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Arbitration Inter-frame Space
Arbitration inter-frame spacing (AIFS), in wireless LAN communications, is a method of prioritizing one Access Category (AC) over the other, such as giving voice or video priority over email. AIFS functions by shortening or expanding the period a wireless node has to wait before it is allowed to transmit its next frame. A shorter AIFS period means a message has a higher probability of being transmitted with low latency, which is particularly important for delay-critical data such as voice or streaming video. AIFS is a time interval between frames being transmitted under the IEEE 802.11e EDCA MAC. It depends on the Access Category and generally depends on the AIFSN, or AIFS-number. AIFS is defined by the formula AIFSN C* ST + SIFS, where the AIFSN depends on the Access Category. Slot time ST (also denoted by \sigma) is dependent on the physical layer. Short Interframe Space (SIFS) is the time between a DATA and ACK frame. AIFSN Cwill be set by the AP in the EDCA Parameter set ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wireless LAN
A wireless LAN (WLAN) is a wireless computer network that links two or more devices using wireless communication to form a local area network (LAN) within a limited area such as a home, school, computer laboratory, campus, or office building. This gives users the ability to move around within the area and remain connected to the network. Through a gateway, a WLAN can also provide a connection to the wider Internet. Wireless LANs based on the IEEE 802.11 standards are the most widely used computer networks in the world. These are commonly called Wi-Fi, which is a trademark belonging to the Wi-Fi Alliance. They are used for home and small office networks that link together laptop computers, printers, smartphones, Web TVs and gaming devices with a wireless router, which links them to the internet. Hotspots provided by routers at restaurants, coffee shops, hotels, libraries, and airports allow consumers to access the internet with portable wireless devices. History ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IEEE 802
IEEE 802 is a family of Institute of Electrical and Electronics Engineers (IEEE) standards for local area networks (LAN), personal area network (PAN), and metropolitan area networks (MAN). The IEEE 802 LAN/MAN Standards Committee (LMSC) maintains these standards. The IEEE 802 family of standards has had twenty-four members, numbered 802.1 through 802.24, with a working group of the LMSC devoted to each. However, not all of these working groups are currently active. The IEEE 802 standards are restricted to computer networks carrying variable-size packets, unlike cell relay networks, for example, in which data is transmitted in short, uniformly sized units called cells. Isochronous signal networks, in which data is transmitted as a steady stream of octets, or groups of octets, at regular time intervals, are also outside the scope of the IEEE 802 standards. The number 802 has no significance: it was simply the next number in the sequence that the IEEE used for standards project ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MAC Address
A media access control address (MAC address) is a unique identifier assigned to a network interface controller (NIC) for use as a network address in communications within a network segment. This use is common in most IEEE 802 networking technologies, including Ethernet, Wi-Fi, and Bluetooth. Within the Open Systems Interconnection (OSI) network model, MAC addresses are used in the medium access control protocol sublayer of the data link layer. As typically represented, MAC addresses are recognizable as six groups of two hexadecimal digits, separated by hyphens, colons, or without a separator. MAC addresses are primarily assigned by device manufacturers, and are therefore often referred to as the burned-in address, or as an Ethernet hardware address, hardware address, or physical address. Each address can be stored in hardware, such as the card's read-only memory, or by a firmware mechanism. Many network interfaces, however, support changing their MAC address. The address ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SIFS
Short Interframe Space (SIFS), is the amount of time in microseconds required for a wireless interface to process a received frame and to respond with a response frame. It is the difference in time between the first symbol of the response frame in the air and the last symbol of the received frame in the air. A SIFS time consists of the delay in receiver RF, PLCP delay and the MAC processing delay, which depends on the physical layer used. In IEEE 802.11 networks, SIFS is the interframe spacing prior to transmission of an acknowledgment, a Clear To Send (CTS) frame, a block ack frame that is an immediate response to either a block ack request frame or an A-MPDU, the second or subsequent MPDU of a fragment burst, a station responding to any polling a by point coordination function and during contention free periods of point coordination function. Implications for Software Radio Because most Software-Defined Radios use a host computer for processing, the SIFS imp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
