1. 2 INDEX BACKGROUND CURRENT SITUATION DEFINITION OF INMEDIATE ACTIONS EXPANSION, GROWTH &...
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Transcript of 1. 2 INDEX BACKGROUND CURRENT SITUATION DEFINITION OF INMEDIATE ACTIONS EXPANSION, GROWTH &...
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2
INDEX
BACKGROUND
CURRENT SITUATION
DEFINITION OF INMEDIATE
ACTIONS
EXPANSION, GROWTH &
TECHNOLOGICAL MIGRATION
CONCLUSIONS
EDUSAT NET’S TECHNOLOGICALINFRASTRUCTURE
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BACKGROUND
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Through the program for educational modernization (1989-1994), the Ministry of Public Education created Education Via Satellite Net (Edusat) as an answer to the country’s growing demand for educational services, including disperse and rural populations by using television.
The pupose of this educational tv system is to address: literacy training, basic education, high school and technical and technological education all of which are the responsability of the Public Education Ministry.
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Edusat Net has more than 30,000 installed reception systems throughout the country at several institutions such as: “Telemiddleschools”, Technical middle schools, General middle schools, Grammar schools, Indigenous education centers, Teacher’s centers, State Technical Institutions, Universities, Military bases, Correctional Institutions, Federal Electoral Intstitute in several states, Hospitals, National Council for Educational Encouragement Nacional (CONAFE), National Institute for Adult Education (INEA), State Education Ministries and some Latin American Universities
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Current Situation
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Before commenting on any expansion, growth or technological migration for EDUSAT Net it is important to quickly mention its origin and current characteristics.
Edusat Net was born from the need to continue broadcasting “Telemiddleschool” (Telesecundaria) which in 1991 was done through open tv using Imevisión (Government channel) and its national broadcasting net. When the government sold Imevisión, it was forced to consider an alternative that required less time to implement, since the agreements undersigned by SEP, to continue with the service were too expensive. It also needed to have national coverage because “Telemiddleschools” are found in rural areas.
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The technology that met these requirements was
Digicipher 1, an advanced technology and best
satellite provider at the time (Audio Digital
Compression, Video).
This technology evolved by optimizing the use of a
satellite transponder bandwidth and Digicipher 2
technology was acquired. Both technologies are
currently used side by side and allow quality
coverage for Edusat Net.
By using the most sophisticated encription
technologies Edusat Net was born as a “closed”
technology since the transmitters and receptors
both have to be of the same brand to work
properly, for obvious reasons.
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Taking the disadvantages of this system into account, some processes for the growth of the net have been facilitated by negotiating delivery times and favorable volume pricing. Also, since few brands exist the logistics for control, administration and following of these programs has been simpler.
Almost 17,600 pieces of equipment are DC1 (of which 80% are in “Telemiddleschools”) and almost
14,400 are DC-2.The use of two technologies and two satellites means that these two equipments are not interchangeable without a re-orientation and configuration process that requires skilled technical personnel.
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In this sense any strategy for massive receptor substitution should consider the demand of technical resources, materials and equipment, this would require as well as the time that such a job would take.
Motorola has stopped producing DC-1 and although it claims it can service DC-2 for five more years, it does so under mandatory upgrading conditions and at very high prices.
It may be worth mentioning that pulling this equipment from the market has been done purely from a commercial and not technological standpoint, thus the argument for obsolescence is not precise.
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Edusat Net’s satellite uplink is currently being done by“Telecomunicaciones de México (TELECOMM)” at its “Contel Iztapalapa” facilities, where the signal is digitalized, encoded and multiplexed for:
12 TV channels through DC-2 encoder technology,8 TV channels vía DC-1 encoder.
To transmit these services through two satellites (Sol 2 and Satmex 5), as well as 4 corresponding channels to radio signals. For satellite transmission and reception, General Instruments proprietary technology is used (now Motorola).
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EDUSAT’s NETWORK SIGNAL PROCESSINGEDUSAT’s NETWORK SIGNAL PROCESSING
MICROWAVES
COMPRESSION
ENCODING MULTIPLEXING MODULATION
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ILCE
1112
13
1417
1516
DGTVEFILTER
FILTER
FILTER
DECODIINGDEMODULATION
DESCOMPRESSIONMODULATIONTV
CONTEL
SATELLITES
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EDUSAT COVERAGE DC-1 SYSTEM (8 TV CHANNELS)
Edusat Net on Solidaridad II
satellite uses Digicipher 1
(DC-1) technology. It
currently covers 16,600
receptors placed mainly in
rural areas, as is the case of
“Telemiddleschools” and
Indigenous grammar
schools.
SOLIDARIDAD II SATELLITESOLIDARIDAD II SATELLITE
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EDUSAT COVERAGESYSTEM DC-2 (16 TV CHANNELS)
Edusat Net on Satmex 5 satellite uses
Digicipher 2 (DC-2) technology ,
approximate coverage is of 13,400
receptors.
