{"schema_version":1,"research_id":"eoa_inverse_innovation_exp04_external_evaluation_20260802","source_assessment_id":"negative_space_design__information_theory:PROPOSAL_FIRST:v0","cell_id":"negative_space_design__information_theory","search_queries":["RFC event notification heartbeat silence monitoring protocol keepalive unchanged state bandwidth","MQTT 5.0 specification Keep Alive PINGREQ no control packets official","OASIS MQTT Sparkplug report by exception birth death certificate official specification","event-triggered communication periodic heartbeat sensor network state estimation research","site:reference.opcfoundation.org Core Part4 Subscription keep-alive no notifications publishing interval lifetime count","site:datatracker.ietf.org RFC 7641 Observe suppress notification unchanged Max-Age","site:community.rti.com DDS liveliness QoS lease duration official documentation","site:sparkplug.eclipse.org specification report by exception bandwidth keep alive death certificate","site:nist.gov industrial control systems heartbeat keepalive monitoring communication failure SP 800-82","site:sparkplug.eclipse.org \"Report by Exception\" bandwidth Sparkplug specification","site:eclipse.org sparkplug working group charter industrial IoT interoperability need members","primary research event-triggered transmission communication load no transmissions implicit information packet loss ambiguity","NIST SP 800-82 Revision 3 operational technology security loss communication fail safe official PDF","site:nvlpubs.nist.gov/nistpubs/SpecialPublications NIST.SP.800-82r3 pdf","site:csrc.nist.gov/pubs/sp/800/82/r3/final"],"sources":[{"source_id":"S1","title":"RFC 7641: Observing Resources in the Constrained Application Protocol (CoAP)","publisher":"Internet Engineering Task Force","url":"https://datatracker.ietf.org/doc/rfc7641/","source_class":"STANDARD","publication_date":"2015-09","accessed_at":"2026-08-02","claims_supported":["A server need not send a notification while an observed resource remains unchanged.","Silence becomes unsafe to interpret after the representation's Max-Age expires; the client must no longer assume it reflects current state.","The server can renew freshness with an unchanged notification, while sequence numbers support reordering detection.","This is a close standardized implementation of bounded, meaningful silence with an explicit expiry rule."]},{"source_id":"S2","title":"OPC Unified Architecture Part 4: Services — Subscription Service Set","publisher":"OPC Foundation","url":"https://reference.opcfoundation.org/specs/OPC-10000-4/5.14","source_class":"STANDARD","publication_date":"current online edition; date not stated","accessed_at":"2026-08-02","claims_supported":["OPC UA suppresses notification messages when no notifications are available and sends a keep-alive after a configurable number of publishing cycles.","Subscription lifetime counters turn excessive absence of client activity into closure and Bad_Timeout rather than continued known-good state.","Sequence numbers, acknowledgements, and retransmission queues support loss detection and recovery.","Client throttling can reduce responses under load but may increase notification latency."]},{"source_id":"S3","title":"MQTT Version 5.0","publisher":"OASIS Open","url":"https://docs.oasis-open.org/mqtt/mqtt/v5.0/mqtt-v5.0.html","source_class":"STANDARD","publication_date":"2019-03-07","accessed_at":"2026-08-02","claims_supported":["When no other control packet is sent, MQTT requires a PINGREQ within the negotiated nonzero Keep Alive period.","Failure to receive traffic within 1.5 times Keep Alive makes the server close the connection as if the network failed.","PINGREQ/PINGRESP separates connection-liveness checking from application payload reporting.","Keep Alive does not guarantee the client remains connected, limiting what silence alone can establish."]},{"source_id":"S4","title":"Sparkplug Specification 3.0.0","publisher":"Eclipse Foundation Sparkplug Specification Project","url":"https://sparkplug.eclipse.org/specification/version/3.0/documents/sparkplug-specification-3.0.0.pdf","source_class":"STANDARD","publication_date":"2022-11-16","accessed_at":"2026-08-02","claims_supported":["Sparkplug reports that polling all data was infeasible over VSAT because of propagation delay and cost, motivating report-by-exception transmission.","Sparkplug combines report-by-exception state-change messages with MQTT continuous-session awareness and BIRTH/DEATH certificates.","The specification discourages periodic publication and recommends publishing when metrics change.","Upon NDEATH, host applications must mark nodes offline and prior metrics stale rather than infer continued stability.","The specification was designed for bandwidth-limited and outage-prone cellular, satellite, and radio networks."]