What Frequencies are Used in Cellular, Electronic, Radio and Wireless Communications and Power Lines? September 8, 2006Posted by healthyself in .5 mG - 4 MG, .9 mG, 1 mG, 1.6 W/kg, 1.8 GHz, 10 kV/m, 10 Mbit/s, 10 mG, 10 Watts Per Kb in the Head, 100 Mbit/s, 100 mG, 1000 mG, 10000 gauss, 11 mG, 115 kV, 13.56 MHz, 15 mG, 17 mG, 1800-2000 MHz, 2 mG, 2 W/kg, 2.32.5 GHz, 2.4 GHz, 2.5 GHz, 20 mG, 200 mG, 217 Hz, 230 kV, 250 kbit/s, 3 GHz, 3 kHz, 3.1-10.6 GHz, 3.5 GHz, 300 GHz, 33 mG, 4 mG, 4.4 mG, 40 Kbit/s, 40000 bit/s, 410 Kbit/s, 450 mG, 5 GHz, 500 HMz, 500 kV, 6.6 mG, 60 Hz Magnetic Fields, 7 mG, 800-1800 MHz, 824-849 MHz, 868 MHz, 9.6 kbit/s-16 Mbit/s, 900 mHz, 902-924 MHz, 908.42 MHz, 914 MHz, 935-960 MHz, 9600 bit/s, Cell phone safety, Frequencies.
FREQUENCIES AND OPERATING PROTOCOLS OF CELLULAR WIRELESS COMMUNICATION SYSTEMS
The early cellular networks used an analog transmission protocol (called frequency-division multiple access – FDMA), in which speech frequency modulates a continuous wave carrier. In the USA these cellular systems operate in the 824 – 894 MHz frequency range (824-849 MHz for the mobile/hand-helds and 869-894 MHz for the base stations), which was formerly allocated to UHF television channels 69-84.
At the beginning of the 1990s these systems were reaching the limits of their capacity in many service areas. This led to the introduction of new classes of cellular service using digital techniques, such as time-division multiple-access (TDMA), hybrid TDMA/FDMA, and more recently code-division multiple-access (CDMA). These digital systems operate in the same frequency band as the analog systems, but provide more voice channels per radio channel. In Europe, the most commonly used cellular system is called GSM (Global System for Mobile Communication), which is a hybrid TDMA/FDMA system, and operates in the 935-960 frequency band.
Personal Communication Services (PCS) is a newer wireless technology that operates in the 1800-2000 MHz band, using both TDMA and CDMA technologies. Compared with analog cellular systems, PCS systems operate at lower power levels, with more closely spaced cells and lower power handsets.
In the USA, the Federal Communications Commission originally authorized up to two cellular service providers per service area. However, to promote competition, new frequency bands have been created, and new services are being introduced. These include specialized mobile radio (SMR) and enhanced specialized radio (ESMR), which operate at frequencies just below those used for cellular service. In addition, two PCS carriers are also licensed to operate in many regions of the United States.
RF energy includes waves with frequencies ranging from about 3000 waves per second (3 kHz) to 300 billion waves per second (300 GHz). Microwaves are a subset of radio waves that have frequencies ranging from around 300 million waves per second (300 MHz) to three billion waves per second (3 GHz).
Current mobile phone systems operate at frequencies between 800 and 1800 MHz. It is important not to confuse such RF fields with ionizing radiation, such as X-rays or gamma rays. Unlike ionizing radiation, RF fields cannot cause ionization or radioactivity in the body. Because of this, RF fields are called non-ionizing.
802.11b and 802.11g standards use the 2.4 gigahertz (GHz) band, operating (in the USA) under Part 15 of the FCC Rules and Regulations. Because of this choice of frequency band, 802.11b and 802.11g equipment can incur interference from microwave ovens, cordless telephones, Bluetooth devices, and other appliances using this same band. The 802.11a standard uses the 5 GHz band, and is therefore not affected by products operating on the 2.4 GHz band.
Which part of the radio frequency spectrum may be used varies between countries, with the strictest limitations in the USA. While it is true that in the USA 802.11a and g devices may be legally operated without a license, it is not true that 802.11a and g operate in an unlicensed portion of the radio frequency spectrum. Unlicensed (legal) operation of 802.11 a & g is covered under Part 15 of the FCC Rules and Regulations. Frequencies used by channels one (1) through six (6) (802.11b) fall within the range of the 2.4 gigahertz amateur radio band. Licensed amateur radio operators may operate 802.11b devices under Part 97 of the FCC Rules and Regulations that apply.
Ultra-Wideband (UWB) is a technology for transmitting information spread over a large bandwidth that should, in theory and under the right circumstances, be able to share spectrum with other users. A February 14, 2002 Report and Order by the Federal Communications Commission (FCC)  authorizes the unlicensed use of UWB in 3.1–10.6 GHz.
Ultra Wideband was traditionally accepted as impulse radio, but the FCC and ITU-R now define UWB in terms of a transmission from an antenna for which the emitted signal bandwidth exceeds the lesser of 500 MHz or 20% bandwidth.
Cypress’s “WirelessUSB™” is a protocol that uses the 2.4 GHz ISM band with a range from 10 meters (at max 1 Mbit/s) to 50 meters (at max 62.5 kbit/s) and is designed for Human Interface Devices (HIDs), with current offerings from companies such as Belkin, Logitech, and Virtual Ink.
HomeRF used FHSS (frequency hopping spread spectrum) in the 2.4 GHz frequency band and could achieve a maximum of 10 Mbit/s throughput; its nodes can travel within a 50 meter range of an access point while remaining connected to the PAN (personal area network).
