1. what is direct broadcasting satellite (dbs)?
dbs is the english direct broadcasting satellite (direct broadcast satellite) abbreviation.
direct broadcast satellite is the use of satellite radio and television, multimedia data directly to the user to send a satellite transmission mode, through digital image compression technology, each satellite transponder transmits several sets to dozens of sets of television programs, the user uses a smaller fixed satellite antenna, you can directly receive multiple channels of television programs. digital direct broadcast satellite with high transmission quality, large capacity, can provide multimedia services and other advantages, it is booming in the world. on june 9, 2008, china successfully launched the first satellite broadcast satellite, zhongxing no. 9, and fixed it over the equator of 92.2 degrees east. satellite downlink frequency band is used by the international telecommunication union (itu) specifically for the broadcast satellite service (bss) planning ku band.
2. what is direct to home (dth)?
dth is the abbreviation of english direct to home, literally translated as direct to the home, is the use of synchronous satellite communications ku-band transponder for the "direct home" tv services and systems. dth way transponder power is bigger, can receive with smaller aerial. china's current direct broadcast satellite in the star no. 9 to provide dth services, the frequency band of 11.7-12.2ghz.
3. what is the direct broadcast satellite public service?
direct broadcast satellite public service is through the direct broadcast satellite to the cable network is not accessible in rural areas to provide public service radio and television services, and into the scope of public cultural service system. users can buy direct broadcast satellite reception facilities for free to listen to watch live satellite 25 sets of television and 17 sets of radio programs, to further meet the rural masses of television programs on the quantity and quality of growing demand.
4. what is radio and television "village"?
radio and television "village" project is to solve more than 20 households, has electricity village "blind" people listen to radio, watch tv difficult problem, by the state in 1998 began organizing the implementation of a benefit project.
5. what is the direct broadcast satellite "household"?
direct broadcast satellite "habitat" refers to the use of direct broadcast satellite networks for the cable network is not accessible to the rural areas to provide radio and television services.
6. what is a direct broadcast satellite service area?
direct broadcast satellite service area is defined by the sarft administrative departments of the wired network is not accessible to rural areas. users can specify the site or in the direct broadcast satellite reception facilities, franchised service outlets for the region's direct broadcast satellite service area, but also to the local radio and television administrative departments or local service agencies.
7. what are the characteristics of direct broadcast satellite tv compared with digital cable television?
direct broadcast satellite and traditional cable digital tv compared to its biggest feature is the wide coverage and low cost. cable television is mainly in densely populated areas of the town, the use of cable connected to various families, thus forming a cable television network, the region for radio and television coverage. non-densely populated areas, if adopted in the above manner, the cost will be great. especially in the vast rural areas, mountainous areas and remote areas, cable television network for radio and television coverage is difficult to achieve, and the use of a high-power direct broadcast satellite, you can get 100% of the population coverage and land area coverage. according to estimates, the use of cable television, population coverage for each additional one percentage point, need to invest 3 billion yuan, and further expand the coverage, the price must also sharply increased. while the launch of a medium-capacity, high-power direct broadcast satellite only 1.6 billion.
8. who is responsible for the operation and management of the satellite live broadcasting business?
the state administration of radio, film and television (sarft) is a public institution affiliated to the state administration of radio, film and television (sarft), which is responsible for the operation and management of direct broadcast satellite services.
9. what is a local satellite service?
the local service organization of the direct broadcast satellite is authorized by the state administration of radio, film and television (sarft), which is responsible for managing the sales and installation services of the local receiving facilities.
10. what is the direct broadcast satellite reception facilities franchise service network?
the service network of the direct broadcast satellite receiving facilities is authorized by the local satellite service agencies. it is mainly responsible for accepting applications and receiving facilities, service and so on in the service area.
11. what is the direct broadcast satellite installation service team?
direct broadcast satellite installation service team from the direct broadcast satellite local service agencies authorized, which is mainly responsible for receiving facilities at the door installation.
12. what is a direct broadcast satellite reception facility?
direct broadcast satellite reception facilities are used to receive direct broadcast satellite public service signal equipment, including set-top boxes, antennas, tuner, encryption cards, feeder cables and conventional installation of auxiliary materials.
