2.4.6. Digital TV property parameters

2.4.6.1. DTV_UNDEFINED

Used internally. A GET/SET operation for it won’t change or return anything.

2.4.6.2. DTV_TUNE

Interpret the cache of data, build either a traditional frontend tunerequest so we can pass validation in the FE_SET_FRONTEND ioctl.

2.4.6.3. DTV_CLEAR

Reset a cache of data specific to the frontend here. This does not effect hardware.

2.4.6.4. DTV_FREQUENCY

Frequency of the digital TV transponder/channel.

Note

  1. For satellite delivery systems, the frequency is in kHz.
  2. For cable and terrestrial delivery systems, the frequency is in Hz.
  3. On most delivery systems, the frequency is the center frequency of the transponder/channel. The exception is for ISDB-T, where the main carrier has a 1/7 offset from the center.
  4. For ISDB-T, the channels are usually transmitted with an offset of about 143kHz. E.g. a valid frequency could be 474,143 kHz. The stepping is bound to the bandwidth of the channel which is typically 6MHz.
  5. In ISDB-Tsb, the channel consists of only one or three segments the frequency step is 429kHz, 3*429 respectively.

2.4.6.5. DTV_MODULATION

Specifies the frontend modulation type for delivery systems that supports more than one modulation type. The modulation can be one of the types defined by enum fe_modulation.

fe_modulation

2.4.6.5.1. Modulation property

Most of the digital TV standards currently offers more than one possible modulation (sometimes called as “constellation” on some standards). This enum contains the values used by the Kernel. Please note that not all modulations are supported by a given standard.

enum fe_modulation
ID Description

QPSK

QPSK modulation

QAM_16

16-QAM modulation

QAM_32

32-QAM modulation

QAM_64

64-QAM modulation

QAM_128

128-QAM modulation

QAM_256

256-QAM modulation

QAM_AUTO

Autodetect QAM modulation

VSB_8

8-VSB modulation

VSB_16

16-VSB modulation

PSK_8

8-PSK modulation

APSK_16

16-APSK modulation

APSK_32

32-APSK modulation

DQPSK

DQPSK modulation

QAM_4_NR

4-QAM-NR modulation

2.4.6.6. DTV_BANDWIDTH_HZ

Bandwidth for the channel, in HZ.

Possible values: 1712000, 5000000, 6000000, 7000000, 8000000, 10000000.

Note

  1. DVB-T supports 6, 7 and 8MHz.
  2. DVB-T2 supports 1.172, 5, 6, 7, 8 and 10MHz.
  3. ISDB-T supports 5MHz, 6MHz, 7MHz and 8MHz, although most places use 6MHz.
  4. On DVB-C and DVB-S/S2, the bandwidth depends on the symbol rate. So, the Kernel will silently ignore setting DTV_BANDWIDTH_HZ.
  5. For DVB-C and DVB-S/S2, the Kernel will return an estimation of the bandwidth, calculated from DTV_SYMBOL_RATE and from the rolloff, with is fixed for DVB-C and DVB-S.
  6. For DVB-S2, the bandwidth estimation will use DTV_ROLLOFF.
  7. For ISDB-Tsb, it can vary depending on the number of connected segments.
  8. Bandwidth in ISDB-Tsb can be easily derived from other parameters (DTV_ISDBT_SB_SEGMENT_IDX, DTV_ISDBT_SB_SEGMENT_COUNT).

2.4.6.7. DTV_INVERSION

Specifies if the frontend should do spectral inversion or not.

fe_spectral_inversion

2.4.6.7.1. enum fe_modulation: Frontend spectral inversion

This parameter indicates if spectral inversion should be presumed or not. In the automatic setting (INVERSION_AUTO) the hardware will try to figure out the correct setting by itself. If the hardware doesn’t support, the DVB core will try to lock at the carrier first with inversion off. If it fails, it will try to enable inversion.

enum fe_modulation
ID Description

INVERSION_OFF

Don’t do spectral band inversion.

INVERSION_ON

Do spectral band inversion.

INVERSION_AUTO

Autodetect spectral band inversion.

2.4.6.8. DTV_DISEQC_MASTER

Currently not implemented.

2.4.6.9. DTV_SYMBOL_RATE

Digital TV symbol rate, in bauds (symbols/second). Used on cable standards.

