V2X Hub Layer 2

Owned by Sudhakar Nallamothu
Last updated: Dec 22, 2021 by Andrew Loughran
4 min read

For V2X Hub project, there were 6 SET-IT service packages selected and customized to display the architecture details based on the main functionality and current plugins, for e.g., Preemption, Pedestrian Safety, SPaT, MAP etc.

V2X Hub PS03 - Emergency Vehicle Preemption

This service package displays how the Preemption plugin works in V2X Hub by preempting the traffic signal timing plan for first responders (police, fire, and emergency medical services) by enabling TSCs to detect emergency vehicles using BSMs and change the light using signal preemption, holding traffic until the emergency vehicle passes through the intersection.

In the below diagram, the request for preemption is received by Emergency Vehicle’s OBU via the input from the Emergency Vehicle Operator in the field, in a BSM message sent from the OBU to the RSE. V2X Hub looks for the extended portion of the BSM message to check for emergency vehicles with lights and sirens ON. The preemption request is passed to V2X Hub by RSE. Once V2X Hub receives the preemption request, it checks if the vehicle is inside the geofence defined as an active boundary for triggering preemption, and if so, passes the request to the Traffic Signal Controller, which flushes the signal phases so that the emergency vehicle has a clear path through the intersection.  

 

V2X Hub PT09 - Transit Signal Priority

This service package displays how the Transit Signal Priority currently works in V2X Hub. Please note that this functionality is partially developed in V2X Hub.  The SRM messages are being broadcasted by the transit vehicles and received by V2X Hub, but they will need to processed further based on the priority list for signal controllers. This work will be performed in a future release.

 

V2X Hub SU04 - Map Management

This service package shows how the MAP plugin works in V2X Hub. This plugin produces intersection geometry by creating J2735 MAP messages. The J2735 2016 MAP files are input to V2X Hub using the ISD Message Creator online tool separately (not shown in the diagram). V2X Hub will forward the map updates which could include a new underlying static or real-time map or map layer(s) updates, and the physical geometry of the intersection including the location and width of approaching lanes to the connected vehicles via the RSE.

 

V2X Hub TM04 - Connected Vehicle Traffic Signal System

This service package shows different interactions of SPaT, MAP, DSRC Immediate Forward and RTCM plugins in V2X Hub. SPaT plugin communicates with the Traffic Signal Controller using NTCIP 1202, and creates a J2735 SPaT message. RTCM plugin communicates with NTRIP network to create J2735 RTCM position correction messages and DSRC Immediate Forward plugin sends all J2735 traffic to RSU for transmission out of DSRC radio.

 

V2X Hub VS05 - Curve Speed Warning

This service package shows how the Curve Speed Warning and DMS plugins work in V2X Hub, by monitoring J2735 BSM messages at a curve, and sending a message to the DMS, when it detects that the vehicle is approaching the curve too fast.

 

V2X Hub VS12 - Pedestrian and Cyclist Mobility

This service package shows how the Pedestrian Safety plugin works in V2X Hub, by taking information about pedestrian location from either a detector or a pedestrian mobile device, and repackaging this into a SAE J2735 standard Personal Safety Message (PSM) for broadcast by an RSU to nearby vehicles.

V2X Hub ODE

This service package shows how the ODE plugins in V2X Hub including ODE Logger Plugin, SPaT Logger, and Message Logger. These plugins enable the use of ODE for data distribution of SPaT and BSM SAE J2735 messages through Kafka topics and raw bin dumpfiles. More information can be found in the comment of the diagram below.