Full Description of IP DATA

For reception of satellite Internet users apply to the utility IP DATA and the driver «Virtual MPE Decoder Adapter». This article is aimed at providing fuller understanding of software operation principles of satellite Internet receiving system. We hope that our material will ruin a number of legends and will allow you finding errors in settings faster and helping you save your time and spare your nerves.

Brief description of IP DATA operation

Driver of DVB-card sends the traffic flow to the utility IP DATA.
IP DATA first filters the flow on the basis of the flow indicator – PID and then on the basis of MAC-address.
IP-packages that «have been extracted» from the traffic flow are being sent to the virtual network adaptor «Virtual MPE Decoder Adapter».

Installation of IP DATA

You have already installed DVB-card to PC or have connected it via USB-cable. Meanwhile you followed operation rules of the device and all actions were performed when the laptop was switched off. After that you installed the latest driver of DVB-card. And probably by now you have already watched satellite TV with the help of AltDVB or DVBDream.

Now you decided to make a system of the single-sided (simplex) satellite Internet reception from the multi-media device known under the name of DVB-card.

If the antenna is tuned to the satellite required for you, the converter is connected, the cable connects the converter and DVB-card and you already have a subscribing of satellite provider then it is left for you to install additional software and to set it correctly.

Prior to the release of Windows Vista all developers of DVB-cards used WDM-drivers for DVB-cards. Such driver architecture allowed working more comfortable with DVB-card on the level of hardware. All the manufactures were forced by Microsoft which applied different methods to switch to BDA-drivers. Therefore at present company Prof Tuners Group along with the developers of Conexant chips has completely switched to use of drivers of BDA- architecture. A switched to PBDA (Protected Broadcast Driver Architecture) is not planned by our company in the near future.

DVB-card with BDA-architecture of driver is not a network device. That’s why you can easily find it in “Device Manager”. On the other hand in multimedia devices two tag marks appear after the connection of DVB-card. For example, ""Prof 6200 DVB-S" and "Prof 6200 DVB-S TS Capture". Thus, "Prof 6200 DVB-S" are BDA-drivers themselves and "Prof 6200 DVB-S TS Capture" is a driver of the analogous signal, a remote control driver and etc. It is impossible to use drivers separately in applied software that’s why there is no sense to find out what function each of them fulfill separately.

To use DVB-card with BDA-driver for satellite Internet traffic reception are required: virtual network adapter and utility that constitutes the filers graph and utility that receives the traffic flow from BDA-driver, process it and changes packages names and transfers them to the virtual network adapter.

Software for DVB-cards satellite Internet is called IP DATA. To install and use it you should download the file-installer ProfIPData from the web-site prof-tuners.com. Setup.exe (the real file name contains version number).

There are two components in the installer: utility IP DATD and driver «Virtual MPE Decoder Adapter». If you install IP DATD for the first time then you must install “MPE-adapter” (remain the tick when installing). If you upgrade IP DATA then it is not necessary to install “MPE-adapter” because it is already in the system with your settings (remove the tick when installing).

When installing IP DATA you should agree with License of use of software «PTG Engine». All the steps of IP DATA installation can be seen at the web-page:
http://www.prof-tuners.com/eng/ipdata_install.html

If you remained the tick in «Virtual MPE Decoder Adapter» then in the background of IP DATA installation the following will take place: specially programmed utility will identify MAC-address of DVB-card, will add it to the information file with MPE-adapter installation and will start MPE-driver installation. Set by this way MPER-driver will contain MAC-address corresponding to MAC-address braided in chip EEPROM in DVB-card.

To change manually MAC-address of MPE-adapter you should go to: “Features”, “Set up”, “Additionally”.

