1 .. SPDX-License-Identifier: GFDL-1.1-no-invari 1 .. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later
2 2
3 .. _frontend-stat-properties: 3 .. _frontend-stat-properties:
4 4
5 ****************************** 5 ******************************
6 Frontend statistics indicators 6 Frontend statistics indicators
7 ****************************** 7 ******************************
8 8
9 The values are returned via ``dtv_property.sta 9 The values are returned via ``dtv_property.stat``. If the property is
10 supported, ``dtv_property.stat.len`` is bigger 10 supported, ``dtv_property.stat.len`` is bigger than zero.
11 11
12 For most delivery systems, ``dtv_property.stat 12 For most delivery systems, ``dtv_property.stat.len`` will be 1 if the
13 stats is supported, and the properties will re 13 stats is supported, and the properties will return a single value for
14 each parameter. 14 each parameter.
15 15
16 It should be noted, however, that new OFDM del 16 It should be noted, however, that new OFDM delivery systems like ISDB
17 can use different modulation types for each gr 17 can use different modulation types for each group of carriers. On such
18 standards, up to 3 groups of statistics can be 18 standards, up to 3 groups of statistics can be provided, and
19 ``dtv_property.stat.len`` is updated to reflec 19 ``dtv_property.stat.len`` is updated to reflect the "global" metrics,
20 plus one metric per each carrier group (called 20 plus one metric per each carrier group (called "layer" on ISDB).
21 21
22 So, in order to be consistent with other deliv 22 So, in order to be consistent with other delivery systems, the first
23 value at :c:type:`dtv_property.stat.dtv_stats 23 value at :c:type:`dtv_property.stat.dtv_stats <dtv_stats>` array refers
24 to the global metric. The other elements of th 24 to the global metric. The other elements of the array represent each
25 layer, starting from layer A(index 1), layer B 25 layer, starting from layer A(index 1), layer B (index 2) and so on.
26 26
27 The number of filled elements are stored at `` 27 The number of filled elements are stored at ``dtv_property.stat.len``.
28 28
29 Each element of the ``dtv_property.stat.dtv_st 29 Each element of the ``dtv_property.stat.dtv_stats`` array consists on
30 two elements: 30 two elements:
31 31
32 - ``svalue`` or ``uvalue``, where ``svalue`` 32 - ``svalue`` or ``uvalue``, where ``svalue`` is for signed values of
33 the measure (dB measures) and ``uvalue`` is 33 the measure (dB measures) and ``uvalue`` is for unsigned values
34 (counters, relative scale) 34 (counters, relative scale)
35 35
36 - ``scale`` - Scale for the value. It can be: 36 - ``scale`` - Scale for the value. It can be:
37 37
38 - ``FE_SCALE_NOT_AVAILABLE`` - The paramet 38 - ``FE_SCALE_NOT_AVAILABLE`` - The parameter is supported by the
39 frontend, but it was not possible to col 39 frontend, but it was not possible to collect it (could be a
40 transitory or permanent condition) 40 transitory or permanent condition)
41 41
42 - ``FE_SCALE_DECIBEL`` - parameter is a si 42 - ``FE_SCALE_DECIBEL`` - parameter is a signed value, measured in
43 1/1000 dB 43 1/1000 dB
44 44
45 - ``FE_SCALE_RELATIVE`` - parameter is a u 45 - ``FE_SCALE_RELATIVE`` - parameter is a unsigned value, where 0
46 means 0% and 65535 means 100%. 46 means 0% and 65535 means 100%.
47 47
48 - ``FE_SCALE_COUNTER`` - parameter is a un 48 - ``FE_SCALE_COUNTER`` - parameter is a unsigned value that counts
49 the occurrence of an event, like bit err 49 the occurrence of an event, like bit error, block error, or lapsed
50 time. 50 time.
51 51
52 52
53 .. _DTV-STAT-SIGNAL-STRENGTH: 53 .. _DTV-STAT-SIGNAL-STRENGTH:
54 54
55 DTV_STAT_SIGNAL_STRENGTH 55 DTV_STAT_SIGNAL_STRENGTH
56 ======================== 56 ========================
57 57
58 Indicates the signal strength level at the ana 58 Indicates the signal strength level at the analog part of the tuner or
59 of the demod. 59 of the demod.
60 60
61 Possible scales for this metric are: 61 Possible scales for this metric are:
62 62
63 - ``FE_SCALE_NOT_AVAILABLE`` - it failed to m 63 - ``FE_SCALE_NOT_AVAILABLE`` - it failed to measure it, or the
64 measurement was not complete yet. 64 measurement was not complete yet.
