> For the complete documentation index, see [llms.txt](https://docs.therisk.global/organization/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.therisk.global/organization/systems/nxs-sig.md). # NXS-SIG NXS-SIG, the authorized signal, spectrum, timing and PNT integrity system of the Nexus ecosystem: purpose, rooms, inputs and outputs, areas, standards and boundaries. {% hint style="info" %} This page is generated from the twenty-system charters, the system profiles, the interface and authority registers, the room register, the areas of work, the systems article of the constitution set and the programme spine. Do not edit it in GitBook: change the source and export again. {% endhint %} **NXS-SIG** is one of the twenty systems of the Nexus ecosystem: the authorized signal, spectrum, timing and PNT integrity system. It is described here as a system of the ecosystem, with its purpose, its rooms, what it receives and provides, the areas it serves, the standards that apply and its boundaries. ## Purpose and context Signal quality and integrity records within authorized scopes. Its domain is authorized signal, spectrum, timing, PNT and communications-integrity observation. A typical setting is a permitted RF and timing-integrity assessment of critical-site communications. ## What it is the authority for | Record | What the system must keep | | ----------------- | ------------------------------------------------------------------------------ | | authorization | Confirm the observation is permitted for the subject, band, place and purpose. | | frequency support | Distinguish center frequency, bandwidth and resolution bandwidth. | | sampling clock | Preserve reference source, synchronization quality and uncertainty. | | power measurement | Record linear or logarithmic representation and detector settings. | | pnt evidence | Separate positioning quality, anomalies and unsupported attribution. | ## Rooms and areas of work Every system has ten rooms: eight shared rooms, which work the same way across systems with this system's domain, and two specialist rooms. | Room | Kind | Purpose | | ------------- | ---------- | ----------------------------------------------------------------------------------------------------------------------------------------------- | | Station | Shared | The system's home: posture of the system's own records, freshness, refusals and next actions; never a summary of another system's truth | | Mission | Shared | Mission and task work for the system's domain, linked to Universe missions and Project OS plans | | Builder | Shared | Composition of the system's artifacts and configurations from admitted packages (NXS-STU, NXS-FAC and NXS-NXQ boundaries apply) | | Maps | Shared | Spatial views of the system's records and NXS-GRX products, under the boundary licence gate | | Data | Shared | The system's datasets, sources and lineage as NXS-GRX products or system-owned records | | Commons | Shared | Shared methods, standards, templates and reusable artifacts, including Nexus Standards (NXS, a programme of the Nexus Consortium) participation | | Reports | Shared | Reports and editions built from the system's evidence, with cutoffs and correction history | | Knowledge | Shared | Institutional knowledge, records, runbooks and learning linked to NXS-HUB | | Spectrum | Specialist | Records: spectrum observation plan, spectrum observation, signal event, interference assessment | | PNT Integrity | Specialist | Records: pnt source, pnt observation, integrity rule set, pnt integrity assessment, integrity advisory | **Kinds of work it carries:** Spectrum assessments; PNT assurance cases; RF/Spectrum Posture; Interference Product; PNT Integrity Product; Signal Quality Product; Band occupancy watches; New-site RF surveys; Major event spectrum plans; Interference investigations; Recurring interference watches; Radio quiet zones; Satellite ground-station links; PNT integrity watches; Timing resilience programmes; Route GNSS disruption watches; Signal quality watches; Emergency radio integrity; Warning dissemination coverage; IoT radio network health; Licence compliance audits; Monitoring authority programmes. **This system in the Nexus model.** Generated from the Nexus Standards index and the programme spine; statuses are registry statuses, never adoption or certification. | | | | -------------------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | Descriptor | Authorized signal, spectrum, timing and PNT integrity | | In the programme | Built, simulated and prepared in the [Foundry pillar](/organization/programme/foundry.md); its records serve the other pillars through the handoffs of [the programme year](/organization/programme/the-programme-year.md), and the competent authority decides outside the programme. | | System profile | [NRS-S12](https://nexustandards.com/standards/nrs/#nrs-s12): NXS-SIG (Signal, spectrum, timing and PNT) (status OPEN) | | Nexus Risk Standards that apply | 3 in 2 series: system: [NRS-S12](https://nexustandards.com/standards/nrs/#nrs-s12); technology: [NRS-T5](https://nexustandards.com/standards/nrs/#nrs-t5), [NRS-T14](https://nexustandards.com/standards/nrs/#nrs-t14) | | Nexus Reports technology streams | SNS Sensing, timing and positioning | ## Outputs What it provides, and to whom. Consumers read projections; the system stays the authority for its own records and their corrections. | To | What it provides | | ------------------------------------------- | ----------------------------------------------- | | [NXS-GRX](/organization/systems/nxs-grx.md) | authorized RF/PNT/signal integrity observations | | [NXS-NST](/organization/systems/nxs-nst.md) | signal integrity posture | | [NXS-NSF](/organization/systems/nxs-nsf.md) | authorization/policy evaluation request | | the evidence fabric | append consequential receipt/evidence | ## Standards that apply Every record of the system is identified through the UNI identifier fabric of Nexus Standards (NS-1), and its public name follows the Nexus Standards naming rules. ## Governance boundaries Policy authority for the system sits with [NXS-NSF](/organization/systems/nxs-nsf.md); identifiers come from the UNI identifier fabric. The system exports read projections and commands through typed contracts, and no other system writes its records. It does not own, and never stands in for: * interception or surveillance (prohibited) * jamming / adversarial squelch / targeting (prohibited) * network topology ownership (NXS-NET) * sensor orchestration ownership (NXS-OPS) * proof / legal authority (NXS-NSF) **Method boundary.** Power aggregation must convert logarithmic quantities correctly and respect bandwidth. PNT integrity evidence must include reference uncertainty; anomalies do not by themselves identify an actor or establish spoofing. Do not treat signal anomalies as proof of malicious intent or authorize interception from a workspace selection. [All twenty systems](/organization/systems.md) ยท [Areas](/organization/systems/areas.md) *** *Generated page. It records names, roles and design for reading, not readiness: release is on hold, and nothing here is presented as ready, certified or official.* --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation by asking a question. Perform an HTTP GET request on the following URL with the `ask` and `goal` query parameters: ``` GET https://docs.therisk.global/organization/systems/nxs-sig.md?ask=&goal= ``` `ask` is the immediate question: it should be specific, self-contained, and written in natural language. `goal` is what the user is ultimately trying to achieve, the reason they need the answer. Sharing it helps GitBook give you a better, more relevant answer. 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