259109 Telecommunications in Thailand
Submarine Cable Networks
Instructor Dr. Ukrit Mankong,
Department of Electrical Engineering, Chiang Mai University
Number of lectures
3 hours
Objectives
1. Students should understand basic network topologies
2. Students should understand the importance of optical backbone networks
3. Students should be familiar with Thailand's fiber optic on-land backbone networks
4. Students should be familiar with Thailand's and Global submarine networks
version 1.1 on 3 June 2009
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1. History of submarine cable networks
A short history of submarine cables © Telstra
The story really began in 1795 when a Spaniard named Salva suggested the idea of underwater
telegraphic communication. But nothing significant happened until 1850 when a single wire cable
manufactured by the Gutta Percha Company was laid between England and France. International
telecommunications had started.
Unfortunately, the first cable did not last very long - on the night after it was connected a
French fisherman caught the cable and cut a length out of it. A heavier armoured cable with four
conductors was successfully laid the following year. For the first time two countries separated by
sea were able to communicate by means of the electric telegraph.
A boom in the laying of submarine cables followed. Many cables were placed in service
across the Irish Sea, the North Sea, the Mediterranean and even the Black Sea.
Then came the greatest challenge - the laying of the first trans-Atlantic cable. It is hard now
to realize just what an enormous task this was. The 2,500 miles (4025km) of cable took a total of
20,500 miles (33,000km) of copper wire for the conductor, and the outer sheathing took 367,000
miles (590,500km) of iron wire. The total length of wire used was enough to go round the world
thirteen times.
The cable was loaded into two specially converted warships, one British and one American.
Laying from the USS Niagara, steaming west from Ireland lasted only a few days. After 300 miles
(482km) the cable snapped.
A second attempt with laying commencing in mid-Atlantic suffered the same fate. But on
the third attempt, despite some very rough weather, luck - and the cable - held, and in August, 1858
the Old World and the New were joined telegraphically if only for a short time. The cable failed on
September 1, and it was not until July, 1866, that the first really successful Atlantic cable was laid
by the S.S. Great Eastern.
Cables multiplied. News which had previously taken up to six months to reach distant parts
of the world could now be relayed in a matter of hours, In 1902 the "All Red" route was completed.
This consisted of a series of cable links across the Pacific Ocean, connecting New Zealand
and Australia with Vancouver and through the Trans-Canada and Atlantic lines to Europe.
Charges for messages sent over the cable were high. An ordinary message from Australia or
New Zealand to England cost 15 shillings a word; newspaper messages three shillings and eleven
pence a word. As a result the cable news section of newspapers seldom reached half a column and
in some cases was so scanty as to be barely intelligible.
Submarine telegraph cables remained the only fast means of international communication
for 75 years. Then, in the 1920s came the dramatic impact of radio. Shortwave, high frequency
radio could transmit voices or pictures. International telex was also made possible by radio. For 30
years radio carried all the world's conversations and most of its messages. But the weaknesses of
radio soon became apparent. Its capacity was too limited, conversations were often difficult, and
certain atmospheric conditions could disrupt radio communications for days at a time.
Some alternative communication system had to be found, combining the dependability of
submarine cable and the diversity of radio. The break-through came with two new technical
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developments. First, in the 1940s, came the submersible repeater which made trans-oceanic speech
transmission possible. Until its development engineers did not have any means of overcoming the
loss of signal strength over long cables.
In 1956 the first submarine cable incorporating repeaters came into operation across the
Atlantic. With a capacity of 36 two-way voice channels, each capable of subdivision into a number
of telegraph channels, TAT-1 as it was called, demonstrated the great potential of this new form of
telecommunications and triggered an explosion in public demand for international
telecommunications facilities.
Next, research teams working for the British Post Office in the 1950s developed the modern
lightweight coaxial cable which had a high-tensile steel core and a Polythene outer skin and did not
need to be armoured in deep water. This cable, instead of using a number of wires grouped together
consisted basically of an inner and an outer concentric conductor which carried the electrical
speech signals.
