V2X On-Board Unit, IEEE 1609.x protocol stack

An automotive-grade V2X on-board unit with IEEE 1609.2/3/4 stack running on ThreadX RTOS, OBU-201U enables direct V2X application software porting on the SDK and API to meet "Tomorrow's V2X Innovation, Today."

Preloaded 1609.x stack and the SDK to Enable Innovative V2X Applications

Automotive-grade design and feature rich I/O ports provide the flexibility to explore innovative V2X applications. The open approaches enable direct V2X application software porting to shorten the development time of software-enabled service for time-to-market.


Powerful V2X Platform
Processor, DSRC RF, 128MB DDR3, 32MB NOR
Preloaded Firmware
IEEE 1609.2, 1609.3, 1609.4 and SAE J2735
Operation System
ThreadX RTOS
Development Tool
Unex® SDK, User’s Guide, support
Craton processor, Pluton RF
GNSS Positioning
GPS/Glonass/Galileo/QZSS constellations
Hardware Security
ECDSA 256 signing, secure private keys storage
Power Supply
DC 6-32V power-in
GNSS Hot Start
Vbatt. power for GNSS RTC hot start
Delay Power-On
Programmable cranking delay on
Power Management
Idle, ON, and OFF
File Integrity
Safe FAT, 8GB microSD
DSRC Antenna
GNSS Antenna
FAKRA C active x 1
Automotive Design
-40°C ~ +85°C (Infineon SLE97: -20°C ~ +85°C)


DSRC Performance
Class C spectrum masks: +20dBm RF power at antenna port
Fading Sensitivity
Superior performance in multipath scenarios
Frequency Deviation
Frequency accuracy at ± 6.0ppm in –40°C ~ +85°C
Power Accuracy
Dynamic and accurate power in 4.5dBm ~ 25dBm
GNSS Performance
1.5m accuracy (CEP50 with SBAS), 10Hz refresh rate
Security Verification
over 2,000 ECDSA 256-bit verifications per second
Security Signing
< 50ms latency on ECDSA 256-bit signing
ESD Protection
IEC 61000-4-2 Level 4, Contact ±8kV, Air ±15kV


Feature Rich I/O
Ethernet, CAN, RS232, audio-out, microSD
External GNSS
RS232 supports external GNSS
GNSS Antenna
on-board MMCX connector, in addition to FAKRA C
Dual Power Input
4-pin or round jack
Data Storage
microSD slot, 8GB SDHC
V2X Enabling
Enabling V2X on the external host device


a standalone V2X on-board unit running on ThreadX OS in vehicle. A group of vehicles communicating with each other with OBU and V2X software installed.



Enables V2X on external host device with no impact on existing system architecture

Simply connects OBU-201U to external host device and programs preloaded OSLink firmware to provide software interfaces via UDP/Ethernet connection. The OSLink will behave as a relay of UDP/WSM payload which allows the external host device to send and receive J2735 compliant messages over DSRC.

Use DSRC V2X to forward data stream through UDP/Ethernet

The OBU-201U/OSLink will behave as a relay of UDP/WSM payload to forwards data stream of software-enabled applications over DSRC between two OBU-201U connected nodes.

Frequency Accuracy

Power Control Accuracy

Class C mask performance at +20dBm from -40°C ~ +85°C

Consistent EVM performance over a wide 5~22dBm power levels and -40ºC~+85ºC temperature range provide high channel efficiency.

25 degrees C 85 degrees C -40 degrees C
dut1 -28 -28 -29 -27.8 -27.7 -27.5
dut2 -30.5 -27.5 -30 -27 -30 -27.4
dut3 -31.4 -26.3 -30.2 -28.8 -28 -27

Connect OBU-201U RS-232 to PC USB port. Directly compile and deploy V2X applications on OBU-201U based on Unex's SDK

Innovative V2X safety, mobility, and environment applications on OBU-201U


Operation System
ThreadX RTOS
  • Preloaded standard compliance stack and firmware including:
  • IEEE 802.11p - 2010
  • IEEE 1609.2 - 2016
  • IEEE 1609.3 - 2016
  • IEEE 1609.4 - 2016
  • SAE J2735_201603
  • OSLink: WSM-UDP converter
Development Tool
  • Unex’s SDK (contains header files (.h), archived object codes (.a), example codes (.c), makefile, API guide, environment setup guide, quick start guide)
  • GCC cross compiler to compile ThreadX OS image under Linux
  • Hardware Guide
  • User’s Guide
System Service
RS-232 console, baud rate 115200 bps


Main Chipset
32MB NOR, 128MB DDR3
  • 5.85 ~ 5.925 GHz
  • 802.11p
  • ± 6.0ppm deviation
  • Class C +20dBm RF power
DSRC Sensitivity (typical, tolerance +2/-2dB)
-73 ~ -97dB (typical)
Learn more
Fading Sensitivity
  • Rural LOS: -92.5dBm
  • Highway LOS: -91.5dBm
  • Urban Approaching LOS: -91.5dBm
  • Crossing NLOS: -89.5dBm
  • Highway NLOS: -88.5dBm
  • 1.5m accuracy (CEP50 with SBAS)
  • -135dBm sensitivity
  • NMEA 0183
  • ECDSA 256-bit signing (<50ms)
  • private and public keys verification
  • secure storage of private keys in HSM
External Connector
  • two CAN 2.0b
  • one 10/100 Ethernet
  • one RS-232 console
  • one audio jack
  • ne reset button
  • one microSD socket
On-Board Interface
  • nine GPIO pins
  • MMCX connector
  • two DSRC FAKRA Z
  • one GNSS FAKRA C
Power Supply
4-pin or round jack
Operation Voltage
DC 6-32 V ± 5%
Power Consumption
0.29 ~ 0.315A
Learn more
Power Management
Idle, ON. and OFF
Operation Range
  • ambient: -40°C ~ +85°C
  • (Infineon SLE97 -20°C ~ +85°C)
Product Dimension
125(L)x109.5(W)x30(H) mm

Package Contents

  • 1

    OBU-201U x 1 with preloaded IEEE 1609.2/3/4 stack running on ThreadX.

  • 2

    Two DSRC omni dipole detachable antennas, 5.9GHz FAKRA type Z.

  • 3

    One GPS active detachable antenna, FAKRA type C, cable length 5 meters.

  • 4

    One 4-pin power cable.

  • 5

    One 12V/1A 110~240V round-jack power adaptor.

  • 6

    SDK, Hardware Guide and User’s Guide downloaded from Unex server.

Ordering Information

V2X On-Board Unit, 1609.x protocol stack
V2X On-Board Unit, ETSI TC-ITS protocol stack
V2X On-Board Unit
USB (A-male) to RS-232 (DE-9 male) cable, Prolific PL2303 chipset, cable length 1.8 meters

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