Wave Service Advertisement (WSA) implementation

[Kifayat Ullah]

I am working on the implementation of the following scenario using OMNET++ & VEINS simulators.

1. Every RSU will broadcast WSA (Wave Service Advertisement) Beacon once per second. (i.e. I2V communication).
2. Every passing vehicle would store these WSAs. (i.e. Caching)
3. Vehicles interested in a WSA, would query nearby vehicles. (i.e. Searching for WSA) (i.e. V2V communication).
4. Vehicles after receiving the query, would response to the query (if the required WSA is inside the vehicle cache). (i.e. V2V communication)

Issues regarding implementation:

• Do I need to define a new .msg files for each of the above phases (for RSU broadcast, for vehicles query, and for vehicles responding) ? or I need to amend the WaveShortMessage.msg file only ?
• Do I need to define my own .cc, .h, .ned files for RSU and CAR or I can amend the traci examples (of Veins)?

[Anmol Dalmia]

Hello Kifayat

Yes, most certainly you should create your own .msg files by extending the WaveShortMessage. You may also amend this file only to make your things work but there are two catches:

1. You will need to add more functions to actuate your new message format, which, if you write in the same file, may cause some legacy behaviour to get altered.
2. WSM is used everywhere in 802.11p applications, as far as I know. But you would like to use your message format to work only on certain connections I suppose. Editing wsm will cause message size to increase everywhere which may cause more packets to be dropped in the network or more noise in the received packet due to increase in the length.

So it is advisable to create your own .msg files.

As for your second query, the same arguments do as the previous one. However, I personally feel that the given definitions of RSU and Car are sufficient for all applications. What you might wanna change is the accident parameters in the .ned or the accidentCount variable in your nodes. Since these are just to facilitate the accident scenario and will not have any effect on the network, as you will not be simulating that scenario, you just need to default some values to them rather than totally delete the parameters.

Cheers

Anmol Dalmia

Summer Research Intern

Technische Universität Chemnitz, Germany