Then came a vast new concept - a high quality global submarine cable network linking the
nations of the Commonwealth. By December 1961, the first link, CANTAT-1 providing 80 twoway voice circuits had been opened between Britain and Canada, and by July 1 962 Australia and
New Zealand were in communication through the first stage of the second link, COMPAC. In
December of the same year the second stage from Auckland to Fiji was opened. The laying of the
final stages, Fiji to Hawaii and Hawaii to Canada soon followed and the completed COMPAC
cable was opened on December 3, 1963.
Although these new telecommunications systems were created to satisfy a demand, they in
turn created heavier demands and a vast network of cables has been laid beneath the seas of the
world.
In 1975 the 480 circuit TASMAN Cable was completed to Australia. ANZCAN Cable,
which replaced COMPAC Cable, was the last of the Pacific Ocean analogue cables to be installed
to Australia. A-I-S Cable (1986) which lands at Perth, WA is of the same design as ANZCAN
Cable and was the last of Telstra's analogue cables to be installed. All cables installed since A-I-S
have been of fibre optic design.
World fiber optic submarine cables map
Fig. 1 Current map of global fiber optic submarine networks (www.nrc.nl)
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2. Network topologies
Network topology is a way that we can connect different places to each other in a communication
system. For example, we can link 76 provinces of Thailand in many different ways. However, the
final choice of a network must be most economical and there are only three basic designs from
which all other layouts are derived.
2.1 Bus topology
We have a length of optical fiber called the bus, and nodes are connected to the bus one after the
other. A Node is a location in the network which can be a single computer, an equipment, a
large router or a set of network elements that share a physical location, etc. The bus layout is
shown in Fig. I. Bus topology is very simple to construct and can be expanded simply by joining
new devices to the bus cable. If the bus cable is damaged, the whole network may fail.
Fig. 2 Bus topology
2.2 Star topology
In this design, we have a central connection called a hub. This is a central router that is
connected to all of the nodes as in Fig. 3. Providing the hub is fast enough it can handle all
routing requirements. It can also do more than this. It can provide the management with the
details of who is sending what data to whom. This can monitor data holdups so that the system can
be upgraded if necessary.
As each node can easily be disconnected without interfering with the whole system, faults
can be isolated more easily. The disadvantage is that if the hub fails, the whole system goes
down.
Fig. 3 Star topology
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2.3 Ring topology
Fig. 4 Ring topology
This is simply a modified version of the bus topology. The two ends of the bus are simply joined
together to form a ring as shown in Fig. 4.
There are a couple of problems with this system in that a failure of any node will stop the
rotation of the token and the whole network will fail immediately. Expanding the network by
adding another node is only possible if the ring is broken and the network is shut down. (Note that
this information is a little outdated as modern ring has a failsafe in the opposite direction, i.e. the
data can be sent both ways around the ring. Hence a break between a pair of nodes will not render
the network unusable.)
2.4 Hybrid
Fig. 5 Hybrid topology
In real life, hybrid topologies are often used, for example in Fig. 5. Geography as well as
population size and economic importance among the nodes will determine the type of topology that
will be used. In the next section we will study a core network of one of the fiber optic systems in
Thailand.
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3. Fiber optic backbone networks
A backbone network is a part of data network that connects a diverse locations and regions
together. It usually covers a large distance and handles very high traffic. If we consider data
network within Thailand. A backbone network will be the one that links different provinces and
regions together. For example, there may be several subnetworks in Chiang Mai but all of them
must connect to the same backbone network to send information to Bangkok.
It is important that a backbone link must have very high capacity. If we compare
different types of links as in Table 1, we will see that optical fibers will be the best choice. In fact,
the reason that we have broadband Internet today to everywhere on earth is because we have fiber
optic systems.
