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https://github.com/amyangxyz/deterix

Deterministic network emulator with microsecond timing precision written in Rust
https://github.com/amyangxyz/deterix

deterministic network real-time rust tdma

Last synced: 3 days ago
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Deterministic network emulator with microsecond timing precision written in Rust

Host: GitHub
URL: https://github.com/amyangxyz/deterix
Owner: AmyangXYZ
License: gpl-3.0
Created: 2024-10-30T01:03:27.000Z (21 days ago)
Default Branch: main
Last Pushed: 2024-11-08T22:21:30.000Z (11 days ago)
Last Synced: 2024-11-08T23:22:32.383Z (11 days ago)
Topics: deterministic, network, real-time, rust, tdma
Language: Rust
Homepage:
Size: 442 KB
Stars: 0
Watchers: 1
Forks: 0
Open Issues: 0
Metadata Files:
- Readme: README.md
- License: LICENSE

Awesome Lists containing this project

README

# Deterix: Deterministic Network Emulator with Microsecond Timing Precision

Deterix is a lightweight communication framework designed specifically for modular digital twins requiring deterministic data exchange. Built on PREEMPT_RT Linux, it achieves microsecond-precision timing on commodity hardware through pure software implementation, enabling reliable real-time communication between digital twin components without requiring specialized hardware. The framework leverages standard Commercial Off-The-Shelf (COTS) computers and regular network infrastructure, making it an accessible solution for distributed digital twin deployments.

## Features

- Time-slotted communication (TDMA)
- Guaranteed message delivery windows
- Microsecond timing precision of [slot ticker](https://github.com/AmyangXYZ/rt_ticker)
- No GC interruptions
- Zero-copy packet handling
- Distributed architecture
- Runs on any modern COTS hardware

## Network Architecture

### Overview

The network operates on a Time Division Multiple Access (TDMA) protocol with Node 0 serving as the network orchestrator. Key architectural features include:

- Distributed time synchronization with <1µs precision
- Deterministic slot-based communication
- Dynamic network formation and management

### Slot Structure

```
|<------------------------ SLOTFRAME (8 slots) ------------------------>|
+--------+--------+--------+--------+--------+--------+--------+--------+
| Slot 0 | Slot 1 | Slot 2 | Slot 3 | Slot 4 | Slot 5 | Slot 6 | Slot 7 |
| IDLE | DEDIC | DEDIC | DEDIC | SHARED | SHARED | SHARED | SHARED |
| -/- | 1/2 | 2/3 | 3/1 | */0 | */0 | 0/* | */0 |
+--------+--------+--------+--------+--------+--------+--------+--------+

|<----------------------------- Single Slot ----------------------------->|
+-------+-----------------------------------+---------------------+-------+
| CLEAR | TX/RX | ACK | GUARD |
| 10% | 50% | 30% | 10% |
+-------+-----------------------------------+---------------------+-------+
```

Example transmission-slot chart showing two nodes join and synchronize with orchestrator and send 10 data packets in their dedicate slots.

![](./slot_chart/chart_1.png)

### Time Synchronization

- **Node 0 (Orchestrator)**

- Provides network-wide time reference using system clock
- Manages slot timing and synchronization
- Broadcasts periodic sync messages

- **Other Nodes**
- Maintain synchronized local clocks
- Update timing based on sync messages
- Calculate slot boundaries locally

## Network Operations

### Network Formation

1. **Initialization Phase**

- Node 0 starts as orchestrator
- Dedicated join slots are reserved in each slotframe
- New nodes begin in unsynchronized state

2. **Join Process**
```
New Node Node 0 (Orchestrator)
| |
|------ Join Request --------->| (in shared slot)
| | - Records node and add schedule
| | - Prepares timing info
|<----- Join Response ---------|
| |
|- Synchronize local clock |
|- Start normal operation |
```

### Communication Protocol

1. **Slot Assignment**

- Deterministic sender/receiver pairs per slot
- Scheduled transmission windows
- Guard bands prevent overlap

2. **Transmission Process**
- Reliable delivery with ACK mechanism
- Automatic retransmission
- Sequence number tracking

### Implementation Details

- **Core Components**

- TX/RX Queue Management
- Slot Ticker System
- Zero-copy Packet Pool
- RT Thread Scheduling

- **Performance Features**
- Thread affinity optimization
- RT scheduler prioritization
- Efficient buffer management
- Microsecond-precision timing

## LICENSE

GPL-3.0