Whether MAC-address in MPE-adapter is needed or not needed depends on the requirements of satellite providers engineers who developed certain accelerators and software. Some of them in their programs used MACX-address from virtual network device, others did not. It is not regulated by the standard in any way that’s why it has happened this way, “At sixes and sevens”

MAC-address in MPE-adapter may always be manually changed: http://www.prof-tuners.com/eng/ipdata_mpe.html. Naturally when doing this MAC-address in the chip EEPROM will not be changed because the virtual network adapter («Virtual MPE Decoder Adapter») does not have any physical connection with any hardware item including the hardware of DVB-card. As well no change of MAC-address in IP DATA will take place.

The description of control elements of the utility IP DATD you can find at this web page:
http://www.prof-tuners.com/eng/ipdata.html

Tabs in IP DATA

The first three tabs i.e. “Tuner”, “LNB”and “DiSEqC” are responsible whether the signal will be locked (whether the traffic flow will be identified) or not. They shoud be set up first. After the signal is locked you can set up the parameters of traffic flow filtration in the last two tabs: “MPE-filter” and “PID-filter”.

Tab «Tuner» in IP DATA

Transponder in IP DATA could be described with the help of five parameters: frequency, symbol rate, polarization, modulation type, FEC. This is the minimal set of the parameters required for the transponder description.

Frequency is the main transponder parameter, is entered in MHz (10700-12750 for Qu-range and 3000-4200 for C-band).

Symbol rate is entered in kilo symbols, values can be from 1000 to 45000.

Interesting fact: you can program the driver, programmatically try different symbol rates (trial and error method) and furthermore determine the symbol rate automatically. But in terms of time expenditures it is useless to apply to the method of automatic symbol rate determination.

Polarization of the signal

Interesting fact: according to the information from www.lyngsat.com at sattelites in the range 73°E-0°E there is only one satellite which has transponders of the similar frequency and different polarization. That means that such case happens not frequently.

Two DVB-devices cannot be used to the utmost at on cable from one converter. If you connect the second DVB-device (second DVB-card or TV-receiver) via a loopback outlet or a splitter then both devices can be used simultaneously either in vertical polarization or horizontal polarization. The thing is that it is impossible to keep the cable simultaneously under the voltage +13 V and +18 V.

IP DATA allows setting only 2 polarizations. If you are interested in circular polarization (left «L», right - «R») then you should mention in the settings of Prof IP DATA «H» instead of «L» or «V» instead of «R».

Modulation type - DVB-S or DVB-S2. The parameter is blocked (dropdown list is in grey color or does not open) if frontend of DVB-card detect modulation type automatically or DVB-card does not allow using DVB-S2-modulation.

FEC – parameter is aimed at mistakes correction. Modulation type is more frequently being determined automatically. And if frontend of DVB-card allows determine automatically FEC in S2 then the parameter is blocked (dropdown list is in grey color or does not open).

Signal indicators for users

These indicators were designed for users at the very beginning of DVB-receivers development. Originally only one indicator was designed. Then a decision to make the second one was taken. Meanwhile there is no established methodology to calculate these parameters. All of them are calculated in different ways. The sense of these indicators is simple – “The more the better”. Percents don’t have any interpretation and that is why very often they are not shown picturing signal indicator only graphically with the help of color palette.

Besides some TV-receivers so far has only one parameter. The second parameters may be absent, be equal to the first one, be always 100% or be calculated with the help of different methods.

As you have already understood the most important peculiarity of these indicators is that data for calculation of these parameters in different DVB-devices is taken from different places and is calculated totally different.

What for was created the data “Indicators for users”?

Digital signal quality is estimated with the help of BER (S), PER (S2) and others. There is an industrial method of testing the parameters" Signal quality "(abstract notion) - "Measurement guidelines for DVB systems". But this method has one defect which makes it inapplicable in domestic DVB-receivers and DVB-cards. The defect is that in order to calculate the signal indicator it is required to receive a big number of packages (not less than 1 million packages). In other words to get the signal indicator we should wait for a long period of time until a sufficient amount of packages will be received and the signal indicator could be calculated by means of statistics method according to the official methodology accepted for the digital signal. And for transponders with low flow transmission we will have to wait for much longer time.

Because of the fact that in domestic conditions of reception users don’t want to wait for a long time and especially for them signal indicator imaging was developed in percents: “Signal power” and “Signal quality”.

