All the features of OCABS, except for enhanced CAMs, are now integrated into the CA Basic Service module of OScar, our open implementation of the ETSI C-ITS stack. You can find more information on OScar here.
Therefore, OCABS is no longer going to be maintained with the exclusion of the enhanced CAM features. The latter are going to be maintained as part of this repository, until they will be integrated into OScar.
This repository contains OCABS, a C++ open implementation of the CA Basic Service, to be used for deployement into real hardware, running, for instance, OpenWrt-V2X.
This project includes a full open source implementation of the ETSI CA Basic Service, with reference to the standard ETSI EN 302 637-2 V1.4.1, including the BTP and GeoNetworking layers. CAMs version 2 are currently being managed (there is no official support for the older CAMs version 1).
As the project is still work-in-progress, it currently provides only the dissemination of CAMs, while the reception of the same messages should be managed by any other V2X service requiring the reception of CAMs.
Important: OCABS needs a source of PVT (Position-Velocity-Time) GNSS data through gpsd. Thus, a GNSS device must be available (either real, or emulated, for instance thanks to tools like gpsfake) and it must be connected to a gpsd instance.
The OCABS main help, with all the possibile options, can be displayed with ./OCABS --help, after compiling the OCABS binary.
OCABS also supports a proposed enhancement to CAM messages (i.e., the Enhanced CAMs), to be used in conjunction with the AIM Local Dynamic Map. The transmission of the enhanced messages may break compatibility with other existing standard-compliant stacks (e.g., the Cohda Wireless stack, the ms-van3t stack in emulation mode), and it is thus enabled only when explicitly specified through the option --enable-enhanced-CAMs (or, in short, -E) . If not enabled, standard-compliant version 2 CAMs are sent, without any modification.
When enhanced CAMs are not enabled, the following options (and the corresponding short versions) are no longer valid and thus should not be specified: --own-public-ip, --own-private-ip, --extra-comp-dev-ip, --rssi-aux-update-interval, --aux-dev-ip.
OCABS can be easily compiled on the same device in which it will be run thanks to make.
As the only pre-requisite, libgps-dev must be installed and available.
To download and build the latest version of OCABS, first, clone this repository:
git clone https://github.com/francescoraves483/OCABS-project
Then, cd into the newly created directory:
cd OCABS-project
Finally, build OCABS:
make
The OCABS binary file will be called OCABS.
Then, make sure that a GNSS data provider is active and gpsd is running (you can use the gpsmon tool to check if GNSS PVT data is actively being received).
You can then launch OCABS with (a stationID should be specified all the times with the --vehicle-id option):
./OCABS --vehicle-id <unsigned 32-bit integer stationID> --gnss-device <IP or URL of the device where gpsd is being run - usually localhost/127.0.0.1> --gnss-port <port to use for the connection to gpsd> --interface <interface from which CAMs will be disseminated>
If you get a permission denied error (as OCABS is internally using raw sockets), you can try launching again OCABS with sudo or from the root user.
OCABS is also though to be easily cross-compiled for any embedded platform or router running OpenWrt.
Cross-compilation also leverages make. However, it requires a few additional steps, after cloning the repository.
First of all, an OpenWrt toolchain must be available in the device used for cross-compilation, with the PATH and STAGING_DIR environment variables being properly set. You can find additional information on how to set up the OpenWrt toolchain here. When performing the build procedure steps, select the libgps package with make menuconfig.
Then, open the OCABS Makefile and update lines 3 and 4 (this needs to be done only once per development PC):
- Line 3 (
OPENWRT_STAGING_DIR) should be updated to point to the directory where the OpenWrt toolchain./usr/includeis located (you can start from the already available path to properly update this line) - Line 4 (
OPENWRT_LIBGPS_VER) should be updated with the libgps version which came with the OpenWrt toolchain installation (currently, it should be kept to3.23, but it may change in the future)
After performing these modifications, cd into the OCABS project main directory:
cd OCABS-project
Finally, build OCABS with the compileAPU target:
make compileAPU
As in the previous case, a binary file named OCABS will be generated. The executable can be then transferred to the device running OpenWrt and launched with:
./OCABS --vehicle-id <unsigned 32-bit integer stationID> --gnss-device <IP or URL of the device where gpsd is being run - usually localhost/127.0.0.1> --gnss-port <port to use for the connection to gpsd> --interface <interface from which CAMs will be disseminated>
You can also make OCABS run as a service, by creating two new files inside OpenWrt:
/etc/init.d/OCABS, to create a new service/etc/config/OCABS, to configure the OCABS service
A sample of the two files is reported below:
This sample shows how to create the OCABS service through an init.d script. More details are available here and here.
For a basic working service setup (without Enhanced CAMs), you can freely copy the whole content reported below. This sample init.d assumes that the OCABS executable has been placed inside a directory named /root/OCABS (see the procd_set_param command line).
#!/bin/sh /etc/rc.common
USE_PROCD=1
START=99
STOP=01
CONFIGURATION=OCABS
start_service() {
# Reading configuration parameters (i.e. interface and port)
config_load "${CONFIGURATION}"
local name
local every
config_get interface OCABS interface
config_get gnssport OCABS gnssport
config_get vehicleID OCABS vehicleID
config_get gpsdaddress OCABS gpsdaddress
procd_open_instance
# pass config to script on start
procd_set_param command /bin/bash -c "cd /root/OCABS && ./OCABS --interface $interface --gnss-port $gnssport --vehicle-id $vehicleID --gnss-device $gpsdaddress"
procd_set_param file /etc/config/OCABS
procd_set_param stdout 1
procd_set_param stderr 1
procd_set_param respawn ${respawn_threshold:-3600} ${respawn_timeout:-60} ${respawn_retry:-0}
procd_close_instance
}
This sample shows how to create an OCABS configuration file, after setting up the proper init.d script.
The configuration file options should match the ones reported in the config_get lines of the init.d script.
config myservice 'OCABS'
option interface 'wlan1'
option gnssport '2947'
option vehicleID '3000112'
option gpsdaddress '127.0.0.1'
In general, this sample allows the user to set the dissemination interface (interface option), the gpsd service address (gpsdaddress option), to retrieve the PVT data from, the port at which the gpsd address is available (gnssport option) and the device station ID (vehicleID option). This sample is related to an OCABS service set to disseminate non-Enhanced CAMs only.
After setting up the OCABS OpenWrt service, you can start it with:
service OCABS start
And stop it with:
service OCABS stop
The service can also be enabled to run at start-up with:
service OCABS enable
The execution at start-up can be disabled, instead, with:
service OCABS disable
When running as a service, the output of OCABS is not directly available, but it can be retrieved with:
logread
This project is licensed under a GPL-2.0 License. Please see also the LICENSE file for more details.
For any question, please write to francescorav.es483@gmail.com. Thanks!
This project uses internally the TCLAP - Templatized Command Line Argument Parser library.