RSU-351U Information Sheet

C-V2X Roadside Unit, C-V2X stack, V2Xcast®

RSU-351U:C-V2X Roadside Unit, C-V2X stack, V2Xcas


RSU-351U is a 3GPP C-V2X (LTE-V2X) PC5 roadside unit with waterproof IP67 enclosure designed to enable V2X in the Cooperative Intelligent Transport Systems (C-ITS) environment. RSU-351U provides secure data communication between vehicles and infrastructure, such as Advanced Traffic Controller or roadside sensor system, to enable cooperative ITS applications. Preloaded with C-V2X stack and V2Xcast® software, RSU-351U provides highest Vehicle-to-Infrastructure (V2I or I2V) application flexibility to fit the various deployment needs for different ITS and V2X system integrators.


  • A rich SDK containing facility-layer messages, APIs and example codes accelerates development of V2X applications.
  • Seamlessly enable LTE-V2X PC5 on roadside Linux host via Ethernet connection and V2Xcast®.
  • On-board mPCIe socket allows add-on module such as LTE modem.
  • Surge protection on the antenna ports and PoE enhance immunity and robustness in voltage spike events.


  • Autotalks® CRATON2 V2X communication processor
    • dual 600MHz ARM Cortex-A7 32-bit CPU cores
    • 1140 DMIPS processing power each Cortex-A7 core
    • ARM Cortex M3 32-bit processor with memory protection unit (MPU) and ECC protected memory
  • Autotalks® PLUTON2 V2X RF Transceiver
  • Embedded Hardware Secure Module (eHSM)
    • Dedicated ARM Cortex-M0 CPU
  • Telit® SL869-V3 GNSS module
Operation System Linux Yocto
System Service
  • RS-232 console through on-board interface
  • Ethernet
System Memory 128MB NAND, 128MB DDR3
Preloaded Firmware LTE-V2X PC5 EU stack includes GeoNetwork, BTP, DCC, and Security and CCMS client
Development Tool V2Xcast® SDK, including APIs and facility-layer messages
Hardware Security
  • Dedicated ROM containing certified secure V2X signing firmware
  • Secure encrypted off-chip storage of private keys
  • Private material is inaccessible outside HSM
  • Capable of >110 signatures / second, with <9ms signing latency for ECDSA NIST P256 or ECDSA Brainpool P256R1
  • Line-rate ECDSA verification engine (>2500 ECDSA NIST P256 verifications / second)
  • FIPS 140-2 Level 3 certification
  • Tamper detection* (*. Support by project)
  • Frequency band: 5.895 ~ 5.925 GHz
  • Radio mode: 3GPP LTE-V2X Rel. 14 PC5 sidelink
  • Channel bandwidth: 10/20 MHz
  • RF transmit power: max. +20dBm on antenna port, Class C RF spectrum mask compliant with margins
  • RF receive power: typ. < -92dBm
  • Refresh rate: 10Hz
  • Sensitivity:
    • Acquisition: -146dBm
    • Navigation: -158dBm
    • Tracking: -162dBm
  • NMEA Standard: NMEA 0183
  • Accuracy: 1.5m (CEP50 with SBAS)
  • Telit® SL869-V3 GNSS receiver supports GPS/Glonass/Galileo/QZSS constellations*. SBAS like EGNOS (EU), WAAS (US), and MSAS (JP) are also supported. (*. GPS and Glonass are supported by default)
External Connector
  • one M25 waterproof Ethernet port with 802.3af PoE
  • two Type-N RF port for LTE-V2X
  • one Type-N RF port for GNSS
On-Board Interface
  • Two MHF RF connector (LTE-V2X)
  • One MMCX RF connector (GNSS)
  • One Mini PCIe slot (for LTE module) *
  • One SIM slot*
  • One PoE Module slot
  • LED headers

(*. Support by project)

    • Start-up: Blinking Green
    • Operational: Solid Green
    • FW upgrade: Amber (R+G)
    • Fault: Red
  • two Type-N outdoor 7.6dBi LTE-V2X antennas (for diversity)
  • one Type-N outdoor GNSS antenna
Power Supply 802.3af PoE (12W)
Operation Temperature Range ambient: -40°C ~ +70°C
Operating Humidity 10% ~ 95%, non-condensing
Product Dimension 220.5mm (L) x 127.5mm (W) x 72.3mm (H) (excluding antennas)


Featuring with V2Xcast®, Unex’s innovative software technology, RSU-351U allows two modes of operation:

1. Hostless Mode: RSU works as a standalone full-featured V2X unit

RSU-351E Roadside Unit,Applicaon Host

2. Hosted Mode: RSU works as a V2X communication unit to the application host

RSU-351E Roadside Unit,Applicaon Host

Unex RSU-351U 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 RSU-351U to facilitate V2I/I2V application development. It includes two parts – V2Xcast Service and V2Xcast SDK.

V2Xcast SDK

Deploy V2Xcast SDK in either RSU-351U or external application host, it includes APIs to get the services from V2Xcast Service and the main functions of facility layer, such as message encoder/decoder and example code.

V2Xcast Service

V2Xcast Service image resides in RSU-351U, it combines PC5 EU stack that includes GeoNetwork, BTP, DCC, Security, and POTI. V2X communication protocols will be easily enabled via configuration input without any programming.


RSU-301E Roadside Unit,V2X safety msg, app

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 RSU-351U.

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.

Typical Using Case

RSU, Intelligent Transportation SystemETSI TC-ITS: CAM, DENM, SPATEM, MAPEM 1609.x: J2735 BSM, SPaT, MAP

The traffic controller unit acts as SPATEM/MAPEM or SPAT/MAP generator to perform the relative encode/ decode. Implement the required V2X stack on RSU-351U to co-operatively work with the traffic controller unit and serves to receive and forward the SPATEM/MAPEM or SPAT/MAP messages as a payload for communication between vehicles and traffic controllers in co-operative ITS. V2I/I2V applications can be flexibly implemented on the traffic controller unit or RSU-351U.


Package contents

  1. One RSU-351U
  2. Two outdoor LTE-V2X antennas
  3. One outdoor GNSS antenna
  4. One PoE surge protector
  5. One cable gland
  6. Mounting Bracket and accessories
  7. One earth wire
  8. Hardware Guide and software development kit available on Unex server

    Contact Unex

    Discover unlimited V2X opportunities & start the journey with V2Xcast®

    Global Headquarters

    7F-2, No.100, Sec.1, Jiafeng 11th Road., Zhubei City, Hsinchu County 302052, Taiwan




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