Moumita has Published 175 Answers

Automatic Power Save Delivery (APSD)

Moumita

Moumita

Updated on 19-Nov-2019 10:55:38

In IEEE 802.11 wireless LANs, automatic power save delivery (APSD) is a mechanism that aims to reduce power consumption by the devices connected in the network. It was originally introduced to IEEE 802.11e in 2005.TechniqueAPSD is generally deployed in infrastructure BSS (basic service set). In infrastructure BSS, there is are ... Read More

What are beacon frames?

Moumita

Moumita

Updated on 19-Nov-2019 10:53:53

In computer networks, beacon frames management frames used in IEEE 802.11 based wireless local area networks (WLANs). A beacon frame contains network information needed by a station before it can transmit a frame. They are used for announcing the presence of devices in a WLAN as well as synchronisation of ... Read More

Virtual channel sensing using CSMA/CA

Moumita

Moumita

Updated on 19-Nov-2019 10:51:20

Virtual channel sense or virtual carrier sense is a mechanism to predict future traffic in wireless networks that uses carrier sense multiple access with collision avoidance (CSMA/CA). It is implemented in wireless network protocols, IEEE 802.11 and IEEE 802.16, which operates in the medium access control (MAC) layer.In virtual channel ... Read More

Network Allocation Vector (NAV)

Moumita

Moumita

Updated on 19-Nov-2019 10:48:28

The network allocation vector (NAV) is a virtual carrier sensing mechanism that forms an important part of the carrier sense multiple access with collision avoidance (CSMA/CA). It is implemented in wireless network protocols, IEEE 802.11 and IEEE 802.16, which operates in the medium access control (MAC) layer.TechniqueThe network allocation vector ... Read More

Point Coordination Function (PCF)

Moumita

Moumita

Updated on 19-Nov-2019 10:44:48

Point coordination function (PCF) is an optional technique used to prevent collisions in IEEE 802.11-based WLAN standard including Wi-Fi. It is a medium access control (MAC) sublayer technique used in areas where carrier-sense multiple access with collision avoidance (CSMA/CA) is used.PCF is used additionally along with the mandatory distributed coordination ... Read More

Distributed Coordination Function (DCF)

Moumita

Moumita

Updated on 19-Nov-2019 10:41:47

Distributed coordination function (DCF) is a mandatory technique used to prevent collisions in IEEE 802.11-based WLAN standard (Wi-Fi). It is a medium access control (MAC) sublayer technique used in areas where carrier-sense multiple access with collision avoidance (CSMA/CA) is used.TechniqueThe basic technique of DCF is as follows −When a station ... Read More

The 802.11 MAC Sublayer Protocol

Moumita

Moumita

Updated on 19-Nov-2019 10:32:16

IEEE 802.11 standard, popularly known as WiFi, lays down the architecture and specifications of wireless LANs (WLANs). WiFi or WLAN uses high frequency radio waves instead of cables for connecting the devices in LAN. Users connected by WLANs can move around within the area of network coverage.The 802.11 MAC sublayer ... Read More

Multiple Input Multiple Output (MIMO)

Moumita

Moumita

Updated on 19-Nov-2019 10:18:16

In wireless communications, when multiple antennas are used both at the transmitting end as well as the receiving end, the configuration is said to be multiple input, multiple output or MIMO. MIMO helps in sending and receiving multiple data signals simultaneously over the same radio channel. MIMO is a smart ... Read More

Orthogonal Frequency Division Multiplexing (OFDM)

Moumita

Moumita

Updated on 07-Oct-2019 08:02:17

In data communications and networking, orthogonal frequency-division multiplexing (OFDM) is a method of digital data modulation, whereby a single stream of data is divided into several separate sub-streams for transmission via multiple channels.OFDM uses the principle of frequency division multiplexing (FDM), where the available bandwidth is divided into a set ... Read More

Complementary Code Keying (CCK)

Moumita

Moumita

Updated on 07-Oct-2019 08:00:13

Complementary Code Keying (CCK) is a modulation technique deployed in wireless local area networks (WLANs) that follow IEEE 802.11b specification. CCK came into use in 1999 whereby it replaced the Barker code in wireless networks. CCK helps in attaining data rates higher than 2 Mbps, though at the cost of ... Read More

Advertisements