SHIP-TO-GROUND COMMUNICATIONS

	The next higher organizational level for the overall communications 
system involves contact and information exchange between the starship and 
planetside personnel and remote equipment.

	Communications external to the spacecraft are routed from the main 
computers to the radio frequency (RF) and subspace radio system nodes. 
While the term ÒradioÓ is something of an anachronism, since Starfleet 
communications more often than not involve visual information, it 
nevertheless continues to describe the basic function of the system. Normal 
radio frequencies are set aside as backups to the primary subspace bands, 
though RF is in continued use by numerous cultures maintaining relations 
with the Federation, and Starfleet vessels must sometimes rely on this older 
system when subspace bands prove unusable due to stellar or geological 
phenomena, or when hardware difficulties arise with either the host or 
remote sides. Such space-normal radio communications are, of course, 
restricted by the speed of light, resulting in severe time and distance 
limitations.

INSTALLED HARDWARE

	The RF section consists of a network of fifteen triply redundant 
transceiver assemblies cross-connected by ODN and copper-yttrium 2153 
hardlines and linked to the main computer comm processors. All are partially 
imbedded within the structural hull material at degree and distance intervals 
about the starship for maximum antenna coverage and manageable antenna 
timesharing loads.

	Each transceiver assembly is a hexagonal solid measuring three 
meters across the faces and one-half meter in thickness. Each consists of 
separate voice and data subprocessors, eight six-stage variable amplifiers, 
realtime signal analysis shunts, and input/output signal conditioners at the 
hull antenna level. RF section power is obtained from Type III taps from the 
electro plasma system. The basic limitations of the RF section stem from the 
c velocity limit, and a normal useful range at moderate power on the order of 
5.2 Astronomical Units (A.U.). RF frequencies directed through the steerable 
central component of the main deflector can extend the useful range to 
some 1000 A.U., though no practical applications of this power have yet been 
demonstrated.

	The subspace transceiver specifications, in proportion, are roughly 
akin to the warp propulsion system being compared to its less powerful 
impulse cousin. Approximately one hundred times more energy is required to 
drive voice and data signals across the threshold into the faster subspace 
frequencies, and even when applied to relatively short distances, the 
transmission reliability climbs dramatically. As with the RF section, small 
transceivers such as the standard subspace transceiver assembly (STA) in 
the personnel communicators need not emit great amounts of power if the 
large transmitters and receivers remain on the starship.

	A series of twenty medium-power subspace transceivers are 
imbedded within the starship hull at various locations to provide 
communications coverage similar to that of the RF units. Each triply 
redundant device is contained within a trapezoidal solid measuring 1.5 x 2 
meters by 1 meter in thickness. The system is powered by Type II electro 
plasma system (EPS) taps with a total maximum power load across the 
twenty nodes of 1.43 x 10® MW. Each transceiver consists of voice and data 
processors, EPS power modulation conditioners, subspace field coil 
subassemblies and directional focusing arrays, and related control 
hardware. Signal handoff from the optical data network is done with a 
combination of realtime and sequence anticipation AI routines for maximum 
intelligibility, given the FTL nature of the outgoing and incoming subspace 
signals.

APPLICATIONS

	Communications between the starship and a destination typically 
38,000 km to 60,000 km away from the antennae are handled by the above-
mentioned radio systems. Situations encountered cover a broad range, but 
most notably include discussions with planetside governments, 
communication and control of Away Team operations, local and regional 
crisis management, data collection from remote and active occupied 
research stations, shuttlecraft departure and approach terminal guidance, 
and Starfleet search and rescue. The subspace transceiver network is the 
active system linked to the transporter for personnel locator and coordinate 
lock-on functions. A minimum of three transceivers covering a given portion 
of the spacecraft sky coverage must be available for reliable transporter 
lock. The maximum reliable distance for routine transport is 40,000 km, owing 
to the median matter stream blooming tolerance of 0.005 arc-seconds, 
though subspace communications by the medium-power network can 
extend to some 60,000 km.

	Normal contact with the starship, if externally initiated, is divided into 
two basic types: Starfleet personnel, especially those persons directly 
assigned to the ship, and non-Starfleet agents. Away Team members will call 
directly to the Bridge or other active departments during the course of their 
work. Normal contact from outside agents will be held by Security for 
presentation to the captain or other senior officers. Emergency 
transmissions will usually be passed without computer delay for appropriate 
action.

	Standard encryption/decryption, plus enhanced security encryption 
protocols, are handled by FTL processors within the main computers. 
Starfleet encryption algorithms are rotated and updated on a random 
schedule. Multiple private key portions are retained with the starship 
computers, and the public portions are transmitted to Starfleet-issue 
hardware, such as handheld instrumentation, communicators, personal 
access display devices, and other pieces of expendable gear vulnerable to 
possible capture by Threat forces. Calling for a secure channel on either the 
spacecraft or remote side will be detected by the main computer, which will 
place higher encryption schemes in standby mode to await confirmation by 
command personnel.

	With certain non-Starfleet subspace transmisison protocols, 
particularly for data burst receiving, protocol matching delays may be forced 
by the computer until matrix translation values are calculated and applied in 
realtime. True Starfleet burst modes, as designed into the standard and 
medical tricorders, allow rapid emergency transmissions of stored 
information via the subspace system. Single antenna coverage is 
acceptable, though the physical layout of the antenna groups assures at 
least two arrays will be visible if the spacecraft is in line-of-sight of a 
transmitter.  Æ