Decisions for acquiring technologies should weigh heavily on obtaining integrated solutions that provide the least complexity in the all-too-complex radio environment. The tools should fit with the existing infrastructure and provide flexibility to expand into new methods of content sharing and distribution. Bandwidth limitations are a typical roadblock and are nothing new to anyone who has transported critical audio. In the past, the solution has been expensive — bandwidth is available in linear increments (T1, ISDN) — with each additional link increasing costs linearly. What is needed is a cost-effective way to increase bandwidth and capabilities within and between facilities across the country and around the world: equipment that can serve as the facility's STL or studio-to-studio link, and when needed, expand to provide bi-directional communications (audio, data voice) within a group of affiliated stations/studios and transmitters.
T1 vs. IP-based Ethernet
As reported in the online publication Heavy Reading, “Ethernet is a widely used, simple, cost-effective, granular and scaleable technology that can enable service providers to roll out and quickly provision a range of tailored services at competitive prices — leveraging a lower cost base than that associated with traditional transport and switching technologies….Legacy services offer no compelling value.”
T1 dedicated circuits have long been the long-distance wireline technology of choice. They offer dedicated, point-to-point, bidirectional communication at guaranteed data rates. They are also expensive. A recent review of FCC tariffs in the Midwestern United States shows that a T1 line typically costs $400 to $450 plus mileage costs of around $100 to $300 per month. A typical cost of $600 to $700, or $420 per Mb/s of data per month, is required and will serve only the basic needs for one broadcast channel.
The Internet has changed many things, including the cost and concept of bandwidth. Ethernet wide area network (WAN) connections are becoming ubiquitous throughout the world. Ethernet services account for nearly 66 percent of all new data services installed during the last two years in the United States. For a similar price as a T1 line, customers can get a 10Mb/s Ethernet Private Line (EPL) with six times the bandwidth. This additional bandwidth can support multiple audio channels over an STL and studio-to-studio sharing of audio and data from anywhere in the world. Other applications might include transmitter telemetry and remote control, surveillance and confidence monitoring. Whether you're looking for cost savings or increased bandwidth, moving from dedicated T1 services to IP-based services over Ethernet is worth considering.
The cost of additional TDM/T1 circuits increases linearly. The scaleable nature of Ethernet changes this dynamic. In 2005, the typical cost increase from a service provider to go from a 10Mb/s link to 100Mb/s is two times. This is a substantial difference from the expected 10-time increase. For about the cost of two T1 lines (3Mb/s), a user can have 100Mb/s of Ethernet connectivity to manage and expand their offerings.
Figure 1. Comparison of T1 vs. IP costs.
When considering the use of an EPL/WAN link, it's important to consider other services and applications that the provider has available. For instance, the additional cost of the 100Mb/s connection may allow voice over IP (VoIP) service to lower phone costs, off-site data storage for mission critical information and other applications to reduce the overall cost of operations. There are currently more than 120 service providers offering Ethernet services in the United States for enterprise customers.
Partners in migration
Migrating from T1 circuits to an IP-based system is an adventure that, until recently, was not for the faint-hearted. Moving to IP-based systems required numerous devices from various manufacturers as well as an IT expert capable of integrating and troubleshooting. At best, this was an expensive venture — typically only attempted by well-funded organizations. At worst, attempts at this type of migration produced only large expenses with no working solution. Down the road, support could easily have become an issue because of the various manufacturers involved.
IP-based systems present numerous challenges to systems that operate in real time. Program audio, streaming media and other high priority data need to arrive at their destination reliably, with minimum delay and in a manner that appears seamless. IP-based systems were not designed for that. Instead they were designed to get data from point A to point B in a reasonable time (typically measured in tens of milliseconds to seconds, depending on network traffic), and if something got lost along the way, it was resent whenever possible. Although that type of network may work fine for getting a file to the printer or browsing a static Web page, it is not acceptable within a broadcast setting.
A managed platform approach to professional audio transport over IP, Intraplex Netxpress offers not only audio transport but also a suite of hardware and software tools to manage and implement a variety of digital services over packet-switched networks. Hardware redundancy, network monitoring and error mitigation as well as input policing, allow broadcasters to migrate services off of dedicated lines and onto readily available and lower cost IP networks. Additionally, Intraplex Netxpress is designed to use existing Intraplex modules.
|Service||Data Rate (Mb/s)||Cost ($/month)||Bandwidth Cost ($/Mb/s)|
|Ethernet Private Line||10||$600-1,000||$80|
|Ethernet Private Line||100||$1,500-2,000||$18|
|Table 1. Cost comparison of various types of connectivity.|
Netxpress provides a bridge between a station's current infrastructure and the networked systems needed for upcoming product offerings including HD Radio, data services and audio streaming applications over the Internet. You can begin with just two Netxpress frames, one at the studio and the second at the transmitter. Add a third at a sister station across town and both studios can share content. Either studio can feed the transmitter. A fourth unit at a second transmitter means you have real backup capabilities in the event of a disaster. Either studio can feed either transmitter, or both. All that is needed are a few simple configuration changes. A fifth unit located halfway across the country at the group's corporate base could easily share and provide content to any of the other four.
Netxpress offers new possibilities for content sharing, collaboration and system-level redundancies. Radio groups can consolidate studios and share content among multiple locations, while national broadcasters can more easily feed multiple transmitters from a few primary studios. Having the audio as a series of digital packets also makes it easy to use standard server technology for store-and-forward as well as streaming applications.
IT personnel will tell you that much of their cost reduction is done through centralized management and deployment of software and services. Intraplex Netxpress provides the capabilities and monitoring tools needed to support centralized management of IT and audio services. This is done through SNMP, Web browsers, software downloads that allow immediate return to a previous version and access to network statistics. With this Netxpress can be used in varied applications including point-to-point and point-to-multi-point audio transfer; multiple audio programs using multiple compression algorithms (or no compression); support for existing PBX/PABX telephone systems; and a variety of data circuits, even those not inherently designed for IP transport.
As various services are centralized and moved from T1 TDM circuits, engineering resources can be redeployed into other areas, such as moving ancillary services off of dedicated systems and onto Netxpress, simplifying the system and increasing resource and bandwidth utilization. Monitoring tools show problems and areas that can be better utilized. Hardware redundancy keeps minor problems from affecting services. With broadcast services and IT functions built on the same platform, the need for spares is reduced.
Edie is the Intraplex product manager at Harris, Cincinnati.
Reference: Heavy Reading, Stan Hubbard, “Ethernet Services Carrier Scorecard: North America”, Vol. 3, No. 7, April 2005