2.4.6.10. DTV_INNER_FEC

Used cable/satellite transmissions. The acceptable values are:

fe_code_rate

2.4.6.10.1. enum fe_code_rate: type of the Forward Error Correction.

enum fe_code_rate
ID Description

FEC_NONE

No Forward Error Correction Code

FEC_AUTO

Autodetect Error Correction Code

FEC_1_2

Forward Error Correction Code 1/2

FEC_2_3

Forward Error Correction Code 2/3

FEC_3_4

Forward Error Correction Code 3/4

FEC_4_5

Forward Error Correction Code 4/5

FEC_5_6

Forward Error Correction Code 5/6

FEC_6_7

Forward Error Correction Code 6/7

FEC_7_8

Forward Error Correction Code 7/8

FEC_8_9

Forward Error Correction Code 8/9

FEC_9_10

Forward Error Correction Code 9/10

FEC_2_5

Forward Error Correction Code 2/5

FEC_3_5

Forward Error Correction Code 3/5

2.4.6.11. DTV_VOLTAGE

The voltage is usually used with non-DiSEqC capable LNBs to switch the polarzation (horizontal/vertical). When using DiSEqC epuipment this voltage has to be switched consistently to the DiSEqC commands as described in the DiSEqC spec.

fe_sec_voltage
enum fe_sec_voltage
ID Description

SEC_VOLTAGE_13

Set DC voltage level to 13V

SEC_VOLTAGE_18

Set DC voltage level to 18V

SEC_VOLTAGE_OFF

Don’t send any voltage to the antenna

2.4.6.12. DTV_TONE

Currently not used.

2.4.6.13. DTV_PILOT

Sets DVB-S2 pilot

fe_pilot

2.4.6.13.1. fe_pilot type

enum fe_pilot
ID Description

PILOT_ON

Pilot tones enabled

PILOT_OFF

Pilot tones disabled

PILOT_AUTO

Autodetect pilot tones

2.4.6.14. DTV_ROLLOFF

Sets DVB-S2 rolloff

fe_rolloff

2.4.6.14.1. fe_rolloff type

enum fe_rolloff
ID Description

ROLLOFF_35

Roloff factor: α=35%

ROLLOFF_20

Roloff factor: α=20%

ROLLOFF_25

Roloff factor: α=25%

ROLLOFF_AUTO

Auto-detect the roloff factor.

2.4.6.15. DTV_DISEQC_SLAVE_REPLY

Currently not implemented.

2.4.6.16. DTV_FE_CAPABILITY_COUNT

Currently not implemented.

2.4.6.17. DTV_FE_CAPABILITY

Currently not implemented.

2.4.6.18. DTV_DELIVERY_SYSTEM

Specifies the type of Delivery system

fe_delivery_system

2.4.6.18.1. fe_delivery_system type

Possible values:

enum fe_delivery_system
ID Description

SYS_UNDEFINED

Undefined standard. Generally, indicates an error

SYS_DVBC_ANNEX_A

Cable TV: DVB-C following ITU-T J.83 Annex A spec

SYS_DVBC_ANNEX_B

Cable TV: DVB-C following ITU-T J.83 Annex B spec (ClearQAM)

SYS_DVBC_ANNEX_C

Cable TV: DVB-C following ITU-T J.83 Annex C spec

SYS_ISDBC

Cable TV: ISDB-C (no drivers yet)

SYS_DVBT

Terrestral TV: DVB-T

SYS_DVBT2

Terrestral TV: DVB-T2

SYS_ISDBT

Terrestral TV: ISDB-T

SYS_ATSC

Terrestral TV: ATSC

SYS_ATSCMH

Terrestral TV (mobile): ATSC-M/H

SYS_DTMB

Terrestrial TV: DTMB

SYS_DVBS

Satellite TV: DVB-S

SYS_DVBS2

Satellite TV: DVB-S2

SYS_TURBO

Satellite TV: DVB-S Turbo

SYS_ISDBS

Satellite TV: ISDB-S

SYS_DAB

Digital audio: DAB (not fully supported)

SYS_DSS

Satellite TV:”DSS (not fully supported)

SYS_CMMB

Terrestral TV (mobile):CMMB (not fully supported)

SYS_DVBH

Terrestral TV (mobile): DVB-H (standard deprecated)

2.4.6.19. DTV_ISDBT_PARTIAL_RECEPTION

If DTV_ISDBT_SOUND_BROADCASTING is ‘0’ this bit-field represents whether the channel is in partial reception mode or not.

