Editing Superluminal communications

{{Status|Canon}}
Different civilizations have developed various technologies which enable communications at superluminal (faster-than-light) speeds over interstellar or even cross-[[Milky Way|galactic]] distances.

==United Nations Space Command==
For much of their spacefaring history, [[human]]ity and the [[UNSC]] were reliant on starships to carry information across interstellar distances. By the final years of the [[Human-Covenant War]], however, the UNSC had developed technology enabling them to tap into [[wavespace]], a dimensional realm similar to [[slipspace]], to carry messages across short interstellar distances along a series of relays and retransmission stations, allowing colonies and ships to be connected in virtual real real time.<ref name="warfleet10">'''[[Halo: Warfleet]]''' p.10</ref>{{Ref/Site|URL=https://www.halowaypoint.com/news/the-new-halo-encyclopedia-is-out-today|Site=Halo Waypoint|Page=The New Halo Encyclopedia is Out Today|D=11|M=03|Y=2023}}{{Ref/Note|In ''[[Halo: The Fall of Reach]]'' Chapter 16, [[Jacob Keyes|Captain Jacob Keyes]] contacts [[Michael Stanforth|Vice Admiral Michael Stanforth]] from the [[Sigma Octanus system]] on a FLEETCOM priority channel and they have a real-time exchange. Stanforth is implied to be in a different system at the time. In addition, in [[Dr. Halsey's personal journal|her journal]], Halsey receives an after-action report of the [[Battle of Sigma Octanus IV]] on July 18, 2552, the same day the battle took place. This would be impossible without a near-instantaneous communications system, as a ship could not have possibly traveled from Sigma Octanus system to [[Reach]] in a matter of hours; it took two weeks for [[Battle Group Leviathan]] to make the journey. Furthermore, according to [[Halo Graphic Novel, Page 122|page 122]] of the ''[[Halo Graphic Novel]]'', some sort of superluminal communications system was used by [[Catherine Halsey|Dr. Catherine Halsey]] to contact Earth while onboard the {{UNSCShip|Gettysburg}}. The transcript seems to show Halsey transmitting commands in real time. Even if this is accomplished using a script, it still takes about 36 minutes for the data to be transmitted from Earth to somewhere near [[Eridanus Secundus]]. The log in the ''Graphic Novel'' has an opening timestamp of 04:16 on September 12th, 2552; chapter 27 of ''Halo: First Strike'' opens at 04:50 on September 12th, at which point the data has apparently been received. The distance is unknown, however, and so the exact speed can not be calculated. Further examples of such superluminal communication are seen in the [[Data Drop]]s.}} The energy required to open a wavespace link is immense, however, bandwidth across the relay is limited, and signals carried in wavespace are prone to distortion the further they travel, limiting their effectiveness.{{Ref/Reuse|warfleet10}} Using [[Forerunner]] technology, signals can instead be carried across slipspace, allowing colonies and even starships to remain in contact at much faster speeds.{{Ref/Reuse|warfleet10}} The UNSC's discovery of Forerunner technology on [[Trevelyan]] in early [[2553]] enabled even smoother information transfer and the capability for ships to maintain communications while in slipspace; this technology was installed on the {{UNSCShip|Infinity}} and select ONI vessels.<ref>'''Halo: The Thursday War''', ''page 287''</ref><ref>'''Halo: Mortal Dictata''', ''page 202''</ref>{{Ref/Note|In ''Halo: Mortal Dictata'', it is stated that the discoveries on Trevelyan are what enabled the UNSC instantaneous interstellar communications. Since there are multiple examples of effectively real-time communication before the discovery of the shield world in earlier media (including the first ''Kilo-Five Trilogy'' novel ''Halo: Glasslands'') it can be assumed that the discussed upgrades improve the system already allowing practical near real-time correspondence on timescales imperceptible to humans but relevant to AIs and data transfer.}} Such communicators can be built compact enough to fit into man-portable communications kits.<ref>'''Halo: Glasslands''', ''page 418''</ref> UNSC ''Infinity''<nowiki>'</nowiki>s superluminal communications capability includes 16-channel "slipspace wavecom datalinks".<ref>'''[[Halo Mythos]]''', ''pages 132-133''</ref>

