The emerging interest in vehicular networks (VANET) led to the deployment of several small and medium-scale testbeds to evaluate the characteristics of this technology in real-world scenarios. Despite this, due to the low availability and high cost of IEEE 802.11p/WAVE fully compliant hardware and software, many of these experiments have been performed with other communication standards, which generate, in many cases, misleading results, that are not representative of real-world vehicular communications. As a mean of solving this problem, this paper presents the implementation and validation of a fully compliant MAC/PHY solution developed in the scope of the DRIVE-IN project, which will be used in a 500-node testbed. Contrarily to what happens with most of the solutions existent in the market, our system complies with the strict channel switching timings using GPS time synchronization, providing access to two different types of wireless channels (e.g. control and service channels as defined in IEEE 1609.4) in a seamless way for the end user. This feature allows safety-critical and control messages to be sent in a dedicated channel, with very low latency, while another channel may be used for less critical services (e.g. infotainment applications, advertisement). The results of the conducted tests show that indeed it is possible to assure the support of critical safety services in the presence of other traffic.