Table 1 Summarization of various data transmission technologies
Physical medium
Speed
Technology
Application
Wireless
9.6 – 14.4 kbit/s
GSM
Mobile phones
Twisted pair copper wire
Up to 56 kbit/s
POTS
Landline phones
Wireless
56-384 kbit/s
GPRS/EDGE
Mobile phones
Wireless
400 kbit/s
Satellite
Internet access
Wireless
Up to 42 Mbit/s
UMTS
3G mobile phones
Twisted pair copper wire
512 kbit/s – 8 Mbit/s
DSL
Home Internet
Coaxial cable
512 kbit/s – 52 Mbit/s Cable modem
Home Internet
Wireless
Up to 70 Mbit/s
WiMAX
Mobile Internet
Twisted pair / optical fiber 100 Mbit/s
Fast Ethernet
LAN Access
Optical fiber
100-1000 Mbit/s
PON
Home Internet
Optical fiber
155 Mbit/s
OC-3/STM-1
Internet backbone
Optical fiber
2.5 Gbit/s
OC-48/STM-16
Internet backbone
Optical fiber
10 Gbit/s
OC-192/STM-64 Internet backbone
4. Thailand's ground fiber optic networks
Currently in Thailand, telecommunication network operators have their own on-land fiber optic
cable networks. The reasons are their difference in network structures, equipments, corporate
structures and their paces of development. Government is not fast enough to provide backbone
cables for all network operator. Operators that own optical fiber networks include CAT, TOT,
TT&T, AIS, DTAC and True. Moreover there are two other players in fiber infrastructure
consisting of Electricity Generating Authority of Thailand (EGAT) and Provincial Electricity
Authority (PEA).
Most fiber optic cables on-land are along power lines and main roads. It is not uncommon
to find 5 or more bundles of cables provided by several operators on a single route. We will thus
pick only the backbone network of one operator to study. Fig. 6 shows the fiber optic backbone
network of TOT.
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Fig. 6 TOT backbone fiber optic network (as of 2009)
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5. Thailand's and Global submarine cable network
The submarine cable networks of Thailand and the world are now fiber optics. The networks in
our country will have to connect with cable networks of this region and eventually to the
intercontinental networks to make up the world backbone systems.
There are two Thai investors of submarine networks: CAT and Jasmine International. The
systems owned by both corporations will be covered in our lectures.
5.1 Submarine cable systems by CAT
(http://www.catdatacom.com)
CAT owns International and Domestic Submarine Cable systems. Their international systems are
the ones that connect to the international route. Most of these networks are joint investment with
the carriers in other countries. CAT also has domestic submarine cable network (DSCN) along the
gulf of Thailand.
5.1.1 International routes
1. Malysia – Thai (M-T) optical fiber submarine cable system
M-T links between Thailand and Malaysia. It is 1,318 km (711.66 nmi) in length. It operates with
PDH system and has the capacity of 560 Mbits/s. The operation began in August 1994.
Fig. 7 M-T fiber network
2. Thailand-Vietnam-Hongkong (T-V-H) optical fiber submarine cable system
The cable links Thailand and Hong Kong, and is approximately 3,400 km. The cable use PDH
technology which again has the capacity of 560 Mbits/s. The cable started operation in December
1995.
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Fig. 8 T-V-H fiber network
3. Asia Pacific Cable Network (APCN) optical fiber submarine cable system
APCN links 9 Asian countries including Thailand, Malaysia, Singapore, Indonesia, Philippines,
Taiwan, Hong Kong, Japan and South Korea and is approximately 12,000 km long. The cable uses
newer SDH technology with optical amplifier. It has the capacity of 5 Gbits/s. The operation
started in 1996.
The cable landing points are in Petchaburi (Thailand), Mersing (Malaysia), Changi
(Singapore), Ancol (Indonesia), Lantau (Hong Kong), Batangas (Philippines), Toucheng (Taiwan),
Pusan (Korea) and Miyazaki (Japan).