If ‘1’ DTV_ISDBT_LAYERA_* values are assigned to the center segment and DTV_ISDBT_LAYERA_SEGMENT_COUNT has to be ‘1’.

If in addition DTV_ISDBT_SOUND_BROADCASTING is ‘1’ DTV_ISDBT_PARTIAL_RECEPTION represents whether this ISDB-Tsb channel is consisting of one segment and layer or three segments and two layers.

Possible values: 0, 1, -1 (AUTO)

2.4.6.20. DTV_ISDBT_SOUND_BROADCASTING

This field represents whether the other DTV_ISDBT_*-parameters are referring to an ISDB-T and an ISDB-Tsb channel. (See also DTV_ISDBT_PARTIAL_RECEPTION).

Possible values: 0, 1, -1 (AUTO)

2.4.6.21. DTV_ISDBT_SB_SUBCHANNEL_ID

This field only applies if DTV_ISDBT_SOUND_BROADCASTING is ‘1’.

(Note of the author: This might not be the correct description of the SUBCHANNEL-ID in all details, but it is my understanding of the technical background needed to program a device)

An ISDB-Tsb channel (1 or 3 segments) can be broadcasted alone or in a set of connected ISDB-Tsb channels. In this set of channels every channel can be received independently. The number of connected ISDB-Tsb segment can vary, e.g. depending on the frequency spectrum bandwidth available.

Example: Assume 8 ISDB-Tsb connected segments are broadcasted. The broadcaster has several possibilities to put those channels in the air: Assuming a normal 13-segment ISDB-T spectrum he can align the 8 segments from position 1-8 to 5-13 or anything in between.

The underlying layer of segments are subchannels: each segment is consisting of several subchannels with a predefined IDs. A sub-channel is used to help the demodulator to synchronize on the channel.

An ISDB-T channel is always centered over all sub-channels. As for the example above, in ISDB-Tsb it is no longer as simple as that.

The DTV_ISDBT_SB_SUBCHANNEL_ID parameter is used to give the sub-channel ID of the segment to be demodulated.

Possible values: 0 .. 41, -1 (AUTO)

2.4.6.22. DTV_ISDBT_SB_SEGMENT_IDX

This field only applies if DTV_ISDBT_SOUND_BROADCASTING is ‘1’.

DTV_ISDBT_SB_SEGMENT_IDX gives the index of the segment to be demodulated for an ISDB-Tsb channel where several of them are transmitted in the connected manner.

Possible values: 0 .. DTV_ISDBT_SB_SEGMENT_COUNT - 1

Note: This value cannot be determined by an automatic channel search.

2.4.6.23. DTV_ISDBT_SB_SEGMENT_COUNT

This field only applies if DTV_ISDBT_SOUND_BROADCASTING is ‘1’.

DTV_ISDBT_SB_SEGMENT_COUNT gives the total count of connected ISDB-Tsb channels.

Possible values: 1 .. 13

Note: This value cannot be determined by an automatic channel search.

2.4.6.24. DTV-ISDBT-LAYER[A-C] parameters

ISDB-T channels can be coded hierarchically. As opposed to DVB-T in ISDB-T hierarchical layers can be decoded simultaneously. For that reason a ISDB-T demodulator has 3 Viterbi and 3 Reed-Solomon decoders.

ISDB-T has 3 hierarchical layers which each can use a part of the available segments. The total number of segments over all layers has to 13 in ISDB-T.

There are 3 parameter sets, for Layers A, B and C.

2.4.6.24.1. DTV_ISDBT_LAYER_ENABLED

Hierarchical reception in ISDB-T is achieved by enabling or disabling layers in the decoding process. Setting all bits of DTV_ISDBT_LAYER_ENABLED to ‘1’ forces all layers (if applicable) to be demodulated. This is the default.

If the channel is in the partial reception mode (DTV_ISDBT_PARTIAL_RECEPTION = 1) the central segment can be decoded independently of the other 12 segments. In that mode layer A has to have a SEGMENT_COUNT of 1.

In ISDB-Tsb only layer A is used, it can be 1 or 3 in ISDB-Tsb according to DTV_ISDBT_PARTIAL_RECEPTION. SEGMENT_COUNT must be filled accordingly.