},{"source_id":"S5","title":"Sparkplug Working Group Charter","publisher":"Eclipse Foundation","url":"https://www.eclipse.org/collaborations/working-groups/sparkplug/charter/","source_class":"OFFICIAL_ORGANIZATION_DATA","publication_date":"2025-10","accessed_at":"2026-08-02","claims_supported":["The working group expressly seeks interoperable and scalable IIoT solutions and manages Sparkplug's technical and business strategy.","Its Specification and Steering Committees can approve specifications, profiles, roadmaps, compatibility rules, and budgets.","Strategic members commit developers and fees, providing identifiable authorizers and resource-bearing stakeholders.","The expressed need concerns industrial-data scalability and interoperability, not a request for this candidate's already-standardized mechanism."]},{"source_id":"S6","title":"Event-Triggered State Estimation with Multiple Noisy Sensor Nodes","publisher":"arXiv / authors","url":"https://arxiv.org/abs/2108.04591","source_class":"PRIMARY_RESEARCH","publication_date":"2021-12-08","accessed_at":"2026-08-02","claims_supported":["Event-triggered and time-triggered transmissions can be evaluated in the same packet-network state-estimation framework.","Under stated design conditions, event-triggered estimation can retain input-to-state stability and avoid Zeno behavior.","A numerical case study supports technical feasibility but does not establish this candidate's superiority in an operational channel."]},{"source_id":"S7","title":"RTI Connext C API: DDS_LivelinessQosPolicy","publisher":"Real-Time Innovations","url":"https://community.rti.com/static/documentation/connext-dds/current/doc/api/connext_dds/api_c/structDDS__LivelinessQosPolicy.html","source_class":"OFFICIAL_PRODUCT_DOCUMENTATION","publication_date":"current documentation; date not stated","accessed_at":"2026-08-02","claims_supported":["DDS writers assert liveliness within a lease duration and readers detect and notify applications of lease violations.","The liveliness policy accommodates periodically updated and sporadically changing data.","Automatic liveliness offers low overhead; manual modes allow application-level assertions.","This deployed product mechanism closely matches bounded health leases and explicit failure interpretation."]},{"source_id":"S8","title":"NIST SP 800-82 Rev. 3: Guide to Operational Technology Security","publisher":"National Institute of Standards and Technology","url":"https://csrc.nist.gov/pubs/sp/800/82/r3/final","source_class":"GOVERNMENT_OR_REGULATOR","publication_date":"2023-09-28","accessed_at":"2026-08-02","claims_supported":["Operational technology includes monitoring and control systems that interact with the physical environment.","OT changes must account for distinctive performance, reliability, security, and safety requirements.","Industrial deployment therefore requires owner authorization, change control, security review, and safety-sensitive validation beyond a protocol simulation."]}],"problem_evidence":{"support":"STRONG","rationale":"The problem is directly visible in standardized practice. Sparkplug documents that transmitting all data in every poll was infeasible on costly, delayed VSAT links and recommends report-by-exception instead. CoAP explicitly states both sides of the ambiguity: unchanged resources need no notification, but after Max-Age the receiver cannot treat silence as current state. MQTT, OPC UA, and DDS all add bounded liveness or keep-alive mechanisms, confirming that payload suppression and silence/failure discrimination matter. What remains unmeasured is prevalence and material contention in the candidate's unspecified target channel.","source_ids":["S1","S2","S3","S4","S7"]},"stakeholder_evidence":{"support":"MODERATE","rationale":"The Eclipse Sparkplug Working Group is an identifiable, funded, member-driven authorizer whose committees control specifications, compatibility, roadmaps, and budgets and whose charter expresses need for scalable, interoperable industrial data access. However, it already governs a standard implementing the core proposal, and no source expresses demand for the candidate's additional quiet-epoch vocabulary or source-log rule.","source_ids":["S4","S5"]},"prior_art":{"proximity":"ESTABLISHED_PRACTICE","closest_analogues":[{"name":"Sparkplug report-by-exception with MQTT session awareness and BIRTH/DEATH certificates","similarity":"Near-direct match: changed metrics