CSD » History » Version 7
fixeria, 01/25/2024 11:32 PM
1 | 1 | fixeria | h1. CSD (Circuit Switched Data) |
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2 | |||
3 | {{>toc}} |
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4 | |||
5 | This page documents Circuit Switched Data support in the [[mobile]] application (see #4396). |
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6 | 2 | fixeria | |
7 | h2. L1 PHY support |
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8 | |||
9 | At the time of writing this wiki page, CSD support is implemented for the following L1 PHYs: |
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10 | |||
11 | * [[Layer1bin]] firmware for [[Phones#TI-Calypso-based|Calypso based phones]] |
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12 | * SDR PHY ([[osmotrx:|osmo-trx-ms]]) + [[TRX_Interface#The-trxcon-application|trxcon]] application |
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13 | * SDR PHY ([[osmocom-bb-sdr-phy:|grgsm_trx]]) + [[TRX_Interface#The-trxcon-application|trxcon]] application |
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14 | * [[FakeTRX]] (virtual Um) + [[TRX_Interface#The-trxcon-application|trxcon]] application |
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15 | 3 | fixeria | |
16 | h2. L23 support state |
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17 | |||
18 | * async (soft-UART) transparent V.110 calls |
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19 | * [not tested] sync transparent V.110 calls |
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20 | ** [not tested] including fax calls |
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21 | * TCH/F9.4, TCH/F4.8, TCH/F2.4 (only @ 2400 bps) |
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22 | * [not tested] TCH/H4.8, TCH/H2.4 (only @ 2400 bps) |
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23 | |||
24 | h3. TODO/limitations |
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25 | |||
26 | * non-transparent calls (V.110 RLP, V.120) |
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27 | * TCH/F14.4 (see also #6167) |
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28 | * TCH/F2.4 and TCH/H2.4 @ 300 bps, 1200/75 bps |
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29 | * ECSD (multi-TCH support) |
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30 | * "CUSE (Character devices in user space)":https://lwn.net/Articles/308445/ |
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31 | 4 | fixeria | |
32 | h2. VTY configuration |
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33 | |||
34 | Below is an example configuration snippet (only relevant params): |
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35 | |||
36 | <pre> |
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37 | ms 1 |
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38 | support |
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39 | no full-data-14400 |
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40 | full-data-9600 |
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41 | full-data-4800 |
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42 | half-data-4800 |
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43 | full-data-2400 |
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44 | half-data-2400 |
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45 | tch-data |
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46 | io-handler unix-sock |
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47 | ! 'ti' is valid for Calypso PHY, change to 'osmo' for trxcon |
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48 | io-tch-format ti |
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49 | unix-socket /tmp/ms_data |
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50 | call-params type-rate 71 |
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51 | call-params ce transparent |
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52 | call-params async |
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53 | call-params async nr-stop-bits 1 |
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54 | call-params async nr-data-bits 8 |
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55 | call-params async parity none |
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56 | </pre> |
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57 | |||
58 | 5 | fixeria | (you can use @osmo-config-merge@ from [[libosmocore]] to merge this snippet into your mobile.cfg) |
59 | 4 | fixeria | |
60 | h3. Call parameters |
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61 | |||
62 | You can configure data call parameters either using @call MS_NAME params@ command: |
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63 | |||
64 | <pre> |
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65 | OsmocomBB(mobile)> enable |
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66 | OsmocomBB(mobile)# call 1 params ? |
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67 | data Parameters for data calls |
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68 | OsmocomBB(mobile)# call 1 params data ? |
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69 | type-rate Type and rate (values like in AT+CBST; see 3GPP TS 27.007, section 6.7) |
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70 | ce Connection element (does not apply to FAX calls) |
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71 | sync Synchronous connection (always used for FAX calls) |
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72 | async Asynchronous connection (does not apply to FAX calls) |
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73 | </pre> |
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74 | |||
75 | ... or by entering the configuration node: |
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76 | |||
77 | <pre> |
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78 | OsmocomBB(mobile)> enable |
