4G and other options

A few stations are lucky enough to be located in cities chosen for early deployment of 4G Wimax services, and are having good success on these networks. Wimax offers higher throughput and lower latency and jitter than 3G networks, providing a “wire-like” experience to users. Deployment has slowed during the economic rough patch, but some of the cities on the roadmap for 2009 include Chicago, Dallas and Philadelphia. Verizon is leading the charge with deploying the main 4G competitor to Wimax, called LTE, and plans to have a handful of cities online by the end of 2009.

Andy Denoncour of the Comrex engineering team specs out a 3-mile 5.8GHz IP radio link.

Another attractive network for IP codecs is the Inmarsat BGAN network, which utilizes portable satellite terminals that are ever decreasing in cost and size. The BGAN network also sports a per-minute cost for a codec-capable IP channel that is a fraction of what previous generation satellite networks charged. With BGAN, worries about coverage are non-existent, as long as a reasonable view of the sky in the direction of the nearest satellite is achieved. And the terminals can be set up in minutes by non-technical users.

Some manufacturers have introduced simple, low-cost versions of their IP codecs, and these products mate well with the new breed of inexpensive IP point-to-point radios. Many of these work in the relatively uncongested 5.8GHz unlicensed band, and carry enough bandwidth to provide full-duplex uncompressed audio links. Several brands are available in weather-proof packages with built-in directional antennas and cost less than $500 per end. These make an attractive alternative for cross-city links, or even for extending IP access to non-wired locations.

Migration to IP audio can save money as well as offer new choices in the way audio is shipped for remotes, STLs and other real-time links. As the demand for mobile data increases, so will these choices. It's wise to keep an eye on this changing market when considering solutions.

Hartnett is technical director of Comrex.