Such indicators work fast but they are absolutely not correlated between different DVB-devices including DVB-cards and DVB-receivers. Applying to Prof production this phrase should be understood approximately as follows: different levels of signal indicators will be reflected from one satellite, at one antenna and one computer at Prof-6200, 7300, 7301, 7500. And this does not mean that any of DVB-cards Prof is “more sensitive” and “receives signals better”. All DVB-cards Prof and all DVB-cards in the world have same “sensitivity”, there does not exist “more sensitive” and “less sensitive” chips, tuners, DVB-cards and DVB-receivers.

Different signal parameters at the same receiving equipment, from one satellite and at the same time of testing will more surely mean that these DVB-cards have different methods of calculation of “Signal indicators for users”.

Chips Conexant are used on Prof-7300 that’s why in the driver Prof-7300 method of parameters calculation developed by Conexant with supplemental development by engineers of Prof Tuners Group is applied. In order to learn about the physical sense of these indicators it is better to read in FAQ section questions 5, 6 and 7:
http://www.prof-tuners.com/eng/faq.html#q5
http://www.prof-tuners.com/eng/faq.html#q6
http://www.prof-tuners.com/eng/faq.html#q7

Prof-7301 and Prof-7500 has a frontend of another chips manufacture with other basic parameters and that’s why we applied another methodology of calculation that is described on 17 pages of documentation. Meanwhile 7301 and 7500 will also reflect different levels of signal indicators.

We will not describe on the analogy of Prof-7300 what indicators for users in Prof Revolution models mean. Appeal to the main rule for these indicators:”The more the better”.

How to calculate “Indicators for users”

No one from chips at DVB-card contains such parameters as “Signal level in %” and “Signal quality in %”. That’s why it is impossible simply to get these parameters with the help of a driver and to transfer them to the program of imaging at a user’s monitor. They are calculated on the basis of other parameters which are given by the frontend.

The calculation function of “Signal indicators for users” is located in then driver. It gets the parameters and calculates graphical indicators that are seen to users by means of statistics method.

The main problem of these algorithms is that starting point from which calculation should be started is unknown. That is a limit lower which the signal is bad and higher which it is good.

Conclusions on the section “Indicators for users”

Such phrases as “I have bought a new DVB-card and signal power has become higher at once. That means the new card is better in the respect of sensibility” are ridiculous. It is ridiculous as well to try to compare different models of DVB-cards including those from different manufactures in the respect of sensibility. The phrases “I have installed new/ old drivers and signal indicator has become higher / lower than it used to be” don’t bear any information. They simply mean that engineers in different versions of drivers use different methods of calculating such surrogate parameters as “Signal power in %” and “Signal quality in %”.

It is impossible to reduce to one scale the parameters “Signal power in %” in different DVB-cards. Such phrase as “Power signal in DVB-card X1 of the manufacturer Y1 at 80% correspond to 60% in DVB-card X2 of the manufacturer Y2” are ridiculous. This parameter as it was described above is being calculated by means of program method in the driver (not by the chip) on the basis of different basic parameters, on the basis of different time period, by different methods with different starting point (a limit above which the signal is good and below which is bad).

It is correct to compare these parameters only when the same model of DVB-card with the same version of driver (which mean with the same calculation method) is being used.

Tab “LNB” in IP DATA

The tab “LNB” contains converter parameters. The dropdown list “LNB-type” allows selecting one of the widely spread type of converters. If to choose “CUSTOM” (manual set up) than the boxes “LOF 1” (frequency of the 1st heterodyne) and “LOF 2” (frequency of the 2nd heterodyne) will be activated, “Switching” (frequency of heterodynes switching), “LOF 2” (frequency of the 2nd heterodyne).

The key “Power” switches off/ on converter power supply with the help of this DVB-card. The green color of indicator signifies the power of LND is turned on.

It is possible not to know what LOF1, LOF2 and frequency of heterodyne switching but in case if you use one converter of one type. The main thing is that to trace the parameters coincide with those indicated on the converter itself.