13. what is the role of dst?
direct broadcast satellite set-top box is a satellite signal conversion into video and audio signal conversion equipment for television reception, divided into single-mode set-top boxes and dual-mode set-top box two. single-mode set-top box is a set-top box that can only receive broadcast satellite broadcast signals. a dual-mode set-top box is a set-top box that can receive both direct broadcast satellite broadcast signals and terrestrial digital broadcast television signals.
14. why must i use an encryption card to watch live satellite programs?
for the realization of each set-top box, each set of programs for effective management, direct broadcast satellite programs are encrypted broadcast. the use of encryption cards to receive direct broadcast satellite front-end authorization, the normal watch live satellite programs.
15. how to limit the use of direct broadcast satellite set-top box only in the service area?
direct broadcast satellite set-top box built-in positioning module, with positioning function, can not be used in the area of direct broadcast satellite service.
policy articles
16. what is the significance of the direct broadcast satellite public service?
direct broadcast satellite public service has established the direct broadcast satellite in our country broadcast television transmission overlay network important position and the function. direct broadcast satellite as a rural radio and television coverage is the main means of china's radio and television coverage policy of major adjustments, is the lowest cost, fastest speed, the most effective way to fundamentally solve china's vast rural households, households, , watching tv.
17. what programs are offered free of charge by the direct broadcast satellite public service?
at this stage, the direct broadcast satellite public service provides free programs including 25 sets of television and 17 sets of radio. tv programs, including cctv 1 to 16 sets of programs, china education television, the first set of programs, 7 sets of minority language tv programs and a set of the province's tv programs. radio programs include the central people's broadcasting station 1 to 13 sets of programs, china radio international 3 sets of programs and the province's first radio program.
18. what are the features of the direct broadcast satellite reception facility?
through the broadcast satellite reception facilities in addition to listening to radio and television, but also in the case of not open the tv set-top box built-in speaker directly listen to the radio. if the user selects to open the telephone service, but also call. at the same time, if you buy dual-mode set-top box, you can choose to watch live satellite programs, you can also choose to watch the local terrestrial digital tv programs.
19. how to buy direct broadcast satellite reception facilities?
direct broadcast satellite reception facilities using the franchise model sales. users in the service area of the direct broadcast satellite service may purchase the valid satellite id service at the direct broadcast satellite reception facility.
20. what information does the user need to provide when purchasing a direct broadcast satellite reception facility?
meet the conditions of the user to purchase information to provide, including: user name, contact phone number, valid document number, zip code, reported loading address.
21. can i purchase direct broadcast satellite reception facilities in the field?
no. the purchase and installation services of the dbs receiving facilities are complementary and can therefore only be purchased from a franchised service network within the local dbs service area.
22. can i purchase multiple sets of direct broadcast satellite reception facilities?
if it is in the same installation location, you can buy multiple sets of direct broadcast satellite reception facilities to meet the family has more than one tv viewing needs.
23. how to open direct broadcast satellite public services?
live satellite service area users with valid documents in the direct broadcast satellite reception facilities to purchase direct broadcast satellite service facilities, and correctly fill in the user sales installation orders, by the installation service team door-to-door installation of receiving facilities, and open direct broadcast satellite public service .
24. open satellite public services need to pay installation fees, subscription fees?
users to buy a direct broadcast satellite reception facilities, no need to pay additional installation services and subscription fees.
25. can users install their own direct broadcast satellite reception facilities?
can not. as the need to verify the installation site to open the user information to authorize, therefore, users to buy direct broadcast satellite reception facilities, the need to install the door opened by the service team.
26. "village" users can buy direct broadcast satellite reception facilities?
live in the direct broadcast satellite service area of the "village" users, can bring their own valid documents in the direct broadcast satellite reception facilities to buy service outlets, "habitat" direct broadcast satellite reception facilities.
27. what is the difference between direct broadcast satellite reception facilities and existing "village-village" reception facilities?
direct broadcast satellite receiving facilities to increase the positioning management module, and has received the same time, terrestrial digital tv "dual mode" function, the user can also choose to increase the phone function.
28. are you using the "every village" set-top box or other set-top box can receive direct broadcast satellite "habitat" program?
can not. direct broadcast satellite "household through" set-top box is a dedicated set-top boxes, other set-top boxes can not be universal.
29. how many companies now provide direct broadcast satellite reception facilities?
now there are 31 enterprises to provide direct broadcast satellite reception facilities.
30. can i watch tv programs in other provinces and cities?
at present, in addition to free direct broadcast satellite public service programs, the temporary not to watch tv programs in other provinces and cities.
