REVOLUTION IN COMMUNICATION

• Document Type: CREST
• Collection: General CIA Records
• Document Number (FOIA) /ESDN (CREST): CIA-RDP92B00181R000300270028-9
• Release Decision: RIFPUB
• Original Classification: K
• Document Page Count: 3
• Document Creation Date: December 27, 2016
• Document Release Date: April 22, 2013
• Sequence Number: 28
• Publication Date: February 14, 1987
• Content Type: OPEN SOURCE

Declassified and Approved For Release 2013/04/23 :CIA-RDP92B00181 8000300270028-9
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DURING the last two decades; military
radio communications ~ have been
revolutionised by the application of solid-
state and digital technology., _
As a result, equipment has .become more
versatile, mole reliable and, in real terms, less
expensive.. It is more compact than its
predecessors and able to operate with less
power.
At the same time, the widespread
:application of modular design techniques
has, to an extent, provided opportunities for
tailoring the miz of standard components
and subsystems to meet the' peculiar
requirements of particular users.
Modular desigrrhas.also been responsible
for extending the functional repertoire of
certain types of kit; a good example of this
is NAPCO's CITQ-270 `snap-on' applique
which is designed to convert the VRG-12 and
other tactical manpack radios for meteor
burst working within the space of a few
minutes. ~ .
The bad news is .that the rate of
technological change is now such that there
is a very rea] danger of systems becoming
obsolete before they are fully fielded. This
is only partially offset ~by the ease of
upgrading, which is a product of the
increased software content of modern
military radio.
In this period, VHF has established itself
.as the favoured band for short-range land- .
based communisations, and FM as the-most
common form of modulation. Here, as the
reduction in channel spacing has continued,
digital frequency synthesizers have played an
important part in arriving at the modern
forward area equipment.
Tactical systems have become smaller and
lighter, to the point where almost identical
By John Williamson~~
sets can appear as either vehicle
communications centres or peripheral
manpacks.
Now, the tactical radio which is entirely
digital up to the IF stage, is just around the
corner. .
Progress in long distance communication
has been less consistent. iJntil quite recently,
HF was the primary means of long haul
military communications.
However, .although in use since 'the early
years of the century, HF had, and has, a
number of intrinsic disadvahtages. While
these were acceptable to earlier generations
of users, by the 1960s they were becoming
increasingly unacceptable for modern
applications.
In particular,.HF propagation was, .and is,
subject to ionospheric disturbance and
distortion, and graphic coverage is variable.
At the. same time, some traffic types -
including high-speed data communications
- were not possible or only possible with a
substantial price penalty.
Moreover, since it was extensively used by
military and non-military users alike, the HF
part of the spectrum was. becoming very
congested.
At the time HF seemed to be running out
of steam,? long haul communications using
geo-synchronously orbiting satellites were
demonstrated to'be a practical proposition,
particularly for naval communications.
One major user, the 'US Navy, began to
put most of its communications eggs into the
~ 1TT's AN/VRC 89 long/short-range SINCGARS
set .
Declassified and Approved For
~ Marconi's Scimitar system at use in combat
conditions
satellite basket, relegating HF to.ammnor fall- .
back role. Initially lacking the financial and
technical .resources to construct their own
military satellite capability, the European
nations continued to develop and refine HF
techniques.
A number of events have subsequently
caused the reliance on satellites as the only
.serious element in long haul, non-wired
military communications to be questioned.
.Even before the suspension of the Shuttle
programme and the latest failure of the
Ariane rocket, the business of actually
launching satellites was rather uncertain.
There was also the related difficulty of
repairing faults in situ. '
More critical, though, was the recognition
that satellites in orbit are highly vulnerable
to hostile attack. Since it was possible to
destroy an incoming high-speed missile at
.near-orbital height, went the reasoning, the
destruction of a virtually stationary object
such as a communications satellite was also
achievable. ?
Growing unease came to a head in the late
19.70s in a US exercise which assumed that
.all friendly satellites had -been knocked out
by enemy .action. Chiefs of staff were
alarmed by the 1950s vintage HF.technology.
which remained at their disposal.' ..
These developments were instrumental in
the revival of US interest in HF, and
-spawned such initiatives as the High
Frequency .Improvement programme and
later, the High.Frequency Anti-Jam (HFAJ) .
project.
. Today, there is much less hostility to
satellite communications than was evident
earlier in the decade. The belief is now that
a hostile force in practice would nor
incapacitate friendly satellites, since this
would be an unequivocal indication c,f irc
Release 2013/04/23 :CIA-RDP92B00181 8000300270028-9
 ~.To make fhe.task?of the enemv.even riinrP Y.
pproved For Release 2013/04/23 :CIA-RDP92B00181 8000300270028-9
comomea;with'an encryption capability.or,:
in what are known as~hybt`id systems, direct
sequence modulafion.'The'latter is.designed
to counter the effects of jamming with
increased signal ,gain: __ -
An example is Teletra's"Hydra series. of
radio sets, one of which _-the Hydra/Y -
future intentions. .
