written 6.8 years ago by | modified 2.8 years ago by |
Subject: Mobile Communication and Computing
Topic: Wireless Local area Network
Difficulty: Low
written 6.8 years ago by | modified 2.8 years ago by |
Subject: Mobile Communication and Computing
Topic: Wireless Local area Network
Difficulty: Low
written 6.7 years ago by | • modified 6.7 years ago |
Hidden and exposed terminal problems: The reason for these two problems is the broadcast nature of the radio channel, namely, all the nodes within a node’s transmission range receive its transmission.
Hidden terminal problem – two nodes that are outside each-other’s range perform simultaneous transmission to a node that is within the range of each of them, hence, there is a packet collision.
Exposed terminal problem – the node is within the range of a node that is transmitting, and it cannot transmit to any node.
Solution
o A and C want to send to B
o A sends RTS(Ready to Send) first
o C waits after receiving CTS (Clear to Send) from B
o B wants to send to A, C to another terminal
o now C does not have to wait for it cannot receive CTS from A