65 65
66 - ``FE_SCALE_DECIBEL`` - signal strength is i 66 - ``FE_SCALE_DECIBEL`` - signal strength is in 0.001 dBm units, power
67 measured in miliwatts. This value is genera 67 measured in miliwatts. This value is generally negative.
68 68
69 - ``FE_SCALE_RELATIVE`` - The frontend provid 69 - ``FE_SCALE_RELATIVE`` - The frontend provides a 0% to 100%
70 measurement for power (actually, 0 to 65535 70 measurement for power (actually, 0 to 65535).
71 71
72 72
73 .. _DTV-STAT-CNR: 73 .. _DTV-STAT-CNR:
74 74
75 DTV_STAT_CNR 75 DTV_STAT_CNR
76 ============ 76 ============
77 77
78 Indicates the Signal to Noise ratio for the ma 78 Indicates the Signal to Noise ratio for the main carrier.
79 79
80 Possible scales for this metric are: 80 Possible scales for this metric are:
81 81
82 - ``FE_SCALE_NOT_AVAILABLE`` - it failed to m 82 - ``FE_SCALE_NOT_AVAILABLE`` - it failed to measure it, or the
83 measurement was not complete yet. 83 measurement was not complete yet.
84 84
85 - ``FE_SCALE_DECIBEL`` - Signal/Noise ratio i 85 - ``FE_SCALE_DECIBEL`` - Signal/Noise ratio is in 0.001 dB units.
86 86
87 - ``FE_SCALE_RELATIVE`` - The frontend provid 87 - ``FE_SCALE_RELATIVE`` - The frontend provides a 0% to 100%
88 measurement for Signal/Noise (actually, 0 t 88 measurement for Signal/Noise (actually, 0 to 65535).
89 89
90 90
91 .. _DTV-STAT-PRE-ERROR-BIT-COUNT: 91 .. _DTV-STAT-PRE-ERROR-BIT-COUNT:
92 92
93 DTV_STAT_PRE_ERROR_BIT_COUNT 93 DTV_STAT_PRE_ERROR_BIT_COUNT
94 ============================ 94 ============================
95 95
96 Measures the number of bit errors before the f 96 Measures the number of bit errors before the forward error correction
97 (FEC) on the inner coding block (before Viterb 97 (FEC) on the inner coding block (before Viterbi, LDPC or other inner
98 code). 98 code).
99 99
100 This measure is taken during the same interval 100 This measure is taken during the same interval as
101 ``DTV_STAT_PRE_TOTAL_BIT_COUNT``. 101 ``DTV_STAT_PRE_TOTAL_BIT_COUNT``.
102 102
103 In order to get the BER (Bit Error Rate) measu 103 In order to get the BER (Bit Error Rate) measurement, it should be
104 divided by 104 divided by
105 :ref:`DTV_STAT_PRE_TOTAL_BIT_COUNT <DTV-STAT-P 105 :ref:`DTV_STAT_PRE_TOTAL_BIT_COUNT <DTV-STAT-PRE-TOTAL-BIT-COUNT>`.
106 106
107 This measurement is monotonically increased, a 107 This measurement is monotonically increased, as the frontend gets more
108 bit count measurements. The frontend may reset 108 bit count measurements. The frontend may reset it when a
109 channel/transponder is tuned. 109 channel/transponder is tuned.
110 110
111 Possible scales for this metric are: 111 Possible scales for this metric are:
112 112
113 - ``FE_SCALE_NOT_AVAILABLE`` - it failed to m 113 - ``FE_SCALE_NOT_AVAILABLE`` - it failed to measure it, or the
114 measurement was not complete yet. 114 measurement was not complete yet.
115 115
116 - ``FE_SCALE_COUNTER`` - Number of error bits 116 - ``FE_SCALE_COUNTER`` - Number of error bits counted before the inner
117 coding. 117 coding.
118 118
119 119
120 .. _DTV-STAT-PRE-TOTAL-BIT-COUNT: 120 .. _DTV-STAT-PRE-TOTAL-BIT-COUNT:
121 121
122 DTV_STAT_PRE_TOTAL_BIT_COUNT 122 DTV_STAT_PRE_TOTAL_BIT_COUNT
123 ============================ 123 ============================
124 124
125 Measures the amount of bits received before th 125 Measures the amount of bits received before the inner code block, during
126 the same period as 126 the same period as
127 :ref:`DTV_STAT_PRE_ERROR_BIT_COUNT <DTV-STAT-P 127 :ref:`DTV_STAT_PRE_ERROR_BIT_COUNT <DTV-STAT-PRE-ERROR-BIT-COUNT>`
128 measurement was taken. 128 measurement was taken.