This system may be related to a form of communication known as "slipstream packets", which are, in essence, recorded audio messages, rather like letters. Human [[civilian]]s were able to use slipstream packets by [[2552#September|September 2552]].<ref>[http://transmit.ilovebees.com/surveillance_archive/week6_subject3.wav '''i love bees''': ''week6_subject3.wav'']</ref><ref>[[Axon Clips Chapter 6#Kamal|'''Axon Clips''': ''Chapter 6'']]</ref> These messages are sent through [[Waypoint]], a UNSC communications network similar to the 21st-century Internet.<ref>[http://www.youtube.com/watch?feature=player_embedded&v=rPeMxbvCjYo '''YouTube''': ''Halo: From A to Z with Frank O'Connor'']</ref><ref>'''[[Halo 4 Limited Edition]]''', ''[[Infinity Briefing Packet]] (Ship R&R Opportunity Schedule)''</ref>

Before the advent of superluminal communications, most human long-range communiques were carried on the shipboard memory of starships such as [[DCS light freighter|automated freighter]]s. On the other end of the ship's slipspace journey, the message would be relayed to the intended recipient.<ref>'''Halo: Contact Harvest''', ''page 35''</ref> At the time of the establishment of the [[Cole Protocol]] in [[2531]], while unable to send messages through slipspace itself, the UNSC was able to use a form of slipspace manipulation to obfuscate radio transmissions sent from Earth centuries earlier in order to prevent the Covenant from using the signals to triangulate Earth's location.<ref>'''Halo: Evolutions - Essential Tales of the Halo Universe''', ''"The Impossible Life and the Possible Death of Preston J. Cole"'', ''page 469''</ref>

The UNSC also developed a piece of technology known as the [[Slipspace COM launcher]], which sent independently guided probes through slipspace as fast as any UNSC starship. The strength of this system was the probes' ability to precisely home in on the designated target and securely deliver the message to the recipient. However, this technology was highly expensive and as a result there were only three such launchers in existence by 2552: one on [[Reach]], one on [[Onyx]] and one on [[Earth]]. As of the conclusion of the [[Human-Covenant War]], both the devices on Reach and Onyx have been destroyed, with the fate of the Earth device unknown.<ref>'''Halo: Ghosts of Onyx,''' ''page 176''</ref>

UNSC [[emergency locator beacon]]s,<ref name="fs">'''[[Halo: First Strike|Halo: First Strike (2010)]]''', "[[Tug o' War]]"</ref> judging by their nickname of "slipbeacons",<ref name="blood">'''[[Halo: Blood Line]]''', ''[[Halo: Blood Line Issue 1|Issue 1]]''</ref> can apparently send signals through slipspace.

==Forerunner==
The Forerunners had virtually abandoned the electromagnetic spectrum as a means to carry their communications,<ref>'''Halo: Cryptum''', ''page 144''</ref> instead relying on more secure [[Wikipedia:Quantum entanglement|quantum entanglement]]. These communications were routed over proprietary encryption protocols, which could be used to track the source or destination of the communication.<ref name="c125">'''Halo: Cryptum''', ''page 125''</ref> This allowed instant data transfer over vast distances: [[Offensive Bias]], for example, was capable of simultaneously coordinating the deployment of the [[Halo Array]] at [[Installation 00]] outside the galaxy and its fleet of war at the [[Maginot Line]].<ref>'''Halo: Silentium''', ''pages 326-328''</ref>

The [[Domain]], the Forerunners' collective information repository, was not usually employed for the purpose of communications due to its unreliability: it had a known propensity to alter information without explanation.{{Ref/Reuse|c125}} However, it was still known to be used for communications on certain occasions.<ref name="CEAterminal4">'''Halo: Combat Evolved Anniversary''', ''[[Terminal (Halo: Combat Evolved Anniversary)|Terminal 4]]''</ref>

The Forerunners also used a form of superluminal communication involving wormholes; however, these communications were significantly slower than communication via the Domain.{{Ref/Reuse|CEAterminal4}}