Only the values of the first 3 bits are used. Other bits will be silently ignored:

DTV_ISDBT_LAYER_ENABLED bit 0: layer A enabled

DTV_ISDBT_LAYER_ENABLED bit 1: layer B enabled

DTV_ISDBT_LAYER_ENABLED bit 2: layer C enabled

DTV_ISDBT_LAYER_ENABLED bits 3-31: unused

2.4.6.24.2. DTV_ISDBT_LAYER[A-C]_FEC

Possible values: FEC_AUTO, FEC_1_2, FEC_2_3, FEC_3_4, FEC_5_6, FEC_7_8

2.4.6.24.3. DTV_ISDBT_LAYER[A-C]_MODULATION

Possible values: QAM_AUTO, QPSK, QAM_16, QAM_64, DQPSK

Note: If layer C is DQPSK layer B has to be DQPSK. If layer B is DQPSK and DTV_ISDBT_PARTIAL_RECEPTION=0 layer has to be DQPSK.

2.4.6.24.4. DTV_ISDBT_LAYER[A-C]_SEGMENT_COUNT

Possible values: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, -1 (AUTO)

Note: Truth table for DTV_ISDBT_SOUND_BROADCASTING and DTV_ISDBT_PARTIAL_RECEPTION and LAYER[A-C]_SEGMENT_COUNT

Truth table for ISDB-T Sound Broadcasting
PR SB Layer A width Layer B width Layer C width total width
0 0 1 .. 13 1 .. 13 1 .. 13 13
1 0 1 1 .. 13 1 .. 13 13
0 1 1 0 0 1
1 1 1 2 0 13

2.4.6.24.5. DTV_ISDBT_LAYER[A-C]_TIME_INTERLEAVING

Valid values: 0, 1, 2, 4, -1 (AUTO)

when DTV_ISDBT_SOUND_BROADCASTING is active, value 8 is also valid.

Note: The real time interleaving length depends on the mode (fft-size). The values here are referring to what can be found in the TMCC-structure, as shown in the table below.

isdbt_layer_interleaving_table
ISDB-T time interleaving modes
DTV_ISDBT_LAYER[A-C]_TIME_INTERLEAVING Mode 1 (2K FFT) Mode 2 (4K FFT) Mode 3 (8K FFT)
0 0 0 0
1 4 2 1
2 8 4 2
4 16 8 4

2.4.6.24.6. DTV_ATSCMH_FIC_VER

Version number of the FIC (Fast Information Channel) signaling data.

FIC is used for relaying information to allow rapid service acquisition by the receiver.

Possible values: 0, 1, 2, 3, ..., 30, 31

2.4.6.24.7. DTV_ATSCMH_PARADE_ID

Parade identification number

A parade is a collection of up to eight MH groups, conveying one or two ensembles.

Possible values: 0, 1, 2, 3, ..., 126, 127

2.4.6.24.8. DTV_ATSCMH_NOG

Number of MH groups per MH subframe for a designated parade.

Possible values: 1, 2, 3, 4, 5, 6, 7, 8

2.4.6.24.9. DTV_ATSCMH_TNOG

Total number of MH groups including all MH groups belonging to all MH parades in one MH subframe.

Possible values: 0, 1, 2, 3, ..., 30, 31

2.4.6.24.10. DTV_ATSCMH_SGN

Start group number.

Possible values: 0, 1, 2, 3, ..., 14, 15

2.4.6.24.11. DTV_ATSCMH_PRC

Parade repetition cycle.

Possible values: 1, 2, 3, 4, 5, 6, 7, 8

2.4.6.24.12. DTV_ATSCMH_RS_FRAME_MODE

Reed Solomon (RS) frame mode.

Possible values are:

atscmh_rs_frame_mode
enum atscmh_rs_frame_mode
ID Description

ATSCMH_RSFRAME_PRI_ONLY

Single Frame: There is only a primary RS Frame for all Group Regions.

ATSCMH_RSFRAME_PRI_SEC

Dual Frame: There are two separate RS Frames: Primary RS Frame for Group Region A and B and Secondary RS Frame for Group Region C and D.

2.4.6.24.13. DTV_ATSCMH_RS_FRAME_ENSEMBLE

Reed Solomon(RS) frame ensemble.

