Xalant · Glossary
Reference · 27 terms
Glossary
Every term this site uses that is not plain English, defined in plain English. Each entry is anchored, so a page elsewhere on the site can link straight to the definition it needs.
Where a definition rests on somebody else’s published material, their page is linked under it. Where it does not, it is plain description and carries no link.
Xalant Edge
Compute and the hall
The vocabulary of a data centre: what is measured, what is cooled and what is repeated.
- Direct-to-chip cooling · also Cold-plate liquid cooling
Liquid carried to a cold plate sitting on the processor itself, rather than cooling the air around the rack. It is what lets a rack draw far more power than an air-cooled one in the same footprint.
- Edge data centre · also Edge data center
A small data centre placed close to where the work happens rather than in a distant metro campus, so the round trip between the user or machine and the compute is short.
- Edge-in-a-box
The smallest repeatable unit of the Xalant design: a factory-built enclosure holding racks, cooling and switchgear, delivered to a prepared pad and commissioned there rather than constructed on site.
- Free cooling · also Ambient cooling
Rejecting heat to the outside air without running mechanical refrigeration, possible whenever the ambient temperature is far enough below the target supply temperature. It is the single biggest reason a cold-climate site spends less of its power on cooling.
- MW-IT · also IT load
Megawatts of power available to the computing equipment itself, with cooling and distribution losses excluded. It is the honest way to compare two sites, because a figure for the whole facility flatters an inefficient one.
- N+1
A redundancy pattern: as many units as the load needs, plus one spare of the same kind. One unit can fail or be taken out for service without the load noticing, which is a weaker guarantee than two fully independent systems and a much cheaper one.
- PUE · also Power usage effectiveness
Total facility electrical load divided by the load drawn by the IT equipment inside it. A lower ratio means less of the incoming power is spent on cooling and distribution.
- Web3 node
A machine that participates in a blockchain network by validating or storing its data. It is a workload class rather than a product: steady, tolerant of being a long way from its users, and therefore well suited to a site chosen for cheap power instead of for latency.
- White space
The floor area inside a data centre that holds the IT equipment, measured separately from the plant rooms, corridors and switchrooms around it. Capacity is usually quoted against white space rather than against the whole building.
Xalant Power
Generation and the ground
Engines, wells and reactor classes, plus the regulatory words attached to each.
- Bridge power
Generation that carries a site from commissioning until slower, cleaner generation is available on the same pad. It is sized and permitted to be replaced rather than to last, which is a different specification from a permanent plant.
- EGS · also Enhanced geothermal system
A geothermal system that creates its own reservoir. Conventional geothermal needs hot rock that is already permeable and wet; an enhanced system drills into hot dry rock and engineers the flow paths, which widens the map of where geothermal is possible.
- FHR · also Fluoride-salt-cooled high-temperature reactor, KP-FHR
A reactor class cooled by molten fluoride salt at near-atmospheric pressure instead of by pressurised water. KP-FHR is one vendor's design within that class; claims about how it behaves are quoted from that vendor's own published pages and attributed, never paraphrased.
- Flibe
A molten mixture of lithium fluoride and beryllium fluoride used as a coolant in fluoride-salt reactors. It stays liquid over a wide temperature range and does not need to be pressurised, which is the property the reactor class is designed around.
- Interconnection queue
The waiting list a new generator or large load joins before a transmission operator will connect it. Queue times are the reason an off-grid build can reach power sooner than a grid-tied one.
- Microgrid controller
The supervisory system that decides, moment to moment, which sources are carrying a site's load and how a transfer between them happens. It is the component that makes several generators, a battery and a grid feed behave as one supply.
- NRC Part 50 / Part 52
The two routes to a reactor licence in the United States. Part 50 is the older two-step path, a construction permit followed by an operating licence; Part 52 grants a combined licence covering both. Which route a project takes is a matter of public record.
- SMR · also Small modular reactor
A reactor designed to be built in a factory as repeated modules and assembled on site, rather than engineered once as a single large plant. The argument for it is schedule and repeatability rather than output.
- TRISO · also Tri-structural isotropic fuel
A reactor fuel form in which each fuel kernel is sealed inside layers of carbon and ceramic. Claims about how TRISO behaves are quoted from the reactor vendor and attributed, never paraphrased.
Xalant Communications
Orbit and the link out
Constellations, ground stations and the licensing step between the two.
- Bonded gateway
A gateway built from several antennas at one location whose capacity is aggregated into a single higher-capacity path. It is a satellite operator's product term, and the rating that goes with it is quoted from that operator's published page with the date it was read.
- Community Gateway
A satellite operator's product name for a dedicated gateway placed to serve one region, with its capacity distributed onward by local providers rather than sold directly to households. Xalant's pages use the operator's current name for it and take every figure from the operator's own page.
- Direct-to-cell
Satellite capacity presented to an ordinary mobile handset as if it were a terrestrial cell, with no special hardware on the phone. It depends on an agreement between the constellation operator and the mobile network, not on anything installed at the user's end.
- FCC Part 25
The part of United States communications regulation that governs satellite earth stations, including the authorisation a ground station needs before it may transmit. On this site it is described as a step in a deployment schedule, never as something already held.
- Ground station · also Gateway
The site where a satellite link meets the terrestrial network: antennas on a prepared pad, power, grounding and a fibre hand-off into the local network.
- Ka-band
A range of radio frequencies used for high-capacity satellite links. It carries more data than the older bands and needs a clearer view of the sky.
- Laser mesh · also Optical inter-satellite links
Optical links between satellites, letting traffic travel through the constellation instead of returning to the ground at every hop. It is what allows a satellite with no ground station in view to reach one that has.
- Low Earth orbit · also LEO
The band of orbits closest to the planet. A satellite there passes overhead quickly, so a constellation needs many of them, and the short path keeps the round trip low.
Xalant
How this site talks about itself
Vocabulary that is a rule rather than a technology, and that governs what the rest of the site is allowed to claim.
- Target geography
A place Xalant anticipates building in.
Missing a word?
This list grows from the rest of the site: a term earns an entry when a page uses it and a reader would reasonably stop. Tell us which one stopped you.