Technology is a critical tool for improving interoperability, but it is not the sole driver of an optimal solution. Successful implementa­tion of data and voice communications technology is supported by strong governance and is highly dependent on effective collabo­ration and training among participating agencies and jurisdic­tions.

Technologies should meet the needs of practitioners on the frontlines and should address regional needs, existing infrastruc­ture, cost vs. benefit and sustainability. The technologies described within the Continuum must be scalable in order to effectively support day-to-day incidents as well as large-scale disasters. Many times, a combination of technologies is necessary to provide effective communications among emergency responders. Security and authentication challenges are present in each technology and must be considered in all implementation decisions.

Voice Elements

Swap Radios—Swapping radios, or maintaining a cache of standby radios, is an age-old solution that is time-consuming, management-in­tensive, and likely to provide limited results due to channel availability.

Gateway—Gateways retransmit across multiple frequency bands, providing an interim interoperability solution as agencies move toward shared systems. However, gateways are inefficient in that they require twice as much spectrum because each participating agency must use at least one channel in each band per common talk path and because they are tailored for communications within the geographic coverage area common to all participating systems.

Shared Channels—Interoperability is promoted when agen­cies share a common frequency band or air interface (analog or digital), and are able to agree on common channels. However, the general frequency congestion that exists nationwide can place severe restrictions on the number of independent interoperability talk paths available in some bands.

Proprietary Shared Systems and Standards-Based Shared Systems—Regional shared systems are the optimal solution for interoperability. While proprietary systems limit the user's choice of product with regard to manufacturer and competitive pro­curement, standards-based shared systems promote competitive procurement and a wide selection of products to meet specific user needs. With proper planning of the talk group architecture, in­teroperability is provided as a byproduct of system design thereby creating an optimal technology solution.

Data Elements

Swap Files—Swapping files involves the exchange of stand-alone data/application files or documents through physical or electronic media (e.g., universal serial bus devices, network drives, emails, faxes). This process effectively creates a static “snapshot” of in­formation in a given time period. Though swapping files requires minimal planning and training, it can become difficult to manage beyond one-to-one sharing. With data frequently changing, there may be issues concerning the age and synchronization of infor­mation, timing of exchanges, and version control of documents. Each of these issues can hinder real-time collaborative efforts. In addition, the method of sharing files across unprotected networks raises security concerns.

Common Applications—The use of common proprietary applica­tions requires agencies to purchase and use the same or compatible applications and a common vocabulary (e.g., time stamps) to share data. Common proprietary applications can increase access to in­formation, improve user functionality, and permit real-time infor­mation sharing between agencies. However, the use of common proprietary applications requires strong governance to coordinate operations and maintenance among multiple independent agencies and users; these coordinated efforts are further compounded as the region expands and additional agencies use applications. Com­mon proprietary applications also limit functionality choices as all participating agencies must use compatible applications.

Custom-Interfaced Applications—Custom-interfaced applications allow multiple agencies to link disparate proprietary applications using single, custom “one-off” links or a proprietary middle­ware application. As with common applications, this system can increase access to information, improve user functionality, and permit real-time information sharing among agencies. Improving upon common applications, this system allows agencies to choose their own application and control the functionality choices. How­ever, if using one-to-one interfaces, the use of multiple applications requires custom-interfaces for each linked system. As the region grows and additional agencies participate, the required number of one-to-one links will grow significantly. Proprietary middleware applications allow for a more simplified regional expansion; how­ever, all participants must invest in a single “one-off” link to the middleware, including any state or Federal partners. Additionally, custom-interfaced applications typically require more expensive maintenance and upgrade costs. Changes to the functionality of linked systems often require changes to the interfaces as well.

One-Way Standards-Based Sharing—One-way standards-based sharing enables applications to “broadcast/push” or “receive/pull” information from disparate applications and data sources. This system enhances the real-time common operating picture and is established without direct access to the source data; this system can also support one-to-many relationships through standards-based middleware. However, because one-way standards-based shar­ing is not interactive, it does not support real-time collaboration between agencies.

Two-Way Standards-Based Sharing—Two-way standards-based sharing is the ideal solution for data interoperability. Using standards, this approach permits applications to share information from disparate applications and data sources and to process the in­formation seamlessly. As with other solutions, a two-way approach can increase access to information, improve user functionality, and permit real-time collaborative information sharing between agen­cies. This form of sharing allows participating agencies to choose their own applications. Two-way standards-based sharing does not face the same problems as other solutions because it can support many-to-many relationships through standards-based middleware. Building on the attributes of other solutions, this system is most effective in establishing interoperability.