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79 | OsmocomBB(mobile)# configure terminal |
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80 | OsmocomBB(mobile)(config)# ms 1 |
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81 | OsmocomBB(mobile)(ms)# tch-data |
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82 | OsmocomBB(mobile)(tch-data)# list |
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83 | ... |
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84 | io-handler (none|unix-sock|loopback) |
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85 | no io-handler |
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86 | io-tch-format (osmo|ti) |
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87 | unix-socket PATH |
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88 | call-params type-rate (4|5|6|7|68|70|71) |
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89 | call-params ce (transparent|non-transparent) [prefer] |
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90 | call-params (sync|async) |
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91 | call-params async nr-stop-bits <1-2> |
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92 | call-params async nr-data-bits <7-8> |
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93 | call-params async parity (none|even|odd|mark|space) |
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94 | </pre> |
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95 | |||
96 | Below is the list of supported bearer type/rate combinations: |
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97 | |||
98 | <pre> |
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99 | OsmocomBB(mobile)# call 1 params data type-rate? |
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100 | type-rate Type and rate (values like in AT+CBST; see 3GPP TS 27.007, section 6.7) |
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101 | OsmocomBB(mobile)# call 1 params data type-rate ? |
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102 | 4 2400 bps (V.22bis) |
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103 | 5 2400 bps (V.26ter) |
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104 | 6 4800 bps (V.32) |
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105 | 7 9600 bps (V.32) |
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106 | 68 2400 bps (V.110 or X.31 flag stuffing) |
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107 | 70 4800 bps (V.110 or X.31 flag stuffing) |
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108 | 71 9600 bps (V.110 or X.31 flag stuffing) |
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109 | </pre> |
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110 | 6 | fixeria | |
111 | This list may be extended in the future, e.g. after adding support for TCH/[FH]2.4 @ 300 bps, 1200/75 bps. |
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112 | 7 | fixeria | |
113 | h2. Making calls |
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114 | |||
115 | Making a data call is as easy as making a regular voice call: |
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116 | |||
117 | <pre> |
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118 | OsmocomBB(mobile)# call 1 MSISDN ? |
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119 | [voice] Initiate a regular voice call (default) |
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120 | [data] Initiate a data call (UDI or 3.1 kHz audio) |
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121 | [fax] Initiate a data call (Facsimile group 3) |
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122 | </pre> |
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123 | |||
124 | An incoming data call is answered just like a voice call: |
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125 | |||
126 | <pre> |
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127 | OsmocomBB(mobile)# call 1 answer |
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128 | </pre> |
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129 | |||
130 | After the call is connected (i.e. answered either locally or remotely), you can connect to the UNIX socket. |
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131 | |||
132 | An ongoing call can be terminated just like a regular voice call: |
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133 | |||
134 | <pre> |
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135 | OsmocomBB(mobile)# call 1 hangup |
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136 | </pre> |
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137 | |||
138 | An incoming call can also be rejected using this command. |
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139 | |||
140 | h3. Example: sending text using @socat@ |
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141 | |||
142 | <pre><code class="shell"> |
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143 | socat UNIX-CONNECT:/tmp/ms_data STDIO,echo=0,icanon=0 |
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144 | </code></pre> |
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145 | |||
146 | h3. Example: sending files using @socat@ and @[xyz]modem@ |
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147 | |||
148 | On the receiving side: |
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149 | |||
150 | <pre><code class="shell"> |
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151 | socat UNIX-CONNECT:/tmp/ms_data EXEC:"lrzsz-rz -v" |
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152 | </code></pre> |
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153 | |||
154 | On the sending side: |
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155 | |||
156 | <pre><code class="shell"> |
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157 | socat UNIX-CONNECT:/tmp/ms_data EXEC:"lrzsz-sz -v /usr/share/licenses/spdx/GPL-2.0-or-later.txt" |
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158 | </code></pre> |