Possible values are:

atscmh_rs_frame_ensemble
enum atscmh_rs_frame_ensemble
ID Description

ATSCMH_RSFRAME_ENS_PRI

Primary Ensemble.

AATSCMH_RSFRAME_PRI_SEC

Secondary Ensemble.

AATSCMH_RSFRAME_RES

Reserved. Shouldn’t be used.

2.4.6.24.14. DTV_ATSCMH_RS_CODE_MODE_PRI

Reed Solomon (RS) code mode (primary).

Possible values are:

atscmh_rs_code_mode
enum atscmh_rs_code_mode
ID Description

ATSCMH_RSCODE_211_187

Reed Solomon code (211,187).

ATSCMH_RSCODE_223_187

Reed Solomon code (223,187).

ATSCMH_RSCODE_235_187

Reed Solomon code (235,187).

ATSCMH_RSCODE_RES

Reserved. Shouldn’t be used.

2.4.6.24.15. DTV_ATSCMH_RS_CODE_MODE_SEC

Reed Solomon (RS) code mode (secondary).

Possible values are the same as documented on enum atscmh_rs_code_mode:

2.4.6.24.16. DTV_ATSCMH_SCCC_BLOCK_MODE

Series Concatenated Convolutional Code Block Mode.

Possible values are:

atscmh_sccc_block_mode
enum atscmh_scc_block_mode
ID Description

ATSCMH_SCCC_BLK_SEP

Separate SCCC: the SCCC outer code mode shall be set independently for each Group Region (A, B, C, D)

ATSCMH_SCCC_BLK_COMB

Combined SCCC: all four Regions shall have the same SCCC outer code mode.

ATSCMH_SCCC_BLK_RES

Reserved. Shouldn’t be used.

2.4.6.24.17. DTV_ATSCMH_SCCC_CODE_MODE_A

Series Concatenated Convolutional Code Rate.

Possible values are:

atscmh_sccc_code_mode
enum atscmh_sccc_code_mode
ID Description

ATSCMH_SCCC_CODE_HLF

The outer code rate of a SCCC Block is 1/2 rate.

ATSCMH_SCCC_CODE_QTR

The outer code rate of a SCCC Block is 1/4 rate.

ATSCMH_SCCC_CODE_RES

to be documented.

2.4.6.24.18. DTV_ATSCMH_SCCC_CODE_MODE_B

Series Concatenated Convolutional Code Rate.

Possible values are the same as documented on enum atscmh_sccc_code_mode.

2.4.6.24.19. DTV_ATSCMH_SCCC_CODE_MODE_C

Series Concatenated Convolutional Code Rate.

Possible values are the same as documented on enum atscmh_sccc_code_mode.

2.4.6.24.20. DTV_ATSCMH_SCCC_CODE_MODE_D

Series Concatenated Convolutional Code Rate.

Possible values are the same as documented on enum atscmh_sccc_code_mode.

2.4.6.25. DTV_API_VERSION

Returns the major/minor version of the DVB API

2.4.6.26. DTV_CODE_RATE_HP

Used on terrestrial transmissions. The acceptable values are the ones described at fe_transmit_mode.

2.4.6.27. DTV_CODE_RATE_LP

Used on terrestrial transmissions. The acceptable values are the ones described at fe_transmit_mode.

2.4.6.28. DTV_GUARD_INTERVAL

Possible values are:

fe_guard_interval

2.4.6.28.1. Modulation guard interval

enum fe_guard_interval
ID Description

GUARD_INTERVAL_AUTO

Autodetect the guard interval

GUARD_INTERVAL_1_128

Guard interval 1/128

GUARD_INTERVAL_1_32

Guard interval 1/32

GUARD_INTERVAL_1_16

Guard interval 1/16

GUARD_INTERVAL_1_8

Guard interval 1/8

GUARD_INTERVAL_1_4

Guard interval 1/4

GUARD_INTERVAL_19_128

Guard interval 19/128

GUARD_INTERVAL_19_256

Guard interval 19/256

GUARD_INTERVAL_PN420

PN length 420 (1/4)

GUARD_INTERVAL_PN595

PN length 595 (1/6)

GUARD_INTERVAL_PN945

PN length 945 (1/9)

Notes:

1) If DTV_GUARD_INTERVAL is set the GUARD_INTERVAL_AUTO the hardware will try to find the correct guard interval (if capable) and will use TMCC to fill in the missing parameters.