During the [[Battle of Installation 05]], [[Cortana]] was able to utilize Forerunner technology to send an emergency signal directly through slipspace, without a physical carrier, declaring codes [[Bandersnatch]] and [[Hydra (code)|Hydra]]. According to [[Endless Summer]], the energy required to send such a transmission would have required more energy than the combined output of all UNSC assets, demonstrating the Forerunners' superior grasp of energy manipulation.<ref>'''Halo: Ghosts of Onyx''', ''page 182-183''</ref> However, this appears to have been an ''ad hoc'' or emergency communication system given the Forerunners abandonment of wave-based communication, likely carried within the anomalous wake of the [[Forerunner]] [[Anodyne Spirit|Dreadnought]]'s passage to the [[Sol system]].{{Ref/Note|1=In ''Halo: Ghosts of Onyx'', the prowler {{UNSCShip|Dusk}} is implied to have followed the Forerunner Dreadnought's slipspace wake, making it to Earth within hours. This creates an inconsistency with later canon, such as [http://www.bungie.net/News/content.aspx?type=topnews&cid=16989 this timeline], which reveals that the Dreadnought took five days to reach the Sol system and another nine days to reach Earth, instead of a few hours. Therefore, the ''Dusk''<nowiki>'</nowiki>s speedy return to Earth may have been the result of a Slipspace anomaly, something that is indeed mentioned by the crew of the ''[[Incorruptible]]'' as taking place in the slipspace dimension [[YED-4]], and likely acted as the carrier of Cortana's message.}} 

Forerunner starship sensors were capable of instantaneous scanning and detection across interstellar distances. As a particularly impressive example of their available sensor ranges, the Forerunners' [[core authority]] routinely tracked individual slipspace jumps across the galaxy.<ref>'''Halo: Cryptum''', ''page 136''</ref> Forerunners shipboard sensors were also capable of providing a detailed analysis of a single planet's geological and ecological composition from light-years away through the use of long-range entanglements.<ref>'''Halo: Silentium''', ''page 121''</ref>

==Covenant==
By studying the [[Dreadnought]]'s transmission systems, the [[San'Shyuum]] discovered how to access a network of Forerunner machines placed in the [[slipspace]] dimension wavespace for interstellar communications.{{Ref/Book|Id=Enc22|Enc22|Page=216}} These studies allowed for nearly instantaneous supraluminal communications.{{Ref/Reuse|Enc22}}{{Ref/Site|Id=HWU|URL=https://www.halowaypoint.com/en-us/universe/factions/covenant|Site=Halo Waypoint|Page=Universe - Covenant|D=26|M=10|Y=2023}} When installed on a planet, for example, Covenant communications relays enable communications to corresponding devices across many light-years.<ref>'''Halo: Mortal Dictata''', ''page 215''</ref> Known as the [[proselytization network]], Procurator supply ships were fitted with such systems in order to keep fleets connected to High Charity and to help spread the power and influence of the Prophets across Covenant space.<ref>'''[[Halo: Warfleet]]''', p. 68</ref> At the Covenant hegemony's height, their starships possessed an automated messaging system which transmitted new orders and communiques from ship to ship upon arrival at or departure from a given star system, enabling them to rapidly relay information across their vast empire. However, as noted by [[Cortana]], these messages were not properly encrypted by UNSC standards, perhaps due to the Covenant's arrogance or ignorance of the workings of their own technology.<ref>'''Halo: First Strike''', ''pages 197-198''</ref>

==Flood==
The [[Flood]]'s collective intelligence, the [[Gravemind]], employs an esoteric mechanism which can quite aptly be described as telepathy, controlling Flood forms across vast distances.<ref>'''[[Bestiarum]]'''</ref> In certain circumstances, the Gravemind has also demonstrated to be capable of using this ability to telepathically communicate with non-Flood beings, namely [[John-117]].<ref>'''Halo 3''', campaign levels ''[[Floodgate]], [[Cortana (level)|Cortana]]''</ref>

==Notes==
{{Ref/Notes}}

==Sources==
{{Ref/Sources|2}}

[[Category:Communications technology]]