31. does dbs public service provide on-demand services?
at this stage, direct broadcast satellite does not provide on-demand services, the future will be based on user needs on-demand business.
32. can i watch high-definition television programs with the dbs public service?
direct broadcast satellite public service does not include high-definition television programs, the next step, direct broadcast satellite can provide hd, interactive and on-demand and other personalized business. users can choose according to their own needs, pay to watch.
33. moving can continue to watch it? can you transfer it to someone else?
if the user 's new home is still direct broadcast satellite "household through" service area, the need to move to the franchise service network to apply for the transfer from the franchise to arrange for professional users to move for the user procedures. if you want to transfer others, the other is in the direct broadcast satellite "household through" service area, the need to apply for transfer to the franchise point, the franchise point for the user to transfer the appropriate procedures, but can not be transferred to people outside the service area.
34. set-top box out of the service area, back to the original service area can be used normally?
can. as long as the set-top box back to the original installation location, and to ensure that the equipment in good condition, can be properly installed correctly.
user services
35. can remote mountain areas receive direct broadcast satellite signals?
direct broadcast satellite signals transmitted through the sky straight to the ground, from terrain effects, remote mountains can also receive the signal.
36. how to determine whether a region is a direct broadcast satellite service area?
users can specify the site or direct broadcast satellite reception facilities, franchised service outlets for the region's direct broadcast satellite service area, but also to the local radio and television administrative departments or local service agencies.
37. what should you pay attention to when purchasing direct broadcast satellite reception facilities?
(1) before purchasing, please check with the franchised service network whether the installation address is in the service area.
(2) set of direct broadcast satellite reception facilities sales, sales price includes set-top boxes, antennas, tuner, encryption cards, feeder cables, installation of auxiliary materials and installation costs.
(3) if the installation of mobile fixed-line, users need to purchase an additional telephone module, and telephone operators with the opening procedures.
(4) direct broadcast satellite reception facilities by a unified professional installation personnel door-to-door, and provide installation, opening service.
(5) the user should ensure that the installation address and installation address consistent, otherwise it will lead to normal installation.
38. how to choose the direct broadcast satellite receiving antenna?
in the star 9, direct broadcast satellite using ku band, the band affected by bad weather such as rain and snow greater impact, generally try to choose a larger diameter antenna.
39. what is the effect of direct broadcast satellite television?
the current public satellite service tv program can achieve the standard definition television effect.
40. what if the mobile direct broadcast satellite receiving antenna causes the received signal to be bad?
re-adjust the satellite antenna elevation and azimuth, or contact the franchise service network, install the service team.
41. a set of direct broadcast satellite reception facilities can simultaneously receive multiple tv sets?
can not.
42. what are the requirements of direct broadcast satellite set-top box for tv?
direct broadcast satellite set-top box on the tv does not have specific requirements, as long as there is a corresponding input interface, the tv can use the broadcast satellite set-top box to watch tv programs.
43. how can we achieve the function of the phone, charges?
live satellite reception facilities to make calls, but users need to purchase an additional telephone module in order to achieve the phone function, the specific charges, please consult the local mobile communications operators.
44. what can i do if i can not receive a call using a direct broadcast satellite reception facility?
please check whether the mobile communication receiving antenna on the set-top box is blocked by metal objects, and then check the connection with the telephone to determine whether the telephone is faulty. if the connection is ok, the telephone is working properly, please consult the local mobile communication operator.
45. what are the main factors that affect the performance of direct broadcast satellite programs?
the main factors that affect the viewing performance of direct broadcast satellite programs include occlusion of the antenna, rain or snow or other bad weather, poor contact of the signal lines, and so on.
46. why is the effect of watching live satellite programs bad in rain or snow or other bad weather?
direct broadcast satellites use a higher frequency of the ku band, and rain and snow can cause radio waves and absorb the energy of radio waves, resulting in rain attenuation phenomenon, may lead to live satellite programs to watch the effect is not good.
47. why can not be placed in the set-top box from the satellite receiving antenna too far away?
if the set-top box is located too far away from the satellite receiving antenna, cable cable will be longer, the signal attenuation, which will affect the quality of watching television programs, therefore, the shorter the better cable cable.
48. why can not set-top box in the absence of mobile signal place?
if the set-top box is placed in a place where there is no movement signal, the positioning module in the set-top box will not receive the base station information, and thus can not be used normally.