2) Intervals 1/128, 19/128 and 19/256 are used only for DVB-T2 at present

  1. DTMB specifies PN420, PN595 and PN945.

2.4.6.29. DTV_TRANSMISSION_MODE

Specifies the number of carriers used by the standard. This is used only on OFTM-based standards, e. g. DVB-T/T2, ISDB-T, DTMB

fe_transmit_mode

2.4.6.29.1. enum fe_transmit_mode: Number of carriers per channel

enum fe_transmit_mode
ID Description

TRANSMISSION_MODE_AUTO

Autodetect transmission mode. The hardware will try to find the correct FFT-size (if capable) to fill in the missing parameters.

TRANSMISSION_MODE_1K

Transmission mode 1K

TRANSMISSION_MODE_2K

Transmission mode 2K

TRANSMISSION_MODE_8K

Transmission mode 8K

TRANSMISSION_MODE_4K

Transmission mode 4K

TRANSMISSION_MODE_16K

Transmission mode 16K

TRANSMISSION_MODE_32K

Transmission mode 32K

TRANSMISSION_MODE_C1

Single Carrier (C=1) transmission mode (DTMB)

TRANSMISSION_MODE_C3780

Multi Carrier (C=3780) transmission mode (DTMB)

Notes:

1) ISDB-T supports three carrier/symbol-size: 8K, 4K, 2K. It is called ‘mode’ in the standard: Mode 1 is 2K, mode 2 is 4K, mode 3 is 8K

2) If DTV_TRANSMISSION_MODE is set the TRANSMISSION_MODE_AUTO the hardware will try to find the correct FFT-size (if capable) and will use TMCC to fill in the missing parameters.

  1. DVB-T specifies 2K and 8K as valid sizes.
  2. DVB-T2 specifies 1K, 2K, 4K, 8K, 16K and 32K.
  3. DTMB specifies C1 and C3780.

2.4.6.30. DTV_HIERARCHY

Frontend hierarchy

fe_hierarchy

2.4.6.30.1. Frontend hierarchy

enum fe_hierarchy
ID Description

HIERARCHY_NONE

No hierarchy

HIERARCHY_AUTO

Autodetect hierarchy (if supported)

HIERARCHY_1

Hierarchy 1

HIERARCHY_2

Hierarchy 2

HIERARCHY_4

Hierarchy 4

2.4.6.31. DTV_STREAM_ID

DVB-S2, DVB-T2 and ISDB-S support the transmission of several streams on a single transport stream. This property enables the DVB driver to handle substream filtering, when supported by the hardware. By default, substream filtering is disabled.

For DVB-S2 and DVB-T2, the valid substream id range is from 0 to 255.

For ISDB, the valid substream id range is from 1 to 65535.

To disable it, you should use the special macro NO_STREAM_ID_FILTER.

Note: any value outside the id range also disables filtering.

2.4.6.32. DTV_DVBT2_PLP_ID_LEGACY

Obsolete, replaced with DTV_STREAM_ID.

2.4.6.33. DTV_ENUM_DELSYS

A Multi standard frontend needs to advertise the delivery systems provided. Applications need to enumerate the provided delivery systems, before using any other operation with the frontend. Prior to it’s introduction, FE_GET_INFO was used to determine a frontend type. A frontend which provides more than a single delivery system, FE_GET_INFO doesn’t help much. Applications which intends to use a multistandard frontend must enumerate the delivery systems associated with it, rather than trying to use FE_GET_INFO. In the case of a legacy frontend, the result is just the same as with FE_GET_INFO, but in a more structured format

2.4.6.34. DTV_INTERLEAVING

Time interleaving to be used. Currently, used only on DTMB.

fe_interleaving
enum fe_interleaving
ID Description

INTERLEAVING_NONE

No interleaving.

INTERLEAVING_AUTO

Auto-detect interleaving.

INTERLEAVING_240

Interleaving of 240 symbols.

INTERLEAVING_720

Interleaving of 720 symbols.

2.4.6.35. DTV_LNA

Low-noise amplifier.

Hardware might offer controllable LNA which can be set manually using that parameter. Usually LNA could be found only from terrestrial devices if at all.

Possible values: 0, 1, LNA_AUTO

0, LNA off

1, LNA on

use the special macro LNA_AUTO to set LNA auto