



Network Working Group                                       L. Melegassi
Internet-Draft                                                  Catellix
Intended status: Informational                              28 May 2026
Expires: 29 November 2026


             MVPS Terrestrial Mobile and Vehicular Profile:
            Coherence Monitoring under Cellular Handover and
                        Radio-Access Scheduling
              draft-melegassi-ippm-mvps-terrestrial-mobile-00


Abstract

   This document defines the terrestrial member of the Multi-Vantage
   Path Snapshot (MVPS) domain trio (space, sea, land).  It targets
   vantages that move on land -- vehicles, trains, drones -- connected
   through cellular (5G/LTE) radio access, where the bounded joint
   clock-skew axiom A1 is stressed not by clock drift (GNSS is normally
   available) but by handover between base stations and slot-based
   scheduling jitter.

   The profile is DEFENSIVE: it concerns detection of coherence
   anomalies (intrusion, communications tampering, rogue base stations).
   It defines no navigation, targeting, or kinetic function.  The
   document proves A1 holds on the deployment tick under explicit
   cellular-timing budgets, gives a closed-form maximum handover
   interruption, proves Doppler is dominated at terrestrial speeds, and
   inherits the core theorems via the MVPS Architecture-Invariance
   Theorem.  All properties are validated by
   scripts/validate_terrestrial_mobile.py (7/7 PASS, exit 0) and
   recorded in evidence/terrestrial_mobile_receipt.json.


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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
     1.1.  The Space/Sea/Land Trio . . . . . . . . . . . . . . . . .   3
     1.2.  Defensive Scope and Non-Goals . . . . . . . . . . . . . .   3
   2.  Terminology . . . . . . . . . . . . . . . . . . . . . . . . .   4
   3.  The Cellular Joint-Skew Model . . . . . . . . . . . . . . . .   5
   4.  Re-establishing Axiom A1 (Lemma L-TER-1)  . . . . . . . . . .   6
   5.  Maximum Handover Interruption (Lemma L-TER-2) . . . . . . . .   6
   6.  Doppler Is Dominated (Lemma L-TER-4)  . . . . . . . . . . . .   7
   7.  Inheritance of the Core Theorems  . . . . . . . . . . . . . .   8
   8.  Byzantine and Spoofed Vantages  . . . . . . . . . . . . . . .   8
   9.  Rogue Base Stations (Conjecture C-TER-1)  . . . . . . . . . .   9
   10. Operational Logging . . . . . . . . . . . . . . . . . . . . .   9
   11. Numerical Receipt . . . . . . . . . . . . . . . . . . . . . .  10
   12. Security Considerations . . . . . . . . . . . . . . . . . . .  10
   13. IANA Considerations . . . . . . . . . . . . . . . . . . . . .  11
   14. References  . . . . . . . . . . . . . . . . . . . . . . . . .  11
     14.1.  Normative References . . . . . . . . . . . . . . . . . .  11
     14.2.  Informative References . . . . . . . . . . . . . . . . .  11
   Appendix A.  Worked Budgets (Normative) . . . . . . . . . . . . .  12
   Author's Address  . . . . . . . . . . . . . . . . . . . . . . . .  12


1.  Introduction

   MVPS detects network-propagating anomalies by measuring the coherence
   of an observed state across multiple spatially independent vantages.
   Its theorems are surface-independent: they hold where the five MVPS
   axioms hold, by the Architecture-Invariance Theorem
   [I-D.melegassi-iab-mvps-architecture].

   Terrestrial deployments where the vantages MOVE -- fleets of
   vehicles, trains, drones operating over cellular radio -- are common
   and important, and they stress the timing assumptions differently
   from sea or space.  On land the satellite sky is normally available,
   so clock holdover is not the issue; the issue is that a moving
   vantage hands over between base stations and rides slot-based
   scheduling, both of which perturb timing.

1.1.  The Space/Sea/Land Trio

   This profile is the land member of the MVPS domain trio:

   o  space: the orbital profile
      [I-D.melegassi-ippm-mvps-orbital-coherence], stressing propagation
      delay and Doppler over LEO links;

   o  sea: the maritime profile [I-D.melegassi-ippm-mvps-maritime-edge],
      stressing intermittent connectivity and GNSS-denied holdover;

   o  land: this document, stressing cellular handover and radio-access
      scheduling jitter.