Fig. 9 APCN fiber network
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4. FLAG EURO-ASIA (Fiber Optic Link Around the Globe) optical fiber submarine cable
system
FLAG (Euro-Asia section) provides telecommunication connection for Asia, Middle East and
West Europe regions. It links the United Kingdom, Spain, Italy, United Arab Emirates, India,
Malaysia, Thailand, Hong Kong, China, South Korea and Japan. It is 28,000 km long. The
landing points in Thailand are located in Satun and Songkhla. The cable uses SDH technology
with optical amplifiers, and has the capacity of 5 Gbit/s. It has been in operation since November
1997.
Fig. 10 FLAG EURO-ASIA fiber network
5. SEA-ME-WE 3 (South East Asia – Middle East – Western Europe 3) Optical fiber
submarine cable system
SEA-ME-WE3 is an optical submarine cable linking South East, Middle East and Western Europe
regions, 33 countries in total. It has landing points in the United Kingdom, Germany, Belgium,
France, Portugal, Morocco, Italy, Greece, Turkey, Cyprus, Egypt, Republic of Djibouti, Saudi
Arabia, Oman, United Arab Emirates, Pakistan, India, Sri Lanka, Myanmar, Thailand, Malaysia,
Singapore, Indonesia, Australia, Brunei Darussalam, Vietnam, Philippines, Macau, Hong Kong,
China, Taiwan and Japan. The cable utilizes WDM (Wavelength Division Multiplexing) or multiwavelength technology with the capacity of 10 Gbit/s and can be upgraded to 20 Gbit/s. The
landing point in Thailand is Satun. The cable was commissioned in August 1999.
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Fig. 11 SEA-ME-WE 3 fiber network
6. Thailand – Indonesia – Singapore (TIS) optical fiber submarine cable system
TIS links Thailand, Indonesia and Singapore and is 1,100 km long. It uses DWDM technology
with the capacity of 30 Gbit/s and can upgrade to 320 Gbit/s. It started operation in November
2003.
Fig. 12 TIS fiber network
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7. SEA-ME-WE 4 (South East Asia – Middle East – Western Europe 4) optical fiber
submarine cable systemu
SEA-ME-WE 4 connects 14 countries in Europe, Middle East and South East Asia which are
France, Algeria, Tunisia, Italy, Egypt, Saudi Arabia, United Arab Emirates, Pakistan, Sri Lanka,
India, Bangladesh, Thailand, Malaysia and Singapore. It is approximately 20,000 km long. The
system uses DWDM technology and has the capacity level of Tbit/s. The cable has a landing point
in Satun. It started operation in November 2001.
Fig. 13 SEA-ME-WE 4 fiber network
8. AAG (Asia America Gateway) optical fiber submarine cable system
It is the first optical fiber submarine cable with high capacity that connects Asia continent with
America continent. It has landing points in Thailand, Malaysia, Singapore, Brunei Darussalam,
Vietnam, Hong Kong, Philippines, Guam, Hawaii and California. It has the capacity of 1.92 Tbit/s
using DWDM technology and SDH. The cable is now under construction and is expected to be in
operation in the first quarter of 2009.
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Fig. 14 AAG fiber network
5.1.2 Domestic routes operated by CAT
CAT domestic submarine cable network links telecommunication circuits within Thailand. It is
890 km long using WDM and optical amplification technology with the capacity of 5 Gbit/s. It
was commissioned on May, 2001, connecting Chonburi, Phetchaburi, Chumporn, Koh Samui and
Songkhla.
Fig. 15 CAT domestic fiber network
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5.2 Submarine cable systems by Jasmine International
Jasmine Submarine Telecommunications Co., Ltd or JSTC was established in 1991. In the same
year, a twenty-year concession was granted by Telephone Organization of Thailand (TOT) in order
for JSTC to carry out the building, transfer and operation of a 1,300 km submarine fiber optic cable
network along the east coast of Thailand (The East Coast project.) the network construction was
completed ahead of schedule which enabled the East Coast project to be in service since September
17, 1993.