49. why can not the antenna be installed on the roof or the antenna has blocked the place?
antenna installed in the roof vulnerable to lightning, tilt the roof is not conducive to fixed antenna. antenna installed in a block or may produce occlusion of the place, may lead to not receive the signal, affecting viewing.
50. how do the users maintain the satellite receiving facilities?
(1) pay attention to lightning. outdoor installation lightning protection facilities, indoor reception facilities, good grounding in the thunderstorm days do not boot work, cut off the power to prevent lightning damage to the receiving device.
(2) pay attention to waterproof. in the rainy season, waterproof outdoor unit is very important, focusing on the cable and the first connection of the waterproof high-frequency processing. usually in the purchase of high-frequency head with a piece of water when the rubber block for the cable and the high-frequency head at the interface of the water treatment. in addition, the peacetime should always check the waterproof plastic waterproofing situation, found that the phenomenon of timely replacement of cracks, or in the first installation of high-frequency waterproof cover.
(3) to keep the set-top box clean.
51. why do i need to manually upgrade the satellite tv set-top box?
in order to enable users to enjoy a better service, in the broadcast satellite business adjustment, the set-top box needs to be upgraded. set-top box built-in software will automatically upgrade, the upgrade process to keep the set-top box is turned on, no manual operation.
52. after installing the set-top box, the tv can use dvd or vcd?
with multiple audio and video input ports of the tv, simply dvd or vcd audio and video output and tv audio and video input terminals are properly connected, and use the tv remote control to select the appropriate program source can be.
53. how to broadcast satellite set-top box connected with the amplifier?
connect the audio output of the set-top box to the amplifier input, you can play the program sound.
54. home computer monitor and direct broadcast satellite set-top box can be connected?
ordinary home computer monitor without composite video and audio input, it can not be directly connected with the set-top box.
55. set-top box input and output interface loosening will affect the viewing quality, how to deal with?
meeting. adjust the i / o connector so that it is tightly connected.
56. can the encryption card be taken out of the set-top box?
no. encryption card from the set-top box will not be able to listen to radio and television programs.
57. direct broadcast satellite channels of the program to notice where to find?
set-top box with electronic program guide function, the user can use the remote control to enter the program guide page, you can see on the tv screen 3-7 days of each channel program schedule. users can also broadcast television news, related sites, etc. to view the program notice.
58. direct broadcast satellite channels, find the channel will not become a problem?
will not. direct broadcast satellite provides electronic program guide and program list function, users can quickly and easily find the desired program.
59. after installing the set-top box, can according to their own preferences set the channel order?
can. for details, refer to the stb operation manual.
60. why use the set-top box for the channel, the tv response is slow?
because the set-top box in the reception of satellite television signals will be more than ordinary analog tv signal processing, including signal detection, decoding and descrambling, so when switching channels will be slightly slower.
61. why is electronic program guide information sometimes inaccurate?
in the electronic program guide, the program information is collected and sent before the program is broadcasted, and the programming of the television stations on the same day is sometimes adjusted according to the temporary situation. if there is no timely feedback of the change information, the electronic program guide the program information and the actual broadcast program does not match the situation.
62. why watch satellite tv programs sometimes appear mosaic?
this is due to poor reception caused by the tv signal. (3) satellite antenna, set-top boxes, tv wiring is not standardized, or use the unqualified (1) the satellite tv platform front-end signal is bad; (2) due to rain, snow and other weather causes signal quality; equipment, or cable aging.
63. how to check the set-top box serial number, smart card number and software serial number?
for details, refer to the stb operation manual.
64. set-top box how to deal with?
under normal circumstances, you can turn off the set-top box power, a moment and then boot, you can return to normal.
65. set-top box how to restore factory settings?
for details, refer to the stb operation manual.
66. what should i do if the dbs reception facility is broken?
users can install a single phone number on the user to call the manufacturer, franchise service outlets, local service agencies or customer service management center. customer service received a telephone repair, the investigation is responsible for troubleshooting, telephone guidance can not be resolved, the home maintenance.
67. how to solve the problem of direct broadcast satellite tv no signal?
first determine the reasons for no direct broadcast satellite tv signal:
(1) whether the set-top box power supply is normal.
(2) the signal connection lines on the connector one by one unscrew, and then screwed.
(3) satellite tv antenna to receive the direction of the satellite to broaden the vision should not be blocked in front of the visual, otherwise it will affect the signal reception quality, serious or even receive the signal.