   Each re-establishes the same axiom (A1) under its domain's specific
   stress and inherits the rest.

1.2.  Defensive Scope and Non-Goals

   This profile is strictly DEFENSIVE: detection of anomalies in network
   and timing telemetry (intrusion, comms tampering, rogue base
   stations).

   This document does NOT define and MUST NOT be claimed to define any
   navigation, guidance, targeting, or kinetic function, nor any output
   other than coherence-anomaly detection and audit logs.


2.  Terminology

   eps_sync:  GNSS/PTP residual at the base station.

   eps_ta:  timing-advance residual of the UE alignment.

   tau_jit:  radio-access scheduling jitter (slot-based).

   tau_ho:  residual mis-timing during or after a handover.

   T_tick:  the deployment coherence tick.

   Make-before-break:  a handover that keeps the source link until the
      target is ready (NR DAPS), giving tau_ho near zero.

   The key words "MUST", "MUST NOT", "SHOULD", "MAY" in this document
   are to be interpreted as described in BCP 14 [RFC2119] [RFC8174]
   when, and only when, they appear in all capitals.


3.  The Cellular Joint-Skew Model

   A GNSS-disciplined base station holds time to eps_sync; the UE is
   aligned by Timing Advance to eps_ta.  Slot-based scheduling bounds
   delivery jitter by tau_jit (5G numerology mu: slot = 1 ms / 2^mu;
   LTE about 1 ms).  A handover adds a residual tau_ho, near zero for
   make-before-break and about the interruption time otherwise.  The
   effective joint skew is

      skew_eff = 2 * ( eps_sync + eps_ta ) + tau_jit + tau_ho .

   Doppler is treated separately and shown dominated in Section 6.


4.  Re-establishing Axiom A1 (Lemma L-TER-1)

   Axiom A1 holds on tick T_tick iff

      skew_eff = 2*(eps_sync+eps_ta) + tau_jit + tau_ho  <  T_tick.

   For representative budgets:

      5G-uRLLC (DAPS): skew_eff = 0.128 ms  < 100 ms tick
      LTE (break-before-make): skew_eff = 33.0 ms  < 1000 ms tick
      high-speed rail (300 km/h, frequent HO): 54.0 ms < 100 ms tick

   All satisfy A1 (validator check L-TER-1).


5.  Maximum Handover Interruption (Lemma L-TER-2)

   Solving skew_eff = T_tick for the handover residual gives

      tau_ho_max = T_tick - tau_jit - 2*(eps_sync + eps_ta).

   For the 5G-uRLLC budget, tau_ho_max is about 99.87 ms at a 100 ms
   tick.  The practical reading is that the binding term on land is the
   handover interruption; make-before-break drives tau_ho toward zero,
   so even sub-second ticks have ample margin.


6.  Doppler Is Dominated (Lemma L-TER-4)

   The time uncertainty contributed by Doppler over one tick is
   (v/c)*T_tick.  At v = 300 km/h, v/c = 2.78e-7, so over a 100 ms tick
   the term is about 27.8 ns -- under 1% of the radio-access jitter.  It
   is therefore absorbed and does not appear in the skew model
   (validator check L-TER-4: 11.0 ns, 83.4 ns, 27.8 ns across the three
   budgets).


7.  Inheritance of the Core Theorems

   If A1 holds (Section 4) and the compromised-vantage fraction f < 1/2,
   then by the Architecture-Invariance Theorem
   [I-D.melegassi-iab-mvps-architecture] the core results inherit
   verbatim:

      T1   multi-vantage D^2 dominates per-vantage max-z;
      T2   Phi_D concentration under the null;
      T3'  empirical-quantile false-alarm calibration;
      T9   Byzantine robustness of the geometric-median aggregator.

   No core theorem is re-derived (validator check A-TER-INHERIT).


