Communications
Real-time communication is possible thanks to networks of expensive mass relay comm buoys that can daisy-chain a transmission via lasers.
Comm buoys are maintained in patterns built outward from each mass relay. The buoys are little more than a cluster of primitive, miniature mass relays. Each individual buoy is connected to a partner on another buoy in the network, forming a corridor of low-mass space. Tightbeam communications lasers are piped through these "tubes" of FTL space, allowing virtually instantaneous communication to anywhere on the network. The networks connect across regions by communications lasers through the mass relays.
With this system, the only delay is the light lag between the source or destination and the closest buoy. So long as all parties remain within half a light-second (150,000 km) of buoys, seamless real time communications are possible. Since buoys are maintained in all traveled areas, most enjoy unlimited instant communications. Ships only suffer communications lag when operating off established deep space routes, around uninhabited outer system gas giants, and other unsettled areas.
During wartime, comm buoy networks are the first target of an attack. Once the network is severed, it can take anywhere from weeks to years to get a message out of a contested system. In systems where a buoy network has not yet been built or has been destroyed, rapid communication means ferrying information through high-speed courier ships and unmanned data drones.
Administration
While comm buoys allow rapid transmission, there is a finite amount of bandwidth available. Given that trillions of people may be trying to pass a message through a given buoy at any one time, access to the network is parceled out on priority tiers.
The Citadel Council and the Spectres have absolute priority; if they are using all the bandwidth, everyone else must wait. Individual governments and their militaries enjoy the next-highest tier. During wartime, civilian communication can suffer hours or even days of lag. Intelligence agencies study ping time through various systems to predict military buildups.
Below the governments and militaries, bandwidth priority is sold to the highest bidder. Media conglomerates, particularly headline news networks, purchase higher priority to provide their viewers with timely information. Corporations that require timely information and response capability (for example, financial institutions and investment firms) also invest heavily in priority access. The funds acquired through sales of bandwidth are used to maintain and expand the communications infrastructure.
While everyone with a computer has guaranteed free and unlimited access to the galactic extranet, they are last in line for bandwidth and may have to wait for their requests to be processed. Bandwidth resale corporations use investment capital to purchase blocks of high priority access, made available by paid subscription.
Methodology
As the population of the galaxy increases and new worlds are settled, timely access for home users and frontier settlements with underdeveloped communications infrastructures is a growing problem. To ameliorate bandwidth issues, a sophisticated array of data caches and virtual intelligence search agent programs are available.
When a user submits a query, it is first routed to the data cache, the user's search agent VI collates mountains of locally-stored data to find the desired material. If the information is not available locally, the query is passed along to neighboring systems, and then outward in an expanding network. VI search agents in those systems replicate the search. If the desired information is found, it is compressed into a "burst" file and queued for transmission to the source system. The burst is assigned a priority based on the number of queries for it; the greater the number of queries, the higher the priority.
When a new solar system is first connected to the net, a selection of the most popular data is installed locally. Though storage hardware is cheap, the capacity required to hold all the data produced everyday by trillions of people on hundreds of worlds is not trivial. It's not economical to store local copies of all the data available on obscure topics just in case.
As colonies mature, older and less-popular chunks of data filter into them as a result of queries and are placed in the local archive. Searches for obscure topics are increasingly likely to produce instant results as the archive grows.
Quantum Entanglement Communicators (QEC)
When a pair of quantum-entangled particles is separated, a change to one particle will affect the other instantaneously, wherever it lies in the universe. QECs exploit this effect to transmit binary data any distance. Two pairs of entangled particles are necessary for transmission and reception.
While QEC technology is extremely expensive and difficult to produce, it offers two enormous advantages. First, it allows instantaneous communication over any distance without reliance on the network of comm buoys, which is limited due to the sheer volume of space. Further, destruction of buoys hampers a foe’s military intelligence; comm buoys are the first targets of raiders in wartime. Second, quantum communications cannot be intercepted between source and destination, allowing no "wiretaps."
Unfortunately, QECs cannot replace the galactic civil communications infrastructure. First, they have extremely limited bandwidth. A single entangled particle can only transmit a single qubit (quantum bit) of data at once. Second, the system’s exclusively point-to-point nature precludes peer-to-peer networking and data dissemination through the galactic extranet.
The most strategically appropriate military application of QECs is at the headquarters level. Each Alliance colony would maintain a QEC at its military headquarters and each fleet flagship in its CIC. All the pairs for these would be located at a central facility within Arcturus Station. During an attack, a facility would signal Arcturus to transmit its information to every other fleet and colony. However, destruction of the comm center at Arcturus would collapse the entire network.