1.
SEA-ME-WE 3
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SEA-ME-WE3 or South-East Asia - Middle East - Western Europe 3 is an optical submarine telecommunications cable linking those regions and is the longest in the world, completed in late 2000. It is led by France Telecom and China Telecom, and is administered by Singtel, the Consortium is formed by 92 other investors from the telecom industry. It was commissioned in March 2000, according to the cable system network administrators website, the system capacity has been upgraded several times. The cable system itself has two pairs, each carrying 48 wavelengths of 10 Gbit/s. In December 2009, the 4th 10G Upgrade increased WDM channels from 48 to 64 per fibre pair, on 1 Jan 2015, the 5th Capacity Expansion was distributed to all the owners. Data capacity of the network is increased significantly with 100G technologies. In November 1996, additional MOUs were signed to extend the system from Singapore to the Far East, finally in January 1997, the Construction and Maintenance Agreement for Sea-Me-We 3 was signed by 92 International Carriers. By end-2000 the entire network was completed, on 26 December 2006 this link severed, causing major disruption to internet services to and from the Far East. The cause of this was suspected to be a magnitude 7.1 earthquake off the coast of Taiwan and it was stated that the link would take 3 weeks to repair. S. and Europe from the Middle East and South Asia. Over 70 percent of the network in Egypt was down, on 19 December 2008, the cable was again severed, simultaneously with SEA-ME-WE4, the FLAG FEA cable, and the GO-1 cable. On 10 January 2013, the cable was severed, this time 1,126 kilometres from the Tuas cable station in Singapore. The repair ship ASEAN Explorer was sent to the site, a tentative repair date of 09 April 2013 has been posted but still position isnt clear when it will get restore. On 30 November 2014, the cable again experienced a problem in the Jakarta to Perth sector, the fault is still being investigated. ASEAN Explorer appeared onsite of the Cable Breakage point on the 24th December 2014 which involved over a week of repairs, Cable restored on 1 January 2015 On 8 January 2015, The cable once again experienced problems on the Perth to Jakarta Section. On 15 September 2015 the cable was cut at segment 3.3 causing significant disruption to services from Australia to Singapore. Service disruptions caused particular impact for Apple customers due to the release of the iPhone 6, iOS9, apples services were reported as being crippled for Telstra customers but the impact was noticeable for all other Australian ISPs. This disruption is expected to be repaired sometime after Mid October 2015 and this is the third time that the cable has been cut in this segment in just over 2 and a half years. On 25 September 2015 at 03,07 UTC, The cable once again experienced problems at SMW3 S3.3 at about 1143 km from Tuas cable station
2.
Satellite
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In the context of spaceflight, a satellite is an artificial object which has been intentionally placed into orbit. Such objects are called artificial satellites to distinguish them from natural satellites such as Earths Moon. In 1957 the Soviet Union launched the worlds first artificial satellite, since then, about 6,600 satellites from more than 40 countries have been launched. According to a 2013 estimate,3,600 remained in orbit, of those, about 1,000 were operational, the rest have lived out their useful lives and become space debris. Approximately 500 operational satellites are in orbit,50 are in medium-Earth orbit. A few large satellites have been launched in parts and assembled in orbit. Over a dozen space probes have been placed into orbit around other bodies and become artificial satellites to the Moon, Mercury, Venus, Mars, Jupiter, Saturn, a few asteroids, Satellites are used for many purposes. Common types include military and civilian Earth observation satellites, communications satellites, navigation satellites, weather satellites, Space stations and human spacecraft in orbit are also satellites. Satellite orbits vary greatly, depending on the purpose of the satellite, well-known classes include low Earth orbit, polar orbit, and geostationary orbit. A launch vehicle is a rocket that throws a satellite into orbit, usually it lifts off from a launch pad on land. Some are launched at sea from a submarine or a mobile maritime platform, Satellites are usually semi-independent computer-controlled systems. Satellite subsystems attend many tasks, such as power generation, thermal control, telemetry, attitude control, the first fictional depiction of a satellite being launched into orbit was a short story by Edward Everett Hale, The Brick Moon. The idea surfaced again in Jules Vernes The Begums Fortune, in 1903, Konstantin Tsiolkovsky published Exploring Space Using Jet Propulsion Devices, which is the first academic treatise on the use of rocketry to launch spacecraft. He calculated the speed required for a minimal orbit. In 1928, Herman Potočnik published his book, The Problem of Space Travel — The Rocket Motor. He described the use of orbiting spacecraft for observation of the ground, in a 1945 Wireless World article, the English science fiction writer Arthur C. Clarke described in detail the possible use of communications satellites for mass communications. He suggested that three geostationary satellites would provide coverage over the entire planet, the first artificial satellite was Sputnik 1, launched by the Soviet Union on October 4,1957, and initiating the Soviet Sputnik program, with Sergei Korolev as chief designer. This in turn triggered the Space Race between the Soviet Union and the United States, Sputnik 1 helped to identify the density of high atmospheric layers through measurement of its orbital change and provided data on radio-signal distribution in the ionosphere
3.
