WiFi abbreviations
From Teknologisk videncenter
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 |