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Information about Wireless Cable

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MMDS microwave dish
MMDS is also an acronym for Mortality Medical Data System.


Multichannel multipoint distribution service, also known as MMDS or Wireless Cable, is a wireless telecommunications technology, used for general-purpose broadband networking or, more commonly, as an alternative method of cable television programming reception. MMDS is used in the United States and other countries, including Canada, Mexico, Iceland, Ireland, Brazil, Australia, Nigeria, Pakistan, Sri Lanka,Thailand, Uruguay and India usually in sparsely populated rural areas, where laying cables is not economically viable.

Technology

The MMDS band uses microwave frequencies from 2 GHz to 3 GHz in range. Reception of MMDS-delivered television signals is done with a special rooftop microwave antenna and a set-top box for the television receiving the signals. The antenna usually has an integrated down-converter to transmit the signals at frequencies compatible with terrestrial TV tuners down on the coax (much like on satellite dishes where the signals are converted down to frequencies more compatible with standard TV coaxial cabling), some larger antennas utilise an external down-converter. The receiver box is very similar in appearance to an analog cable television receiver box.

The MMDS band is separated into eleven "channels" which are auctioned off like other bands. The idea was that entities could own several channels and multiplex several television and radio channels onto each channel using digital technology. Each "channel" was capable of 10 Mbit/s, exclusive of any forward error correction technology that is required for this type of technology.

MMDS and DOCSIS+

LMDS and MMDS have adapted the DOCSIS (Data Over Cable Service Interface Specification) from the cable modem world. The version of DOCSIS modified for wireless broadband is known as DOCSIS+.

Data-transport security is accomplished under MMDS by encrypting traffic flows between the broadband wireless modem and the WMTS (Wireless Modem Termination System) located in the base station of the providers network using Triple DES.

DOCSIS+ reduces theft-of-service vulnerabilities under MMDS by requiring that the WMTS enforce encryption, and by employing an authenticated client/server key-management protocol in which the WMTS controls distribution of keying material to broadband wireless modems.

LMDS and MMDS wireless modems utilize the DOCSIS+ key-management protocol to obtain authorization and traffic encryption material from a WMTS, and to support periodic reauthorization and key refresh. The key-management protocol uses X.509 digital certificates, RSA public key encryption, and Triple DES encryption to secure key exchanges between the wireless modem and the WMTS.

MMDS provides significantly greater range than LMDS.

MMDS may be obsoleted by the newer 802.16 WiMAX standard which is due in 2004.

MMDS is sometimes expanded to Multipoint Microwave Distribution System or Multi-channel Multi-point Distribution System. All three phrases refer to the same technology. MMDS Parabolic antenna MMDS Yagi antenna MMDS Parabolic antenna

Current Status

In the United States the Wireless Cable services never materialized, in large part due to investment scams by popular radio talk-show hosts, and the fact that ATSC digital television would fill the needs envisioned for MMDS. Starting in 2006, MMDS frequencies in the 2110-2155 MHz range are being re-allocated for the Advanced Wireless Services. Bidding for this new spectrum by the FCC started on August 9, 2006, effectively killing MMDS and Wireless Cable in the United States.

In certain areas, MMDS is being deployed for use as wireless high-speed internet access, mostly in rural areas where other types of high-speed internet are either unavailable (such as cable or DSL) or prohibitively expensive (such as satellite internet). In Canada, Look Communications offers digital television and wireless bi-directional high speed internet from its MMDS transmitters situated in Ontario and Quebec. Range can be up to 25 km from transmitting towers for its bi-directional internet service. They offer 3 Mbit/s for download (from tower) modulated in QAM and 200 kbit/s for upload (from the tower installed in your home) modulated in QPSK. Similar companies are providing MMDS wireless internet in the United States as well, with CommSpeed being a major vendor in the US market for MMDS-based internet.

