Allied Command Europe Highband
Allied Command Europe Highband, better known as ACE High, was a fixed service NATO radiocommunication and early warning system dating back to 1956. After extensive testing ACE High was accepted by NATO to become operational in 1964/1965.

The frequency supportability and frequency assignments were profited in accordance with the NATO Joint Civil/Military Frequency Agreement (NJFA).  The system was designed to be a combined  UHF troposcatter/microwave radio system, providing long-range communications in the form of telephone, telegraph and data traffic in the NATO chain of command

Its combined services produced over 200 channels and equipment was in place to multiplex them to contain up to 12 different calls each. There used to be 49 troposcatter links augmented by 40 Line Of Sight Microwave terrestrial stations, located in nine different NATO countries from northern Norway through central Europe to eastern Turkey. The transmitters broadcast at 832.56 - 959.28 MHz producing an average transmitting power of 10 kilowatts.

History
NATO had been established in 1949 with then a supreme command (SHAPE) near Versailles, France, and the regional headquarters (RHQ) Allied Forces Northern Europe (AFNORTH) at Kolsås, Norway (responsible for Denmark, Norway and the UK), Allied Forces Central Europe (AFCENT) at Laffaux, France (responsible for Belgium, France, Germany and the Netherlands) and Allied Forces Southern Europe (AFSOUTH) at Naples, Italy (responsible for Italy, Greece and Turkey).  Supreme command, the three RHQ's and all subordinated units used various communication systems to establish contact: high frequency radio networks, VHF beaming transmitters and civil or military landlines. All systems had their weakness in equipment reliability; in the maximum amount of data transferred; in encryption possibilities and in unauthorized data interception. So in the early 1950s there existed an urgent need for a reliable, foolproof long distance European communications network.

US developed tropospheric diffusion techniques, integrated in a new military communications network appeared to be the solution and in 1956 STC, a planning, design, engineering and installation company had been ordered to develop a new integrated communications network in Europe. This network consisted of a number of "backbone" stations covering the  distance from the north of Norway to the south of Turkey and was initially called the "Over the Horizon Troposperic scatter Communications Net" but was renamed "Allied Command Europe - Highband" (ACE-High). The network would be kept operational until the 1990s as all frequencies then had to be released to the civilian authorities.

After all components had been installed on their locations by Marconi Electronic Systems UK, (from 1968 part of General Electric Company), in 1961 the ACE-High system had officially been transferred to NATO.

In 1966 however France, under president Charles de Gaulle, left NATO and systems had to be rerouted from France to Brunssum in The Netherlands while the former Primary Control Center at Beauvais, was relocated to Lamersdorf, West-Germany.

In the early 1970s, the first geostationary satellites in the "Satellite Communication" network (SATCOM) had been activated thus expanding the ACE-High system.

In 1995 the first British NATO SATCOM IV/B satellites had been activated and because the ACE-High frequencies had to be released for civil TV and mobile phone usage NATO decided to deactivate ACE-High in 1996.  The old NATO connections would be replaced by the "Crisis Response NATO Operating System" (CRONOS) and by connections via internet-routers.

ACE High sites
The ACE High network included the following major sites and terminals, but also connected Line of Sight (LOS) microwave links to other networks reaching C2 centres not listed here.

 AFNORTH-Norway
(NC- Senja) NSEZ Position 69°19'44"N 17°29'49"E TX Equipment:1S + 1R (Scatter Line + Radio Line)
(nca - Höggumpen) NHGZ Pos 69°04'41"N 18°00'16"E 502 m AMSL TX Equipment:1R 
(ND- Bodö) NKLZ *Pos 67°10'23"N 15°01'24"E 801 m AMSL TX Equipment:2S + 1R
(nda - Bodoe Tail - Kletkov) NVAZ Pos 67°10'9"N 15°1'52.25"E TX euipment:1R 
(NE - Mosjöen) NMOZ Pos 65°52'41"N 13°18'11"E 627 m AMSL TX Equipment:2S 
(NF - Trondheim) NSBZ Pos 63°18′41″N 10°56′17"E 677 m AMSL TX Equipment:2S + 1R 
(nfa - Trondheim Tail - Graakallen) Pos 63°25'15"N 10°15'06"E 543 m AMSL TX Equipment:1R 
(NG - Oslo AAA) NSOZ *Pos 60°03'34"N 11°16'09"E 246 m AMSL TX Equipment:2S + 1R 
(Oslo YYY - Svartas) NVAZ Pos 68°18'3"N 14°14'16"E TX Equipment:3R 
(nga - Oslo Tail 01 - Kolsaas)NKOZ Pos 59°55'7"N 10°30'58"E Transmitter Equipment:1R (Radio Line)
(ngb - Oslo Tail 02 - Maakeroy) NVEZ Pos 59°09'22"N 10°26'19"E 14  m AMSL TX Equipment:1R 
(NH - Grimstad - Stormyrheia/hørte) NSMZ Pos 58°27'19"N 08°27'43"E 326 m AMSL TX Equipment:3S 
(NJ - Sola - Lysenut)NLYZ Pos 59°31'40"N 05°54'12"E 792 m AMSL TX Equipment:2S

