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Mauro Carvalho Chehab131db3a2009-10-24 21:18:46 -03001<section id="FE_GET_PROPERTY">
2<title>FE_GET_PROPERTY/FE_SET_PROPERTY</title>
3
Mauro Carvalho Chehab453d63c2009-09-16 23:22:05 -03004<section id="isdbt">
5 <title>ISDB-T frontend</title>
6 <para>This section describes shortly what are the possible parameters in the Linux
7 DVB-API called "S2API" and now DVB API 5 in order to tune an ISDB-T/ISDB-Tsb
8 demodulator:</para>
9
10 <para>This ISDB-T/ISDB-Tsb API extension should reflect all information
11 needed to tune any ISDB-T/ISDB-Tsb hardware. Of course it is possible
12 that some very sophisticated devices won't need certain parameters to
13 tune.</para>
14
15 <para>The information given here should help application writers to know how
16 to handle ISDB-T and ISDB-Tsb hardware using the Linux DVB-API.</para>
17
18 <para>The details given here about ISDB-T and ISDB-Tsb are just enough to
19 basically show the dependencies between the needed parameter values,
20 but surely some information is left out. For more detailed information
21 see the following documents:</para>
22
23 <para>ARIB STD-B31 - "Transmission System for Digital Terrestrial
24 Television Broadcasting" and</para>
25 <para>ARIB TR-B14 - "Operational Guidelines for Digital Terrestrial
26 Television Broadcasting".</para>
27
28 <para>In order to read this document one has to have some knowledge the
29 channel structure in ISDB-T and ISDB-Tsb. I.e. it has to be known to
30 the reader that an ISDB-T channel consists of 13 segments, that it can
31 have up to 3 layer sharing those segments, and things like that.</para>
32
33 <para>Parameters used by ISDB-T and ISDB-Tsb.</para>
34
35 <section id="isdbt-parms">
36 <title>Parameters that are common with DVB-T and ATSC</title>
37
38 <section id="isdbt-freq">
39 <title><constant>DTV_FREQUENCY</constant></title>
40
41 <para>Central frequency of the channel.</para>
42
43 <para>For ISDB-T the channels are usally transmitted with an offset of 143kHz. E.g. a
44 valid frequncy could be 474143 kHz. The stepping is bound to the bandwidth of
45 the channel which is 6MHz.</para>
46
47 <para>As in ISDB-Tsb the channel consists of only one or three segments the
48 frequency step is 429kHz, 3*429 respectively. As for ISDB-T the
49 central frequency of the channel is expected.</para>
50 </section>
51
52 <section id="isdbt-bw">
53 <title><constant>DTV_BANDWIDTH_HZ</constant> (optional)</title>
54
55 <para>Possible values:</para>
56
57 <para>For ISDB-T it should be always 6000000Hz (6MHz)</para>
58 <para>For ISDB-Tsb it can vary depending on the number of connected segments</para>
59
60 <para>Note: Hardware specific values might be given here, but standard
61 applications should not bother to set a value to this field as
62 standard demods are ignoring it anyway.</para>
63
64 <para>Bandwidth in ISDB-T is fixed (6MHz) or can be easily derived from
65 other parameters (DTV_ISDBT_SB_SEGMENT_IDX,
66 DTV_ISDBT_SB_SEGMENT_COUNT).</para>
67 </section>
68
69 <section id="isdbt-delivery-sys">
70 <title><constant>DTV_DELIVERY_SYSTEM</constant></title>
71
72 <para>Possible values: <constant>SYS_ISDBT</constant></para>
73 </section>
74
75 <section id="isdbt-tx-mode">
76 <title><constant>DTV_TRANSMISSION_MODE</constant></title>
77
78 <para>ISDB-T supports three carrier/symbol-size: 8K, 4K, 2K. It is called