(4) wind to make the receiving antenna deviation.
(5) is close to the power lines, high voltage power lines and other facilities.
(6) whether the set-top box failure.
(7) high-frequency head is burned.
follow the steps below to check:
(1) check that the set-top box is properly connected to the tv.
(2) check the satellite tv program parameters have changed, if the parameters have changed, please re-search to correct set-top box parameters.
(3) check that the lnb power is turned on in the set-top box menu.
(4) check the coaxial cable is broken, each connector is off.
(5) with a good tuner to replace the original tuner to eliminate the possibility of damage to the tuner.
(6) if the tuner no problem, then a good set-top box to replace the original set-top box to remove the problem set-top box.
(7) if the satellite tv set-top box is no problem, it must consider the antenna position is moving, re-adjust the elevation and azimuth.
68. when using dual-mode set-top box, can not watch terrestrial digital tv programs how to do?
please check the connection cable of the terrestrial dtv receiving antenna to the set-top box first. if there is no problem, please consult the franchised service network or the local service organization.
69. set-top box is turned on, the machine automatically restarts how to do?
may be due to the antenna to the set-top box signal line or connector short-circuit. please check the signal lines and connectors, excluding short-circuit situation.
70. how to identify and eliminate several common faults?
(1) the display on the front panel of the set-top box does not light. check that the power plug of the set-top box is correctly plugged into the ac220v power outlet and the power switch of the set-top box is turned on.
(2) no sound no image. check in the following order: check if the tv is defective or the tv switches to the "av" state; check that each cable is correct. check if the audio and video cables on the set-top box are connected to the audio and video input jacks of the tv set. if there is no image, connect the audio and video cables of the set-top box to the audio and video input jacks of the tv set. if the connection of the satellite antennas is not connected to the rf input jack of the set-top box, there is also a possibility that the signal level is too low or the bit error rate is too high, which is mainly caused by the cable being too long, the connector not being well or broken.
(3) the remote control does not work. first, the battery power is low, please replace the two new batteries; second, the remote control transmitter when the transmitter is not aligned with the infrared receiver set-top window; third set-top box infrared receiver window obstruction, if any, please remove.
(4) set-top box suddenly no response. if this situation is due to the user's misuse of the machine caused by the time to be closed and re-open the set-top box power switch, you can return to normal.
(5) some programs only sound without images. it is possible to listen to the status of the broadcast program and check if the video cable is connected.
(6) some programs only images without sound. please check whether the cables of the left and right channels are connected; whether the channel of the set-top box is set in the stereo state.
if the above method still can not solve the problem, the user can install a single telephone sales to the manufacturer, the franchise service network, local service agency customer service or management center customer service, customer service will arrange for professional maintenance.
71. what is "signal strength" and "signal quality"?
in the debugging of satellite signals, the tv screen "signal strength" and "signal quality" two display items do not need to set, usually in color bars or percentage of the form of the two that received the signal "strength "and" good or bad ", you can view these two parameters to adjust the antenna to receive the best location.
72. what is the heading angle south of the azimuth?
southward deviation refers to the south of the reference antenna deviation from the angle, that is south of 0 degrees, the south angle is positive when the antenna west of the south, south of the negative angle when the antenna to the south east.
73. how to watch the tv screen tuning antenna?
adjust the receiving antenna, according to the picture quality of the tv, and gradually adjust the antenna azimuth and elevation, transferred to the screen does not appear mosaic, and set-top box menu "signal strength" and "signal quality" has reached the maximum.
74. do not boot for a long time can not normally watch how to do?
please call customer service, apply for re-authorization.
75. how to apply for transfer machines, transfer?
(1) users have transfer machines, transfer needs, the need to apply for franchised service network, franchise service network is still in the service area to confirm, notify the installation of live satellite service team moving door, transfer service. to move to non-broadcast satellite service area, not transfer machines, transfer.
(2) the installation team of the direct broadcast satellite installation service shall follow the installation of the receiving facilities, the opening service flow of the service and the moving and transferring procedures of the local mobile communication operator when handling transfer and transfer. fees should be clearly marked.
76. what is a customer service call center?
customer service call center for the direct broadcast satellite users with a range of services and technical support. users call the customer service call center phone number, follow the voice prompts to obtain the required services.
