Dear Rajitha,
On Thu, Feb 09, 2017 at 03:40:31AM +0000, Rajitha peiris wrote:
here i have attached my openbsc.cfg file
no, you have not attached the config file. What you have attached is a (partial) screenshot of your config file. Please actually attach the config file, thanks.
Also, it is customary to collect all relevant information in one mail before sending message to this list. Otherwise you will have literally hundreds of people reading your mail. Some might be interested in helping out, but then they cannot due to lack of information.
Getting back to your actual question: It is many years since I last used aa nanoBTS (and never one for 1900 MHz), but irrespective of that you definitely do not need lcr or mISDN for simple voice call connectivity.
Regards, Harald