79 'mode' in the standard: Mode 1 is 2K, mode 2 is 4K, mode 3 is 8K</para>
80
81 <para>Possible values: <constant>TRANSMISSION_MODE_2K</constant>, <constant>TRANSMISSION_MODE_8K</constant>,
82 <constant>TRANSMISSION_MODE_AUTO</constant>, <constant>TRANSMISSION_MODE_4K</constant></para>
83
84 <para>If <constant>DTV_TRANSMISSION_MODE</constant> is set the <constant>TRANSMISSION_MODE_AUTO</constant> the
85 hardware will try to find the correct FFT-size (if capable) and will
86 use TMCC to fill in the missing parameters.</para>
87
88 <para><constant>TRANSMISSION_MODE_4K</constant> is added at the same time as the other new parameters.</para>
89 </section>
90
91 <section id="isdbt-guard-interval">
92 <title><constant>DTV_GUARD_INTERVAL</constant></title>
93
94 <para>Possible values: <constant>GUARD_INTERVAL_1_32</constant>, <constant>GUARD_INTERVAL_1_16</constant>, <constant>GUARD_INTERVAL_1_8</constant>,
95 <constant>GUARD_INTERVAL_1_4</constant>, <constant>GUARD_INTERVAL_AUTO</constant></para>
96
97 <para>If <constant>DTV_GUARD_INTERVAL</constant> is set the <constant>GUARD_INTERVAL_AUTO</constant> the hardware will
98 try to find the correct guard interval (if capable) and will use TMCC to fill
99 in the missing parameters.</para>
100 </section>
101 </section>
Mauro Carvalho Chehabc18038d2009-09-17 01:25:41 -0300102 <section id="isdbt-new-parms">
103 <title>ISDB-T only parameters</title>
Mauro Carvalho Chehab453d63c2009-09-16 23:22:05 -0300104
105 <section id="isdbt-part-rec">
106 <title><constant>DTV_ISDBT_PARTIAL_RECEPTION</constant></title>
107
108 <para><constant>If DTV_ISDBT_SOUND_BROADCASTING</constant> is '0' this bit-field represents whether
109 the channel is in partial reception mode or not.</para>
110
111 <para>If '1' <constant>DTV_ISDBT_LAYERA_*</constant> values are assigned to the center segment and
112 <constant>DTV_ISDBT_LAYERA_SEGMENT_COUNT</constant> has to be '1'.</para>
113
114 <para>If in addition <constant>DTV_ISDBT_SOUND_BROADCASTING</constant> is '1'
115 <constant>DTV_ISDBT_PARTIAL_RECEPTION</constant> represents whether this ISDB-Tsb channel
116 is consisting of one segment and layer or three segments and two layers.</para>
117
118 <para>Possible values: 0, 1, -1 (AUTO)</para>
119 </section>
120
121 <section id="isdbt-sound-bcast">
122 <title><constant>DTV_ISDBT_SOUND_BROADCASTING</constant></title>
123
124 <para>This field represents whether the other DTV_ISDBT_*-parameters are
125 referring to an ISDB-T and an ISDB-Tsb channel. (See also
126 <constant>DTV_ISDBT_PARTIAL_RECEPTION</constant>).</para>
127
Mauro Carvalho Chehabc18038d2009-09-17 01:25:41 -0300128 <para>Possible values: 0, 1, -1 (AUTO)</para>
Mauro Carvalho Chehab453d63c2009-09-16 23:22:05 -0300129 </section>
130
131 <section id="isdbt-sb-ch-id">
132 <title><constant>DTV_ISDBT_SB_SUBCHANNEL_ID</constant></title>
133
134 <para>This field only applies if <constant>DTV_ISDBT_SOUND_BROADCASTING</constant> is '1'.</para>
135
136 <para>(Note of the author: This might not be the correct description of the
137 <constant>SUBCHANNEL-ID</constant> in all details, but it is my understanding of the technical
138 background needed to program a device)</para>
139
140 <para>An ISDB-Tsb channel (1 or 3 segments) can be broadcasted alone or in a
141 set of connected ISDB-Tsb channels. In this set of channels every