Tab “DiSEqC” in IP DATA

In the tab “DiSEqC” parameters of DiSEqC-switch are located etc. This tab is orientated towards more experienced users and is located at the page:
http://www.prof-tuners.com/eng/ipdata.html

We will consider that you don’t have DiSEqC-switch and that is why you left the parameters at this tab «On default».

Settings profiles

In the head of IP DATA there is a key “Add”. This function allows saving all the parameters from three tabs (“Tuner”, “LNB” and “DiSEqC”) in one profile of settings. You can save an unlimited number of settings profiles.

Digital signal lock

The key “Apply” in the tab “Tuner” is the main one. It applies all the parameters in all tabs and allows locking the digital signal.

If you entered all the transponder parameters correctly, indicated LNB-parameters correctly then you can successfully lock the transponder (blue or green status-icon). The blue icon – the transponder is locked and information is not being received. The green icon – the transponder is not locked and information is being received.

Lock shows that there is traffic flow. Different equipment has a unique lock criterion.

Prof-7300 has several lock levels:
1. Tuner found carrier wave.
2. Demodulator identified the type of carrier wave.
3. It is possible to determine FEC.
4. Viterby-decoder can reconstruct information.

Any of the points could be considered as a lock. The traffic flow even with errors will be received only in the 4th case. Prof-7300 will acquire transponder lock only in the 4th case.

In fact the number of lock levels of Prof-7300 exceeds this quantity and Prof Revolution has about 30 levels. The main conclusion: lock takes place when there is the traffic flow at the exit of DVB-card at the output of DVB-card. If there is no traffic flow (although there is an incoming flow from the satellite) then there is no lock, if there is the traffic flow then there is a lock.

An Example of mistake in understanding of lock principle and signal level

To state that it is believed worldwide that there is “sensibility” of DVD-cards and that according to it DVB-cards can be compared between each other we would like to cite an example:

Hot Bird (13E) satellite: 11,334 GHz, pol. H, SR: 27500 and 11,432 GHz, pol. V SR: 27500, both DVB-S2 - they will find some interesting signals. Both frequencies are not listed on Lyngsat, Flysat etc. But Prof-7301 lock signal and find some channels (italian Mediaset package, few channels are FTA, for example BBC World from second frequency - after choose it from channel list I see picture and hear sound, but it look like weak signal - unstable, can’t watch, but something is broadcasting there for real). Signal is unstable. At other receivers & DVB-cards - no signal. Ive got question: is there ability to do some corrections and force card to get stable signal?

When testing in Poland, in June 2009 DVB-card-Prof-7301 was able to lock transponders (frequencies are mentioned) which are not in the lists of satellites Lyngsat and Flysat. Meanwhile no other DVB-card or a receiver could not lock them. The tester who wrote these lines is involved in testing and selling satellite devices since the end of 80ths and has tested many DVB-cards, DVB-receivers and analogous satellite receivers within 20 years.

Speaking about marketing we shall state that Prof-7301 is the best card in the world in respect of sensibility. But it will be the perversion of the truth. All DVB-cards worldwide are equal in the matter of sensibility. The thing is that at this signal level the driver Prof-7301 showed that lock is present and calculated signal indicators and transferred the traffic flow to AltDVB. Other DVB-cards and receivers counted this signal insufficient for the normal reception of digital signal and showed that the lock was absent. The thing is that they differ in starting point. Before this limit the signal is good, after it – bad.

That’s why the answer to the question «Is there ability to do some corrections and force card to get stable signal?» is simple: «We are not able to enforce the signal and make it stable. It is what it is. A bigger antenna is needed».

What happened when the key “Apply” was pressed?

Frontend (the main chip of DVB-card) has received transponder parameters and other parameters via the bus-line I2C, a graph has been built. The graph is being built by means of program method but visually can be presented as it is presented in Fig. 1. The graph can have another view and that depends on how it is built.

