OBU-301E Information Sheet
V2X On-Board Unit, ITS-G5 stack, V2Xcast®

Overview
OBU-301E is a comprehensive V2X (Vehicle to Everything) on-board unit featuring with automotivegrade hardware and ITS-G5 stack. OBU-301E has complete V2X hardware and software to fit the various deployment needs of different OEMs and V2X system integrators. The model enables direct V2X application development to support innovative connected vehicles solutions. Featuring with intuitive V2Xcast® software that provides ready-to-use V2X communication services, OBU-301E supports highest application flexibility for connected vehicles ecosystem development.
Feature
- Feature rich I/O ports provide the most flexible options to integrate with variable devices.
- Painlessly enable V2X on external Linux host device via USB or Ethernet connection and V2Xcast®.
- On-board mPCIe socket allows add-on module.
- Onboard RF compensators provide compensation against RF cable loss. (available in OBU-311 series)
- 5.9GHz and GPS antennas diagnostic detection in case of antenna open or cable pinch.
Specifications
Chipset |
|
---|---|
Operation System | Linux Yocto |
System Service | RS-232 console interface (baud rate 115200 bps) |
System Memory | 128MB NAND, 128MB DDR3 |
Preloaded Firmware | ETSI ITS-G5 includes IEEE 802.11p, GeoNetwork, BTP, DCC, and Security and CCMS client* (*. Est. in Q2 ’21) |
Development Tool | V2Xcast® SDK, including APIs and ITS-G5 facility layer messages |
Hardware Security |
|
DSRC |
|
GNSS |
|
External GNSS Support | NMEA input interface |
External Connector |
|
On-Board Interface |
(*. Support by project) |
LED |
|
Antenna |
|
Channel Bandwidth | 10MHz |
Frequency Band | 5.850 ~ 5.925 GHz (DSRC) |
Operation Power |
5V: Imax=2A (during RF transmission, usually less than 2ms), Ityp=0.7A 3.3V: Imax=110mA, Ityp=105mA (preliminary data) |
On-board Interface |
RF interfaces:
|
Antenna |
+20dBm Class C RF spectrum mask Connectors:
|
Operation Temperature Range | ambient: -40ºC ~ +85ºC |
Storage Temperature Range | -45ºC ~ +90ºC |
Operating Humidity | 10% – 95%, non-condensing |
Storage Humidity | max. 95%, non-condensing |
Housing | aluminum plate, thickness: 1.0mm |
Product Dimension | 103mm (L) x 95mm(W) x 31mm (H) |
Software
Unex OBU-301E enables ease of V2X software development through its V2Xcast® technology. Previously, V2X protocol software had to be built and verified complicated APIs, resulting in a duplicated effort, risk and cost. With Unex intuitive V2Xcast solution that provides ready-to-use V2X communication services for V2X applications, customers can significantly cut time-to-market with less development and testing cost.
V2Xcast is supported in OBU-301E to facilitate V2X application development. It includes two parts – V2Xcast Service and V2Xcast SDK.
V2Xcast SDK
Deploy V2Xcast SDK in either OBU-301E or external application host, it includes APIs to get the services from V2Xcast Service and the main functions of facility layer (ITS-MSG), such as message encoder/decoder and example code.
V2Xcast Service
V2Xcast Service image resides in OBU-301E, it combines ETSI ITS-G5 protocol stack that includes GeoNetwork, BTP, DCC, Security, and POTI. V2X communication protocols will be easily enabled via configuration input without any programming.
Security
A self-contained and highly integrated V2X system-on-module capable of highly secure V2X applications.
Security functions provided by V2Xcast® are designed based on a highly secure HSM (Hardware Security Module).
The highly secure HSM with FIPS 140-2 Level 3 certification is embedded in OBU-301E.
Cryptographic processor eliminates bottlenecks, maximizes application performance and offload CPU’s computation. To protect your sensitive cryptographic keys in a high-assurance key vault, the design provides leverage a keys-in-hardware solution. With the keys-in-hardware solution, all the cryptographic operations are inside HSM and those keys never leave the HSM.
Input Output Interface
Function | Pin |
---|---|
Console (DCE) |
TX(I) RX(O) GND |
Ext GNSS (DTE) |
Ext_GNSS_TX(O) Ext_GNSS_RX(I) Ext_1PPS(I) GND |
CAN0 | CAN0_H CAN0_L |
CAN1 | CAN1_H CAN1_L |
USB | USB_DP USB_DN USB5V GND |
GPIO | GPIO1 GPIO2 |
PWR | POWER RESET GND |
Pin Definition
20 Pin Connector

Pin | Pin Name | Type | Description |
---|---|---|---|
1 | POWER | I | 6-48V System main power |
2 | RESET | I | Reboot the device with rising edge |
3 | TX | I | Serial data from DTE |
4 | RX | O | Serial data to DTE |
5 | GND | G | Ground |
6 | CAN0_H | I/O | CAN0 High |
7 | CAN1_H | I/O | CAN1 High |
8 | USB_DP | I/O | USB Data + |
9 | USB_5V | O | 5V USB bus power |
10 | GPIO1 | I/O | GPIO |
11 | GND | G | Ground |
12 | EXT_1PPS | I | External 1PPS signal |
13 | EXT_GNSS_RX | I | Serial data from external GNSS module |
14 | EXT_GNSS_TX | O | Serial data to external GNSS moduleCAN0 High |
15 | GND | G | Ground |
16 | CAN0_L | I/O | CAN0 Low |
17 | CAN1_L | I/O | CAN1 Low |
18 | USB_DN | I/O | USB Data – |
19 | GND | G | Ground |
20 | GPIO2 | I/O | GPIO |
RJ45
Pin | Pin Name | Type | Description |
---|---|---|---|
1 | TX+ / BI_DA+ | I/O | 10/100Mbps: Transmit data + 1000Mbps: Bi-directional data + |
2 | TX+ / BI_DA- | I/O | 10/100Mbps: Transmit data – 1000Mbps: Bi-directional data – |
3 | RX+ / BI_DB+ | I/O | 10/100Mbps: Receive data + 1000Mbps: Bi-directional data + |
4 | BI_DC+ | I/O | 10/100Mbps: Not connected 1000Mbps: Bi-directional data + |
5 | BI_DC- | I/O | 10/100Mbps: Not connected 1000Mbps: Bi-directional data – |
6 | RX- / BI_DB- | I/O | 10/100Mbps: Receive data – 1000Mbps: Bi-directional data – |
7 | BI_DD+ | I/O | 10/100Mbps: Not connected 1000Mbps: Bi-directional data + |
8 | BI_DD- | I/O | 10/100Mbps: Not connected 1000Mbps: Bi-directional data – |
USB Mini-B

Pin | Pin Name | Type | Description |
---|---|---|---|
1 | VBUS | O | +5V USB bus power |
2 | D- | I/O | Data – |
3 | D+ | I/O | Data + |
4 | BI_DC+ | – | Not connected |
5 | GND | G | Ground |
Typical Using Case
1. Vehicle to Vehicle (V2V) and Vehicle to Infrastructure (V2I) applications in standard compliance ITS-G5 stack and messages:
2. Enables V2X on external host device with no impact on existing system architecture:
Simply connect external host device to OBU-301E with preloaded V2Xcast Service, and deploy V2Xcast SDK in the external host device which allows it to send and receive ITS-G5 compliant messages.
Package contents
- One OBU-301E
- Two DSRC omni dipole detachable antennas, 5.9GHz FAKRA type Z
- One GPS active detachable antenna, FAKRA type C, cable length 3 meters
- One power supply unit
- Hardware Guide, software development kit available on Unex server