142 channel can be received independently. The number of connected
143 ISDB-Tsb segment can vary, e.g. depending on the frequency spectrum
144 bandwidth available.</para>
145
146 <para>Example: Assume 8 ISDB-Tsb connected segments are broadcasted. The
147 broadcaster has several possibilities to put those channels in the
148 air: Assuming a normal 13-segment ISDB-T spectrum he can align the 8
149 segments from position 1-8 to 5-13 or anything in between.</para>
150
151 <para>The underlying layer of segments are subchannels: each segment is
152 consisting of several subchannels with a predefined IDs. A sub-channel
153 is used to help the demodulator to synchronize on the channel.</para>
154
155 <para>An ISDB-T channel is always centered over all sub-channels. As for
156 the example above, in ISDB-Tsb it is no longer as simple as that.</para>
157
158 <para><constant>The DTV_ISDBT_SB_SUBCHANNEL_ID</constant> parameter is used to give the
159 sub-channel ID of the segment to be demodulated.</para>
160
161 <para>Possible values: 0 .. 41, -1 (AUTO)</para>
162 </section>
163
164 <section id="isdbt-sb-seg-idx">
165
166 <title><constant>DTV_ISDBT_SB_SEGMENT_IDX</constant></title>
167
168 <para>This field only applies if <constant>DTV_ISDBT_SOUND_BROADCASTING</constant> is '1'.</para>
169
170 <para><constant>DTV_ISDBT_SB_SEGMENT_IDX</constant> gives the index of the segment to be
171 demodulated for an ISDB-Tsb channel where several of them are
172 transmitted in the connected manner.</para>
173
174 <para>Possible values: 0 .. <constant>DTV_ISDBT_SB_SEGMENT_COUNT</constant> - 1</para>
175
176 <para>Note: This value cannot be determined by an automatic channel search.</para>
177 </section>
178
179 <section id="isdbt-sb-seg-cnt">
180 <title><constant>DTV_ISDBT_SB_SEGMENT_COUNT</constant></title>
181
182 <para>This field only applies if <constant>DTV_ISDBT_SOUND_BROADCASTING</constant> is '1'.</para>
183
184 <para><constant>DTV_ISDBT_SB_SEGMENT_COUNT</constant> gives the total count of connected ISDB-Tsb
185 channels.</para>
186
187 <para>Possible values: 1 .. 13</para>
188
189 <para>Note: This value cannot be determined by an automatic channel search.</para>
190 </section>
191
192 <section id="isdb-hierq-layers">
193 <title>Hierarchical layers</title>
194
195 <para>ISDB-T channels can be coded hierarchically. As opposed to DVB-T in
196 ISDB-T hierarchical layers can be decoded simultaneously. For that
197 reason a ISDB-T demodulator has 3 viterbi and 3 reed-solomon-decoders.</para>
198
199 <para>ISDB-T has 3 hierarchical layers which each can use a part of the
200 available segments. The total number of segments over all layers has
201 to 13 in ISDB-T.</para>
202
203 <section id="isdbt-layer-ena">
204 <title><constant>DTV_ISDBT_LAYER_ENABLED</constant></title>
205
206 <para>Hierarchical reception in ISDB-T is achieved by enabling or disabling
207 layers in the decoding process. Setting all bits of
208 <constant>DTV_ISDBT_LAYER_ENABLED</constant> to '1' forces all layers (if applicable) to be
209 demodulated. This is the default.</para>
210
211 <para>If the channel is in the partial reception mode
212 (<constant>DTV_ISDBT_PARTIAL_RECEPTION</constant> = 1) the central segment can be decoded
213 independently of the other 12 segments. In that mode layer A has to
214 have a <constant>SEGMENT_COUNT</constant> of 1.</para>
215
