7.3 Station-to-Ground Communications

Communications traffic flowing between Deep Space 9 and Bajor is considered station-to-ground. All other traffic between the station and mobile entities is considered under ship-to-ship, and transmissions to distant planetside or orbital bases is part of the deep subspace network (see 7.4, 7.5). All forms are handled by subspace and more limited RF systems of both Cardassian and Starfleet design. The principal differences between the two systems are range and speed.

Subspace remains the primary high-speed carrier environment and RF continues as the short-range backup transmission mode, followed by modulated versions of standard phaser, X-ray laser, and infrared (IR) emitters. Most subspace radio propagates at warp 9.9997, and all RF energy is limited to light-speed velocity (c). New methodologies are being explored for increasing the warp-equivalent velocities of modulated subspace energy waves. These include the adaptation of helical verteron membranes akin to that found at the wormhole interface, essentially creating a microwormhole jacketed around the com stream, as well as a variant on the soliton wave phenomenon. Soliton-based communications may take advantage of the self-sustaining nature of the wave energy fields, possibly extending the range of intelligible messages beyond the 22.65 light-year limit for standard subspace.

Installed Hardware

The total space station external communications hardware consists of twenty-one RF and twenty-four subspace transceiver assemblies as original Cardassian installs, plus Starfleet upgrades incorporating twelve RF and six subspace transceivers. Power for all transceivers is supplied through stage-3 EPS conduits, with multiple backups provided by stage-3 conduits normally allocated for turbolift use.

Each Cardassian RF unit is a flat, elongated double trapezoid measuring 0.45 by 1.27 meters by 0.31 meters thick. Each contains a soft-partitioned voice and data subprocessor section, three amplification-type frequency-spread analyzers, two variable signal compression isolinear banks, and three cross-linked hardware-level encryption subprocessors. Prior to the reinitialization of the RF nodes in 2369, all of the encryption devices were severed from the main signal paths, deep purged, and returned to service with new cross-links to the Starfleet computer CPG (see 7.6). Though all unmodified RF equipment is limited to light-speed transmissions, Starfleet and Bajoran com specialists have recommended that the units be kept operational. The key point involves subspace instabilities that can occur in the station environment due to wormhole energy fluctuations, active jamming by threat forces, or other battle-related com problems. The useful transmission distance has been extended from 778 million kilometers to 1.6 billion kilometers at moderate power, and up to 3.4 billion kilometers at high power. This greater distance represents some three hours one-way light time, but is deemed acceptable for distress calls, transfer of sensitive data, or other crisis traffic.

The typical Cardassian subspace transceiver is a vertical trumpet-shaped solid related in X-Y symmetry to the computer core housings, and directly connected to conductive areas of the exterior hull plating by integral waveguides. The device measures 0.98 meters in diameter and 2.41 meters in height. It contains voice and data processors, EPS power conditioners, and two separate subspace field generator/modulators for omnidirectional and focused antenna arrays. All noise elimination in audio and visual data streams is done by the com system ODN input subprocessors prior to passage of the signal through the transceiver. The effective radiated power at the antenna plate is 15.3 megawatts, with a total load across all twenty-four nodes of 367.2 megawatts, though the load was not normally driven at this level except in extreme crisis situations. Most high-power transmissions usually involved only three transceivers aimed back toward Cardassia Prime. A suite of subspace EM sensors is incorporated into each antenna to aid in commanding optimum coverage.

Attached to the same CPG signal-switching blocks as the Cardassian transceivers are the Starfleet RF and subspace upgrades. Both types of units are salvaged components from normal starship hardware rotations, still within their MTBF periods. All hardware refurbishments have been certified as spaceworthy for nonwarp installations, since they will not fatigue as rapidly in the Bajor orbital environment. The RF units are small standard hexagonal solids, 1.1 meters across the faces and 0.23 meter in thickness. In the Deep Space 9 installation, most of the RF units are mounted within station access tunnels, close to the hull surfaces, with doubly redundant waveguides leading to the exterior antennae. Three are installed in the ops antenna farm.

The Starfleet subspace transceivers are all taken from Soyuz-class starships nearing the end of the vessels' primary operational lifetimes. Each triply redundant device is housed within an octagonal solid measuring 1.33 meters across the faces and 0.56 meters in thickness. Since the most recent swapout of subspace equipment from the Soyuz class was performed only eight years earlier, the predicted nonwarp MTBF will carry them another twenty-five years with periodic maintenance. The internal components available to the engineering staff include familiar voice and data processors, EPS power conditioners, subspace field coils, and optronically steerable focusing arrays. One unit is mounted with the Lower Core, two are mounted in the ops antennae farm, and the other three are installed at 120-degree intervals along the Docking Ring, equidistant between the pylons. As with the RF units, the subspace devices are protected within the Docking Ring hull and connected to the surface plates via jacketed waveguides.

The subspace and RF antennae farm present on the roof of the ops module dates back to the Terok Nor construction and remains in serviceable condition. The two RF antennae are elongated tetrahedrons of niobium-copper-disellenide over a duranium substrate. The subspace antennae involve two related types. The first is a cylindrical omnidirectional emitter fabricated from niobium-yttrium-toranite and mounted atop a duranium-kelindide composite mast. The second is a large, bladed high-gain steerable emitter/receiver, a build-up of seven layers of copper-borokine field elements encased in a toranium-graphite housing. The 32,673 individual energized elements are steerable by computer command, allowing for multiple transmissions in different directions. A fifth mast contains an emergency subspace beacon and distress transmission receiver set.

Applications

The original station-to-ground communications linked Terok Nor with the Cardassian operations on the surface of Bajor. Once the station had been relocated, all low-power com devices on the planet could no longer reach Deep Space 9 and, at the very least, dedicated high-power RF transceivers were required by the Bajoran provisional government to maintain contact with the station. Subspace relays were eventually set up on Bajor, allowing networked voice and data traffic from combadges, padds, tricorders, and visiting spacecraft to pass to the station.

As with most communications and other optronic systems on Deep Space 9, frequency and hardware usage is split between the Starfleet-Bajoran administration and the commercial sector. Power allocations and transceiver amortization related to transmissions to Bajor are calculated and charged to residential and commercial hailing accounts. Commercial customers may use their own encryption schemes, restricted only by a maximum of 1.25 x 10⁶ digits in either public or private encryption keys. Emergency com from either Bajor or the station will be routed by the computer without delay to the appropriate recipients, given the proper com access codes. All Starfleet military communications with Bajor are conducted according to strict security protocols and filtered through the CPG (see 7.6). All routine traffic between Starfleet personnel and Bajor is also channeled through the CPG and logged for compression and transfer to Starfleet Headquarters.

Any nonstandard com signals or modulated EM detected between Bajor and Deep Space 9 is recorded and analyzed for possible distress hails or other significance. At the time of custodial handover, all signal and linguistic translation routines between Starfleet and Bajoran equipment had been established, with algorithm patches made to the com protocols as needed. Most unknown signals encountered in recent years have originated with newcomer cultures, refugees, and threat forces, including those from the mirror universe incursions. Those EM signatures have been catalogued and analyzed, and added to the overall com database.