Resources
Recommended Books
Terminology
| Radio Frequency | RF | circuits and systems transmitting and receiving radiated wireless signals |
| Intermediate Frequency | IF | intermediate stage in a receiver or transmitter signal path where further filtering and amplification is applied (450kHz to 400MHz) |
| Time Domain Multiple Access | TDMA | method of sharing the same radio channel by assigning short time slots for transmission. employed by digital cellular standards IS-136, IS-54, and GSM/GPRS |
| Code Division Multiple Access | CDMA | method of sharing the same radio channel by spread-spectrum (DS-SS) transmitters. the set of spreading codes is carefully selected to minimize interference with each other |
| Frequency Division Multiple Access | FDMA | method of sharing a range of frequency spectrum by dividing up the spectrum into individual channels, as with all radio systems |
| Orthogonal Frequency Division Multiplexing | OFDM | digital modulation technique which uses DSP to combine multiple subcarriers in a manner so as to achieve high bitrates and spectral efficiency. used in IEEE 802.11a. |
| Carrier Sense Multiple Access Collision Detection | CSMA-CD | method of sharing the same radio channel. sharing devices monitor the channel for activity before transmission. in the event two devices begin to transmit at the same time, each detects the resulting collision and backs off for a random period before retrying |
| Frequency Modulation | FM | analog modulation scheme where the instantaneous frequency of an RF carrier is varied in accordance with the voltage of a message signal such as voice or music |
| Frequency Shift Keying | FSK | digital modulation scheme where a “1″ could be represented by an RF carrier being offset in frequency by a small positive amount known as the FM Deviation and a “0″ is represented by the carrier being offset by the same negative amount. |
| Gaussian-filtered FSK | GFSK | FSK with a Gaussian filter applied to the baseband data signal which has the effect of shaping the resultant modulated RF spectrum. |
| Gaussian Minimum Shift Keying | GMSK | digital modulation scheme. robust and spectrally efficient. |
| Amplitude Shift Keying | ASK | digital modulation scheme where a “1″ is represented by one RF carrier wave amplitude level and a “0″ is represented by another, lower amplitude level |
| On/Off Keying | OOK | digital modulation scheme where a “1″ is represented as an RF carrier wave being on and a “0″ is represented by the RF carrier being off |
| Frequency Hopping Spread Spectrum | FH-SS | transmission scheme where the carrier frequency changes rapidly in a secret pseudo-random pattern, which has the effect of distributing the average signal power over a large frequency range |
| Direct Sequence Spread Spectrum | DS-SS | transmission scheme where each data symbol is chipped or spread over a large bandwidth in a pseudo-random secret pattern. |
| unit of RF power | dBm | Decibels of power relative to one milliWatt.PdBm = 10 x log(PW) + 30 |
| sensitivity | measure of receiver performance - specifies minimum signal level that a receiver can decode with a certain minimum performance such as <1% BER, <20% BLER, or >12dB SINAD. | |
| Wireless Local Area Network | WLAN | system allowing wireless communication between multiple computers, such as Wi-Fi |
| Wireless Personal Area Network | WPAN | short-range wireless system interconnecting simple devices such as cellular phones, audio devices, or sensors, such as Bluetooth |
Regulatory Approvals Agencies
| European Telecommunications Standards Institute | ETSI | Europe |
| Federal Communications Commission | FCC | USA |
| Industry Canada | Canada |
Wireless Standards
| Industrial Scientific Medical | ISM | license-free set of North American bands allowing about 1mW of power for narrowband transmitters (FCC 15.249) and 1W for spread-spectrum transmitters (FCC 15.247). 902-928MHz, 2.400-2.483GHz, and 5.725-5.850GHz bands. |
| Short Range Device | SRD | low-power, low-range devices operating in 433-434MHz (10mW, <10% duty cycle) and 868-870MHz European bands |
| Remote Keyless Entry | RKE | keyfob wireless door unlocking for automobiles. typically at 315MHz and 433MHz (FCC Part 15.231 for Intermittent Control Signals) |
| IEEE 802.11 | original WLAN standard created in 1997 for 1 or 2Mbps in the 2.4GHz ISM band | |
| IEEE 802.11b | Wi-Fi | WLAN standard, 2.4GHz global band, 1~11Mbps, 100mW power, 150ft indoor range typical, 300ft outdoor range typical |
| IEEE 802.11a | WLAN standard, 5.8GHz ISM band, 1~54Mbps, 50ft range typical, OFDM | |
| IEEE 802.11g | WLAN standard, 2.4GHz global band, up to 54Mbps | |
| Bluetooth (IEEE 802.15.1) | WPAN standard targeted at cable replacement for cellular phones and audio headsets for example. Operates in the 2.4GHz band. <1Mbps GFSK, FH-SS | |
| ZigBee (IEEE 802.15.4) | Emerging WPAN standard targeted at low-cost, long battery life sensor, home and industrial automation. Operates in the 868MHz (20kbps), 915MHz (40kbps), and 2.4GHz (250kbps) ISM bands | |
| Ultra Wide Band (IEEE 802.15.3) | UWB | Emerging WPAN standard targeted at high-rate (11~110Mbps) multimedia consumer applications. 3.1GHz to 10.6GHz band. |
| WiMax (IEEE 802.16a) | Emerging standard intended for fixed broadband applications such as multimedia and high-speed internet access replacing wired T1 links. Operates in the 2.4GHz global band, 5.8GHz and 3.5GHz bands | |
| Global Standard for Mobile communication | GSM | digital cellular standard operating at 1900/850MHz in North America and 900/1800MHz in Europe. GMSK modulation. |
| General Packet Radio Service | GPRS | enhancement to GSM networks providing packet data networking. practical datarates up to 53kb/s are possible using multi-slot downlinks |
| Mobitex | Wireless packet data standard (8kb/s GMSK) developed by Ericsson, operating at 900MHz in North/South America, 400MHz in Europe, and 850MHz in China. | |
| Global Positioning System | GPS | navigation system involving 24 satellites covering the Earth which generate signals at 1575MHz that a GPS receiver uses to triangulate it’s position anywhere around the globe within about 5m |
