{"id":843,"date":"2021-02-08T02:01:00","date_gmt":"2021-02-08T01:01:00","guid":{"rendered":"https:\/\/mobiletidings.com\/?p=843"},"modified":"2021-04-29T09:13:21","modified_gmt":"2021-04-29T08:13:21","slug":"voicemail-waiting-indication-sms","status":"publish","type":"post","link":"https:\/\/techsofar.com\/voicemail-waiting-indication-sms\/","title":{"rendered":"Setting Voicemail Waiting Indication via SMS"},"content":{"rendered":"\n<p>As shown in an&nbsp;<a href=\"https:\/\/mobiletidings.com\/sending-a-flash-sms-message\/\" data-abc=\"true\" target=\"_blank\" rel=\"noopener\">earlier post<\/a>, the Data Coding Scheme (DCS) octet in the SMS PDU can be used to turn a regular text message into a flash message.<\/p>\n\n\n\n<p>Another feature of SMS that is enabled through the use of the DCS is the Message Waiting Indication:<\/p>\n\n\n\n<ul><li>When someone leaves you a voicemail, the voicemail system communicates with the SMSC to send your phone a special SMS message that turns on the little icon on your phone that indicates that you have a new voicemail.<\/li><li>When you listen to your voicemail, the voicemail system also communicates with the SMSC to send your phone an SMS message that turns the little icon off again.<\/li><\/ul>\n\n\n\n<p>Using the DCS you can turn the voicemail icon on or off yourself.<\/p>\n\n\n\n<p>This is an example of PDU to set a voicemail indication:<\/p>\n\n\n\n<div>\n<div>\n<div>\n<pre>AT+CMGS=27<\/pre>\n<pre>0001AB0B915121551532F400C80F3190BB7C07D9DFE971B91D4EB301&lt;Ctrl-Z&gt;<\/pre>\n<\/div>\n<\/div>\n<\/div>\n\n\n\n<p>Here is what the individual octets represent:<\/p>\n\n\n\n<figure class=\"wp-block-table\"><table><tbody><tr><td><strong>Size<\/strong><\/td><td><strong>Value<\/strong><\/td><td><strong>Description<\/strong><\/td><\/tr><tr><td>1 octet<\/td><td>00<\/td><td>We don\u2019t supply an SMSC number.<\/td><\/tr><tr><td>1 octet<\/td><td>01<\/td><td>PDU type and options. This is a plain SUBMIT-PDU.<\/td><\/tr><tr><td>1 octet<\/td><td>AB<\/td><td>Our message reference.<\/td><\/tr><tr><td>1 octet<\/td><td>0B<\/td><td>Size of the destination telephone number (in digits)<\/td><\/tr><tr><td>1 octet<\/td><td>91<\/td><td>International numbering plan.<\/td><\/tr><tr><td>6 octets<\/td><td>5121551532f4<\/td><td>This represents the destination and it translates to 1 512 555 1234<\/td><\/tr><tr><td>1 octet<\/td><td>00<\/td><td>Protocol identifier.<\/td><\/tr><tr><td>1 octet<\/td><td>C8<\/td><td>Data Coding Scheme. This is the value that causes the message to be a voicemail notification as opposed to a standard SMS. The first nibble can be:\n<p>&nbsp;<\/p>\n<ul>\n<li>0xC for Message Waiting Discard (do not store the text that is in this message)<\/li>\n<li>0XD for Message Waiting Store (do store the text that is in this message<\/li>\n<\/ul>\n<p>The second nibble\u2019s first bit represents on\/off:<\/p>\n<ul>\n<li>0\u00d70 is a set indication inactive<\/li>\n<li>0\u00d78 is a set indication active<\/li>\n<\/ul>\n<p>The second nibble\u2019s last 2 bits determine the type of message:<\/p>\n<ul>\n<li>0\u00d70 stand for voicemail<\/li>\n<li>0\u00d71 stands for fax<\/li>\n<li>0\u00d72 stands for email<\/li>\n<li>0\u00d73 stands for other messages.<\/li>\n<\/ul>\n<p>So 0xC8 stands for turn on voicemail message waiting and discard this message.<\/p>\n<\/td><\/tr><tr><td>1 octet<\/td><td>0F<\/td><td>User Data Length or payload size (in characters).<\/td><\/tr><tr><td>15 septets<\/td><td>3190BB7C07D9DFE971B91D4EB301<\/td><td>The payload, also known as User Data. In this case, it is just GSM encoded text. This particular string represents \u201c1 new voicemail\u201d<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<p>And for completeness, here is a command to turn it off again:<\/p>\n\n\n\n<div>\n<div>\n<div>\n<pre>AT+CMGS=28<\/pre>\n<pre>0001AC0B915121551532F400C011EE37C85DBE83ECEFF4B8DC0EA7D973&lt;Ctrl-Z&gt;<\/pre>\n<\/div>\n<\/div>\n<\/div>\n\n\n\n<div>\n<table style=\"height: 511px;\" border=\"1\" width=\"587\">\n<tbody>\n<tr>\n<td><strong>Size<\/strong><\/td>\n<td><strong>Value<\/strong><\/td>\n<td><strong>Description<\/strong><\/td>\n<\/tr>\n<tr>\n<td>1 octet<\/td>\n<td>00<\/td>\n<td>We don\u2019t supply an SMSC number.