 AFNORTH-Denmark
(DA - Karup - Torphøj) DTOZ Pos 55°52'28"N 09°21'00"E 135  m AMSL TX Equipment:2S + 1R (Scatter Line + Radio Line)
(daa - Karup Tail - Lundbakke) DLUZ Pos 56°13'49"N 09°09'48"E 68  m AMSL TX Equipment:1R (Radio Line)

AFNORTH-United Kingdom
(EAA - Faroes - Sandfelli 2)
(EA - Shetlands - Mossy Hill) > UMSZ - Mossy Hill > 59°57'17.15"N 01°18'11.60"W 227 m AMSL
(eab - Shetlands Tail Relay - Collofirth Hill) > UCOZ - Collafirth Hill > 60°32'00.75"N 01°23'28.30"W 239 m AMSL
(eac - Shetlands Tail - Saxa Vord) USVZ - Saxa Vord 60°49'37.20"N 00°50'22.59"W 276 m AMSL
(EB - Aberdeen - Mormond Hill) > UMOZ - Mormond Hill 57°36'11.19"N 02°01'51.86"W 227 m AMSL
(eba - Aberdeen Tail - Long Haven Hill) > UBUZ - Long Haven Hill 57°27'31.94"N 1°48'46.07"W 95 m AMSL
(EC - Boulmer - Brizlee Wood) > UBOZ - Brizlee Wood 55°25'05.28"N 1°46'04.26"W 250 m AMSL
(ED - Binbrook - Stenigot) > UBIZ - Stenigot  53°19'36.08"N 00°06'57.44"E 153 m AMSL
(EE - London - Coldblow Lane) > UMAZ - Coldblow Lane  51°17'44.95"N 00°36'51.52"E 194 m AMSL
(eeb - London Tail Relay - Woldingham - RAF Botley Hill Farm)
(eea - London tail - Hillingdon)
RAF Uxbridge – local terminus

AFCENT-France
 (FAN - Paris - Mont Florentin)  FFLZ - Paris North  49°20'27.59"N 02°03'06.79"E 222 m AMSL
 FTAZ - Taverny  49°02'02.88"N 02°13'45.85"E 178 m AMSL
 (fac - Paris Tail (2)- Sant Germain)  48°54'44.67"N 02°01'25.44"E 71 m AMSL
 (fae - Paris Tail (2) - Extension (SHAPE)  48°50'34'19"N 02°06'14.30"E 178 m AMSL
 (fa - Relais Paris - Emeville)  FEMZ - Emeville  49°18'01.83"N 03°00'41.00"E 247 m AMSL
 (faa - Paris Tail (1) - Laffaux)  49°27'15.05"N 03°24'57.39"E 143 m AMSL
 (fad - Relay Paris - Rozoy Bellevalle)  FRBZ - Rozoy Bellevalle  48°55'56.05"N 03°28'24.62"E 219 m AMSL
 (FAS - Paris - Mont Aout)  FAOZ - Paris South  48°46'14.78"N 03°53'25.33"E 216 m AMSL
 (FA - Trier - Rohrbach)  FROZ - Rohrbach  49°03'18.47"N 07°14'40.74"E 376 m AMSL
 (fay - Trier Tail - Kindsbach)  ABHZ - Kindsbach  49°23'48.11"N 07°35'38.32"E 458 m AMSL
 (FC - Lyon - Pierre sur Haute) FLYZ - Lyon  45°39'11.52"N 03°48'33.07"E 1632 m AMSL
 (FD - Nice - Signal de la Chens)  FNIZ - Nice  43°44'53.67"N 06°39'44.85"E 1703 m AMSL