77. users are not satisfied with the services provided by the direct broadcast satellite, how to complain or give advice?
can be installed by the user to install a single satellite service provided by the local customer service phone complaints, can also call the radio and television satellite live management center customer service phone or visit the website www.huhutv.com.cn message.
system technology
78. has promulgated the technical standards for direct broadcast satellite reception facilities which?
at present, sarft has promulgated technical standards for direct broadcast satellite reception facilities, such as "technical requirements and measurement methods for integrated receiving decoders for satellite direct broadcasting system (encrypted standard definition location)" (gd / j035-2011), "integrated receiver decoder for satellite direct broadcasting system (gd / j027-001), "technical requirements and measurement methods for satellite direct broadcasting system integrated receiver decoders (gd / j027- 2011).
79. how is the system of live satellite technology structured?
direct broadcast satellite technology system consists of front-end coding reuse, distribution transmission, modulation and transmission, the user receiving system and other technical aspects. in order to ensure the quality of service, protect the interests of users, the system also increased the encryption authority, user management, location management, call center.
80. in the satellite 9, the main performance of the satellite is what?
① the working frequency band: ku band; ② to provide payload power supply power: 8 ~ 10kw; ③ traveling-wave tube amplifier output power: 120w / 240w (single / parallel); ④ traveling-wave tube amplifier number 40-50 standby); ⑤ in orbit life: 12 to 16 years.
81. what are the video and audio coding standards for live satellite programs?
the video coding standard adopted by the direct broadcast satellite program is gb / t 17975.2-2000 "information technology - generic coding of moving pictures and associated audio information part 2: video", audio coding standard gb / t 17191.3-1997 "information technology with 1.5mbit digital video recording of moving pictures and their accompanying sounds - part 3: audio "and gb / t 17975.3-2003" information technology - generic coding of moving pictures and associated audio information - part 3: audio ".
82. what is the source, what is the channel, what is the letter?
information dissemination process can be simply described as: source → channel → sink. the "source" is the sender of the information, that is, the uploader; "channel" is the transmission of information, that is, the transmission network; "sink" is the recipient of information, that is, the end user.
83. what is polarization? polarization of several ways?
polarization is the vibration direction of the electromagnetic field. satellite signals to the ground, the polarization used in two ways: one is linear polarization, a circular polarization. linear polarization is divided into horizontal polarization and vertical polarization, circular polarization is divided into left circular polarization and right circular polarization.
84. what type of polarization is used by the live satellite?
direct broadcast satellites use circular polarization. the use of left-handed circular polarization, the downlink using right-handed circular polarization.
85. what is an encoder?
encoder refers to the audio and video raw data information compression encoding in order to facilitate transmission or storage equipment.
86. what is a decoder?
a decoder is a device that recovers information from its encoded form to its original form.
87. what is a multiplexer?
multiplexer is multiple sets of program signal composite package, forming a program stream for transmission, mainly for audio, video, data and other business information reuse.
88. what is statistical multiplexing?
statistical multiplexing is a time-division multiplexing technology, the full name is called "statistical time division multiplexing", also known as "asynchronous time division multiplexing", its essence is the dynamic bandwidth allocation. different from the fixed time slot allocation in the ordinary time division multiplexing, the statistical multiplexing dynamically allocates the time slot according to the demand. the time slot can be allocated according to whether the signal source needs to transmit the data signal and the demand of the signal itself to the bandwidth. using statistical multiplexing technology can ensure the quality of the program while saving bandwidth resources.
89. what is modulation?
modulation is the process of processing the information of a signal source into a form suitable for channel transmission. specifically, the modulation itself is an electrical signal transformation process, is to change the b signal from the a signal to some of the eigenvalues (such as amplitude, frequency, phase, etc.), resulting in the b signal of the eigenvalues of a regular change, of course, this law is determined by the law of the a signal itself. thus, the b signal carries the information of the a signal. in some cases, the b signal carries the information of the a signal to be released, thereby realizing the a signal reproduction, which is the role of modulation.
direct broadcast satellite is used qpsk modulation.
90. what is a modulator?
modulator broadly speaking, there are two definitions: first, the optical and electrical signals to some of the parameters (such as amplitude, intensity, frequency or phase) in accordance with the law of the other signal changes in the components; the second is a control oscillation or a characteristic quantity of a wave so that it varies with the change of the signal or another oscillation wave.