interrupt quiescence; an initial BIRTH establishes state; MQTT Keep Alive monitors connection health; DEATH changes node state to offline and metrics to stale.","remaining_difference":"Sparkplug uses a persistent session rather than explicitly named application quiet epochs and does not mandate retention of every suppressed source sample in an audit log.","source_ids":["S3","S4"]},{"name":"CoAP Observe with Max-Age freshness","similarity":"Near-direct semantic match: unchanged state need not be transmitted, silence is valid only while a bounded freshness lease remains active, and the receiver must stop treating the representation as current after expiry.","remaining_difference":"CoAP specifies freshness and re-registration but not the candidate's complete taxonomy of permission blockage, source failure, and recoverable suppressed-sample logging.","source_ids":["S1"]},{"name":"OPC UA subscriptions, keep-alive counters, lifetime counters, sequence numbers, and retransmission queues","similarity":"Substantial match: state changes generate notifications; quiet cycles are counted; bounded keep-alives confirm subscription operation; timeout becomes an explicit bad state; sequence and retransmission machinery expose loss.","remaining_difference":"OPC UA represents quiet through subscription state and counters rather than declaring absence itself an application codeword; source-side storage of every omitted sample is not required.","source_ids":["S2"]},{"name":"DDS liveliness leases for sporadically changing data","similarity":"Substantial match: writers periodically assert bounded liveliness independently of payload changes, and readers generate explicit status when the lease is violated.","remaining_difference":"DDS liveliness primarily types writer availability, not all proposed causes of application-level silence, and it does not mandate a raw audit log.","source_ids":["S7"]},{"name":"Event-triggered state estimation","similarity":"Research establishes asynchronous event-triggered transmission and remote estimation as technically analyzable alternatives to periodic transmission.","remaining_difference":"The cited work addresses estimator stability, noise, and triggering rather than a standardized semantic taxonomy for silence and audit recovery.","source_ids":["S6"]}],"distinctive_claim_remaining":"Only a narrow implementation claim remains: in a legacy constrained channel lacking Sparkplug-, CoAP-, OPC-UA-, or DDS-equivalent facilities, adding one unified decoder state machine that permits QUIESCENT only inside an explicit source-health lease and retains suppressed raw samples will reduce transmitted symbols relative to transmit-every-sample without increasing false-stability classifications or fault-detection delay relative to those established comparators. This is falsifiable but is not shown to be a distinct protocol invention.","confidence":"HIGH"},"implementation_evidence":{"support":"STRONG","rationale":"Multiple mature standards and commercial implementations demonstrate all core technical elements: change-only reporting, bounded freshness or liveliness leases, keep-alives, stale/timeout states, sequence numbers, retransmission, and callbacks on failure. Synthetic trace replay is straightforward. Remaining feasibility uncertainties concern integration with a particular legacy encoder, timestamp and clock behavior, audit-log integrity and retention, permission-state observability, overload behavior, and the target operator's security and safety case.","source_ids":["S1","S2","S3","S4","S6","S7","S8"]},"scores":{"meaningful_impact":{"score":3,"rationale":"Bandwidth, latency, and false-stability consequences can matter substantially on constrained or outage-prone links, but no target trace quantifies the candidate-specific burden.","source_ids":["S1","S4"]},"stakeholder_pull":{"score":3,"rationale":"A funded industrial standards community expresses strong need for scalable, reliable IIoT data exchange, but no adopter asks for this variant because the community already maintains a close solution.","source_ids":["S4","S5"]},"incremental_advantage":{"score":1,"rationale":"No measured advantage remains over Sparkplug, CoAP Observe, OPC UA subscriptions, or DDS liveliness; the audit-log and unified-state-machine additions are unevaluated.","source_ids":["S1","S2","S4","S7"]},"distinctiveness_plausibility":{"score":1,"rationale":"The defining structure—suppress unchanged reports while bounded liveness/freshness distinguishes quiescence from failure—is established practice across independent standards.","source_ids":["S1","S2","S3","S4","S7"]},"technical_implementability":{"score":5,"rationale":"Standards, product