Intelsat
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Intelsat, S. A. is a communications satellite services provider. As of March 2017, Intelsat is to merge with Softbank backed OneWeb, the agreement is to merge in a share-for-share deal. SoftBank will buy voting and non-voting shares in the company for $1.7 billion in cash. Shares that Softbank-OneWeb will buy in the company will be bought for $5 per share. As of March 2011, Intelsat operates a fleet of 52 communications satellites and they claim to serve around 1,500 customers and employ a staff of approximately 1,100 people. The intergovernmental organization began on 20 August 1964, with 11 participating countries, on 6 April 1965, Intelsat’s first satellite, the Intelsat I, was placed in geostationary orbit above the Atlantic Ocean by a Delta D rocket. In 1973, the name was changed and there were 80 signatories, Intelsat provides service to over 600 Earth stations in more than 149 countries, territories and dependencies. By 2001, INTELSAT had over 100 members and it was also this year that INTELSAT privatized and changed its name to Intelsat. Since its inception, Intelsat has used versions of its dedicated Intelsat satellites. Intelsat completes each block of spacecraft independently, leading to a variety of contractors over the years, Intelsat’s largest spacecraft supplier is Space Systems/Loral, having built 31 spacecraft, or nearly half of the fleet. The network in its early years was not as robust as it is now. Fortunately, during the Apollo 11 moonwalk, the moon was over the Pacific Ocean, and so other antennas were used, as well as INTELSAT III, to avert the US governments interference with Intelsat, Intelsats senior management unsuccessfully considered relocating the IGO to another country. On 18 July 2001, Intelsat became a company,37 years after formation. Prior to Intelsats privatization in 2001, ownership and investment in INTELSAT was distributed among INTELSAT members according to their use of services, investment shares determined each member’s percentage of the total contribution needed to finance capital expenditures. Satellite services were available to any organization, and all paid the same rates. Today, the number of Intelsat satellites, as well as ocean-spanning fibre-optic lines, modern satellites are more robust, lasting longer with much larger capacity. Intelsat Americas-7 experienced a power failure on 29 November 2004. The satellite returned to service with reduced capacity, Intelsat was sold for U. S. $3. 1bn in January 2005 to four private equity firms, Madison Dearborn Partners, Apax Partners, Permira and Apollo Global Management
4.
