hybrid network with broadcast video services delivered via RF and unicast services delivered via IPTV. While Verizon had previously noted its intention to migrate to an all-IP service delivery architecture to deliver its FiOS video in the future, the carrier is now saying it does not have a timeline for suspending its RF broadcast offering. In fact, says Verizon spokesman Jim Smith, �while the IP video is being perfected�the assurance is that it will be as reliable and pure as the broadcast [signal] we send�we�re in no hurry to jump. [RF broadcast] is getting the job done just fine right now, reliably and effectively.�
Smith notes that it costs a little more to support three wavelengths�1,310-, 1,490-, and the 1,550-nm wavelength for the RF broadcast�but for Verizon, it is a quality-of-service assurance issue.
That said, an all-IPTV offering is still on the carrier�s roadmap. Smith says there will likely come a time when the business case for migrating to all-IP video services will make sense for Verizon, perhaps when the volume of traffic reaches, say, 100 HDTV channels or when IPTV technology and all its various component parts have been thoroughly tested and proven in. But just when that crossover will occur �is not discernible at the current time,� he admits.
Calix�s Burke says he also sees video service delivery moving into the all-IP domain, but he agrees that it�s difficult to forecast when that might occur. Moreover, he says, there are other factors that may affect the lifespan of RF broadcast. �You may actually run into a situation in which video is being distributed predominantly over the Internet,� he notes. �That would supersede traditional broadcast delivery in a timeframe that would pull the rug out from underneath the RF delivery mechanism because it�s delivered as digital video over the Internet. So there are a number of different things at play here that make it hard to project,� he admits.
In the near-term, at least, Enablence�s Farmer believes the industry is in the midst of �a swing back toward a more immediate interest in broadcast while still maintaining the interest in IPTV. People are realizing that [IPTV] is an alternative,� he says, �but it�s not the panacea they thought it would be.�
Meghan Fuller Hanna is senior editor at Lightwave.