Region & Channels — the shipped channel tables¶

RaceLink's host carries a small per-region lookup table of named channel slots. The multi-network UI binds against this table rather than against raw P_RfConfig values; the operator picks a channel by name, and the host resolves the seven wire-format fields at apply-time.

The table is shipped as code constants (not operator-editable) so that every entry is pre-audited for compliance, has a stable name-to-frequency mapping, and clears the cross-channel separation validator out of the box.

For the operator-facing flows that consume this table (Network Manager dialog, bind wizard, RF migration, Channel Scan), see ../RaceLink_Host/multi-network.md. For the wire format the table maps to, see ../reference/wire-protocol.md §P_RfConfig.

Table shape¶

Per region, the host ships at most 5 channels. Each entry carries:

Field	Type	Purpose
`id`	`int` (1..5)	Stable operator-visible id, 1-based dense
`name`	`str`	Short label ("Default", "Alt-1", "High")
`freq_hz`	`uint32`	Carrier frequency in Hz
`bw_khz_x10`	`uint16`	Bandwidth × 10 (1250 = 125.0 kHz)
`sf`	`uint8`	Spreading factor (5..12)
`cr_den`	`uint8`	Coding rate denominator (5..8 ⇒ 4/CR)
`sync_word`	`uint8`	LoRa SyncWord (PHY-level discriminator)
`tx_power_dbm`	`int8`	TX power (-9..22, signed)
`preamble`	`uint16`	Preamble symbols

The id is what RL_Network.channel_id stores; the seven wire-format fields below it are what flows into OPC_RF_CONFIG / GW_CMD_SET_RF_CONFIG after a channel_rf_config(region, channel_id) lookup.

EU868 — shipped slots¶

EU868 sits in the 863-870 MHz ISM band. The shipped table picks five widely-separated 125-kHz / SF7 anchors that span the most-used sub-bands so the operator has visible spread without needing custom configs.

Id	Name	Frequency	SF	BW	SyncWord	TX	Sub-band note
1	Default	867.700 MHz	7	125 kHz	`0x12`	14 dBm	The build-flag default. Devices ship on this; matches the pre-Stage-3 deployment.
2	Alt-1	868.200 MHz	7	125 kHz	`0x12`	14 dBm	1 % duty cycle band.
3	Alt-2	868.700 MHz	7	125 kHz	`0x12`	14 dBm	0.1 % duty cycle band.
4	Alt-3	869.200 MHz	7	125 kHz	`0x12`	14 dBm	0.1 % duty cycle band.
5	High	869.700 MHz	7	125 kHz	`0x12`	14 dBm	1 % duty cycle band.

US915 — shipped slots¶

US915 is the 902-928 MHz band. The five slots sit inside the 902.3-914.9 MHz LoRaWAN uplink range; ≥500 kHz separation between every same-SyncWord pair.

Id	Name	Frequency	SF	BW	SyncWord	TX
1	Default	904.300 MHz	7	125 kHz	`0x12`	14 dBm
2	Alt-1	905.300 MHz	7	125 kHz	`0x12`	14 dBm
3	Alt-2	906.300 MHz	7	125 kHz	`0x12`	14 dBm
4	Alt-3	907.300 MHz	7	125 kHz	`0x12`	14 dBm
5	High	908.300 MHz	7	125 kHz	`0x12`	14 dBm

Separation rule¶

Two networks the host drives simultaneously must satisfy at least one of:

abs(freq_a - freq_b) >= 500 kHz, or
sync_word_a != sync_word_b.

The SyncWord short-circuit is the LoRa PHY's native discriminator; two transmitters on the same frequency but different SyncWords look like noise to each other's receiver. The 500 kHz threshold leaves headroom for transient drift on 125 kHz channels. The validator lives in racelink/domain/rf_policy.py::validate_networks_separation and is exercised by the channel-edit save path as well as the bind / migrate flows in ../RaceLink_Host/multi-network.md.

Compliance disclaimer¶

The shipped channels are picked to fit common operator deployments in EU and US ISM bands and pass a desk review against the relevant ETSI / FCC documents. Operators are responsible for verifying their own deployment is legal — duty cycles, power limits, and antenna conventions vary by country, local frequency coordination, and the actual deployment context (indoor vs outdoor, fixed vs mobile). RaceLink does not enforce duty-cycle limits in firmware; the operator stays within the ceiling by configuring scenes that don't saturate the airtime budget.