Difference between revisions of "WiFi abbreviations"
From Teknologisk videncenter
m (→Abbreviations) |
m (→Abbreviations) |
||
| Line 105: | Line 105: | ||
| AP || Access point || Gives wireless clients access to the network services. | | AP || Access point || Gives wireless clients access to the network services. | ||
|- | |- | ||
| + | | DCF || Distributed Coordination Function || The 802.11 fundamental media access method. | ||
| + | |- | ||
| + | | PCF || Point Coordination Function || Access Point coordinated media access. | ||
| + | |- | ||
| + | | HCF || Hybrid Coordination Function || | ||
| + | |- | ||
| + | | CSMA/CA || Carrier Sense Multiple Access with Collision Avoidance || Wireless media access method principle. | ||
| + | |- | ||
| + | | IFS || Interframe Space || period of time that exists between transmissions of wireless frames. | ||
| + | |- | ||
| + | | RIFS || Reduced Interframe Space || Highest priority IFS | ||
| + | |- | ||
| + | | SIFS || Short Interframe Space || Second highest priority IFS | ||
| + | |- | ||
| + | | PIFS || PCF Interframe Space || Middle priority IFS | ||
| + | |- | ||
| + | | DIFS || DCF Interframe Space || Lowest priority IFS | ||
| + | |- | ||
| + | | AIFS || Arbitration Interframe Space || IFS used by QoS stations | ||
| + | |- | ||
| + | | EIFS || Extended Interframe Space || IFS used with retransmissions. | ||
| + | |- | ||
| + | | ACK frame || Acknowledge Frame|| Acknowledge the reception of a frame by transmitting an acknowledge frame. | ||
| + | |- | ||
| + | | RTS || Request To Send || A signal requesting the wireless media. | ||
| + | |- | ||
| + | | CTS ||Clear To Send || A signal after RTS acknowledging permission to transmit. | ||
| + | | | ||
|} | |} | ||
[[Category:WiFi]] | [[Category:WiFi]] | ||
Revision as of 09:01, 24 February 2014
Abbreviations
| Abb. | meaning | Notes | |
|---|---|---|---|
| ASK | Amplitude Shift Keying | Keying 0's and 1's by altering the radio carriers amplitude | |
| FSK | Frequency Shift Keying | Keying 0's and 1's by altering the radio carriers frequency | |
| PSK | Phase Shift Keying | Keying 0's and 1's by altering the radio carriers phase | |
| MPSK | Multiple Phase Shift Keying | Keying more than one bit at a time by using four or more phases | |
| IR | Intended Radiator | The active RF transmitter | |
| RF | Radio Frequency | Rate of oscillation in the range of around 3 kHz to 300 GHz corresponding to radio waves | |
| FSPL | Free Space Path Loss | Loss of amplitude of the signal in free space over distance | |
| ISI | Intersymbol Interference | Signal misinterpreted by receiver due to multipath signals out of phase | |
| EIRP | Equivalent isotropically radiated power | The highest RF signal strength transmitted from a particular antenna. Often expressed in dBm | |
| RSSI | Received Signal Strength Indicator | power level received by the receiver radio in dbm | |
| mW | Milli Watt | 0,001 Watt | |
| dB | Decibel | Logarithmic unit used to express the ratio between two values. dB = 10 x log10 Ratio1 / Ratio2 | |
| dBm | Decibel milliwatt | Decibel relative to 1 mW of power. | |
| dBi | Decibel isotropic | Antenna gain compared to a theoretical isotropic antenna | |
| dBd | Decibel dipole | Antenna gain compared to a theoretical isotropic antenna. Add 2,14 dB to get dBi | |
| SNR | Signal to Noise Ratio | Distance between received signal and noise floor. Expressed in dB | |
| DRS | Dynamic Rate Switching | Switching to a higher/lower data rate as the received signal increases/decreases | |
| ISM | Industrial Scientific and Medical | 902 - 928 MHz, 2,4 - 2,5 GHz and 5,725 - 5,875 GHz bands | |
| UNII | Unlicensed National Information Infrastructure | Three 5 Ghz bands each with 100 MHz bandwidth | |