Indian Ocean
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The Indian Ocean is the third largest of the worlds oceanic divisions, covering 70,560,000 km2. It is bounded by Asia on the north, on the west by Africa, on the east by Australia, the Indian Ocean is known as Ratnākara, the mine of gems in ancient Sanskrit literature, and as Hind Mahāsāgar, in Hindi. The northernmost extent of the Indian Ocean is approximately 30° north in the Persian Gulf, the oceans continental shelves are narrow, averaging 200 kilometres in width. An exception is found off Australias western coast, where the width exceeds 1,000 kilometres. The average depth of the ocean is 3,890 m and its deepest point is Diamantina Deep in Diamantina Trench, at 8,047 m deep, Sunda Trench has a depth of 7, 258–7,725 m. North of 50° south latitude, 86% of the basin is covered by pelagic sediments. The remaining 14% is layered with terrigenous sediments, glacial outwash dominates the extreme southern latitudes. The major choke points include Bab el Mandeb, Strait of Hormuz, the Lombok Strait, the Strait of Malacca, the Indian Ocean is artificially connected to the Mediterranean Sea through the Suez Canal, which is accessible via the Red Sea. All of the Indian Ocean is in the Eastern Hemisphere and the centre of the Eastern Hemisphere is in this ocean, marginal seas, gulfs, bays and straits of the Indian Ocean include, The climate north of the equator is affected by a monsoon climate. Strong north-east winds blow from October until April, from May until October south, in the Arabian Sea the violent Monsoon brings rain to the Indian subcontinent. In the southern hemisphere, the winds are milder. When the monsoon winds change, cyclones sometimes strike the shores of the Arabian Sea, the Indian Ocean is the warmest ocean in the world. Long-term ocean temperature records show a rapid, continuous warming in the Indian Ocean, Indian Ocean warming is the largest among the tropical oceans, and about 3 times faster than the warming observed in the Pacific. Research indicates that human induced greenhouse warming, and changes in the frequency, among the few large rivers flowing into the Indian Ocean are the Zambezi, Shatt al-Arab, Indus, Godavari, Krishna, Narmada, Ganges, Brahmaputra, Jubba and Irrawaddy River. The oceans currents are controlled by the monsoon. Two large gyres, one in the northern hemisphere flowing clockwise and one south of the equator moving anticlockwise, during the winter monsoon, however, currents in the north are reversed. Deep water circulation is controlled primarily by inflows from the Atlantic Ocean, the Red Sea, north of 20° south latitude the minimum surface temperature is 22 °C, exceeding 28 °C to the east. Southward of 40° south latitude, temperatures drop quickly, surface water salinity ranges from 32 to 37 parts per 1000, the highest occurring in the Arabian Sea and in a belt between southern Africa and south-western Australia
5.
Base transceiver station
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A base transceiver station is a piece of equipment that facilitates wireless communication between user equipment and a network. UEs are devices like mobile phones, WLL phones, computers with wireless Internet connectivity, the network can be that of any of the wireless communication technologies like GSM, CDMA, wireless local loop, Wi-Fi, WiMAX or other wide area network technology. BTS is also referred to as the base station, node B or, simply. For discussion of the LTE standard the abbreviation eNB for evolved node B is widely used, though the term BTS can be applicable to any of the wireless communication standards, it is generally associated with mobile communication technologies like GSM and CDMA. In this regard, a BTS forms part of the base station subsystem developments for system management, typically a BTS will have several transceivers which allow it to serve several different frequencies and different sectors of the cell. A BTS is controlled by a parent base station controller via the station control function. The BCF is implemented as a unit or even incorporated in a TRX in compact base stations. The BCF provides an operations and maintenance connection to the management system. The basic structure and functions of the BTS remains the same regardless of the wireless technologies, a BTS is usually composed of, Transceiver Quite widely referred to as the driver receiver, DRX are either in form of single, double or a composite double radio unit. It basically does transmission and reception of signals and it also does sending and reception of signals to and from higher network entities. Power amplifier Amplifies the signal from DRX for transmission through antenna, combiner Combines feeds from several DRXs so that they could be sent out through a single antenna. Allows for a reduction in the number of antenna used, multiplexer For separating sending and receiving signals to/from antenna. Does sending and receiving signals through the same antenna ports, antenna This is the structure that the BTS lies underneath, it can be installed as it is or disguised in some way. Alarm extension system Collects working status alarms of various units in the BTS and extends them to operations, control function Controls and manages the various units of BTS, including any software. On-the-spot configurations, status changes, software upgrades, etc. are done through the control function, baseband receiver unit Frequency hopping, signal DSP. Diversity techniques To improve the quality of the signal, often two receiving antennas are used, placed at a distance equal to an odd multiple of a quarter of the corresponding wavelength. For 900 MHz, this wavelength is 30 cm and this technique, known as antenna diversity or space diversity, avoids interruption caused by path fading. The antennas can be spaced horizontally or vertically, horizontal spacing requires more complex installation, but brings better performance
6.