Fig.1. Visual imaging of the graph of filters.

The blocks in this scheme are called filters. Different filters are being used (driver filters, standard, special). The traffic flow is processed and modified into IP-flow that is forwarded to a virtual MPE-adapter. First filtration on the basis of PID is being made, then – on the basis of MAC-address. Filtration on the basis of PID is being performed at the level of TS (Transport Stream – traffic flow) when transport packages are being tested. Filtration on the basis of MAC-address (hardware or given by a provider) is being performed at the level of DMSCC-section.

Further in the received IP-packages the necessary modifications of package header are being performed, control sum is checked and the package is being sent to «Virtual MPE Decoder Adapter».

All operations connected to the protocol in IP DATD are fulfilled on the basis of official standards of data communications: ISO/IEC 13818-1, ETSI EN 301 192 and other connected.

Filtration on the basis of PID

PID (Packet-Identifier) is a package identifier. Signal consists of several package protocols. PID allows identifying a necessary flow.

In order to comprehend the principle of PID work you should make the following comparison: boxes of different colors are coming on a conveying bent. In red boxes parts of machine are located, in green boxes parts of machine B are located, n blue boxes parts of machine C are located. We are standing next to the conveying bent and we should assemble machine B. To do this we wait till a green box arrives to us and we take from it parts for machine B. If the next box is green as well then we take it as well. If the next box is red or blue then we don’t take it and it follow its way. The fact that boxes are of different colors helps us assemble machine B faster. If the boxes were of the same color we would have to check every box to find whether there was a required part for machine B. This is the filtration on the basis of PID (filtration on the basis of packages identifiers).

When satellite Internet is being received we have to assemble not a machine B but DMSCC-section in order to withdraw IP-traffic from it with appeal to complicated modifications.

If providers will use a single PID for all users from one transponder then the DVB-card will be used to check all received packages which is needed to be done in order to identify whom they aimed at: to you or to another user which receives traffic from the given satellite.

At present almost all satellite providers use several PIDs at one transponder. A user account (subscribing) is connected with one of PIDs and all packages are transferred to the satellite with a given identifier.

DVB-card Prof chooses from the entire information flow only those packages PID of which are in the active list and further filters on the basis of MAC-address. You can switch PID-status to active on the last tab IP DATA.

PIDs cam have both decimally or hexidecimal notation. In IP DATA you can see all PIDs that are in the traffic flow. You can make only one PID, or several PIDs or all PIDs active. When a big number of PIDs is active then the charge on CP is increased.

Filtration on the basis of MAC-address

You have tuned the antenna to the satellite and receive from it the single-sided satellite Internet. A satellite provider rents from the satellite the whole transponder or its part. To pay off the project not only you but up to 40, 000 users set up antennas to this transponder.

What shall be done by the satellite provider to help you receive the very file that you want to receive not the file that another user wants to receive? In this case your DVB-card should process only those packages that are intended for you and don’t process those packages that are intended for other users. To fulfill this packages receive an identifier on the basis of MAC-address. With the help of filtration on the basis of MAC-address IP DATD successfully identifies IP-packages that are intended for you.

According to the information acquired from the engineers at teleports in Moscow: “If a provider rents an incapsulator (a device aimed at modification of IP-traffic into DVB-flow) then a provider usually does not have an access to the incapsulator control and that’s why so-called “Autouse-IP” is being applied to”. It happens that «Autouse IP» is when MAC-address is given in the format of IP-address. That’s why some subscribes of satellite providers are connected to your MAC-address (installed in EEPROM chip in DVB-card and stuck on the reverse side of DVB-card and stuck to the carton). Subscribes of another providers are connected to any “IP” and MAC-address of your DVB-card is not used for this purpose. No one of these methods is better or worse, such peculiarity of account set up of satellite provider is explained by economical reason.