documentation, and research demonstrate implementable versions of every central mechanism, and the authorized first step is only offline replay.","source_ids":["S1","S2","S3","S4","S6","S7"]},"adoption_authority_feasibility":{"score":3,"rationale":"Protocol owners and the Sparkplug governance bodies are identifiable, but a live OT change still requires system-owner, security, reliability, and possibly safety approval.","source_ids":["S5","S8"]},"evidence_readiness":{"score":4,"rationale":"A synthetic comparator experiment can be specified and executed with public protocol rules, although representative operational traces and thresholds are missing.","source_ids":["S1","S2","S3","S4","S6","S7"]},"safety_net_benefit":{"score":4,"rationale":"Explicit expiry, stale/unknown states, loss detection, bypass of critical events, and recoverable logs are materially safer than unbounded inference from silence; incorrect lease configuration remains a hazard.","source_ids":["S1","S2","S4","S7","S8"]},"scalability":{"score":4,"rationale":"Report-by-exception and bounded liveness are already used in scalable industrial and constrained protocols, but per-source timers, logs, and renewal traffic may become operational overhead at high cardinality.","source_ids":["S1","S2","S4","S5","S7"]}},"score_confidence":"HIGH","costs":{"first_evidence":{"band_2026_usd":"10K_TO_50K","scope":"Two-to-four-week non-operational standards-gap analysis and deterministic trace-replay harness covering transmit-every-sample, Sparkplug/MQTT, CoAP Observe, OPC UA subscription semantics, DDS-style liveliness, and the candidate decoder.","confidence":"MODERATE","assumptions":["One protocol engineer and part-time reliability reviewer","Synthetic two-state traces only","No live equipment, certification, proprietary data, or safety-significant output","Metrics and falsifiers are predeclared"],"source_ids":["S1","S2","S3","S4","S6","S7"]},"initial_deployment_startup":{"band_2026_usd":"50K_TO_250K","scope":"Develop a non-production adapter, decoder state machine, immutable source-log path, observability, fault injection, security review, and rollback package for one protocol and one site-like test environment.","confidence":"LOW","assumptions":["Two to six engineer-months","Existing broker, simulator, and storage infrastructure","No hardware redesign or formal safety certification","Existing standards libraries can be reused"],"source_ids":["S2","S3","S4","S7","S8"]},"operational_launch":{"band_2026_usd":"250K_TO_1M","scope":"One-site staged OT launch with dual-running baseline, integration testing, hazard and cybersecurity review, operator procedures, monitoring, training, rollback rehearsal, and acceptance testing.","confidence":"LOW","assumptions":["Deployment is limited to a non-safety-critical monitoring channel initially","Target operator supplies system access and subject-matter experts","No multi-site fleet migration or regulated certification program","Safety-critical and legally required messages remain outside suppression"],"source_ids":["S4","S8"]},"annual_recurring":{"band_2026_usd":"50K_TO_250K","scope":"Monitoring, protocol and security maintenance, audit-log retention and integrity checks, incident review, regression testing, training, and periodic lease/threshold validation for one modest deployment.","confidence":"LOW","assumptions":["Approximately 0.25 to 1.0 combined engineering/operations FTE","Moderate audit-log volume","No major protocol rewrite or fleet expansion","Existing security and storage platforms remain available"],"source_ids":["S4","S8"]}},"verified_pipeline_gates":{"externally_supported_problem":{"status":"YES","reason":"Official standards directly document constrained-link costs, changed-only reporting, and the ambiguity between unchanged state and expired or failed communication.","source_ids":["S1","S4"]},"externally_credible_adopter_or_authorizer":{"status":"YES","reason":"The Eclipse Sparkplug Working Group and its Steering and Specification Committees are identifiable, resource-bearing authorities for closely related IIoT protocol evolution, compatibility, and adoption.","source_ids":["S5"]},"distinct_testable_incremental_claim":{"status":"NO","reason":"The stated contrast against ordinary event-triggered reporting is too weak: Sparkplug, CoAP, OPC UA, and DDS already combine suppressed unchanged payloads with bounded liveness/freshness and explicit failure interpretation. The audit-log addition has not been tied to a demonstrated unmet need or advantage.","source_ids":["S1","S2","S4","S7"]},"bounded_next_evidence_step":{"status":"YES","reason":"A