README file:


1. Unzip the file GPRS 16.0.zip into a new folder and change the
   "mod_dirs" in the OPNET setup file to point to the new folder that
  contains the GPRS OPNET model.


2. Launch OPNET 16.0 and open the project: "sgsnSignalling".


3. Inputs required for running the simulation are located in the
   Mobile_Station network node. Open the node model and change
 the packet inter-arrival rate for the processor:
   * detachRequestSource
   * attachRequestSource
   * activationRequestSource
   * deactivationRequestSource
   * userDataSource


4. Open the Attribute window and change the "Packet Interarrival Time"
   attribute for the processors above to meet your simulation preferences.


5. You can also change all the processors' "Packet Interarrival Time"
   attributes to "promoted" and create a scenario to input the inter-arrival
   rate before running the simulation. (Please refer to OPNET Tutorial
   Lesson 4 - Packet Switch I, Section 4, for details on how to create
 scenario for simulation.)


