Sequence of execution of move_base

edit

Hi,

I have a mobile robot and would like it to navigate around the building. I already have a map of the building. I am using Wheel Encoders to generate odometry. I am feeding the output of Wheel encoders and IMU to robot_pose_ekf ( http://wiki.ros.org/robot_pose_ekf ) and then using AMCL for localization. Finally, I have the move_base package which plans the path and sends command velocities to the motors.
Assuming robot is at its starting position and it knows its path to the goal, my question is what is the sequence of steps after that:: ?
1. Local planner generates command velocities and sends its to the motors and then Wheel encoders start and generate odometry message which is fed into move_base. But again move_base needs some input odometry message, will that be just NULL to begin with?
2. Or, you give some initial default odometry message from wheel encoders to move_base which is used by move_base to generate command velocities and the cycle continues?

Hope I have made myself clear.

Thanks in advance.
Naman