Also, the vulnerability of satellites is -not
confined to one side or the other, and in a
tit-for-tat offensive against satellites, the
enemy would probably be.inconvenienced.in
the same measure as the friendly .forces.
Electronic warfare . (EW) . is now . an
established part of short-range military radio
communications and is fast becoming a trend
for HF. General Western interest in the
various EW technologies was heightened
.after the studies of the 1970s Middle East
conflict showed that the Egyptians were able
to use Soviet radio disruption techniques to
some effect against the Israelis.
Frequency hopping, which the South
Africans.claim to have pioneered, is one of
the main weapons in the EW armoury.
Disruption . .
The basic idea of frequency hopping is that
if .a number of synchronised tranceivers
(usually operating in a .net in land.
applications) is .changed sufficiently
frequently throughout the duration of a
message, the disruption?or acquisition of the
message becomes extremely difficult. .
In operation, .radios are. programmed to
dwell for ,a very short time in a pseudo
.random sequence on the aarge-number of
.frequencies which .constitute.-the `.hop. set'.
Two types of hop set are ,possible -
orthogonal and non-orthogonal... , -. .
The first is designed so what there is no
mutual .interference between different hop
sets. With the latter, different hop sets may
occasionally use the same frequency at .the
same time.
However, in operational nets which have
a low. send-to-receive ratio, tt;e probability
of this happening . is quite .small and
deterioration in performance is negligible. .
Non-orthogonal -can also make more
efficient use 'of the available frequency.
spect-rum.
is.claimed `by its manufacturer to give a 9dB ~ Ha
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rns
orp
s RF-3490 digital data buffer s
advantage when compared to more designed fordara applications on the NA/PRC-.117
conventional fro.,,,e..,,.. L___-_- _ --- ro.,,,e.,.,.. ~___---
achieved with frequency hopping. Marconi .between failure) levels required by the
reports that its .Scimitar system has 'be
en military..?
demonstrated working. satisfactorily when Although 'in ahe course of the year the
placed L00 m away from three 1 kW MT
BF of the first examples ofthe frequency . .
jammers. "h
opping variants of .SINCGARS was
This notwithstanding
some early ho
e
,
p
s reportedly lowered from 200 to 400 hours,
'for the technology have not been
fulfilled
h
.
.. t
e official requirement'is for 1250 hours.
The history of one of the .major frequency At present, the army has agreed to.accept
hopping programmes -. the USA's single 300
non-frequency hopping radios in 1.989
channel ground/air radio . system .for field trials in 1990. If successful,.tfie army
(SINCGARS) is instructive in this regard
will
h
:
t
en authorise ITT in 1991 to_produce
SINCGARS is a $5.6 billion .project 300 frequency hopping sets which must meet
designed to furnish:a jam-
roof
l
p
rep
acement .the original MTBF. specification.
for the US Army's old AN/P,RC=77 -and This:means that if the reliability problems
AN/VRC-12 radios.
are .sorted out, no lar a-scale
g .Production
Conceived in the mid=1970s
th
'e
,
e ro
ct
P J quantities of frequency hopping radios will
initially looked at medium hopping (around be released until around 1994, with exports
150 hops/sec) and':fast hopping.(around 2000 banned until the turn of .the .century.
changes per. second) radio variants, and Export -markets aside, there are .mixed
involved a number of US and joint US/UK ~ views about what these developments could
manufacturers. In the event; fast hopping mean for ITT's competitors in this sector.
proved to be unattainable, and in 1983 ITT Some companies envisage ashort-term~US
was.awarded.the main contract to ;produce market opening up with?the military buying
a 200 hops/sec system.. " a proven off-the-shelf frequency hopping
By the spring of last year, SINCGARS was system.
12 ?months behind schedule. Then, last Most .of such equipment is produced by
December, representatives of the army and overseas manufacturers: Leaving aside for
ITT agreed to further restructure .the political reasons 'South African (and
programme. The cause of this was ITT's probably Israeli), sources of supply,
inability to achieve the MTBF (mean time European companies .such as Marconi,
R
~ Part of the Marconi ICS3 broad-band HF system
acal, Plessey, Thomson and Telettra could
compete in a market worth tens of millions
of pounds.
Ii3NE'S DEFENCE VJEEKLI' 74 FEgRUAP,Y lag? - ~ ~ -
Declassified and Approved For Release 2013/04/23 :CIA-RDP92B00181 8000300270028-9
 hopping s Declassified and Approved For Release 2013/04/2
nor woula tney work with SINCGARS.