129 129
130 It should be noted that this measurement can b 130 It should be noted that this measurement can be smaller than the total
131 amount of bits on the transport stream, as the 131 amount of bits on the transport stream, as the frontend may need to
132 manually restart the measurement, losing some 132 manually restart the measurement, losing some data between each
133 measurement interval. 133 measurement interval.
134 134
135 This measurement is monotonically increased, a 135 This measurement is monotonically increased, as the frontend gets more
136 bit count measurements. The frontend may reset 136 bit count measurements. The frontend may reset it when a
137 channel/transponder is tuned. 137 channel/transponder is tuned.
138 138
139 Possible scales for this metric are: 139 Possible scales for this metric are:
140 140
141 - ``FE_SCALE_NOT_AVAILABLE`` - it failed to m 141 - ``FE_SCALE_NOT_AVAILABLE`` - it failed to measure it, or the
142 measurement was not complete yet. 142 measurement was not complete yet.
143 143
144 - ``FE_SCALE_COUNTER`` - Number of bits count 144 - ``FE_SCALE_COUNTER`` - Number of bits counted while measuring
145 :ref:`DTV_STAT_PRE_ERROR_BIT_COUNT <DTV-STA 145 :ref:`DTV_STAT_PRE_ERROR_BIT_COUNT <DTV-STAT-PRE-ERROR-BIT-COUNT>`.
146 146
147 147
148 .. _DTV-STAT-POST-ERROR-BIT-COUNT: 148 .. _DTV-STAT-POST-ERROR-BIT-COUNT:
149 149
150 DTV_STAT_POST_ERROR_BIT_COUNT 150 DTV_STAT_POST_ERROR_BIT_COUNT
151 ============================= 151 =============================
152 152
153 Measures the number of bit errors after the fo 153 Measures the number of bit errors after the forward error correction
154 (FEC) done by inner code block (after Viterbi, 154 (FEC) done by inner code block (after Viterbi, LDPC or other inner
155 code). 155 code).
156 156
157 This measure is taken during the same interval 157 This measure is taken during the same interval as
158 ``DTV_STAT_POST_TOTAL_BIT_COUNT``. 158 ``DTV_STAT_POST_TOTAL_BIT_COUNT``.
159 159
160 In order to get the BER (Bit Error Rate) measu 160 In order to get the BER (Bit Error Rate) measurement, it should be
161 divided by 161 divided by
162 :ref:`DTV_STAT_POST_TOTAL_BIT_COUNT <DTV-STAT- 162 :ref:`DTV_STAT_POST_TOTAL_BIT_COUNT <DTV-STAT-POST-TOTAL-BIT-COUNT>`.
163 163
164 This measurement is monotonically increased, a 164 This measurement is monotonically increased, as the frontend gets more
165 bit count measurements. The frontend may reset 165 bit count measurements. The frontend may reset it when a
166 channel/transponder is tuned. 166 channel/transponder is tuned.
167 167
168 Possible scales for this metric are: 168 Possible scales for this metric are:
169 169
170 - ``FE_SCALE_NOT_AVAILABLE`` - it failed to m 170 - ``FE_SCALE_NOT_AVAILABLE`` - it failed to measure it, or the
171 measurement was not complete yet. 171 measurement was not complete yet.
172 172
173 - ``FE_SCALE_COUNTER`` - Number of error bits 173 - ``FE_SCALE_COUNTER`` - Number of error bits counted after the inner
174 coding. 174 coding.
175 175
176 176
177 .. _DTV-STAT-POST-TOTAL-BIT-COUNT: 177 .. _DTV-STAT-POST-TOTAL-BIT-COUNT:
178 178
179 DTV_STAT_POST_TOTAL_BIT_COUNT 179 DTV_STAT_POST_TOTAL_BIT_COUNT
180 ============================= 180 =============================
181 181
182 Measures the amount of bits received after the 182 Measures the amount of bits received after the inner coding, during the
183 same period as 183 same period as
184 :ref:`DTV_STAT_POST_ERROR_BIT_COUNT <DTV-STAT- 184 :ref:`DTV_STAT_POST_ERROR_BIT_COUNT <DTV-STAT-POST-ERROR-BIT-COUNT>`
185 measurement was taken. 185 measurement was taken.
186 186
187 It should be noted that this measurement can b 187 It should be noted that this measurement can be smaller than the total
188 amount of bits on the transport stream, as the 188 amount of bits on the transport stream, as the frontend may need to
189 manually restart the measurement, losing some 189 manually restart the measurement, losing some data between each
190 measurement interval. 190 measurement interval.
