- peer_range_once(): DS-TWR initiator role toward a peer anchor (POLL → RESP → FINAL, one-sided range estimate Ra - Da/2) - AT+PEER_RANGE=<id>: returns +PEER_RANGE:<my>,<peer>,<mm>,<rssi> or +PEER_RANGE:ERR,<peer>,TIMEOUT Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>