Exposed Terminal Problem

In wireless LAN (local area network) communication, the exposed terminal problem is a frequent difficulty. It happens when a wireless node cannot transfer data because another node that is outside its communication range is sending data to another node that is inside it. Throughput and network performance may suffer as a consequence. This happens when a station can be seen by a wireless access point but not by other stations that are connected to the access point.

Let’s assume there are four stations with the names A, B, C, and D, where B and C are transmitters and A and D are receivers. The stations are set up so that the two emitters B and C can hear each other but the two receivers A and D cannot hear each other over radio waves. Transmission from B to A is happening. As a result, C ceases attempting to transmit to D after mistakenly assuming that the above transmission will cause interference. However, since the communication from C to D is outside of B’s range, interference would not have happened. Known as the exposed terminal issue.

Wireless LAN is used to transmit data from one device to another without using connected medium. There are normally several problems in wireless LAN. One of them is the Exposed terminal Problem.