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 provides an abstraction of the physical layer to the logical link control sublayer and upper layers of the OSI network. It is responsible for encapsulating frames and describing frame formats.MAC Sublayer frame of IEEE 802.11The main fields of a frame of wireless LANs as laid down by IEEE 802.11 are ... Read More

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 antenna technology, the other popular technology being multiple input, single output (MISO) and single input, multiple output (SIMO).The following diagram shows MIMO configuration −Advantage of MIMO over Traditional Wireless SystemsIn traditional wireless communication systems, a single antenna is used at the transmitter site, and another single antenna is used at ... Read More

Setting up a wireless internet connection without router is usually done using adhoc network. It is a latin phrase sometimes used to describe a quick fix which can be temporary. Small businesses generally establish ad-hoc computer to computer network, if they do not have access to a router. They use a wireless internet session to do different works like checking email, attending a web-based meeting or browsing the web for a short period of time.Ad-hoc NetworkMany are unaware that, if they have Windows Vista, Windows 7 or Windows XP installed in their system, they can build their own wireless network ... Read More

People who have been using windows operating system usually encounter persistent messages to upgrade to Windows 10. The good news is that, upgrading to Windows 10 is now free. But in case of Apple, it allows its users to upgrade to newest operating system for free at any point. If users delay, they might land themselves in trouble as Windows is taking a very different approach.All those who have not upgraded their system to Windows 10 by June 29, 2016, they need to spend about $119. And those who consider, the cost of upgradation is more than they can handle. ... Read More

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 shorter ranges.Features of CCKCCK is used in wireless LANs to attain theoretical maximum data rates of 11 Mbps.CCK is implemented for transmission in the radio frequency range (RF band) of 2.4GHz – 2.4835GHz.CCK includes a pair of codes called chipping sequences which are complementary to each other. In complementary codes, ... Read More

Rate adaptation is a criteria that determines the performance of IEEE 802.11 wireless networks, or WiFi. Rate adaptation allows transmission to be done at different rates within the wireless network, depending upon the network conditions.In wireless networks, the signal may be strong or weak. Through rate adaptation technique, the data transfer date can be changed depending upon the signal strength, i.e. when the signal is strong, high data rates are adopted, while low data rates are adopted during weak signals.Rate Adaptation AlgorithmsIn traditional rate adaptation algorithms, the lowest permissible data rate was selected for data transfer. Though this ensured that ... Read More

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.IEEE 802.11 ArchitectureThe physical layer architecture of IEEE 802.11 has the following components −Stations (STA) − Stations comprises of all devices and equipment that are connected to the wireless LAN. A station can be of two types −Wireless Access Point (WAP) − WAPs or simply access points (AP) are generally wireless routers that form ... Read More

An ad hoc network is one that is spontaneously formed when devices connect and communicate with each other. The term ad hoc is a Latin word that literally means "for this, " implying improvised or impromptu.Ad hoc networks are mostly wireless local area networks (WLANs). The devices communicate with each other directly instead of relying on a base station or access points as in wireless LANs for data transfer co-ordination. Each device participates in routing activity, by determining the route using the routing algorithm and forwarding data to other devices via this route.Classifications of Ad Hoc NetworksAd hoc networks can ... Read More

Wireless LANs (WLANs) are wireless computer networks that use high-frequency radio waves instead of cables for connecting the devices within a limited area forming LAN (Local Area Network). Users connected by wireless LANs can move around within this limited area such as home, school, campus, office building, railway platform, etc.Most WLANs are based upon the standard IEEE 802.11 standard or WiFi.Components of WLANsThe components of WLAN architecture as laid down in IEEE 802.11 are −Stations (STA) − Stations comprises of all devices and equipment that are connected to the wireless LAN. Each station has a wireless network interface controller. A ... Read More

Carrier Ethernet is an application of Ethernet technology that allows network providers to offer Ethernet services to their customers and to use Ethernet technology. It enables Internet access and communication among local area networks (LANs) of business, academic, private and government organizations.The services and standards of carrier Ethernet have been defined by the Metro Ethernet Forum (MEF). MEF has also developed certification programs and it promotes the global adoption of carrier Ethernet.Carrier Ethernet versus EthernetThe primary attributes of Carrier Ethernet that differentiates it from Ethernet are −A carrier Ethernet network provides service to many organizations, while an Ethernet LAN renders ... Read More