Due to its high performances, JSTC was awarded the second concession by TOT in form of
a supplement to the Concession Agreement in the year 1996.
Thai Long Distance
Telecommunications Co., LTD or TLDT was hence established in the same year in order to fully
support the Supplementary Agreement. The company's mission is to carry out the design,
construction and maintenance of a 1,000 km submarine fiber optic cable network, which is
inclusive of 720 km submarine cable and 280 km of land cable along the west coast of Thailand
(The West Coast project). The West Coast project includes a land bridge to connect each end of
both projects and the international links (Thai-Malaysia).
Fig. 16 Jasmine international fiber network
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6. Exercises
Please select the best answer.
1. Which choice is not a basic network topology?
a) Bus
b) Star
c) Ring
d) Chain
2. Which statement is correct?
a) A backbone network should be a star layout for greatest capacity.
b) A backbone network is usually a hybrid between different topologies.
c) A connection break in a ring network will cause the network unusable.
d) Connecting to ends of a bus layout will form star layout.
3. Which physical medium should be used in backbone network?
a) copper wire
b) coaxial cable
c) satellite
d) optical fiber
4. Which transmission medium provides greatest mobility?
a) wireless
b) optical fiber
c) coaxial cable
d) twisted pair copper
5. The first submarine cable in the world was laid between which two countries?
a) England – France
b) England – USA
c) Ireland – USA
d) France – USA
6. Why are optical fibers used in on-land backbone infrastructure in Thailand?
a) optical fibers provide the most bandwidth
b) optical fibers are provided by the Government
c) optical fibers cost much less than other media
d) optical fibers can withstand natural disasters
7. What is the speed that can be provided by optical fibers?
a) 56 kb/s
b) 400 kb/s
c) 2 Mb/s
d) >100 Mb/s
8. Which is the earliest fiber project of Thailand in operation?
a) M-T network
b) Jasmine east coast c) AAG network
d) APCN
9. The system that sends several wavelengths of light along the same optical fiber is called …
a) ATM
b) WDM
c) SDH
d) PDH
10. Which of these fiber optic network does not provide international access?
a) M-T network
b) T-V-H network
c) APCN
d) Jasmine East Coast project
11. Which submarine fiber network connects Thailand to North America?
a) FLAG
b) SEA-ME-WE 3
c) AAG
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d) T-I-S
12. Old submarine fiber networks use a system that can provide maximum data rate of 560
Mbit/s. What is the system called?
a) PDH
b) WDM
c) SDH
d) SONET
13. Which submarine fiber network connect the largest number of countries together?
a) T-I-S
b) M-T
c) APCN
d) SEA-ME-WE 3
14. Which is not a landing point for submarine fiber networks within Thailand?
a) Satun
b) Petchaburi
c) Samut Prakarn
d) Songkhla
15. What is the most recent submarine cable project in Thailand?
a) APCN
b) AAG
c) T-I-S
d) FLAG Euro-Asia
16. What is not true about submarine fiber network?
a) it is the main communication channel to outside of Thailand
b) the optical fiber cables require strong outer protection
c) it is slower than Satellite network
d) it can be damaged by natural disasters
17. Thailand does not have a fiber optic communication system that links directly to …
a) Philippines
b) Canada
c) India
d) France
18. Most long distance international submarine fiber networks resemble which network
topology?
a) Bus
b) Star
c) Ring
d) Cluster
19. Which submarine fiber network does not provide access to Europe from Thailand?
a) FLAG Euro-Asia
b) SEA-ME-WE 3
c) SEA-ME-WE 4
d) APCN
20. Which submarine fiber network that connects to Thailand has capacity over 1 Tbit/s?
a) M-T
b) T-V-H
c) AAG
d) APCN
Answers: 1d, 2b, 3d, 4a, 5a, 6a, 7d, 8b, 9b, 10d, 11c, 12a, 13d, 14c, 15b, 16c, 17b, 18a, 19d, 20c
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