Modifying equipment to be compatible with
SINCGARS in the future might easily go
beyond the revised schedule for the
introduction of SINCGARS itself, and the
spares holding and maintenance tasks would
. be considerably complicated.
Some observers consider that a more likely
outcome will be to attempt to speed up the
.SINCGARS programme by the appointment
of a major second source supplier with
experience in frequency hopping technology.
If 300 hops/sec is a medium speed for
VHF systems, 100 hops/sec would be quite
,fast for long haul narrowband links. In
simple terms, .the faster the rate of hops
required, the more the energy that has to be
introduced into the system.
This energy is residual, and can produce
problems of side-lobes, interference and
noise to compound the difficulties of the
already less than optimum HF environment.
The relationship between hop rate and the
defensive and operational requirement of
pazticulaz forces is quite complex. An enemy
will find it useful to intercept and analyse a
friendly force's signal traffic at some times,
and shut communications down by jamming
on spot frequencies at other times.
To circumvent this, the friendly force
frequency hops its communications.
Hop sequence
In the first circumstance this leaves the
hostiles with the task of replicating the hop
sequence and rate to access any message's
content. At very high hop rates, the laws of
physics intervene and due to the propagation
times of signals, it becomes impossible for
an enemy receiver to change frequency with
sufficient rapidity to accomplish its task.
So far as jamming is concerned, frequency
hopping can be countered by either using a
follower jammer or spreading power over a
wide frequency band.
In both cases, the amount of power
available to the jammer on any one
frequency will probably be lower than that
originally transmitted. This means that to
succeed in its task, the jammer will be obliged
to move closer to its target, thereby providing
some opportunity for cat and mouse
manoeuvring on the part of the friendly force
until the source of disruption is brought
within range of defensive assets.
Among the survivors of the recent US
enthusiasm for HF is the HFAJ. Originally
inspired by the US Navy, HFAJ now has
multi-service applications and could be worth
an initial $3 billion to an equipment supplier..
The technological requirement has so far
proven so complex that only proposals
submitted by a team led by Rockwell and
Marconi, ?and supported by Westinghouse
and Magnavox, have received serious
attention.
Although.this, singularity flies in the face
bf conventional US procurement practices,
the partners are optimistic that they will get
the go-ahead.
Latest reports suggest that the first HFAJ
contracts will be announced in March, and
involve systems for the US Navy. These will
be based on Marconi's ICS3 broadband
system architecture, which is used by the
Royal Navy, the Royal Netherlands Navy
and the Hellenic Navy, and has been sold to
the US Navy for use in its new LHD1 class
of combined assault ships.
ICS3 is a broadband system which, its
manufacturers argue, has key advantages
when it comes to frequency hopping at HF.
The system's architecture enables all
transmissions to be amplified and radiated
simultaneously using a single power bank of
amplifiers and broadband antennas. This
arrangement removes the need for any RF
mechanical units. ~ ~?
The net result is that frequency changes
are relatively fast, and can be made in rapid
succession.
Additionally, the radiated HF power can
be adjusted instantly and independently for
each frequency, and the separation between
adjacent HF channels can be reduced to as
little as 50 kHz. - _.
Moreover, narrowband HF and MF
channels can be incorporated to suit
BAGLIET
' FAST OFF SHORE PATROL ANO ATTACK CRAF
t tL. (06) 57.56.223.57.82.709
TELEX 625824 SAMI I -FAX (O6) 5782709
~ Harness system for the Scimitar family of radios
particular users' requirements. ICS3 has the
US nomenclature AN/URC-109.
Not all armies or navies share the US belief
in the value or practicality of frequency.
hopping in modern military
communications.
The British Army, for example, has not
yet made a final commitment to the
.technology, although it has conducted trials
with Racal's Jaguar and 1`4arconi's Scimitar
systems.
In part, these trials were designed to test
the feasibility of managing large numbers of
frequency hopping radios in very close
proximity - an environment which would
be encountered in a European theatre of war.
Initial scepticism has apparently been
reduced after 100 radios were operated
satisfactorily inside a single field.
In the absence of a large home mazket, UK
manufacturers have had to turn their
attentions abroad where, indeed, they have
had some considerable success in selling the
idea and the technology. ' .
Racal has sold over ?70 million worth of
its system, _ a sum which includes a ?20
million deal with Oman.
Australia's .planned Raven system, in
which Plessey is the major contractor, has
major frequency hopping capabilities.
Meanwhile, Marconi has most recently
been awarded a ?40 milion-plus contract to
supply derivatives of its broadband Scimitar
system to the Swedish Army and elements
of the Swedish Navy. ~~~~
244
JANE'S DEFENCE WEEKLY la FERRUARV iag7
Declassified and Approved For Release 2013/04/23 :CIA-RDP92B00181 8000300270028-9