Georgia, USA

Georgia Cooperatives shared TETRA Network

Introduction

The mission or purpose of America’s electric cooperatives is to power communities and empower members to improve the quality of their lives. Electric cooperatives in Georgia provide power to almost half of the over 9.4 million residents and more than 70 percent of the land area of Georgia. 

Georgia’s electric cooperatives have for over 70 years been dedicated to providing reliable, low-cost electricity to their member-owners on a not-for-profit basis.  Their success comes not only from responsible power supply planning, but also proactive efficiency initiatives. 

Save case study for later

Georgia Cooperatives shared TETRA Network

The mission or purpose of America’s electric cooperatives is to power communities and empower members to improve the quality of their lives.

Challenge

New Radio Network

One such initiative by Diverse Power created a mission-critical TETRA radio network in Georgia.  This project started as a need to replace an analog radio system with limited functionality that was at end of life for support.  Diverse Power began in 2011 acquiring radio channels that provide coverage across Georgia and into Alabama.  Diverse Power provides power to more than 27,000 residential, commercial, and industrial members in 13 counties in Georgia and 1 county in Alabama.

Diverse Power was seeking a solution to provide an open standard system with scalability, reliability, flexibility, security, and redundancy.  The requirements were for excellent voice quality, messaging, location services, and the ability to support data services.  They wanted a spectrally efficient solution to meet the current needs and for growth.  They were looking for user equipment that was suited to the working conditions, rugged, water-resistant, easy to use, and with long battery life.  They needed dispatch capability with AVL able to interact with existing systems, interconnection to other radio systems, and geo-redundancy of key equipment.  Future growth should support Smart Grid and a bridge to broadband technology.

Solution

Why TETRA meets the requirements

Researching technology to replace the existing radio system, they discovered TETRA technology that was just becoming available in the US.  This technology had been in use in Europe for over 10 years as the standard for public safety critical communications systems.  TETRA provided as a core part of the radio system excellent voice quality, text messaging, data services, and AVL services.  TETRA provided enhanced redundancy and reliability needed for a quality emergency communications system.  TETRA also provided the ability to share the radio system with other users without compromising security or privacy of each user.  This technology could not only significantly enhance communications for Diverse Power, but for the communities within its service area. 

Diverse Power went through an extensive process of evaluating many different technologies and providers before selecting their technology partner, PowerTrunk. 

Once selected, PowerTrunk provided complete system design and commissioning services.   The combination of the PowerTrunk project implementation team and local partners went to work installing and commissioning the equipment. Local customization of the services provided a match to the requirements for coverage, redundancy, reliability, and security for each user group.  PowerTrunk also provided future capabilities to support broadband technology.

One of the key new features for all the users is the gateway function of the mobile radio.  This TETRA-only feature allows a portable radio to talk back through the mobile to the network.  For economic reasons, the network is built out as a mobile network, thus portable radios sometimes do not have the power to remain connected to the TETRA network in all areas.  The solution is to use the gateway mode in the mobile to allow the portable to talk to the mobile, which is still on the TETRA network in gateway mode, and the portable is passed through to the TETRA network.  This extends the coverage of the portables.  The portable maintains its own individual ID, GPS location, and emergency function.  The dispatcher is able to still see all this information and communicate with the portable as well as the mobile acting as the gateway.  This feature enhances the efficiency and safety of all users.  This intelligent system provides high level features while keeping the user interface simple and easy to use.

Diverse Power built several radio towers throughout the service area in preparation for the launch of the new TETRA radio system which, combined with an extensive fiber network and radio licensing, enhances employee communications and enables line crews to conveniently communicate with each other, with law enforcement, and with emergency responders during post-storm power outages or other emergencies.

Benefits

Simultaneously, Diverse Power partnered with the Harris County government to share the mission-critical radio system in order to improve safety communications for emergency responders there, where prior to assistance from Diverse Power, the county only had radio coverage over two-thirds of its landmass. Now, emergency providers can communicate throughout almost all of Harris County despite its numerous valleys and hilly terrain. This joint venture saved funds for both the co-op and the county while creating an advanced radio system with a larger coverage area that vastly improves communications for the county’s emergency providers. The Harris County Sheriff, local police, 11 fire departments, EMS, area hospitals, and the county wide 911 center all take advantage of this new system. In addition, the Harris County water system operates 25 large water tanks using TETRA data modems for communications of the SCADA system.

01 Cobb EMC was the second to join the Diverse Power TETRA network, adding 6 additional sites to the system covering 5 counties in Georgia. They service over 200,500 meters in the northwestern greater Atlanta area.
02 Each cooperative, municipality, and county government that has joined the Diverse Power TETRA network has security of its own information. The voice communications, AVL information, and other messaging is only shared within the separate entities. Emergency communications between groups is controlled. Everyone has their own virtual network during normal operations, just as if they had their own separate radio system. When needed, groups can be setup between anyone on the network or other connected networks.
03 Diverse Power welcomed several electric cooperatives who partnered to benefit from the focus on advanced radio technology, and the opportunity was provided for other cooperatives, municipalities, and county governments to join our growing communications network. By looking to partner with each new entity, the network has grown in coverage and capacity without significant cost for sites and connectivity. Each group brings resources to the common good of the network, such as tower sites, fiber connectivity, right-of-way, or facilities.
04 Snapping Shoals EMC joined the network in 2018, adding 4 additional sites to the network covering 8 counties in Georgia. They service over 95,000 meters in eastern metro Atlanta.
05 The network continues to grow as more cooperatives consider replacement of their aging radio systems. The current system has over 50 base station sites in the UHF band, with more than 1500 subscriber terminals, covering over 60% of Georgia.
06 Several system gateways to other radio systems are provided to allow for emergency communications to other critical service providers, even when they use different technology.

Technology that we used


TETRA (Terrestrial Trunked Radio) is the accepted digital radio standard for critical communications. TETRA is an open standard where the focus is on meeting the critical communications needs of public safety and security agencies and an increasingly wide range of other market sectors. The technology has been standardized by ETSI (The European Telecommunications Standards Institute).

Solutions

Keep up with mission-critical communications updates Sign up