Actually, there are tools like Matlab used in the simulation for locating nodes using RSSI levels. I'm looking for other tools to work this out. Maybe Contiki or other similar systems can be used.
RSSI is a fluctuating level because there are so many factors impacted. Normally it is used in average value by estimation only. There is no exactly instrument to measure the localization yet for this. So, if you want this may be this is a new novelty thing to create for further research.
Sorry If my answer might wrong. Just like to share.
Wireless Sensor Network Localization Simulator v2.1 and v1.1 are localization simulation tools which comes integrated with well known localization protocols, it also provides the user to incorporate their own localization algorithms as well. Below are the links of these simulators:
Wireless Sensor Network Localization Simulator v2.1 allows motes such as Mica2 and TelOSB to be selected for simulation and it also provides the features to select different propagation models.
Use this Simulator: WSN Localization Simulator 2.1 . The Link is Below. it is best simulator if you want to do specific research in WSN Localization Module..