FHWA TMC/EOC/FC Handbook: 2.6 Communications Links

2.6 Communications Links

2.6.1 TMCs

TMC management often includes an approach to interagency cooperation—where the strategic missions of multiple stakeholders have overlapping elements. In these cases, open lines of communication are important for sharing information and coordinating in common mission areas. Common TMC communications linkages include:

Face-to-face communications consist of personal interactions between staff from different agencies in co-located facilities such as joint operations centers or mobile command posts. When possible, it is effective for sharing information and coordinating response. Regular face-to-face interaction facilitates collaboration and trust.
Radio is the most common form of communication between the field and operations centers to communicate on-scene traffic incident information. First responders such as law enforcement and safety/service patrols frequently use it. However, radio is often a challenging medium of communication between agencies because of the many different radio types and frequencies employed to maintain clear communications within each agency’s own operating units.
Wired telephones are the primary means of center-to-center interagency communication. They are still the most accurate and immediate method to describe transportation incidents. Hotlines can also establish a constant direct audio feed.
Cellular telephones, which continue to improve technologically and gain in popularity, provide radio-like operability and wired-telephone connectivity and improve mobility. Push-to-talk systems and priority access mimic radio features.
Alphanumeric pagers, cellular SMS text messaging, and email are used to communicate within and among agencies. Although still not a primary means of communication, advanced systems can include graphical maps, AVL, and in-vehicle mobile data terminals (MDTs) that can interact with CAD systems.
CAD systems automatically dispatch services via a computer. A CAD system consists of a suite of software programs that can route calls, make dispatches, and monitor status. The program can send messages to responders via an MDT and can also be used to store and retrieve data. Responders in the field can receive messages via two-way radio, text message, pagers, and/or wireless telephone. Often, multiple agencies share systems to facilitate communication and increase efficiency.
Video-imaging systems can be shared easily where partner agency staff members are co-located at TMCs. Video and still images can also be shared remotely via Internet portal. Video and images can also be shared with the media. Control of the pan-tilt-zoom functions on cameras can also be shared by agencies if desired. If such access is granted, protocols must be established on how and when such functions can be used.

Table 2-15 provides a summary of the TMC communication systems in terms of reliability, speed, security, and availability.

Table 2-15: TMC Communications Summary
Link System	Speed	Availability
Face-to-face
Radio
Wired telephone
Cellular telephone
Pager/Text Messaging/Email
CAD
Video imaging
Key	= Good	= Poor

2.6.2 EOCs

The communications capabilities available to an EOC will generally depend on its primary jurisdiction. For example, a local community EOC’s communications capabilities are likely to be more basic than those of EOCs serving a densely populated metropolitan area or a State. Table 2-16 presents the communications capabilities available and describes some of the characteristics associated with each.

Table 2-16: Available EOC Communications Capabilities
Capability	Characteristics
Wireline telecommunications	The wireline network (Public Switched Network) is ubiquitous. Although it is susceptible to physical damage (a backhoe operator may cut a fiber cable; a hurricane may uproot telephone poles; an accidental—or intentional—fire may destroy or damage key telecommunications facilities), telecommunications service providers have advanced technologies for rapidly rerouting communications traffic and have more than 100 years of experience restoring the physical infrastructure.
Wireless telecommunications	Although there are some areas where coverage may be limited or non-existent, the wireless network is rapidly becoming as ubiquitous as the wireline network. It offers greater mobility to users than the wireline network.
Two-way/high-frequency radio	The advantage of this communications capability is that it does not depend on the same communications infrastructure as the wireline and wireless networks and it offers mobility to emergency responders. However, it is often the case that the radio communications used by different emergency responders are not interoperable, even within the same jurisdiction (e.g., law enforcement officers may not be able to communicate with fire department personnel).
Commercial broadcast communications	Although these media offer only one-way communications, EOCs can use this communications capability to issue alerts to the general public and obtain information about developing incidents of interest.
Direct feeds	Some EOCs may have continuous, direct feeds from weather services and news organizations. This may provide information of interest more quickly than is the case with commercial broadcast communications.
Data links	Some EOCs may have data links to various information sources, which may give them access to sources of information not otherwise available and may also allow them to receive content in formats the other communications capabilities do not support (e.g., maps).
Human interaction	When ESF representatives are physically present in the EOC, and when emergency responders (e.g., police officers, firefighters, EMTs) are in the field, they exchange information (and have insights about that information and the situation) that make a substantial contribution to the coordination of the response effort.

2.6.3 FCs

Because of the investment, expertise, and capabilities that exist with FCs, the FC guidelines suggest that center plans support the jurisdiction’s emergency management structure during crises. Since the State police primarily operate and control most FCs, the centers are involved in any natural disasters that may occur. Additionally, some FCs are beginning to co-locate with EOCs and have emergency management personnel working in their centers full time to help facilitate communications. FCs are expected to play a role during crisis management and recovery operations in coordination with the ICS, NIMS, and NRF.

Many FCs communicate via networks like HSIN. As an example of one of the main networks FCs use to communicate, HSIN gives FCs the ability to collaborate with other FCs and their Federal partner over an end-to-end encrypted network. HSIN provides communication, collaborative tools, and information.

June 2010
Publication #FHWA-HOP-09-003