| UNII-1 | UNII-1 (lower band) | 5,150 - 5,250 GHz band ( 4 channels ) | |
| UNII-2 | UNII-2 (Middle band) | 5,250 - 5,350 GHz band ( 4 channels ) | |
| UNII-2E | UNII-2 Extended | 5,470 - 5,725 GHz band 255 MHz bandwidth ( 11 channels ) | |
| UNII-3 | UNII-3 (Upper band) | 5,725 - 5,825 GHz band ( 4 channels ) | |
| FHSS | Frequency Hopping Spread Spectrum | Transmitting data in small chunks hopping from frequency to frequency | |
| DSSS | Direct Sequence Spread Spectrum | Transmitting data is spread across the range of frequencies of the channel. 11 bit PN | |
| GFSK | Gaussian Frequency Shift Keying | FSK modulator using a Gaussian filter to reduce spectral width. | |
| PN | Pseudorandom number | Used with DSSS to encode 1 bit to 11 bits to reduce transmission errors. | |
| CCK | Complementary Code Keying | Used with HR-DSSS to encode 4 bits data to 8 bits using a 8 bit PN | |
| HR-DSSS | High Rate DSSS | Uses CCK encoding to get higher data rate than DSSS | |
| DQPSK | Differential Quadrature Phase Shift Keying | Modulation using four phase shifts each representing two bits | |
| OFDM | Orthogonal Frequency Division Multiplexing | Popular Spread Spectrum technology transmitting between 52 subcarriers | |
| FEC | Forward Error Correction | Allows the receiving system to detect and correct bit errors. | |
| WWAN | Wireless Wide Area Network | Wireless Network spanning wide areas for example GSM or LTE | |
| WMAN | Wireless Metropolitan Area Network | Wireless Network spanning cities for example WiMax | |
| WPAN | Wireless Personal Area Network | Wireless Network spanning small personal areas for example Bluetooth or infrared | |
| WLAN | Wireless Local Area Network | Wireless Network spanning buildings/campusses for example WiFi/802.11 | |
| IS | Integration Service | The process of transforming the MSDU (802.11) frame to other frame standards. Normally ethernet | |
| DS | Distribution System | ||
| CAM | Content Addressable Memory | MAC address table in a switch used to process packets based on destination MAC address | |
| DSS | Distributed System Services | ||
| MSDU | MAC Service Data Unit | Upper layer information in data unit in the body of a 802.11 data frame | |
| WDS | Wireless Distribution System | ||
| SSID | Service Set Identifier | ||
| BSS | Basic Service Set | ||
| BSSID | Basic Service Set Identifier | ||
| BSA | Basic Service Area | ||
| ESS | Extended Service Set | ||
| IBSS | Independent Basic Service Set | ||
| MBSS | Mesh Basic Service Set | ||
| AP | Access point | Gives wireless clients access to the network services. | |
| DCF | Distributed Coordination Function | The 802.11 fundamental media access method. | |
| PCF | Point Coordination Function | Access Point coordinated media access. | |
| HCF | Hybrid Coordination Function | ||
| CSMA/CA | Carrier Sense Multiple Access with Collision Avoidance | Wireless media access method principle. | |
| IFS | Interframe Space | period of time that exists between transmissions of wireless frames. | |
| RIFS | Reduced Interframe Space | Highest priority IFS | |
| SIFS | Short Interframe Space | Second highest priority IFS | |
| PIFS | PCF Interframe Space | Middle priority IFS | |
| DIFS | DCF Interframe Space | Lowest priority IFS | |
| AIFS | Arbitration Interframe Space | IFS used by QoS stations | |
| EIFS | Extended Interframe Space | IFS used with retransmissions. | |
| ACK frame | Acknowledge Frame | Acknowledge the reception of a frame by transmitting an acknowledge frame. | |
| RTS | Request To Send | A signal requesting the wireless media. | |
| CTS | Clear To Send | A signal after RTS acknowledging permission to transmit. |