8.  Byzantine and Spoofed Vantages

   A vehicular fleet must assume some vantages are compromised or
   spoofed.  For f < 1/2 the geometric-median aggregator has finite
   max-bias b(f) = C*f/(1-2f) (after [Minsker]; MVPS imported result
   I12), diverging only as f -> 1/2 (validator check B-TER-1:
   b(0.2)=0.333, b(0.4)=2.000).


9.  Rogue Base Stations (Conjecture C-TER-1)

   It is plausible that a coordinated rogue / false base-station cluster
   (an IMSI-catcher fleet) injects a rank-low, correlated
   timing/identity signature across mobile vantages that the
   multi-vantage detector flags before any single UE alarms.  This is
   stated as a CONJECTURE, not a theorem, with a falsification protocol
   (observable: cross-vantage correlated TA / cell-identity anomaly vs
   per-UE max-z; data: fleet RAN measurement reports plus a controlled
   false-base-station testbed; test: Wilson 95% lower bound on
   detection-time gain > 0; blocker: licensed spectrum for the testbed).
   The profile's guarantees do NOT depend on this conjecture.


10.  Operational Logging

   Deployments SHOULD log events using the MVPS operational log format
   [I-D.melegassi-opsawg-mvps-logging], anchoring opportunistically; the
   handover and cell-change events are themselves useful audit records.


11.  Numerical Receipt

   scripts/validate_terrestrial_mobile.py evaluates seven checks
   (L-TER-1..4, A-TER-INHERIT, B-TER-1, C-TER-1) over the budgets above
   and writes evidence/terrestrial_mobile_receipt.json with per-scenario
   skew and Doppler values, the closed-form handover tolerance, the
   inherited theorem list, the defensive non-claims, and a SHA-256 of
   its own canonical body.  All seven checks PASS (exit 0).


12.  Security Considerations

   The profile is a detection and audit capability; no kinetic or
   targeting surface is added.  Its value is early, coherent detection
   of intrusion, comms tampering, and radio-layer attacks across a
   mobile fleet, with a tamper-evident audit trail (Section 10).

   Rogue-base-station detection is a conjecture (Section 9) and MUST NOT
   be relied upon as a guarantee.  Quantum-era integrity of logs and
   anchors follows the Proof Envelope
   [I-D.melegassi-ippm-mvps-proof-envelope].


13.  IANA Considerations

   This document has no IANA actions.


14.  References

14.1.  Normative References

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119, March 1997.

   [RFC8174]  Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
              2119 Key Words", BCP 14, RFC 8174, May 2017.

   [I-D.melegassi-iab-mvps-architecture]
              Melegassi, L., "MVPS Architecture Invariance",
              draft-melegassi-iab-mvps-architecture-00, 2026.

14.2.  Informative References

   [I-D.melegassi-ippm-mvps-orbital-coherence]
              Melegassi, L., "MVPS Orbital Coherence",
              draft-melegassi-ippm-mvps-orbital-coherence-00, 2026.

   [I-D.melegassi-ippm-mvps-maritime-edge]
              Melegassi, L., "MVPS Maritime and Tactical-Edge Profile",
              draft-melegassi-ippm-mvps-maritime-edge-00, 2026.

   [I-D.melegassi-opsawg-mvps-logging]
              Melegassi, L., "The MVPS Operational Log Format",
              draft-melegassi-opsawg-mvps-logging-00, 2026.

   [I-D.melegassi-ippm-mvps-proof-envelope]
              Melegassi, L., "MVPS Proof Envelope", draft-melegassi-
              ippm-mvps-proof-envelope-00, 2026.

   [Minsker]  Minsker, S., "Geometric median and robust estimation in
              Banach spaces", Bernoulli 21(4), 2015.


Appendix A.  Worked Budgets (Normative)

   The three budgets of Section 4 (5G-uRLLC, LTE, high-speed rail) and
   the infeasible control (150 ms handover at a 100 ms tick) are the
   normative vectors.  A conformant implementation MUST reproduce, for
   each, the skew_eff value and the A1 verdict emitted by
   scripts/validate_terrestrial_mobile.py.


Author's Address

   Leonardo Melegassi
   Catellix
   Brazil
   Email: melegassi@catellix.com


