Home' RTCA Documents for Review : DO-230H FRAC Contents 272
© 2017, RTCA, Inc.
Unlicensed wireless devices are permitted by the FCC under Part 15 of its rules to emit radio frequency
energy, without specific authorization, registration, or grant of a license. The technical standards contained
in Part 15 are designed to ensure a low probability that these unlicensed devices will cause harmful
interference to other users of the radio spectrum. Level of performance and freedom from interference,
however, are not guaranteed.
A wireless LAN (WLAN) consists of:
Base stations with antennas selected for the desired area of coverage and the range of client-side
A wireless network fabric, typically meshed radio nodes, known as access points, for fail-safe client
coverage, and gap filling radios for areas which cannot be served from centralized base stations.
Ruggedized client vehicle (wireless equipped laptop) and on-foot equipment (wireless equipped
System software including software to secure wireless network from unauthorized access.
The design of a wireless network should begin by mapping the areas of coverage for signal strength for
received signals transmitted from the candidate transmission sites and for interference from existing, or
expected, emitters on and in the vicinity of the airport. A spectrum analyzer should be employed for
interference testing, and the testing should be performed over a representative period of airport operations.
This will typically require testing several times during the day, especially at peak periods of operation,
conducted for at least a week.
The communications network should support mobile communications with field users, with special
attention to the needs of patrolling security and law enforcement personnel. The mobile network should be
able to locate responder personnel as well as targets on a facility map and/or drawing which cover both
interior and exterior areas; provide for secure duplex voice communications with the SOC; and deliver
content-sensitive video and data information appropriate for the situation(s) which can be displayed on
mobile notebook computers and PDAs.
Due to the potential of interference between radio transmissions of the various wireless communications
methods, adherence to regulations and standards should be required by the ISSA system designer, in
particular the regulations issued by the FCC and standards published by the IEEE, TIA, and other standards
The ISSA system designer should also monitor new developments in the wireless communications, and
where practical anticipate and provide for the insertion of new technologies, to assure the most cost-
effective solution is developed for the life of the system.
Interoperability with public safety organizations which have responsibilities during security incidents and
civil emergencies should be addressed during system design. Systems enabling constant, interagency
communication between all parties responding to an incident using disparate radio equipment may now be
achieved utilizing communications interoperability bridges over various networks.
Interoperability bridges link mobile and portable radios, both military and civilian, as well as
cell/satellite/direct-connect and land-line telephones allowing responders to communicate across
technological and organizational boundaries, without changing equipment or monopolizing their
communications systems. Typical bridges are P25 and VoIP compatible and sometimes coupled with 800
Wi-Fi systems are generally considered to operate over relatively short ranges because of FCC restrictions
on radiated power and because, as a shared medium, as the number of users increases the range for all users
Links Archive Navigation Previous Page Next Page