Anyone did trial and changed CP based on area situation?
Extended CP is only for cells with large propagation delays.
Have you changed it in Ericsson?
No, there was no need for this.
As I checked all the sites considerin those located in Rural /villiga/remote area and also those sites located in City have same CP (CP is vibile with full amos command), do you think if we change CP to extend for roady area we can have gain?
Changing CP from normal to extended is a major change.
I think it will be only 6 symbols per slots instead of 7 so cell throughput may decrease.
You need solid evidence that your rural cells have a delay larger than 4-5 microseconds to use extended CP.