AFCENT-Netherlands
HBRZ - Brunssum 50°56'19.11"N 05°58'35.60"E 95 m AMSL TX equipment 1S + 1R
HMAZ - Maastricht 50°50'25.05"N 05°39'33.78"E 82 m AMSL TX equipment 1S +2R

AFCENT-Belgium
BADZ - Adinkerke
BCAZ - Casteau  Supreme HQ Allied Powers Europe Pos 50°30'05.56"N 03°58'15.69"E 87 m AMSL TX Equipment 2S +2R
BCHZ - Chievres Pos  50°35'7.75"N  3°48'59.84"E TX Equipment 2S +2R
BFRZ - Baraque de Fraiture 50°15'07.94"N 05°43'56.13"E 654 m AMSL TX Equipment 3R

AFCENT-Germany
ABHZ - Kindsbach 49°23'51.24"N 07°35'41.17"E 458 m ü. NN
(AA - Emden - Aurich) AEMZ - Aurich 53°30'32.04"N 07°26'34.83"E 10 m ü. NN
(AB - Moenchengladbach - Roetgen) ALAZ -Lammersdorf 50°39'57.59"N 06°17'14.58"E 593 m ü. NN
(abb - Moenchengladbach Tail (1) - Hehn) AHEZ - Hehn 51°10'51.44"N 06°23'37.77"E 81 m ü. NN
(aba - Moenchengladbach Tail (2) - Millen) 50°45'57.87"N 05°33'47.26"E 151 m ü. NN
(abc - Uedem) AUEZ - Uedem 51°39'39.08"N 06°16'58.97"E 47 m ü. NN
AFEZ - Feldberg 47°52'23.09"N 08°00'59.73"E 1458 m ü. NN

AFSOUTH-Italy
 IDGZ - Dosso dei Galli  45°51'13.66"N 10°22'32.28"E 2174 m AMSL
 IVTZ - Verona Tail ( im West Star Bunker )  45°33'17.89"N 10°45'46.83"E 334 m AMSL
 (IA - Livorno - Monte Giogo)  IMXZ - Livorno  44°19'17.38"N 10°07'30.94"E 1496 m AMSL
 (IAZ - Cavriana - Monte Bosco Scuro)  IMBZ - Cavriana  45°21'00.79"N 10°37'01.46"E 189 m AMSL
 (iaa - Verona Torre 4)  45°27'11.35"N 11°00'30.55"E 164 m AMSL
 (IAY - Lame - Cavanella)  ICEZ - Lame Concordia  45°44'55.99"N 12°52'08.75"E 7 m AMSL
 (iax - Aviano)  IAVZ - Aviano  46°01'23.02"N 12°35'34.19"E 99 m AMSL
 (IB - Rome - Tolfa)  ITLZ - Rome  42°09'01.76"N 11°54'32.73"E 621 m AMSL
 (iba - Rome Tail - Monte Cavo)  IMCZ - Monte Cavo  41°45'04.86"N 12°42'31.03"E 930 m AMSL
 (IC - Neaples - Ischia - Punta Fetto)  IICZ - Neaples  40°35'50.88"N 13°54'08.54"E 639 m AMSL
 (ica - Neaples Tail - Monte Pecorara)  IPEZ - Monte Petrino  41°13'24.29"N 13°57'57.75"E 335 m AMSL
 (icy - Monte Vergine) IMNZ - Monte Nardello  40°56'33.27"N 14°43'07.28"E 1516 m AMSL
 (icz - Monte Vulture)  IVUZ - Monte Vulture  40°57'03.12"N 15°38'10.75"E 1301 m AMSL
 (icv - Monte Iacontenente) IIAZ - Monte Iacontenente 
 (icf - Pietra Ficcata)  IPFZ - Pietra Ficcata  40°34'04.90"N 16°19'21.31"E 586 m AMSL
 (icw - Martina Franca)  IAMZ - Martina Franca 
 (ID - Catanzaro - Monte Mancuso)  IMMZ - Catanzaro  39°01'09.13"N 16°13'32.02"E 1319 m AMSL
 (IDA - Monte Lauro - Cozzo tre Grotte)  ICCZ - Monte Lauro 37°06'52.13"N 14°51'18.96"E 944 m AMSL

