ALLISS

Disambiguation
* Financial Instruments: The Alliss Grant a US Financial Aid instrument, see [http://www.lsc.cc.mn.us/FinancialAid/allissGrant.cfm] & [http://www.mnscu.edu/students/specialprograms/alliss.html] .
* People: Peter Alliss (UK golfer and radio/TV personality) [http://www.peteralliss.co.uk/ Official Website] .

ALLISS is a fully rotatable antenna system for high power shortwave radio broadcasting in the 6 MHz to 26 MHz range. An ALLISS module is a self contained shortwave relay station that is used for international broadcasting.

FAQ

ALLISS is a special design case of HRS type antennas. True ALLISS systems have solid radiators (horizontal radiating elements) versus tensioned flexible (open) radiators found with all other variations of ITU HRS type antennas systems. The names is based on a concatenation of two French villages ALLois and ISSoudun.

Technological ambiguites

There are some factors that separate true ALLISS technology from run of the mill rotatable HRS Type antennas
* Thales pseudo-ALLISS rotatable antenna designs were acquired from other antenna manufacturers that Thales acquired by corporate transactions.
* Technically only solid radiators distinguish true ALLISS systems from all other rotatable HRS type antennas.
* Only about 12% (estimate) of all HRS antennas in use globally are rotatable, and of these only 28 of the ALLISS systems have solid radiators.
* One must assume that only about 10% of HRS type antennas are rotatable, but compiled statistics are fragmentary. Only about 20% of rotatatble HRS antennas are ALLISS, but this may be a slight overestimate.
* The Transmitter Documentation Project (tdp.org ?) has most but not all stats on shortwave relay station antennas in use or historical.

Corporate name changes

Information about ALLISS can also be found associated with Thomson-CSF -- the previous name of Thales.

Technology FAQ (overview)

ALLISS technology, due to its cost and complexity -- is out of reach to most consumers as a consumer product. Cheaper solutions to ALLISS exist in the shortwave broadcasting technology area.
* Any competent and reasonable transmission planning person should look at all other shortwave transmission options before considering ALLISS.
* As a rule of thumb ALLISS systems should only be purchased if 180 degrees of coverage is necessary.
* ALLISS is only used by well funded broadcasting and telecommunications corporations that intend to use the modules over their design lifespan of 50-60 years.

Technology FAQ (operation)

ALLISS allows a broadcaster to change the following shortwave transmission parameters
* direction (azimuths from 0 to 360 degrees, rate: ~1 deg / 6 sec)
* broadcast frequency
* antenna configuration (ie: HR 4/4/1 -> HR 6/4/1) at any time.

All of these transmission mode changes can take effect in as little as 5 minutes. This flexibility can allow a broadcaster to redirect the entire shortwave transmission network to a strategically important target area in as little as 15 minutes.

ALLISS advantages vs traditional shortwave relay stations

Modular construction
* ALLISS relay stations can be built on a module by module basis.
* An ALLISS module can start broadcasting as soon as construction is completed.

Higher RFI & EMF (electromagnetic) compatibility vs traditional relay stations
* ALLISS modules should be geographically scattered for security and RFI exposure reasons. However, few broadcasters have chosen this option mainly due to poor understanding of the technology.
* Ironically, TDF did not pursue this option at Allouis or Issoudun — a technological blow to French security.

Each ALLISS module is fully automated, so there is no need for technical staff. When there are 2-5 ALLISS modules scattered over several hundred square kilometers, a three person support staff is enough to keep the modules in operation year round (provided these modules are visited monthly for repair and maintenance).

With conventionally designed HRS type antennas shortwave relay stations with their obligatory: transmitter hall, switch matrix, coaxial or open feeder line systems and multiple antennas (~90% of shortwave relay stations are built this way) much larger staffs are required.

Cost per module

Around US$10 million.
* Some modules have been rumored to cost as much as US$15 million.
* With 4 different module versions cost per module can vary by as much as US$5 million.
* At least 30% of the cost of each module is related to the still exotic metallurgy and metalworking requirements needed to construct each module.
* Because of the costly and complex metallurgy construction requirements, ALLISS technology is 'off limits' to many developing nations including even a few advanced nations in the developed world.

Versions of ALLISS modules

According to the current Thales brochure on ALLISS, there are 6 different versions of the ALLISS system. These versions are sorted by date of initial installation.

