DELL INSPIRON 15-3567 WIFI ISSUE

Dear Team,

I have been using INSPIRON 15-3567 laptop from past couple of months. This product was purchased from U.S, and currently in India.

Using WIFI of 10 MBPS high speed internet connection, The kind of issue i am facing with laptop is, speed of wifi after getting connected with router, i was surprised when i came to know that i am getting max. 3 mbps speed (checking through speedtest.net), instead i should have got at least 9 mbps. 

when i checked speed over my cell phone through same speed test website, it shows around 9.83 mbps, which is workable. Moreover my one of HP laptop is showing 9 mbps. 

could you please help me around to get better wifi speed in my laptop?

Email: 

Thank You

Tushar