MAC-address presented in the format of IP-address is modified in hexadecimal notation customized for MAC-address and further on is used in filtration on the basis of MAC-address. There is no filtration on the basis of IP-address when the flow is being transferred from the satellite. The phrase “DVB-utility filters on the basis of IP-address” is ridiculous as in IP DATA there is no filter on the basis of IP. This “IP” is MAC-address that is presented in another format (by mean of the standard accepted in 1982).

Spoofing

Satellite Internet does not operate with switched on UAC in Windows Vista and when programs of computer complex protection are used. These programs mistakenly consider such packages incorrect (sender and receiver addresses are the same or source address is “zeros”). Protection programs “thinks” that they have to deal with IP-spoofing i.e. when a source hides its IP-address in fraudulent purposes and that is why block these packages. IP-packages are simply not transferred to the network interface «Virtual MPE Decoder Adapter». If the protection program can be set up then it is necessary to do this. In other case to receive satellite Internet is required to switch on such protection.

Unicast, Broadcast and Multicast

In the utilities of not up-to-date DVB-cards in filtration tabs such terms as Unicast, Broadcast and Multicast are presented. At present these parameters of set up are considered to be not up-to-date. You can find their description in the Internet.

In IP DATA Unicast is used. If sometimes Broadcast (for example for Software skyDSL) is required then IP DATA analyzing traffic packages determines this and automatically switched to Broadcast-mode. In IP DATD there is as well the protocol Multicast but we are not used to its practical use for any services.

On the matter of Broadcast use in skyDSL software

SkyDSL uses Broadcast i.e. to all users the entire SkyDSL-traffic is being transferred. Further it is being filtered on the level of ETH-interface by means of software skyDSL. The filtration on the basis of MAC is not used in IP DATD.

Conclusions and comments

“Network interface” or “MPE-adapter” or “Virtual MPE Decoder Adapter” has no connection with hardware of DVB-card.
Prof Tuners Group uses the name “Virtual MPE Decoder Adapter” but not “Prof-6200 Net” of any similar to underline that this is “Virtual MPE-adapter” not a physical network device.
Note: Unfortunately some unconscientious small producers of DVB-card (with BDA-drivers) don’t use the name of MPE-adapter in the name of its trademark. Meanwhile users acquire a distorted picture about the fact that DVB-card was found as a network device. In this situation we are especially upset as there is installing staff with insufficient qualification in this field that after work with such DVB-cards start to extrapolate their experience on all DVB-cards saying that there is a glitch in drivers and Prof is not shown as a network device.
Messages that could be found in forums “I have installed drivers Prof but have not seen network device Prof-6200 in “Device Manager” are ridiculous. DVB-card with BDA-architecture of diver is a multimedia device not a network one.
The driver of MPE-adapter cannot directly operate with the driver of DVB-card or hardware of DVB-card. That’s why MPE-adapter cannot “learn” MAC-address of DVB-card from EEPROM chip by itself. MAC-address in «Virtual MPE Decoder Adapter» can be registered manually (the most reliable method) or use the latest installer IP DATD which install IP DATA and generate inf-file for installation of MPE-adapter with MAC-address already registered in it.
It is impossible to use IP DATA at the same time with different software, for example, DVBDream or AltDVB.
Note: In comparison with old DVB-cards with WDM-driver our utility for reception of satellite Internet “doesn’t show current transponder parameters” but serves for reception of the traffic flow and its transfer to the network interface. If your PC has one DVB-card and you use IP DATA then it is required to close DVBDream. And vice versa. Two programs should not struggle for the administration of one device.
If PC has two or more devices Prof then simultaneous work is possible when the principle one DVB-card – one program that uses this DVB-card is preserved.
Indicators for users “Signal power in %” and “Signal quality in %” are abstract parameters and can only be interpreted on the principle “The more the better”.
It does not have any practical sense to compare indicators “Signal power in %” and “Signal quality in %” in different DVB-cards.
All DVB-cards Prof as well as all DVB-cards in the world have same sensibility.

If you still have any questions after having read this article please feel free to ask them. We will answer you and will add the required changes in the article.

Last upgrade of the article 16.10.2009

Unfortunately it is difficult to make an ideal article with the balanced ratio of contents and level of complexity. In addition to the article we publish some comments from engineers.