 AFSOUTH-Malta
 (idb - Malta - Gharghur)  IDBZ - Malta - Gharghur

 AFSOUTH-Greece
(GA - Kefallina) > GKFZ - Kefallonia 38°10'11.18"N 20°37'08.53"E 1001 m AMSL
(GB - Athens - Pendelikon) > GPKZ - Athens 38°04'50.46"N 23°52'58.14"E 1038 m AMSL
(GBZ - Crete - Ziros) > GZIZ - Ziros 35°03'53.52"N 26°09'14.24"E 786 m AMSL
(GBY - Larissa - Phillon) > GPIZ - Phillon 39°25'22.75N 23°03'11.54"E 1513 m AMSL
(GBW - Vitsi) > GVIZ - Vitzi 40°38'43.34"N 21°23'11.07"E 2009 m AMSL
(GBV - Ismaros) > GISZ - Ismaros 40°53'34.67"N 25°32'56.06"E 612 m AMSL

AFSOUTH-Turkey
(TA - Izmir - Bespinar Tepes) > TBPZ - Izmir - Bespinar Tepes 38°18'48.72"N 27°01'29.89"E 964 m AMSL
(taa - Izmir Tail) > TKYZ - Izmir Tail
(TB - Eskisehir) > TKUZ - Eskishir - Kutahya Dagi 39°25'03.25"N 29°51'19.07"E 1820 m AMSL
(tba - Eskirsehir Tail) > TESZ - Eskirsehir Tail
(TC - Ankara) > TEDZ - Ankara - Elan Dagi 39°48'20.59"N 32°59'32.27"E 1856 m AMSL
(TCK - Merzifon) > TKJZ - Merzifon
(TCW - Persembe) > TPEZ - Persembe
(TCV - Pazar) > TPAZ - Pazar 
(TD - Siwas - Pinarbasi) > TPIZ - Pinarbasi 38°40'38.09"N 36°24'10.59"E 2285 m AMSL
(TG - Adana) > TDDZ - Davudi Dağı 36°49'39.37"N 35°38'18.66"E 515 m AMSL
(tga - Adana Tail) > TDAZ - Adana Tail
(TE - Dyarbakir - Karaka Dagi) > TDIZ > Dyarbakir - Karaka Dagi(tea - Dyarbakir Tail) > TDEZ - Dyarbakir TailBloatli, Turkey

AFSOUTH-Cyprus
(TCZ - Cap Greco) > JCGZ -Cavo Greko'  34°58'00.85"N 34°04'11.41"E 62 m AMSL

Equipment usedOperator's, Organizational, Direct Support, General Support, and Depot Maintenance TM's 11-5820-203-15 and 11-5840-401-12

Initially 60, 30 or 15 ft dish or billboard type antennas have been used in combination with General Electric or RCA AN/MRC80 TRC24; AN/FRC-75 or 39 radio sets. Later being replaced by newer Siemens & Halske EM 120/400 and 12/800 types. The type and beaming angle of the antennas depended of the local site position and its distance to the next relays.

Replacement
The rise of the military SATCOM I-III (1971-1994), SATCOM IV (1995-now) network satellites, internet routers, and the Central Region Integrated Communication System (CRICS) and the Crisis Response Operations in NATO Operating Systems (CRONOS)'' made ACE High obsolete. By the end of the 1980s its  replacement was in fact already available but NATO postponed the ACE High phasing-out until 1995 and as of 1996 the 800 MHz band frequencies became available for civilian use again.

See also
Radio propagation
Tropospheric scatter
Microwave
White Alice Communications System - Cold war era Alaskan tropospheric communications link
List of White Alice Communications System sites
List of DEW Line Sites
Distant Early Warning Line

References

External links
History and details
Photographs of an installation
Troposcatter communication network maps
Website by Gerrit Padberg and Roger Camperi
Italian Website

Telecommunications equipment of the Cold War
Military radio systems
1956 introductions
NATO installations in the United Kingdom
NATO installations in Germany
NATO installations in Norway
NATO installations in Italy
NATO installations in Belgium
Cold War military equipment of the United Kingdom
1956 in international relations
Highband
Tropospheric scatter systems