Query regarding network switching of tag

I am working on MDEK1001 kit for asset tracking. I want my tag to switch network for that i am changing network as per the boundaries of network.
I am getting problem when my tag ranges with anchors of a particular network. Time required for ranging is different in every case.
Like sometimes it ranges within 2 seconds and sometimes it takes more than 10 seconds.
So i want to know how it ranges with anchor after i gave the command of changing network on run .
Please help me in solving this.