Another option available to broadcasters is a portion of the 18GHz band that can be licensed for STL use under Part 101. If this makes more sense for you then there are at least two options out there right now. Radio Systems offers a microwave radio link called IP Connect. Hardware configuration is ODU and IDU (single rack unit with all interfaces). It's very configurable, giving the following options: Ethernet up to 250Mb/s, or up to 32 T1s, or 2 DS3s, or 2 STM1 (155Mb/s) plus 2 T1s. Management of the system is done via a Web browser, SNMP or Telnet.

Axia users have made use of various Ethernet radios such as the Dragonwave Air Pair 100. This system also makes use of the ODU/IDU configuration. The native interface of the system is gigabit Ethernet, and it provides for full-duplex 100baseT (200Mb/s of bandwidth). It can also be configured to transport T1s if so desired — that way TDM systems can be kept during a transition period (or maybe forever). Management of the system is done via SNMP.

So there you have it. The original digital STLs are themselves practically in the class of legacy equipment today. Carriage of Ethernet is the primary function of all the radios mentioned herein. So many of the devices we find in a broadcast plant today communicate by way of IP; what was once kind of a luxury (LAN at the transmitter site) has now pretty much become a necessity. If you haven't already jumped on the bandwagon, then in my (humble) opinion, you need to do so as soon as you can. Fortunately there are many, many options today that'll make the job a little easier.

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Irwin is transmission systems supervisor for Clear Channel NYC and chief engineer of WKTU, New York. Contact him at doug@dougirwin.net.

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Resource Guide

Airmux
888-785-7393

Armstrong Transmitter
315-673-1269

Bext
619-239-8462

Bitrage
904-808-0656

Broadcast Electronics
217-224-9600

Dragonwave
613-599-9991

Energy-Onix
888-324-6649

Harris
800-622-0022

Marti Electronics
217-224-9600

Moseley Associates
805-968-9621

Nicom
619-477-6298

OMB America
800-662-4872

Radio Systems
856-467-8000

Superior Broadcast
800-279-3326

TFT
800-347-3383

Trango Systems
888-400-8886