<\/td>\n<\/tr>\n<tr>\n<td>1 octet<\/td>\n<td>01<\/td>\n<td>PDU type and options. This is a plain SUBMIT-PDU.<\/td>\n<\/tr>\n<tr>\n<td>1 octet<\/td>\n<td>AC<\/td>\n<td>Our message reference.<\/td>\n<\/tr>\n<tr>\n<td>1 octet<\/td>\n<td>0B<\/td>\n<td>Size of the destination telephone number (in digits)<\/td>\n<\/tr>\n<tr>\n<td>1 octet<\/td>\n<td>91<\/td>\n<td>International numbering plan.<\/td>\n<\/tr>\n<tr>\n<td>6 octets<\/td>\n<td>5121551532f4<\/td>\n<td>This represents the destination and it translates to 1 512 555 1234<\/td>\n<\/tr>\n<tr>\n<td>1 octet<\/td>\n<td>00<\/td>\n<td>Protocol identifier.<\/td>\n<\/tr>\n<tr>\n<td>1 octet<\/td>\n<td>C0<\/td>\n<td>Data Coding Scheme. 0xC8 stands for turn off voicemail message waiting and discard this message.<\/td>\n<\/tr>\n<tr>\n<td>1 octet<\/td>\n<td>11<\/td>\n<td>User Data Length or payload size (in characters).<\/td>\n<\/tr>\n<tr>\n<td>17 septets<\/td>\n<td>EE37C85DBE83ECEFF4B8DC0EA7D973<\/td>\n<td>The payload, also known as User Data. In this case, it is just GSM encoded text. This particular string represents \u201cno new voicemails\u201d<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>You can play with the DCS field:<\/p>\n<div>In the messages with these DCS the text is discarded:<\/div>\n<ul>\n<li>0xC8 \u2013 turn on voicemail (discard)<\/li>\n<li>0xC9 \u2013 turn on fax (discard)<\/li>\n<li>0xCA \u2013 turn on email (discard)<\/li>\n<li>0xCB \u2013 turn on another message (discard)<\/li>\n<li>0xC0 \u2013 turn off voicemail (discard)<\/li>\n<li>0xC1 \u2013 turn off fax (discard)<\/li>\n<li>0xC2 \u2013 turn off an email (discard)<\/li>\n<li>0xC3 \u2013 turn off other messages (discard)<\/li>\n<\/ul>\n<div>In the messages with these DCS, the text is stored in the SMS inbox and the text is GSM-7 encoded:<\/div>\n<ul>\n<li>0xD8 \u2013 turn on voicemail (store)<\/li>\n<li>0xD9 \u2013 turn on fax (store)<\/li>\n<li>0xDA \u2013 turn on email (store)<\/li>\n<li>0xDB \u2013 turn on other messages (store)<\/li>\n<li>0xD0 \u2013 turn off voicemail (store)<\/li>\n<li>0xD1 \u2013 turn off fax (store)<\/li>\n<li>0xD2 \u2013 turn off an email (store)<\/li>\n<li>0xD3 \u2013 turn off other messages (store)<\/li>\n<\/ul>\n<div>In the messages with these DCS, the text is stored in the SMS inbox and the text is UCS-2 encoded:<\/div>\n<ul>\n<li>0xE8 \u2013 turn on voicemail (store)<\/li>\n<li>0xE9 \u2013 turn on fax (store)<\/li>\n<li>0xEA \u2013 turn on email (store)<\/li>\n<li>0xEB \u2013 turn on other messages (store)<\/li>\n<li>0xE0 \u2013 turn off voicemail (store)<\/li>\n<li>0xE1 \u2013 turn off fax (store)<\/li>\n<li>0xE2 \u2013 turn off an email (store)<\/li>\n<li>0xE3 \u2013 turn off other messages (store)<\/li>\n<\/ul>\n<p>The Data Coding Scheme is just one octet, but the spec&nbsp;3GPP TS 23.038&nbsp;dedicates a whole chapter to it.<\/p>\n<\/div>\n","protected":false},"excerpt":{"rendered":"As shown in an&nbsp;earlier post, the Data Coding Scheme (DCS) octet in the SMS PDU can be used&hellip;\n","protected":false},"author":2,"featured_media":845,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[29],"tags":[],"jetpack_sharing_enabled":true,"jetpack_featured_media_url":"https:\/\/techsofar.com\/wp-content\/uploads\/2020\/03\/voicemail-scaled-1.jpg","_links":{"self":[{"href":"https:\/\/techsofar.com\/wp-json\/wp\/v2\/posts\/843"}],"collection":[{"href":"https:\/\/techsofar.com\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/techsofar.com\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/techsofar.com\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/techsofar.com\/wp-json\/wp\/v2\/comments?post=843"}],"version-history":[{"count":0,"href":"https:\/\/techsofar.com\/wp-json\/wp\/v2\/posts\/843\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/techsofar.com\/wp-json\/wp\/v2\/media\/845"}],"wp:attachment":[{"href":"https:\/\/techsofar.com\/wp-json\/wp\/v2\/media?parent=843"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/techsofar.com\/wp-json\/wp\/v2\/categories?post=843"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/techsofar.com\/wp-json\/wp\/v2\/tags?post=843"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}