91. what is the electronic program guide (epg)?
epg is the english electronic program guide (electronic program guide) abbreviation. epg is an easy-to-use and user-friendly navigation method available to viewers in the era of digital television broadcasting. epg enables viewers to quickly and easily find favorite programs, and to select and view program-related information.
the epg not only can quickly select ordinary tv programs and broadcast programs, but also can view information of interest such as program list, program classification, program reservation, program additional information, parental level control, the program broadcasting table in a certain period of time in the future as well as the broadcast network broadcast information and other programs, you can also select the epg interactive tv services, such as: video on demand, video broadcast, information services, video communications and gaming business. specifically, the service information (si) is inserted in the code stream so that the set-top box can extract the list and information of the broadcasted program and display it on the display device in an intuitive interface.
92. what is conditional access (ca)? what is conditional access system (cas)?
ca is the english conditional access (conditional access) of the acronym. the corresponding system is called a conditional access system (cas).
conditional access is an authorization control technique that allows an authorized user to use a service, and unauthorized users can not use the service. conditional access system (cas) is a system that implements conditional access.
after the digital television program and data compression, you can use the ca system to scramble the program stream, and add encryption control information, this can be done by the user's subscription to set the user's viewing permissions, the user set-top box built-in smart card to achieve the viewing program, which can be achieved by channel, by program or by the number of times required to provide personalized service purposes.
93. what is the business operations support system (boss)? live satellite has no boss?
boss is the english business & operation support system (business operations support system) abbreviation.
the system is a system that records, processes, maintains and manages user information, user equipment information, user ordering information and user authorization information. boss system to customer service, business operations and management as the core, key business operations (customer service and billing as the focus) as the main function of the system for network operators to provide an integrated business operations and management platform.
boss of the composition of the actual situation for the operator and the specific requirements will be different, generally have the following four functional modules: accounting and billing systems, accounting systems, customer service systems, decision support systems.
in order to provide better services to users in the future, dss established the boss system.
94. what is the direct broadcast satellite installation information acquisition device?
direct broadcast satellite installation information acquisition device is the collection of mobile base station information, user information, local geographic information equipment, mainly for the installation service personnel.
95. what is authorization control information (ecm)?
in the ca encryption / decryption system, there are two kinds of encryption information: emm (authorization management information) and ecm (authorization control information) in order to guarantee the security of conditional access system.
ecm is the english entitlement control message (authorization control information) abbreviation. the ecm is a dedicated conditional access information, containing control information for descrambling.
96. what is authorization management information (emm)?
emm is the english entitlement management message (authorization management information) abbreviation. the emm is a proprietary conditional access message that contains user-authorized information that is securely encrypted.
97. what is a satellite transponder?
a satellite transponder is a device that amplifies a signal transmitted from the ground received by a receiving antenna on a satellite and transmits it to the ground at another frequency. a satellite can be equipped with multiple transponders, satellite 9 satellite has 22 transponders.
98. what is the symbol rate (symbol rate)?
symbol rate in a digital communication system, the number of symbols that can be transmitted per unit of time.
the symbol rate of a satellite program refers to the amount of data transmitted per unit time, which is related to the bit rate of the signal and the channel parameters. satellite tv symbol rate is getting higher and higher, when a carrier signal carrying the number of programs, the greater the value.
99. what is an antenna?
an antenna is a device which radiates or receives electromagnetic waves from or into a space in a radio transmission system and is an essential part of a radio communication system. as a result of various equipment required to use different frequency bands, antenna design is different, different uses of the antenna need to design into a variety of styles, that is, we usually call the antenna program. such as in the long, medium and short frequency band, the general composition of the antenna with a wire, a t-shaped, inverted l-shaped, ring, diamond, fish bone, cage antenna. in the microwave band, with the metal plate or mesh made horn antenna, parabolic antenna, metal surface slotted slot antenna, metal or dielectric strips arranged in the lens antenna.
100. what is a lnb?
lnb is the english low noise blockconverter (low noise converter) abbreviation, that is, tuner, commonly known as tuner.
lnb's role is to reduce the frequency amplification, the high-frequency satellite signal down to 950mhz-1450mhz and filter out the noise amplification of the real signal. generally can be divided into c-frequency lnb (3.7ghz-4.2ghz) and ku-frequency lnb (10.7ghz-12.75ghz). because the satellite signal arrives at the antenna before already quite weak, and the coaxial cable transmission frequency is higher the signal loss is bigger, therefore needs through the lnb to improve.
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