Awareness applet provides a convenient way to evaluate network conditions and resulting awareness ranges in VANET environment where communication is based on the cooperative awareness messages. With the help of this applet one can also choose optimum network configurations (minimizing the channel load) to achieve desired awareness range.
Awareness is defined as a probability of receiving at least n packets in a time window T. The awareness range is then a maximum range at which awareness probability is greater than or equal to a desired awareness probability PA. Probability of reception of each individual packet (PPR) is calculated based on the empirical model, packets are sent with the same frequency (same transmission rate) and have the same reception probability during the time window T.
On the left hand side one can specify required network and awareness parameters, the results are plotted and summarized in the table on the right hand side.
Three options are provided:
- "calculate maximum Awareness Range" - calculates maximum awareness range that corresponds to the specified network and awareness parameters. Awareness probability PA is plotted together with corresponding packet reception probability PPR. The table summarizes transmission rate, achieved awareness range and corresponding load on the channel.
- "calculate minimum Tx Range" - calculates minimum transmission range that is needed to achieve indicated awareness range. Transmission range values are provided for a specified awareness parameters, given vehicular density and all possible transmission rates (normally 1-10Hz). Awareness probability PA is plotted together with corresponding packet reception probability PPR. The table summarizes the combinations of transmission rate and transmission range as well as corresponding load on the channel to achieve desired awareness range.
- "calculate minimum Tx Rate" - calculates minimum transmission rate for specified awareness parameters, specified vehicular density and transmission range. Resulting awareness ranges are plotted additionally for other possible transmission rates and summarized in the table along with corresponding channel load.
The concept of this awareness applet can be used to evaluate vehicle-2-X applications as described in the publication