Inertial Navigation Data Transfer Protocol (INDTP)

Inertial Navigation Data Transfer Protocol (INDTP) - is a lightweight, binary application-layer (L7) protocol designed specifically for the Inertial Navigation Systems (INS) and autonomous platforms.

INDTP addresses the critical trade-off between low-latency real-time data streaming, robustness against the noise, and cryptographic security. The protocol features a compact fixed size header, support for data aggregation in order to minimize overhead at high sampling rates, and a flexible multimode security architecture.

🎯 Why INDTP?

INDTP solves the problem of unifying data exchange between different navigation stacks, ensuring reliable, secure, and temporally synchronized data exchange under diverse operational conditions.

⚙️ Core features

• Time-critical accuracy: Absolute and delta timestamps embedded in payload ensure that sensor fusion and trajectory estimation algorithms receive precise measurement times without transmission latency issues.
• Hardware optimized: Uses CRC-16-MCRF4XX and CRC-32-AUTOSAR - both supported by hardware accelerators on modern MCUs.
• Scalable protection:

Mode	Trailer	Use case	Overhead
Lite	None (CRC-16 header only)	Trusted internal buses (SPI/I2C/CAN)	0 bytes
Verified	CRC-32-AUTOSAR	Noisy wireless (BLE, LoRa)	4 bytes
Trusted	CMAC-AES-128	Anti-spoofing	8 bytes
Critical	HMAC-SHA256	Firmware updates, critical commands	32 bytes

• Data aggregation mode: Pack multiple samples per frame & reduce per-sample timestamp overhead.
• Standard payloads: Protocol supports several standard payloads that cover most of the uses and ready to use out the box. All in SI units and in NED coordinate frame.
• Extensible:: Reserved vendor-specific range of payload types enables custom payloads for proprietary hardware and extended functionality.

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📄 Documentation

For complete technical implementation of protocol read technical specification v1.0.

📦 Implementations

• Rust Implementation:
  • Fully no_std compatible. Designed specifically for memory-safe embedded environments.
  • Zero-allocation crate.
  • Minimal external dependencies.
  • Pluggable crypto/integrity engine traits for hardware acceleration.

📜 License

Copyright (C) 2026-present indtp project and contributors.

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.