GSM
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As of 2014 it has become the de facto global standard for mobile communications – with over 90% market share, operating in over 219 countries and territories. This expanded over time to include communications, first by circuit-switched transport, then by packet data transport via GPRS. Subsequently, the 3GPP developed third-generation UMTS standards followed by fourth-generation LTE Advanced standards, GSM is a trademark owned by the GSM Association. It may also refer to the most common voice codec used, the decision to develop a continental standard eventually resulted in a unified, open, standard-based network which was larger than that in the United States. In February 1987 Europe produced the very first agreed GSM Technical Specification, the MoU drew-in mobile operators from across Europe to pledge to invest in new GSM networks to an ambitious common date. In 1989, the Groupe Spécial Mobile committee was transferred from CEPT to the European Telecommunications Standards Institute, in parallel, France and Germany signed a joint development agreement in 1984 and were joined by Italy and the UK in 1986. In 1986 the European Commission proposed reserving the 900 MHz spectrum band for GSM, the former Finnish prime minister Harri Holkeri made the worlds first GSM call on July 1,1991, calling Kaarina Suonio using a network built by Telenokia and Siemens and operated by Radiolinja. In the following year,1992, saw the sending of the first short messaging service message, work began in 1991 to expand the GSM standard to the 1800 MHz frequency band and the first 1800 MHz network became operational in the UK by 1993 called and DCS1800. Also that year, Telecom Australia became the first network operator to deploy a GSM network outside Europe and the first practical hand-held GSM mobile phone became available. In 1995, fax, data and SMS messaging services were launched commercially, in the same year, the GSM Association formed. Pre-paid GSM SIM cards were launched in 1996 and worldwide GSM subscribers passed 100 million in 1998, in 2000 the first commercial GPRS services were launched and the first GPRS-compatible handsets became available for sale. In 2001 the first UMTS network was launched, a 3G technology that is not part of GSM, worldwide GSM subscribers exceeded 500 million. In 2002 the first Multimedia Messaging Service were introduced and the first GSM network in the 800 MHz frequency band became operational, EDGE services first became operational in a network in 2003 and the number of worldwide GSM subscribers exceeded 1 billion in 2004. By 2005, GSM networks accounted for more than 75% of the cellular network market. In 2005 the first HSDPA-capable network also became operational, the first HSUPA network launched in 2007. Worldwide GSM subscribers exceeded three billion in 2008, GSM is a second-generation standard employing time-division multiple-Access spectrum-sharing, issued by the European Telecommunications Standards Institute. GSM, for the first time, set a standard for Europe for wireless networks. It was also adopted by many countries outside Europe and this allowed subscribers to use other GSM networks that have roaming agreements with each other
7.