deterministic, non-operational trace replay can compare the candidate with four named protocol patterns using symbol count, event delay, false stability, decoded-state error, and fault-detection delay, with explicit falsifiers.","source_ids":["S1","S2","S3","S4","S6","S7"]},"no_unresolved_safety_or_authority_stop":{"status":"YES","reason":"The next step is offline and non-operational, with no automatic action. Any deployment remains contingent on the target OT owner's change, cybersecurity, reliability, and safety authorization.","source_ids":["S8"]},"credible_cost_scope_and_range":{"status":"YES","reason":"The four ranges are broad resource-equivalent estimates tied to explicit staffing, site-count, reuse, validation, and safety assumptions. Deployment estimates remain low-confidence until a target protocol, site, retention rule, and safety classification are known.","source_ids":["S4","S5","S8"]}},"next_evidence_step":"Treat this as a standards-selection and diffusion exercise, not a new protocol opportunity. In a two-to-four-week offline study, implement fixed traces for stable state, state change, isolated packet loss, burst loss spanning renewal, source crash, permission loss, reordered messages, and channel saturation. Compare transmit-every-sample, Sparkplug RBE plus MQTT Keep Alive/BIRTH/DEATH, CoAP Observe plus Max-Age, OPC UA subscriptions, DDS-style liveliness, and the candidate. Measure total bytes and symbols, p95 state-change delay, decoded-state error, false-stability count, stale/unknown transition latency, fault-detection delay, renewal overhead, and audit reconstruction accuracy. Falsify the custom candidate if it produces any false-stable classification after lease expiry, delays a critical event beyond baseline, fails exact audit reconstruction, or provides no material benefit over at least one established comparator. Do not connect outputs to operational control.","blocking_evidence":["No representative target-channel trace establishes how often repeated unchanged reports materially contend for capacity.","No adopter has expressed a need unmet by Sparkplug, CoAP Observe, OPC UA subscriptions, or DDS liveliness.","No evidence shows that the unified silence taxonomy or retained-sample log improves outcomes over established standards.","Target-specific change thresholds, clock assumptions, packet-loss model, permission signal, and safety-critical bypass rules are unspecified.","Audit-log retention, privacy, cybersecurity, and legal requirements are jurisdiction- and operator-dependent.","World novelty, patentability, freedom to operate, market size, and realized impact were not measured."],"research_disposition":"KNOWN_PRACTICE_DIFFUSION","world_novelty_boundary":"This bounded web review found substantial independent public collisions and therefore does not support a world-novelty claim. It was not an exhaustive literature, product, standards, patent, source-code, or deployment search and did not assess patentability, freedom to operate, market size, or realized impact. A potentially local distinction remains only in the combined decoder taxonomy and recoverable raw-sample log, whose distinctiveness and value are unverified.","arm":"PROPOSAL_FIRST","candidate_version":0,"controller_recommendation":{"action":"STOP_DIFFUSION","repairable":false,"material_progress_observed":true,"progress_targets":["Reclassify the proposal as an implementation profile or migration aid for established report-by-exception and liveliness standards.","Produce a clause-level gap matrix against Sparkplug 3.0, MQTT 5.0, CoAP Observe, OPC UA subscriptions, and DDS liveliness before claiming any incremental protocol feature.","Identify a specific legacy channel owner and obtain documented evidence that existing standards cannot meet its workflow, data, or authority constraints.","If innovation status is reopened, predeclare a comparator experiment requiring superiority to the strongest established analogue, not merely to transmit-every-sample.","Specify audit-log integrity, retention, permission-loss detection, clock behavior, safety-message bypass, and rollback requirements with the target operator.","Keep all evaluation non-operational until the relevant OT owner grants change, cybersecurity, reliability, and safety authority."],"reason":"The problem is real and implementable, but the proposed architecture is already established across Sparkplug/MQTT, CoAP, OPC UA, and DDS. The candidate lacks a verified distinct incremental claim; the appropriate path is adoption or diffusion of existing practice rather than continued opportunity research."}}