Four fixed transmitters: longer dwell repeats
Same physical MercerMesh fixture and installed firmware as the completed 5.1-symbol run: RAK4631, Heltec T096, MeshTower V2 and T1000-E fixed transmitters; Heltec V4 RX. SF10 / BW125 kHz / CR4/5, four channels spaced 1 MHz apart, 32-symbol preamble, normal SX1262 RX gain, -9 dBm chip TX setting, zero added settling and one frequency write per hop. No firmware was rebuilt or reflashed for these repeats.
6.1-symbol run: user-stopped, incomplete sample
Started 2026-09-14 22:44:47 UTC. Dwell was 49,972 us per channel. All four stationary controls passed 100/100 again.
The user requested stopping this run and proceeding to 7.7 symbols. The collector was interrupted only after verifying its PID, command line and owner. At the last saved checkpoint, 342/348 scored scan packets were received (98.28%), with six timeouts:
| TX / channel | Scored attempts | Received | Timeouts |
|---|---|---|---|
| RAK4631 / 0 | 87 | 87 | 0 |
| Heltec T096 / 1 | 87 | 86 | 1 |
| MeshTower V2 / 2 | 87 | 85 | 2 |
| T1000-E / 3 | 87 | 84 | 3 |
This is not a completed 400-packet run or a validated full-run timing capture. An interrupted in-flight packet can exist beyond the last saved checkpoint; it is not scored as another success or failure. No final switch timing was collected before reboot. The raw capture remains incomplete, and the separate user-stop record documents why. All five radios were then independently verified idle, and ModemManager was restored. Gateway services stayed active; the V4 memory-soak service stayed inactive.
Partial raw capture SHA-256:
ad199124930da19fe56c78a4ea8280a6d94b95ef408589b19a9e165155dbf7fd.
7.7-symbol run
Launched 2026-09-14 22:58:14 UTC; collector ran from 22:58:15 to 23:11:45 UTC with 63,079 us visits. All four fixed-channel controls passed 100/100. The full scan completed with 395/400 received (98.75%), five timeouts and zero wrong-channel or invalid payloads. Thus 7.7 symbols did not achieve a 400/400 pass.
| TX / channel | Scanning result | Timeouts | Mean received RSSI (dBm) | Mean received SNR (dB) |
|---|---|---|---|---|
| RAK4631 / 0 | 100/100 | 0 | -21.05 | +8.14 |
| Heltec T096 / 1 | 99/100 | 1 | -4.35 | +8.98 |
| MeshTower V2 / 2 | 97/100 | 3 | -44.86 | +8.63 |
| T1000-E / 3 | 99/100 | 1 | -18.56 | +8.26 |
All 800 baseline/scan TX sequences were unique, all transmit calls succeeded, and every TX packet reported zero frequency and modulation configuration writes. There were zero packet-response transport replays. All four final TX lifetime checks reported 200 packets and a prepared, non-failed transmitter.
The five timeouts occurred at scan attempts 158 (T1000-E), 184 (T096), and 200, 293, 314 (MeshTower). Each reported RX mode 1 and zero device errors. Final RX failure, RX-mode-error, cache-error and receive-error counters were zero.
Measured switch and sweep timing
| Hop population | Count | Minimum (us) | Mean (us) | Maximum (us) |
|---|---|---|---|---|
| All single-pass switches | 5,046 | 438 | 524.146 | 804 |
| Cached modulation; no 0x8B | 4,651 | 438 | 502.147 | 686 |
| Post-reception modulation refresh | 395 | 760 | 783.180 | 804 |
Exactly 5,046 RF-frequency commands and 5,046 optimized RX resumes were counted, with one retune pass and zero second passes/detours. The 395 modulation writes match the 395 post-reception cache refreshes. This is the same cache behavior as the earlier run, not double-setting the radio. The slightly higher overall mean than the 5.1 run partly reflects a larger fraction of refresh hops.
Across 860 measured idle cycles, the four-channel sweep averaged 254.351 ms, minimum 254.208 ms and maximum 255.482 ms. Relative to the 262.144 ms programmed preamble, that leaves 7.793 ms at the mean and 6.662 ms at the maximum. Nominal dwell was 63.079 ms; measured idle dwell averaged 63.084 ms. Packet-held visits include payload/guard time and are not comparable to idle cycles.
The 7.7 run received three more packets than the earlier 5.1 run (395 versus 392 out of 400). This small, sequential comparison does not establish a reliable improvement or a lossless dwell threshold. The 6.1 result is partial and must not be treated as an equal-size completed comparison.
Evidence and cleanup
Unlike the original 5.1 run's overly strict host assertion, this collector
completed normally with complete: true and exit code 0. Independent offline
validation also passed. The same collector SHA-256 was used for both repeats:
cceb8a570f4aedeaf45d28b4b4590b23df3c1efd490c8e8e9cd74a23ba00024f.
The copied deployment/manifest files are provenance for reused firmware, not
records of a new flash operation. Host options and acknowledged dwell match.
Raw capture SHA-256:
5e3f9a80af1384c3072303428b75c8550ac42d2ac95bd1234bf92cb0aea625e8.
The cleanup wrapper retained three errors from its reboot phase: the T096
primary USB interface was temporarily missing/ambiguous, and attempts to open
the MeshTower/T1000-E ports returned permission denied. Its subsequent final
readbacks nevertheless succeeded for all five radios: each TX was unprepared,
non-failed, packet count zero and autonomous TX disabled; RX scanning was
inactive with zero channels. No further radio access or permission changes
were attempted after those results returned. The wrapper's verified_idle
flag remains false because it retains any earlier cleanup error, and the
outer operation returned nonzero for that reason. These warnings happened
after the complete RF sample; they are not counted as RF packet losses or
silently removed from the record.
ModemManager was restored active; gateway services remained active. The V4 memory-soak service remains inactive with test firmware installed. No firmware restore, commit, push or pull was performed. Previous raw captures are unchanged.
Dwell budget
One chirp at SF10/125 lasts 8.192 ms. For the experiment's nominal budget of one complete four-channel idle sweep inside 32 programmed preamble symbols:
maximum dwell symbols = 32 / 4 - switching_ms / 8.192.
The 5.1-symbol run's mean switch (0.513980 ms) gives about 7.937 symbols; its maximum switch (0.801 ms) gives about 7.902 symbols, before other loop overhead. These are timing ceilings, not proven lossless dwell limits or a complete acquisition model. Near the ceiling there is little timing margin. At 7.7 symbols, four nominal dwell-plus-average-switch intervals total about 254.4 ms, versus a 262.144 ms programmed preamble.
The host keeps the same seed and arrival-randomization rule, spanning about two nominal scan cycles; absolute arrival pauses therefore scale with dwell. The fixed-channel controls, sample counts, switching policy and firmware stay unchanged. As before, external PA/LNA paths and unrelated RF traffic mean this is a finite bench comparison, not a calibrated sensitivity or interference test.