UMTS
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The Universal Mobile Telecommunications System is a third generation mobile cellular system for networks based on the GSM standard. UMTS uses wideband code division multiple access radio access technology to offer greater spectral efficiency, UMTS specifies a complete network system, which includes the radio access network, the core network and the authentication of users via SIM cards. The technology described in UMTS is sometimes referred to as Freedom of Mobile Multimedia Access or 3GSM. Unlike EDGE and CDMA2000, UMTS requires new base stations and new frequency allocations, UMTS supports maximum theoretical data transfer rates of 42 Mbit/s when Evolved HSPA is implemented in the network. Users in deployed networks can expect a transfer rate of up to 384 kbit/s for Release 99 handsets, since 2006, UMTS networks in many countries have been or are in the process of being upgraded with High-Speed Downlink Packet Access, sometimes known as 3. 5G. Currently, HSDPA enables downlink transfer speeds of up to 21 Mbit/s, work is also progressing on improving the uplink transfer speed with the High-Speed Uplink Packet Access. The first national consumer UMTS networks launched in 2002 with a emphasis on telco-provided mobile applications such as mobile TV. UMTS combines three different terrestrial air interfaces, GSMs Mobile Application Part core, and the GSM family of speech codecs, the air interfaces are called UMTS Terrestrial Radio Access. All air interface options are part of ITUs IMT-2000, in the currently most popular variant for cellular mobile telephones, W-CDMA is used. Please note that the terms W-CDMA, TD-CDMA and TD-SCDMA are misleading, while they suggest covering just a channel access method, they are actually the common names for the whole air interface standards. W-CDMA or WCDMA, along with UMTS-FDD, UTRA-FDD, or IMT-2000 CDMA Direct Spread is an air interface found in 3G mobile telecommunications networks. W-CDMA uses the DS-CDMA channel access method with a pair of 5 MHz wide channels, in contrast, the competing CDMA2000 system uses one or more available 1.25 MHz channels for each direction of communication. W-CDMA systems are criticized for their large spectrum usage, which delayed deployment in countries that acted relatively slowly in allocating new frequencies specifically for 3G services. The specific frequency bands originally defined by the UMTS standard are 1885–2025 MHz for the mobile-to-base, in the US, 1710–1755 MHz and 2110–2155 MHz are used instead, as the 1900 MHz band was already used. Some carriers such as T-Mobile use band numbers to identify the UMTS frequencies, in the late 1990s, W-CDMA was developed by NTT DoCoMo as the air interface for their 3G network FOMA. Later NTT DoCoMo submitted the specification to the International Telecommunication Union as a candidate for the international 3G standard known as IMT-2000. The ITU eventually accepted W-CDMA as part of the IMT-2000 family of 3G standards, as an alternative to CDMA2000, EDGE, later, W-CDMA was selected as an air interface for UMTS. As NTT DoCoMo did not wait for the finalisation of the 3G Release 99 specification, however, this has been resolved by NTT DoCoMo updating their network
8.
Code-division multiple access
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Code division multiple access is a channel access method used by various radio communication technologies. CDMA is an example of access, where several transmitters can send information simultaneously over a single communication channel. This allows several users to share a band of frequencies, to permit this without undue interference between the users, CDMA employs spread-spectrum technology and a special coding scheme. CDMA is used as the method in many mobile phone standards. The technology of code division multiple access channels has long been known, in the Soviet Union, the first work devoted to this subject was published in 1935 by professor Dmitriy V. Ageev. It was shown that through the use of methods, there are three types of signal separation, frequency, time and compensatory. LK-1 has a weight of 3 kg, 20–30 km operating distance, the base station, as described by the author, could serve several customers. In 1958, Kupriyanovich made the new experimental pocket model of mobile phone, to serve more customers, Kupriyanovich proposed the device, named by him as correllator. In 1958, the USSR also started the development of the Altai national civil mobile phone service for cars, the phone system weighed 11 kg. It was placed in the trunk of the vehicles of high-ranking officials, the main developers of the Altai system were VNIIS and GSPI. In 1963 this service started in Moscow and in 1970 Altai service was used in 30 USSR cities, one of the early applications for code division multiplexing is in the Global Positioning System. This predates and is distinct from its use in mobile phones, the Qualcomm standard IS-95, marketed as cdmaOne. The Qualcomm standard IS-2000, known as CDMA2000, is used by mobile phone companies. The UMTS 3G mobile phone standard, which uses W-CDMA, CDMA has been used in the OmniTRACS satellite system for transportation logistics. CDMA is a multiple access technique. A spread spectrum technique spreads the bandwidth of the data uniformly for the transmitted power. A spreading code is a code that has a narrow ambiguity function. In CDMA a locally generated code runs at a higher rate than the data to be transmitted