* 1995: Issoudun and Allouis, France
** "Low Band" Modes (HR) : 4/4, 4/3, 4/2, 2/4, 2/3, 2/2
** "High Band" Modes (HR) : 4/6, 4/4, 4/2, 2/6, 2/4
** Band coverage: 5.9 MHz to 26.1 MHz (10 modules)
** Band coverage: 5.9 MHz to 17.9 MHz (2 modules)

* 1997: Nauen-A, Germany
** "Low Band" Modes (HR) : 4/4, 2/2
** "High Band" Modes (HR) : 4/4
** 2 systems installed

* 1997: Nauen-B, Germany
** "Low Band" Modes (HR) : 4/4
** "High Band" Modes (HR) : 4/4
** 2 systems installed

* 2002: Al-Seela, Oman
** "Low Band" Modes (HR) : 4/4, 2/4, 4/2, 2/2
** "High Band" Modes (HR) : 4/4, 2/4, 4/2, 2/2
** 2 systems installed
** Band coverage: 5.9 MHz to 17.9 MHz

* 2003: China
** "Low Band" Modes (HR) : 4/4, 2/4, 4/2, 2/2
** "High Band" Modes (HR) : 4/4, 2/4, 4/2, 2/2
** Band coverage: 5.9 MHz to 26.1 MHz

Transmitter

Typically ALLISS modules possess a 500 kW polyphase shortwave transmitter.

* Digital 'AM' type transmitters are preferred for their compactness, as opposed to 'push-pull' (Class-B) transmitters for ALLISS installations.
* Essentally all 300 kW and 500 kW PDM, PSM, polyphase (4 x PDM) transmitters are preferred for structural reasons.
* It is not customary to install a 300 kW transmitter in an ALLISS module, but such installations are possible.
* TDF's Montsinnery Relay Station has 2 ALLISS modules installed, but without an installed shortwave transmitter. This same design arrangement is used by the BBC World Service Oman Relay Station Al-Seela.

Antennas (high band)

Three HRS array antennas types are available for broadcasting in the traditional shortwave broadcasting bands.

For tropical and lower frequency shortwave broadcasting
* HR 4/2/1 (using low band antenna)
* HR 2/4/1 (using low band antenna)
* HR 2/2/1

For traditional shortwave broadcasting
* HR 4/2/1
* HR 4/4/1

For highly directional shortwave broadcasting
* HR 6/4/1
* HR 6/2/1

The HRS 6/4/1 is not available for use in the 26 MHz band.

Antennas (low band)

One Low Band antenna exists for Tropical Band broadcasting. It takes up the entire back side of the ALLISS module. This Low Band antenna counterbalances the primary transmission antennas used in traditional shortwave broadcasting.

Relay stations with ALLISS modules

Documentation format — Nation : Broadcaster : City (Modules, Date Sold)
* France : TDF : Issoudun (12 modules, 1993/1997)
* Germany : DW : Nauen (4 modules, 1997)
* French Guiana : TDF : Montsinery (2 modules, 1997)
* Oman : BBCWS & VT Merlin : (2 modules, 2002)
* China : SARFT : Xian(?) : (12 modules, 2005)

Total number of modules sold since 1989: 32

Technological shortcomings

ALLISS technology in spite of its near perfection (for the needs of the typical shortwave broadcaster) has not been adopted to the degree that its designers originally intended.

A list of reasons for this design's slow uptake
* most broadcasters cannot afford the design -- at the cost of 15m USD most ALLISS modules are beyond the reach of most broadcasters; Radio Canada International's average budget in the 2000s has been under 35M CAD (as an example)
* new transmission sites are required: this is a universal civil engineering planning problem that is not improved by ALLISS technology
* no universally agreed upon ITU procedure for express approval of ALLISS technology that local telecommunications regulators (like the Federal Communications Commission in the United States or the Canadian Radio-television and Telecommunications Commission in Canada) can use
* most broadcasters can lease transmission capacity from other broadcasters
* in the post Cold War political climate Russia has opened up its shortwave relay stations to other broadcasters -- this has created surplus of transmission capacity in Eurasia
* traditional HRS antenna type shortwave relay stations can be built much more cheaply and can have more optimally designed antennas for each target area
* there are a lot of compromises in the ALLISS antenna design -- no ALLISS configuration will behave as predictably as a fine tuned fixed azimuth HRS type antenna
* shortwave broadcasting does not have the same overall strategic value it once had during most of the Cold War -- therefore implementing ALLISS is not seen as a national priority
* in many nations that may actually need or benefit from ALLISS broadcasting technology (like Australia) there is a leadership gap either within the international broadcaster or within the foreign affairs departments that keeps the technology from being deployed

See also

General category
* shortwave
* international broadcasting
* shortwave relay station
* Issoudun
* Radio France International

Applicable related technologies
* VOACAP can simulate all ITU HRS antenna types
* HRS type antennas

Broadcasters using ALLISS modules
* BBC World Service
* RFI, Radio France International
* Deutsche Welle
* China Radio International

External links

Audio-visual presentations
* http://www.youtube.com/watch?v=WcGDaFG_Guc
* http://www.youtube.com/watch?v=QWZdtF7g8I4
* http://www.youtube.com/watch?v=9cBwrXhW98I

Technology portals (non-Thales)
* http://HireMe.geek.nz/ALLISS.html