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IPTV and mobile technology
|Submitted by |
| ||NBC Universal |
|Technology at work |
| ||NBC Universal: Rob Goldfarb, dir, distribution and affiliate projects; Shadrach Kisten, mgr, eng. & info tech; Bharat Ananthakrishnan, on-air apps. mgr. (TAM); Colin Campbell, enterprise networking architect |
Optibase: Eli Garten, Manager, technical marketing and professional services
|Technology at work |
| ||Amino AmiNET130 STBs |
Cisco 6500 series switches
MGW 5100 encoding
EZ TV server
NBC Universal receives more than one hundred remote feeds to its headquarters in New York City. In the past, these signals were distributed via an analog closed circuit Cat 5 system used for monitoring purposes by the news and sports production staff. This Cat 5 system was available only in key production areas, and every channel of the 850MHz plant was occupied.
Recently MSNBC moved to 30 Rock with an additional 50 new remote feeds that needed to be monitored throughout the facility. Adding to the existing analog system was out of the question. A digital cable (QAM) technology was considered; however, this would require a new digital cable-ready TV or set-top box for every user, a logistical and financial challenge. An IPTV approach operating on the corporate LAN allows all users equal access to content using existing PCs, regardless of the location in the facility.
The system was designed for 200 SD channels, with plans to add more SD and HD channels in the near future. Because bandwidth was a critical factor of the design, we choose H.264 (MPEG-4) compression. Operating each service at about 1.7Mb/s yields sufficient quality for monitoring purposes yet occupies a reasonably streamlined profile in the GigE backbone.
Careful planning of our network infrastructure was required. The IPTV traffic shares the same facilities and pipeline as the rest of our corporate data, including e-mail, Web browsing, archiving and various other production tools. We could not afford to disturb any of these. A large task was ensuring that every switch and router was enabled for multicast (IGMP) traffic. We are fortunate that backbone was previously upgraded to GigE so bandwidth to each switch was not considered an obstacle.
The benefit of multicasting is that bandwidth is not occupied on a local network segment unless a request for a service is made by a user. No matter how many users on a segment request the same service, that service doesn’t require any more bandwidth than the initial request.
NBC chose an enterprise-class encoding system with blade-based processors. Software decoders on the PCs include a browser-based version provided by the vendor that supports multiple, simultaneous decoder windows, as well as a channel guide that can be managed centrally. Care must be taken to use adequate PC hardware to support multiple decoders such as dual-core CPUs with sufficient RAM.
We have also deployed dedicated IPTV set-top decoders for users who need to view services on a dedicated video monitor. The STBs require a dedicated connection to the LAN but require little additional support once activated.
NBC Universal can distribute monitoring video services with far greater reach and flexibility than could have been provided by a conventional cable TV system.