802.11p

Comsis developed a 802.11p modem for automotive applications, using its Wi-Fi knowledge. The characteristics of these transmissions were taken into account as a Doppler effect correcting system was specially designed.

 

Applications

The 802.11p modem can be used for several applications involving wireless communication at longer range than Wi-Fi, especially in the automotive field:

• Traffic regulation (Infrastructure to vehicle communication)
• Traffic light control for emergency vehicles (vehicle to infrastructure)

 

Illustrations

The following pictures illustrate a green light optimized speed advisory (GLOSA) application. The traffic light beams its phase information using the 802.11p modem embedded on Comsis MimoKit II board. This information is collected in the car and the adequate speed range is displayed on a smart phone after analysis.

This test took place on the circuit Beltoise in Trappes. The traffic light position is marked by the green dot. The red dot mark is located roughly on the extreme range.

The picture on the bottom left was taken at extreme range. A speed of 20 up to 55 km/h is advised (highlighted in green). A higher speed will cause to arrive while the traffic light is red. The picture on the bottom right was taken in the vicinity of the traffic light that can be seen near the pedestrian crossing panel.

 

Equipment

The 802.11p modem can be implemented on Comsis development boards MIMOKit 1 and MIMOKit 2. These kits include a motherboard and RF daughter cards.

Features

• Licensed ITS band operation (5.85 GHz – 5.925 GHz)
• 7 available channels of 10 MHz bandwidth
• Doppler effect correcting system
• Ethernet connectivity

	ALUT		ALM	Memory bits	DSP (18*18)
Comsis i3e 802.11p	96688	213	83564	8750788	292
wirelessLanController	78893	203	68664	191172	292
macHard 802.11p	27687	18	23379	78916	22
Phy 802.11p	51198	185	45282	112256	270

 

Advantages / Benefits

The benefits depend on the type of application. A GLOSA system will reduce the fuel consumption thus the carbon dioxide emission as well as the congestion. A traffic regulation system will improve the security on the equipped road broadcasting locally specific traffic information (jam, weather hazards…)

 

Test

This equipment has been tested in our premises and in various locations (circuits, parking lot and city). Comsis is a member of the Co-Drive project and provided the IP on both platforms for field tests, including interoperability testing with other platform from FOTsis project.   The maximum coverage is about 500 meters with MimoKit 2 and 100 meters with MimoKit 1.  Comsis MIMOKIT boards are compliant with Wi-Fi regulations.