WSMP WAVE Short Message Protocol

WSMP (WAVE Short Message Protocol) is a communication protocol designed to facilitate the exchange of short messages and control information between vehicles and roadside infrastructure in vehicular communication systems. It is a part of the Wireless Access in Vehicular Environments (WAVE) standard, also known as IEEE 802.11p, which is an amendment to the IEEE 802.11 standard specifically tailored for wireless communication in vehicular environments. WAVE aims to improve road safety and enable various applications for intelligent transportation systems (ITS) by providing reliable and low-latency communication among vehicles and infrastructure.

The main goal of WSMP is to efficiently deliver short messages, often referred to as Basic Safety Messages (BSMs), between vehicles and infrastructure components, such as traffic lights, road signs, and toll booths. These BSMs contain essential information about a vehicle's status, position, speed, and other relevant parameters, which are crucial for enabling various safety and traffic management applications in vehicular networks.

Key features and characteristics of WSMP include:

1. Low Overhead: WSMP is designed to minimize the protocol overhead to efficiently use the limited available bandwidth in the vehicular communication channel. BSMs typically contain only essential information to keep message sizes small and reduce communication delays.
2. Priority Levels: WSMP allows messages to be assigned different priority levels. Safety-critical messages, such as emergency brake requests, may be assigned higher priority to ensure their timely delivery and reception, even in congested network conditions.
3. Geographic Addressing: WSMP uses geographic addressing to define the intended recipients of messages based on their geographical location. This enables efficient broadcast or targeted delivery of messages to vehicles in specific regions, reducing unnecessary communication overhead.
4. Adaptive Transmission Power: WSMP supports adaptive transmission power, allowing vehicles to adjust their transmit power based on their proximity to other vehicles and infrastructure. This helps in reducing interference and conserving energy.
5. Multichannel Operations: WAVE devices can operate on multiple communication channels simultaneously, allowing them to handle various types of messages and applications efficiently. For example, one channel might be dedicated to safety-critical messages, while another channel is used for non-critical data exchange.
6. Message Scheduling: WSMP provides mechanisms for scheduling message transmissions to avoid collisions and improve message delivery reliability.
7. Security: WSMP includes provisions for ensuring the security and privacy of the exchanged messages. This is crucial to protect against unauthorized access and potential attacks on vehicular communication networks.

WSMP is a critical component of vehicular communication systems that support Cooperative Intelligent Transportation Systems (C-ITS). C-ITS applications include cooperative awareness and collision avoidance, traffic signal preemption, intersection collision warning, and road hazard notifications, among others. By exchanging BSMs and control messages using WSMP, vehicles can be aware of each other's presence, predict potential collisions, and take appropriate action to avoid accidents or reduce traffic congestion.

Vehicular communication systems based on WSMP operate in the Dedicated Short-Range Communications (DSRC) frequency band, which is reserved for intelligent transportation systems in many countries. DSRC provides reliable communication with low-latency and is specifically suited for safety-critical applications, making it an ideal choice for vehicular communication.

WSMP is an essential standard in the development of connected and autonomous vehicles, as it enables the exchange of critical safety information among vehicles and infrastructure. As research and development in the field of intelligent transportation systems continue to progress, WSMP is likely to evolve further to support new applications and accommodate the increasing complexity and scale of vehicular communication networks.