Comments to the article from engineers Prof Tuners Group

1. Addition about the degree of article complexity.

The degree of complexity of material presentation changes greatly. When in detail by the example of boxes filtration on the basis of PID is described it is good. I think it is the most suitable way to get acquainted with the operation principles of satellite Internet. But when meantime it is written about operations on ETSI EN 301 192 or mentioned about BER, algorithms of calculation of digital signal parameters it is like a jump from the earth to the sky.

2. Addition to the term "sensibility".

It written many times that there is no sensibility of DVB-card. Strictly speaking – it is true.

But there are characteristics of receiving system. This system consists of antenna, converter, cable (switches, etc), DVB-card. And one of them is changed transponder reception can be changed in better or worse way. And having read the thought that all DVB-cards are equal in sensibility we can conclude that whatever card you install there is no difference.

Yes, the word sensibility does not suit for a brief characteristic of DVB-cards. But the more complicated tuner at the card the bigger calculating power of frontend then in more complicated conditions the card can assure the stable reception. Bright example: change of card TT S-1401 to Prof-7301. When the signal is low the difference is very vividly noticeable.

3. Addition to the notion "Indicators for users".

These are massifs of values brackets i.e. dependency of value of frontend parameter to dB:

static U16 STB0903_S1_Quality[5][3] =
{
/* PR Min Max */
FE_1_2, 8340, 5980, // 2 dB - 7 dB
FE_2_3, 7970, 5430, // 3 dB - 8 dB
FE_3_4, 7540, 4910, // 4 dB - 9 dB
FE_5_6, 7030, 4425, // 5 dB - 10 dB
FE_7_8, 6530, 3972 // 6 dB - 11 dB
};

static U16 STB0903_S2_Quality[17][3] =
{
/* Mod Cod Min Max */
FE_QPSK_14, 13100, 9202, // -3 dB - 2 dB
FE_QPSK_13, 12247, 8584, // -2 dB - 3 dB
FE_QPSK_25, 11487, 7866, // -1 dB - 4 dB
FE_QPSK_12, 10726, 7110, // 0 dB - 5 dB
FE_QPSK_35, 9966, 6534, // 1 dB - 6 dB
FE_QPSK_23, 9202, 5914, // 2 dB - 7 dB
FE_QPSK_34, 8584, 5346, // 3 dB - 8 dB
FE_QPSK_45, 8584, 5346, // 3 dB - 8 dB
FE_QPSK_56, 7866, 4780, // 4 db - 9 dB
FE_QPSK_89, 7110, 4260, // 5 dB - 10 dB
FE_QPSK_910, 7110, 4260, // 5 dB - 10 dB
FE_8PSK_35, 7866, 4780, // 4 db - 9 dB
FE_8PSK_23, 6534, 3830, // 6 dB - 11 dB
FE_8PSK_34, 5914, 3485, // 7 dB - 12 dB
FE_8PSK_56, 5346, 3077, // 8 dB - 13 dB
FE_8PSK_89, 4780, 2740, // 9 dB - 14 dB
FE_8PSK_910, 4260, 2532 // 10 dB - 15 dB
};

But these are values in dB. Here it is the main difficulty. How can we connect percents to dB? And what shall be taken as a minimum and as a maximum? What value will be 0%? And what value shall be 100%?

4. Addition about analogous and digital signals.

Physically DVB-card receives analogous signal. Satellite sends radio signal which is being transformed to the intermediary frequency by a converter. Analogous signal (with big interference) or to be more exact a mixture of waves is being transferred in the cable from the converter. That is both the signal and the wave always have analogous nature. The signal that has been modulated by the digital data (in contrast to analogous data) is called digital but the signal itself does not become “les analogous”. Indicator “level” is often calculated on the basis of amplitude of the analogous signal in the first cascades of tuner. After demodulation and reconstruction we get a figure – the traffic flow at the entrance from DVB-card at the output of DVB-card.