(VFIR) infrared transceivers available such as the TFDU8108 operating from 9.6 kbit/s to 16 Mbit/s. The UFIR (Ultra Fast Infrared) protocol is also in development. It will support speeds up to 100 Mbit/s.
Bandwidth: 9,600 bit/s or 40,000 bit/s, fully interoperable
Range: Approximately 100 feet (or 30 meters) assuming “open air” conditions, with reduced range indoors depending on building materials, etc.
Frequency band: The Z-Wave Radio uses the 900 MHz ISM frequency bands. 908.42 MHz in the US 868.42 MHz in Europe.
In Europe, the 868 MHz band has a 1% duty cycle limitation, meaning that a Z-wave unit can only transmit 1% of the time. This limitation is not present in the US 908 MHz band, but US legislation imposes a 1 mW transmission power limit (as opposed to 25 mW in Europe). Z-wave units can be in power-save mode and only be active 0.1% of the time, thus reducing power consumption dramatically.
INSTEON-Frequency 902 to 924 MHz
LibertyLink’s transceivers provide 410 kbit/s data rates using time-division-duplexing of a Gaussian Minimum Shift Keyed (GMSK) modulated magnetic field at 13.56 MHz.
Columbia Rural Electric Association subsidiary offers 2.4 GHz Wi-Fi service across a 3,700 mi² (9,500 km²) region within Walla Walla and Columbia counties in Washington and Umatilla County, Oregon.
ZigBee devices are required to conform to the IEEE 802.15.4-2003 Low-Rate Wireless Personal Area Network (WPAN) standard. The standard specifies its lower protocol layers—the physical layer (PHY), and the medium access control (MAC) portion of the data link layer (DLL). This standard specifies operation in the unlicensed 2.4 GHz, 915 MHz and 868 MHz ISM bands. In the 2.4 GHz band there are 16 ZigBee channels, with each channel requiring 3 MHz of bandwidth. The center frequency for each channel can be calculated as, FC = (2400 + 5*k) MHz, where k = 1, 2, …, 16.
The radios use direct-sequence spread spectrum coding, which is managed by the digital stream into the modulator. BPSK is used in the 868 and 915 MHz bands, and orthogonal QPSK that transmits two bits per symbol is used in the 2.4 GHz band. The raw, over-the-air data rate is 250 kbit/s per channel in the 2.4 GHz band, 40 kbit/s per channel in the 915 MHz band, and 20 kbit/s in the 868 MHz band. Transmission range is between 10 and 75 metres (33~246 feet), although it is heavily dependent on the particular environment. The maximum output power of the radios is generally 0 dBm (1 mW).
The 802.16 specification applies across a wide swath of RF spectrum. However, specification is not the same as permission to use! There is no uniform global licensed spectrum for WiMAX. In the US, the biggest segment available is around 2.5 GHz, and is already assigned, primarily to Sprint Nextel, along with Clearwire in more rural areas. Elsewhere in the world, the most likely bands used will be around 3.5 GHz, 2.3/2.5 GHz, or 5 GHz, with 2.3/2.5 GHz probably being most important in Asia.
“At cellular telephone frequency bands of 900MHz and 1.8GHz, the current U.K. NRPB investigation levels raised the U.K. permitted levels to 10 Watts per Kg in the head. The 1991 USA ANSI/IEEE C95.1 guidelines set the SAR at 1.6 W/Kg, and the CENELEC pre-standard states 2 W/Kg for the public. GSM Cellular-phones can deliver well over 2 W/Kg into head tissue during their output pulses, but they are said to comply because the average power is only about one-eighth of the pulse power (GSM & PCN digital phones), as up to eight calls share one channel using Time Division Multiple Access (TDMA) with each handset pulsing in one of eight time slots. Unlike the earlier analogue phones, the digital GSM ones emit a series of short pulses at a basic repetition rate of 217Hz.”
"A typical U.S. home has the Earth's constant magnetic field of about 450 mG and a 60-Hz background magnetic
field level (primarily not from power lines) that ranges from 0.5 mG to 4 mG with an average value of 0.9 mG.
Five percent of the homes have fields above 2.9 mG, and 1% are above 6.6 mG. For comparison sake,
one study reports that electrical powerline workers experience an average field of 11 mG.
Typical transmission power lines produce average fields at distances of 30 and 60 meters as follows: E (V/m at 30/60 m) B (mG at 30/60 m) 115 kV 0.07/0.01 1.7/0.4 230 kV 0.3/0.05 7.1/1.8 500 kV 1.0/0.3 12.6/3.2 "As a simple example, a two wire 500 MW transmission line at 500 kV draws 500 amperes in opposing directions in the two wires. From Ampere's law a single wire of 500 A produces a field of 33 mG at a distance of 30 m. If two opposing currents of 500 A are separated by 4 meters, the field will be 4.4 mG (in the plane of the wires). By reducing the separation to 1 m, the field falls to 1.1 mG. At a doubled distance of 60 m, the field from the single conductor is 17 mG and the fields from the paired conductors are 1.1 mG for a 4-meter separation and 0.3 mG for 1-meter separation. Motor and appliance electrical coils produce either magnetic dipole or quadrupole fields that diminish as the inverse square or cube of the distance, respectively.
Average fields at a distance of 30 cm are: color television (7 mG), microwave (4 mG),
analog clocks (15 mG), electric razors (20 mG, 100 mG at 15 cm) and hair driers (1 mG, 300 mG at 15 cm)."
Questions to peruse….
If every one of these frequencies affect the human body in a different way, some may be positive and some negative. It may affect different people in different ways depending on their frequency. If we are made of energy, what affect are these frequencies having on people individually and collectively?