Multichannel Multipoint Distribution Service

Multichannel Multipoint Distribution Service
MMDS is also an acronym for Mortality Medical Data System.
MMDS microwave dish

Broadband Radio Service (BRS) formerly known as Multichannel Multipoint Distribution Service (MMDS), also known as 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, Canada, Mexico, Dominican Republic, Iceland, Ireland, Ukraine, Russia, Slovakia, Brazil, Barbados, Australia, Nigeria, Pakistan, Panama, Sri Lanka, Thailand, Uruguay, India, Belarus, Lebanon, Cambodia and Kazakhstan. It is most commonly used in sparsely populated rural areas, where laying cables is not economically viable, although some companies may also offer MMDS services in urban areas.



The BRS band uses microwave frequencies at 2.1 GHz and from 2.5 GHz to 2.7 GHz. Reception of BRS-delivered television and data signals is done with a rooftop microwave antenna. The antenna is attached to a down-converter or transceiver to receive and transmit the microwave signal and convert them to frequencies compatible with standard TV tuners (much like on satellite dishes where the signals are converted down to frequencies more compatible with standard TV coaxial cabling), some antennas use an integrated down-converter or transceiver. Digital TV channels can then be decoded with a standard cable set-top box or directly for TVs with integrated digital tuners. Internet data can be received with a standard DOCSIS Cable Modem connected to the same antenna and transceiver.

The MMDS band was separated into 33 6 MHz "channels" which were auctioned off like other bands. The concept was to allow entities to own several channels and multiplex several television, radio, and later Internet data onto each channel using digital technology. Just like with Digital Cable channels, each channel is capable of 30.34 Mbit/s with 64QAM modulation, and 42.88 Mbit/s with 256QAM modulation. Due to forward error correction and other overhead, actual throughput is around 27 Mbit/s for 64QAM and 38 Mbit/s for 256QAM.

The newer BRS Band Plan makes changes to channel size and licensing in order to accommodate new WIMAX TDD fixed and mobile equipment.


Local Multipoint Distribution Service (LMDS) and BRS 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 BRS 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 BRS 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 BRS 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 provided significantly greater range than LMDS.

MMDS may be obsoleted by the newer 802.16 WiMAX standard approved since 2004.

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

Current status

In the United States WATCH Communications (based in Lima, OH), Eagle Vision (based in Kirksville, MO), and several other companies offer MMDS based wireless cable television, internet access, and IP based telephone services.

With T-Mobile USA acquiring the 2.1 GHz AWS band (old MDS band) in most areas of the country, which is used for the modem upstream in MMDS DOCSIS, the future of this kind of service in the USA is in doubt. However, new CPE equipment allows operators to use part of the main 2.5 - 2.7 GHz MMDS Spectrum for modem upstream, ensuring future operation in the United States. With newer WiMAX equipment available, some companies are looking to deploy mobile services instead of fixed services for future expansion.

In certain areas, BRS 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). CommSPEED is a major vendor in the US market for BRS-based internet.[1]

AWI Networks (formerly Sky-View Technologies) operates a number of MMDS sites delivering High-Speed Internet, VoIP, and Digital TV services in Southern Utah USA. AWI has recently upgraded several sites to DOCSIS 3.0 hardware, delivering download speeds up to 100 Mbps. DOCSIS 3.0 has improved peak bandwidth, lower latency, and improved reliability over previous DOCSIS versions.

In the early days of MMDS it was known as Wireless Cable and was used in a variety of investment scams that still surface today.[1] Frequent solicitations of Wireless Cable fraud schemes were often heard on talk radio shows like The Sonny Bloch Show in the mid 1990s.[2]

In Ireland, UPC Ireland (previously Chorus and NTL Ireland) offer MMDS TV services almost nationwide. The frequency band initially allocated was 2500 - 2690 MHz (the “2.6 GHz band”) consisting of 22-23 8 MHz analogue channels, digital TV was restricted to 2524 - 2668 MHz consisting of 18 8 MHz digital channels. Two digital TV standards are used DVB-T/MPEG-2 in the old Chorus franchise area (some areas still broadcast an 11-channel analogue MMDS TV service), and DVB-C/MPEG-2 in the old NTL franchise area. The existing licences expire in 2012 (ntl) and 2014 (Chorus) with an option extend to 2017/2019 following a review which commenced in May 2010.[3]

In Iceland, since Nov 2006 Vodafone Iceland runs Digital Ísland (Digital Iceland) - the broadcasting system for 365 (media corporation), (previously operated by 365 Broadcast Media). Digital Ísland offers digital MMDS television services using DVB-T technology alongside a few analogue channels. The MMDS frequency range extends from 2500-2684 MHz for a total of 23 8 MHz channels, Of these, 21 are considered usable for broadcasting in Iceland. Analogue MMDS broadcasting began in 1993 moving to digital in 2004.

In Dominican Republic, Wind Telecom started operations using MMDS technology in 2008,at that time and ever since it became a pioneer taking advantage of such implementations.The company uses the DVB standard for its digital television transmissions.

See also


  1. ^ Wireless Cable Scams
  2. ^ Sonny Bloch Radio Show Host Charged with Fraud
  3. ^ ComReg Ireland Information Notice - Call for input on potential uses and licensing options of the 2.6 GHz spectrum band

External links

Wikimedia Foundation. 2010.

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