Tech Notes: Communications

One of the key challenges for any spacefaring faction is establishing and maintaining communications over vast distances. Many races develop faster-than-light travel before FTL communications; the two categories rarely use the same underlying technology. The Alliance groups all commtech into four categories, which become more exclusive as distances increase.

It is worth noting that a common interstellar communications 'technology' among the Alliance, at least for civilian purposes, is not a technology at all, but simple physical transport. The Alliance Merchant Marine's Postal Subdivision coordinates the routing of physical mail through its existing infrastructure. Though slower than interstellar transmissions, writing a letter and sending it through the cargo network is reliable, efficient, and far less expensive than any other option.

Local communications operate at the speed of light or slower; they encompass most planetary and shipboard systems. Nearly every Alliance member race has a unique type of local comms, though the vast majority rely on electromagnetic waves, light pulses, or laser technology. There is no standardized local comm system, though most combined-tech Alliance ships use fiber optics due to the market and contract dominance of the fiber optic specialist Prysmastar Systems.

Ship-to-ship (STS) communications are sometimes considered an extension of local comms, as they rarely operate at superluminal speeds. The Alliance classifies them as a separate category due to their significantly different operational requirements. STS systems link spacecraft at relatively short ranges. They permit communications between members of a fleet, but also with any vessels encountered while traveling. As such, STS systems must be able to receive and transmit many different formats based on the origin of the other vessel.

The standard Alliance STS system is the Multifunction Lightwave Relay. For communications between Alliance vessels, the MLR uses a lightweight and efficient line-of-sight laser system; due to the miniscule power requirements of this system, MLR-based laser transceivers can also be carried by spacewalking crew to communicate with their vessel. The MLR is also capable of receiving and transmitting augmented radio waves (used by the Drules and many independent races) and flicker/pulse light signals (used primarily by the Vex-Cha).

Many member races still utilize their own STS systems for their own vessels. These races will often install MLRs only on command vessels; in joint operations the command vessel will relay orders to the rest of its fleet via its native STS comms. Other races have adopted modified MLRs with their own STS system integrated, often to avoid needing to retrofit older vessels.

Hyperbroadcast (HBC) communications are relatively flexible FTL comms, used to transmit across interstellar distances. These comms can move significantly faster than even the fastest FTL ship, but are generally utilized at such distances that messages may still take hours or days to reach their destination. Only three forms of HBC technology exist among the Alliance: hypertachyon, hyperpulse, and augmented laser. Hyperpulse was the technology the Kolaliri used during the time of their empire, while augmented laser systems exist among several member races.

Hypertachyon technology, often considered synonymous with hyperbroadcast, is the Alliance's standard HBC tech. It originated from the ancient Glis Empire's communications web, which utilized 'hypertachyon packets'—a form of specially energized light pulses—to send information at vast distances. Though the underlying technology was lost when the empire fell, thousands of transmitters remained with the Grand Convoys. After the formation of the Alliance of Five Powers, Biboh engineers assisted in attempting to reverse engineer the system, filling in the gaps with their own ship-to-ship wave propagation technology. By the time of the Galaxy Alliance, a useable hybrid system existed; several new member races have helped to refine the technology since.

Hypertachyon transmissions operate at a base rate of roughly 5.7 light years per hour. This can be modified by passing through atmosphere, where the packets are slowed via light scattering; after escaping the atmosphere they can 'snap' back into their original configuration and continue. Due to this scattering, hypertachyon packets produce little more than a garbled mess when received within atmosphere. Planetary bases and civilian facilities must utilize an HBC relay satellite in orbit, connected to the ground by local comms.

The primary use of HBC systems is communication between space stations and nearby planets, or ships and space stations. All known HBC systems require a fixed point as a destination. As such, they are only situationally useful for transmitting to active vessels. A ship wishing to hold a two-way communication via HBC will typically indicate that they are either holding position or moving directly towards the other party, and thus able to receive a return message. Otherwise, HBC transmissions from ships are assumed to be one-way. These are generally routine operational messages; due to their long travel time and relatively unsecure nature, Alliance policy prohibits sending reports or other sensitive information via HBC except in emergencies.

Subspace communications are the Alliance's fastest and longest-ranged system, based on technology originally devised by the Akese. They function by sending laser transmission through a subspace channel, also known as a pinpoint wormhole. These channels operate on the principle of relative spacetime conjoinment, an Akesian theory similar to quantum entanglement. Essentially, all subspace relays on a network are connected on a fifth-dimensional level, permitting messages to be sent over an effective space of mere inches to cover hundreds of light years in an instant.

Though the actual transmission takes only a fraction of a second, subspace relays have several complicating factors. The equipment required is both huge—a single 'compact model' generator is the size of a small house—and delicate, not to mention prohibitively expensive. Generating the subspace channel is a process requiring several minutes and an enormous amount of energy on the transmitting side. The channel itself is unstable and collapses after slightly less than a second, at which point the generator must spend several hours recharging. A receiver assembly has minimal power draw and no recharge time, but a syncing period with the transmitting relay requires both sides to be stationary.

Due to their size and power draw, only large starships or fixed sites can support a subspace relay; due to the limitations of the channel, transmission volume is strictly limited. To maximize efficiency, Alliance-operated subspace facilities limit transmissions to text with basic formatting, except for in cases of military necessity. Some of the rare civilian subspace networks permit more complex data, though it tends to be very costly. Alliance facilities will transmit civilian data when they have the capacity to do so, but military and government transmissions take priority, making them unpredictable and unreliable for civilian use.

A typical ground site subspace relay consists of a hub—the transmission chamber—attached to one or more generators. Depending on the traffic at the location, up to a dozen generators may be used. The receiver assembly is at the bottom of the transmission chamber, which is programmed with multiple terminus points; each time a new subspace channel begins to form, the chamber automatically recalibrates to the next terminus, ensuring multiple messages can be sent and received simultaneously without the channels colliding. (Channel collision is not dangerous, but does hopelessly scramble the messages.) Starship relays usually include five to ten terminus points; only Unity-class flag dreadnoughts and Semaphore-class communications cruisers carry multiple generators.

Like HBC systems, subspace communications with a moving vessel have extra complications, in this case due to the need for a stationary target while syncing. Usually a subspace-capable ship will depart with a prearranged schedule of 'reception stops' in case its home base needs to make contact. Being impossible to intercept, subspace comms are the Alliance's required manner of relaying any sensitive information between ships, stations, and planets.

A fifth theoretical category exists: Planar communications. As of this report, no known communications technology can reach a ship inside of hyperspace, or indeed any other extraspatial plane. Options based on planar scanners and more esoteric theories are being researched by several Alliance-funded programs, but none have yet borne results.