216 <para>In ISDB-Tsb only layer A is used, it can be 1 or 3 in ISDB-Tsb
217 according to <constant>DTV_ISDBT_PARTIAL_RECEPTION</constant>. <constant>SEGMENT_COUNT</constant> must be filled
218 accordingly.</para>
219
220 <para>Possible values: 0x1, 0x2, 0x4 (|-able)</para>
221
222 <para><constant>DTV_ISDBT_LAYER_ENABLED[0:0]</constant> - layer A</para>
223 <para><constant>DTV_ISDBT_LAYER_ENABLED[1:1]</constant> - layer B</para>
224 <para><constant>DTV_ISDBT_LAYER_ENABLED[2:2]</constant> - layer C</para>
225 <para><constant>DTV_ISDBT_LAYER_ENABLED[31:3]</constant> unused</para>
226 </section>
227
228 <section id="isdbt-layer-fec">
229 <title><constant>DTV_ISDBT_LAYER*_FEC</constant></title>
230
231 <para>Possible values: <constant>FEC_AUTO</constant>, <constant>FEC_1_2</constant>, <constant>FEC_2_3</constant>, <constant>FEC_3_4</constant>, <constant>FEC_5_6</constant>, <constant>FEC_7_8</constant></para>
232 </section>
233
234 <section id="isdbt-layer-mod">
235 <title><constant>DTV_ISDBT_LAYER*_MODULATION</constant></title>
236
237 <para>Possible values: <constant>QAM_AUTO</constant>, QP<constant>SK, QAM_16</constant>, <constant>QAM_64</constant>, <constant>DQPSK</constant></para>
238
239 <para>Note: If layer C is <constant>DQPSK</constant> layer B has to be <constant>DQPSK</constant>. If layer B is <constant>DQPSK</constant>
240 and <constant>DTV_ISDBT_PARTIAL_RECEPTION</constant>=0 layer has to be <constant>DQPSK</constant>.</para>
241 </section>
242
243 <section id="isdbt-layer-seg-cnt">
244 <title><constant>DTV_ISDBT_LAYER*_SEGMENT_COUNT</constant></title>
245
246 <para>Possible values: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, -1 (AUTO)</para>
247
248 <para>Note: Truth table for <constant>DTV_ISDBT_SOUND_BROADCASTING</constant> and
249 <constant>DTV_ISDBT_PARTIAL_RECEPTION</constant> and <constant>LAYER</constant>*_SEGMENT_COUNT</para>
250
251 <informaltable id="isdbt-layer_seg-cnt-table">
252 <tgroup cols="6">
253
254 <tbody>
255 <row>
256 <entry>PR</entry>
257 <entry>SB</entry>
258 <entry>Layer A width</entry>
259 <entry>Layer B width</entry>
260 <entry>Layer C width</entry>
261 <entry>total width</entry>
262 </row>
263
264 <row>
265 <entry>0</entry>
266 <entry>0</entry>
267 <entry>1 .. 13</entry>
268 <entry>1 .. 13</entry>
269 <entry>1 .. 13</entry>
270 <entry>13</entry>
271 </row>
272
273 <row>
274 <entry>1</entry>
275 <entry>0</entry>
276 <entry>1</entry>
277 <entry>1 .. 13</entry>
278 <entry>1 .. 13</entry>
279 <entry>13</entry>
280 </row>
281
282 <row>
283 <entry>0</entry>
284 <entry>1</entry>
285 <entry>1</entry>
286 <entry>0</entry>
287 <entry>0</entry>
288 <entry>1</entry>
289 </row>
290
291 <row>
292 <entry>1</entry>
293 <entry>1</entry>
294 <entry>1</entry>
295 <entry>2</entry>
296 <entry>0</entry>
297 <entry>13</entry>
298 </row>
299 </tbody>
300
301 </tgroup>
302 </informaltable>
303
304 </section>
305
306 <section id="isdbt_layer_t_interl">
307 <title><constant>DTV_ISDBT_LAYER*_TIME_INTERLEAVING</constant></title>
308
309 <para>Possible values: 0, 1, 2, 3, -1 (AUTO)</para>
310
311 <para>Note: The real inter-leaver depth-names depend on the mode (fft-size); the values
312 here are referring to what can be found in the TMCC-structure -
313 independent of the mode.</para>
314 </section>
315 </section>
316 </section>
317</section>
Mauro Carvalho Chehab131db3a2009-10-24 21:18:46 -0300318</section>