In March 2007, the FCC¹ encouraged US LMR users to migrate directly from 25kHz to 6.25kHz. This encouragement has accelerated the narrowband trend in the US LMR field. The AAR (Association of American Railroads) was one of those who were in need of a migration path to narrowband. Based on this background, Icom America offered the IDAS™ system to the US Class 1² Railroads who belong to the AAR. After a strict trial period, they were satisfied with the performance of IDAS™ (NXDN™) and chose to implement this system.

The AAR is a main railroad organization which covers freight-traffic lines in Canada, Mexico and the United States. The railroad still plays an important role in the US, accounting for 40% of all the freight transport in this country. On a worldwide basis, the US railroads are busier than railroads in any other country. In fact the US railroads carry more than four times as much freight than all the European railroads combined. The Class 1 Railroads are classified into the utmost rank in the AAR, whose annual revenue is over 250 million US dollars.

Why did the US Class 1 railroads choose NXDN^TM and IDAS™? The most important key was "Multi-channel Spacing Operation" . Originally, the AAR had been on the way to migrate from 25kHz to 12.5kHz and planned to complete it by the end of 2012. (At this stage, 50% of them used 25kHz and the remaining used 12.5kHz.) Even though they have completed the migration to 12.5kHz, they will need to migrate to 6.25kHz, since the FCC has encouraged this. Thus the US Class 1 Railroads decided to look for the possibility of a more efficient path, the direct migration to 6.25kHz. They tested both 6.25kHz FDMA and 6.25kHz equivalent solutions from manufacturers offering such solutions, and in the end found that multi-channel spacing operation including 6.25kHz was the most suitable for them. With this multi-channel spacing capability, they can continue to use the radios in 25kHz and 12.5kHz at the same time, and proceed with the migration to 6.25kHz. As IDAS™ allows this operation and also meets their other needs, they decided to utilize IDAS™ products in their communication system. (The other customer needs and keys to success are listed on the next page.)

NOTE:

1)

Federal Communications Commissions (FCC) is an independent US government agency in charge of regulating interstate and international communications by radio, television, wire, satellite and cable.

2)

BNSF Railway Company, CSX, Kansas City Southern, Norfolk Southern, Union Pacific

"The biggest reason why the US Class 1 railroads chose IDAS™ was the compatibility with digital and the existing analog system." says Mike Utecht, the Icom America sales representative in charge of this project. "The railroads first thought about migrating only to 12.5kHz, but finally decided to migrate directly to 6.25kHz. That' s because IDAS™ allows them a flexible migration path"

The US Class 1 railroads used the IDAS™ system in multichannel spacing operation for a 9 month trial period. During this time, they were also satisfied with the good quality of the products, digital technology and the excellent customer support of Icom America. Thanks to all of these points, the Class 1 railroads officially decided to implement the IDAS™ system. They are also very satisfied as the 6.25kHz digital system became available much earlier than they expected.

So far the US Class 1 railroads have begun to use IDAS™ in digital 6.25kHz mode in some departments like railroad police, where the workers enjoy clear voice communication and a high level of security. As a future plan, the customer expects to simplify their system network after the IDAS™ is linked with IP. (The network will simply be a broadband pipe and no longer channelized between each base station site and the dispatch console.) Over and above that, many IP-linked applications will be available in the future. The US Class 1 railroads are looking forward to what suggestions Icom America will bring to them about these future possibilities.