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dBw
60256025
60116011 60396039
6008.256008.25
MHz
3030
3434
2.52.5 2828 44
60436043
3636
1.51.5
8 TV CHANNELS8 TV CHANNELS4 RADIO CHANNELS4 RADIO CHANNELS
DC-1DC-1
1 TV CHANNEL1 TV CHANNELWEGENERWEGENER
DVBDVB
SOLIDARIDAD 2 SATELLITE SIGNALSSOLIDARIDAD 2 SATELLITE SIGNALSTRANSPONDER 3NTRANSPONDER 3N
16
64056405
63916391 64196419
6421.756421.75
dBw
MHz
2525
2828
3.153.15282844
64236423
3636
1.51.5
12 TV CHANNELS12 TV CHANNELS2 RADIO CHANNELS2 RADIO CHANNELS
DC-2DC-21 IDC DATA1 IDC DATACHANNELCHANNEL
SATMEX 5 SATELLITE SIGNALSSATMEX 5 SATELLITE SIGNALSTRANSPONDER 24CTRANSPONDER 24C
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EDUSAT-DGTVE DVB SIGNAL PROCESSINGEDUSAT-DGTVE DVB SIGNAL PROCESSING
ENCODER 16:1MEPG-2 DVB
MULTIPLEXORMODULATORUP/HPA
SATELLITES
DEMODULATORCONDITIONALACCESS
DEMULTIPLEXOR
RFMODULATOR
DECODER TELEVISION
DGTVESTUDIOS
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EXPANSION, GROWTH & TECHNOLOGICAL
MIGRATION
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Normal equipment deterioration indicates that the
DC-1 equipment is more susceptible to failure, both
in transmission and reception equipment, they are
however more robust and resistant for
“Telemiddleschool” use. Since DC-1 equipment is no
longer made, it must be substituted by DVB
technology when it fails.
Due to the actual state of Edusat Net there are four
fundamental axes that must be consolidated in the
short and medium term.
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Controlled expansion and growth of Edusat Net’s
infrastructure. Keeping current technology,
actively participating in establishing policies and
procedures so that each of the country’s states
implements its investment projects while the
three remaining axes are met.
Edusat Net’s technological migration: Toward
standard international open platform with the
participation of diverse brands and models that
guarantee inter-operability. (DVB-RCS)
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Edusat Net´s Diversification. Using cable TV
systems to broadcast at least two Net channels
having the universal offer of educational TV,
including the National Network of educational and
cultural tv broadcasters.
Technological converging between TV,
computers and Information technology. Edusat
Net’s future will depend on its capacity to add its
teaching advantages, the possibilities of digital
environments, and automated controlled
programming by SUN 12000 servers.
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International DVB Standard
DVB-S
DVB-S, DVB-C
DVB-S, DVB-C, DVB-T
DVB-S
DVB-S, DVB-C, DSS, ATSC
DVB-S: Satellite DVB-C: CableDVB-T:Land
DVB-S: Satellite DVB-C: CableDVB-T:Land
www.dvb.org
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IMMEDIATE ACTION DEFINITIONS
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Migration Program (Stages) 1.- Net widening.- Every new system that is
installed will be done by pointing the Solidaridad 2
satellite in Ku band, we will take advantage of this
point to start training at the national level. 2.- “Telemiddleschool “ susbstitution.- All
equipment will be substituted before the
beginning of the next school cycle (August 2993),
State structural support will be used for this
process. 3.- Satellite change.- Once the 14,000
“telesmiddleschools” migration is completed all
remaining band C equipment, DC1 as well as DC2
will be changed.
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Using DVB standard on Edusat Net.- Performance tests have been done on this standard and they have been acceptable, but we only have one tv channel to support the “Telemiddleschool” system.
Ku band teleport (DGTVE).- Tests have to be performed on the controlled access system (IRDETO) and also verify the access parameters to the Mexican satellites to be able to use less than 90 centimeter diameter receptor antenna (TVRO).
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CONCLUSIONS
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DVB technological standard was created to achieve a uniform environment for digital tv dissemination.
Once DVB standards have been published, they will be available to anyone in the world, notwithstanding were they have been developed and are therefore open standards.
With the introduction of DVB technology, the net will be able to use different brands of satellite receptors (set top box). This diversity of brands on the market will allow the lowering of costs to acquire said receptors.
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The transmitting (Andrew) antenna are 7.3 meters in diameter, this process will take place in 45 days, meantime, 10,214 pieces of DVB equipment have been delivered to different states and 20,000 systems are planned to be delivered before the beginning of the school cycle.
By using these tools and technological support, Educational TV is seeking to contribute to improve the learning environment in classrooms considering the teacher as the axis for this change and who will be previously trained to use the technological media that the SEP has at its disposal.