191 191
192 This measurement is monotonically increased, a 192 This measurement is monotonically increased, as the frontend gets more
193 bit count measurements. The frontend may reset 193 bit count measurements. The frontend may reset it when a
194 channel/transponder is tuned. 194 channel/transponder is tuned.
195 195
196 Possible scales for this metric are: 196 Possible scales for this metric are:
197 197
198 - ``FE_SCALE_NOT_AVAILABLE`` - it failed to m 198 - ``FE_SCALE_NOT_AVAILABLE`` - it failed to measure it, or the
199 measurement was not complete yet. 199 measurement was not complete yet.
200 200
201 - ``FE_SCALE_COUNTER`` - Number of bits count 201 - ``FE_SCALE_COUNTER`` - Number of bits counted while measuring
202 :ref:`DTV_STAT_POST_ERROR_BIT_COUNT <DTV-ST 202 :ref:`DTV_STAT_POST_ERROR_BIT_COUNT <DTV-STAT-POST-ERROR-BIT-COUNT>`.
203 203
204 204
205 .. _DTV-STAT-ERROR-BLOCK-COUNT: 205 .. _DTV-STAT-ERROR-BLOCK-COUNT:
206 206
207 DTV_STAT_ERROR_BLOCK_COUNT 207 DTV_STAT_ERROR_BLOCK_COUNT
208 ========================== 208 ==========================
209 209
210 Measures the number of block errors after the 210 Measures the number of block errors after the outer forward error
211 correction coding (after Reed-Solomon or other 211 correction coding (after Reed-Solomon or other outer code).
212 212
213 This measurement is monotonically increased, a 213 This measurement is monotonically increased, as the frontend gets more
214 bit count measurements. The frontend may reset 214 bit count measurements. The frontend may reset it when a
215 channel/transponder is tuned. 215 channel/transponder is tuned.
216 216
217 Possible scales for this metric are: 217 Possible scales for this metric are:
218 218
219 - ``FE_SCALE_NOT_AVAILABLE`` - it failed to m 219 - ``FE_SCALE_NOT_AVAILABLE`` - it failed to measure it, or the
220 measurement was not complete yet. 220 measurement was not complete yet.
221 221
222 - ``FE_SCALE_COUNTER`` - Number of error bloc 222 - ``FE_SCALE_COUNTER`` - Number of error blocks counted after the outer
223 coding. 223 coding.
224 224
225 225
226 .. _DTV-STAT-TOTAL-BLOCK-COUNT: 226 .. _DTV-STAT-TOTAL-BLOCK-COUNT:
227 227
228 DTV-STAT_TOTAL_BLOCK_COUNT 228 DTV-STAT_TOTAL_BLOCK_COUNT
229 ========================== 229 ==========================
230 230
231 Measures the total number of blocks received d 231 Measures the total number of blocks received during the same period as
232 :ref:`DTV_STAT_ERROR_BLOCK_COUNT <DTV-STAT-ERR 232 :ref:`DTV_STAT_ERROR_BLOCK_COUNT <DTV-STAT-ERROR-BLOCK-COUNT>`
233 measurement was taken. 233 measurement was taken.
234 234
235 It can be used to calculate the PER indicator, 235 It can be used to calculate the PER indicator, by dividing
236 :ref:`DTV_STAT_ERROR_BLOCK_COUNT <DTV-STAT-ERR 236 :ref:`DTV_STAT_ERROR_BLOCK_COUNT <DTV-STAT-ERROR-BLOCK-COUNT>` by
237 :ref:`DTV-STAT-TOTAL-BLOCK-COUNT`. 237 :ref:`DTV-STAT-TOTAL-BLOCK-COUNT`.
238 238
239 Possible scales for this metric are: 239 Possible scales for this metric are:
240 240
241 - ``FE_SCALE_NOT_AVAILABLE`` - it failed to m 241 - ``FE_SCALE_NOT_AVAILABLE`` - it failed to measure it, or the
242 measurement was not complete yet. 242 measurement was not complete yet.
243 243
244 - ``FE_SCALE_COUNTER`` - Number of blocks cou 244 - ``FE_SCALE_COUNTER`` - Number of blocks counted while measuring
245 :ref:`DTV_STAT_ERROR_BLOCK_COUNT <DTV-STAT- 245 :ref:`DTV_STAT_ERROR_BLOCK_COUNT <DTV-STAT-ERROR-BLOCK-COUNT>`.
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