i Am looking for some of wireless protocol with arduino having distance more than 20KM.
i want to communicate two arduino with GPRS. so one of my arduino will send data over a GPRS link and from other side My Other Arduino can get the data which sent by first arduino over GPRS.
so any body can have any idea to make such a Project. i am searching for such a thread since last month over internet but i cant.
please help me out from this.