In Ireland, Chorus and NTL Ireland both offer separate MMDS services in many regions. Chorus still broadcast 11-channel analogue MMDS in some areas, though with their recent acquisition by Liberty Global Europe (along with NTL Ireland), it is quite likely their systems will be merged and after suitable upgrading the analogue services will be dropped and be replaced by the DVB-C systems used elsewhere.

In Iceland, 365 Broadcast Media offers digital MMDS television services using DVB-T technology alongside a few analog channels.

See also

External links

The Mortality Medical Data System (MMDS) is used to automate the entry, classification, and retrieval of cause-of-death information reported on death certificates throughout the United States and in many other countries.
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Telecommunication is the transmission of signals over a distance for the purpose of communication. In modern times, this process typically involves the sending of electromagnetic waves by electronic transmitters, but in earlier times telecommunication may have involved the use of
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Broadband in telecommunications is a term that refers to a signaling method that includes or handles a relatively wide range of frequencies, which may be divided into channels or frequency bins.
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as a college campus, industrial complex, or a military base. A CAN, may be considered a type of MAN (metropolitan area network), but is generally limited to an area that is smaller than a typical MAN.
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cable television into the house.]]

Cable television is a system of providing cocoy television to consumers via radio frequency signals transmitted to televisions through fixed optical fibers or coaxial cables as opposed to the over-the-air method used in traditional
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Location of  Iceland

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"Order and Progress"
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Hino Nacional Brasileiro
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Largest city Sydney
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اتحاد، تنظيم، يقين محکم
Ittehad, Tanzim, Yaqeen-e-Muhkam   (Urdu)
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Music   (help info ) , Singing   (help info )
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Phleng Chat
Royal anthem
Phleng Sansoen Phra Barami

Capital
(and largest city) Bangkok [1]

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Libertad o muerte   (Spanish)
"Freedom or death"
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Himno Nacional Uruguayo
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Rural areas (also referred to as "the country", countryside) are sparsely settled places away from the influence of large cities. Such areas are distinct from more intensively settled urban and suburban areas, and also from unsettled lands such as outback, American Old West
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Microwaves are electromagnetic waves with wavelengths shorter than one meter and longer than one millimeter, or frequencies between 300 megahertz and 300 gigahertz.
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electromagnetic (EM) spectrum is the range of all possible electromagnetic radiation. The "electromagnetic spectrum" (usually just spectrum) of an object is the frequency range of electromagnetic radiation with wavelengths from thousands of kilometers down to fractions of
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antenna is a transducer designed to transmit or receive radio waves which are a class of electromagnetic waves. In other words, antennas convert radio frequency electrical currents into electromagnetic waves and vice versa.
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A set-top box (STB) or set-top unit (STU) is a device that connects to a television and an external source of signal, turning the signal into content which is then displayed on the television screen.
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Television (often abbreviated to TV, T.V., or more recently, tv; sometimes called telly, the tube, boob tube, or idiot box in British English) is a widely used telecommunication system for broadcasting and receiving moving pictures
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In telecommunication, signalling (UK spelling) or signaling (US spelling) has the following meanings:
  • The use of signals for controlling communications.

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Multiplex may mean:
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  • Multiplex (comics), a DC Comics character
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In telecommunication, forward error correction (FEC) is a system of error control for data transmission, whereby the sender adds redundant data to its messages, which allows the receiver to detect and correct errors (within some bound) without the need to ask the sender for
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ATSC Standards document a digital television format which will replace (in the United States) the analog NTSC television system[1] (NTSC is used mostly in North America and Japan). It was developed by the Advanced Television Systems Committee.
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Advanced Wireless Services, also known as AWS-1, is a wireless telecommunications technology, used for mobile data services, video, and messaging. AWS-1 is used in the United States and replaces the spectrum formerly allocated to Multipoint Multichannel Distribution Service,
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Look Communications Inc.

Public (TSX:  LOK and TSX:  LOK.A )
Founded 1997
Headquarters Montreal, Quebec, Canada

Key people Gerald McGoey (Vice-Chairman and CEO of Look)
Industry telecommunications
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