Network Simulator
INTRODUCTION
IEEE 802.11 is the de facto standard for WLANs. It specifies both the medium access control (MAC) and the physical (PHY) layers for WLANs. The MAC layer operates on top of one of several physical layers. Medium access is performed using Carrier Sense Multiple Access with Collision Avoidance. However, simple CSMA is susceptible to the hidden node problem, especially in so called ad hoc networks where a node may communicate directly with every other node in range or using intermediate nodes as relays otherwise. Hidden nodes cause costly packet collisions and thus significantly affect network performance. In order to combat the hidden node problem, a mechanism known as Request to Send/Clear to Send (RTS/CTS) handshake is often used. RTS/CTS mechanism is supported in the IEEE 802.11 family of standards. The RTS/CTS mechanism was initially proposed in a protocol called Multiple- Access with Collision Avoidance (MACA). From a network point of view, one of the primary reasons for using the RTS/CTS mechanism is to avoid network congestion resulting from frequent packet collisions. Figure 1 depicts a conceptual “throughput versus Packet Size” curve for a network. In the presence of congestion, the throughput goes to zero as the Packet Size is increased beyond a certain value. A properly designed network, on the other hand, maintains the maximum throughput as the Packet Size goes to infinity.
LITERATURE REVIEW
The IEEE 802.11 standard includes an optional feature of the RTS/CTS (Request to Send/Clear to Send) function to control station access to the medium when collisions occur due to the hidden node. This option is also known as virtual carrier sensing. Through the proper use of RTS/CTS, you can fine-tune the operation of your wireless LAN since it solves the hidden node problem and provides additional protection against collisions. If you enable RTS/CTS on a particular station, it will refrain from sending a data frame until the station completes a
IEEE 802.11 is the de facto standard for WLANs. It specifies both the medium access control (MAC) and the physical (PHY) layers for WLANs. The MAC layer operates on top of one of several physical layers. Medium access is performed using Carrier Sense Multiple Access with Collision Avoidance. However, simple CSMA is susceptible to the hidden node problem, especially in so called ad hoc networks where a node may communicate directly with every other node in range or using intermediate nodes as relays otherwise. Hidden nodes cause costly packet collisions and thus significantly affect network performance. In order to combat the hidden node problem, a mechanism known as Request to Send/Clear to Send (RTS/CTS) handshake is often used. RTS/CTS mechanism is supported in the IEEE 802.11 family of standards. The RTS/CTS mechanism was initially proposed in a protocol called Multiple- Access with Collision Avoidance (MACA). From a network point of view, one of the primary reasons for using the RTS/CTS mechanism is to avoid network congestion resulting from frequent packet collisions. Figure 1 depicts a conceptual “throughput versus Packet Size” curve for a network. In the presence of congestion, the throughput goes to zero as the Packet Size is increased beyond a certain value. A properly designed network, on the other hand, maintains the maximum throughput as the Packet Size goes to infinity.
LITERATURE REVIEW
The IEEE 802.11 standard includes an optional feature of the RTS/CTS (Request to Send/Clear to Send) function to control station access to the medium when collisions occur due to the hidden node. This option is also known as virtual carrier sensing. Through the proper use of RTS/CTS, you can fine-tune the operation of your wireless LAN since it solves the hidden node problem and provides additional protection against collisions. If you enable RTS/CTS on a particular station, it will refrain from sending a data frame until the station completes a
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