EDACS
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EDACS stands for The Enhanced Digital Access Communication System, a radio communications protocol and product family invented in the General Electric Corporation in the mid 1980s.
[edit] History
A young designer, Jeff Childress, created an autonomous radio base-station controller, known as the GETC (General Electric Trunking Card). The GETC was a general purpose controller with input/output optimized for radio system applications. Considered somewhat of a "jumper demo-kit" the GETC's unparalleled flexibility remains a testament to American industrial engineering, and hundreds of thousands of users in the field continue to rely on this innovation for their daily operations, and millions of citizens rely on it for their safety and security.
Childress and the team demonstrated that a smart controller could be adapted to a variety of applications, but his interest was really in fault tolerance. The competition dealt with fault tolerance by means of the "brute force and ignorance" approach, deploying double the hardware for their controllers, and interconnecting them with massive and problematic relay banks.
The EDACS system architecture supported large communications footprints. By making the GETC's "trunk" among themselves, one GETC per channel, the system was designed to be inherently fault-tolerant. If one channel, or device, experienced problems, the others voted it off the network, and calls continued to be processed with the remaining resources. This provided substantial hardware reductions, and the required software efforts yielded a variety of unique features and options.
This was not a new concept in systems design, however, few other teams have embodied it cleanly into such wide distribution.
[edit] Current status
The EDACS system continues to be sold, and supports a sizable portion of the market today for the public safety, public transit, and industrial two-way radio communications field.
EDACS was developed in competition with Motorola's Smartnet trunking system. It claimed, and continues to hold, significant market share. GE teamed with Sweden's Ericsson, and the company became Ercisson GE, and eventually was sold after the telecom meltdown.
Over 500 large-scale EDACS radio systems have been sold, with hundreds of thousands of radios, and revenues in the billions. M/A-COM Inc, a holding of Tyco Electronics, acquired the asset (see OpenSky), and many of the original team members, some of their children, and even a few grandchildren continue to manufacture and support the product family.
[edit] External links
Software for system managers and radio monitors alike has been developed outside of the vendor. This software, ETrunker, is an off shoot of the Trunker software for Motorola based systems. Users of the software can monitor and log complete system activity. See Trunker Site for more info.
Central controller
Motorola systems: Type I • Type II • Type IIi Hybrid • Type II SmartZone • Type II SmartZone OmniLink • iDEN
Other: EDACS • EDACS Provoice • MPT-1327 • TETRAPOL
Scan-based / distributed control
General Electric Mobile Radio: GE Mark V
Logic Trunked Radio: LTR Standard • LTR Passport • LTR Standard and Passport • LTR MultiNet • LTR-Net