{"id":213,"date":"2025-07-31T14:36:13","date_gmt":"2025-07-31T22:36:13","guid":{"rendered":"https:\/\/salemdata.net\/johnpress\/?p=213"},"modified":"2025-07-31T14:36:13","modified_gmt":"2025-07-31T22:36:13","slug":"iq-multicast","status":"publish","type":"post","link":"https:\/\/salemdata.net\/johnpress\/?p=213","title":{"rendered":"iq Multicast"},"content":{"rendered":"
\n<p class="wp-block-paragraph">I released a tool,<strong> iq_multicast<\/strong>, that broadcasts a USB Software Defined Radio (“SDR”) IQ stream. The tools are written in the C programming language. SDRs range from the $50 (kit on Amazon) RTL-SDR to several hundred dollar versions, e.g. HackRF One ($300) and AirSpy2 ($180).<\/p>\n\n\n\n<figure class="wp-block-table"><table class="has-fixed-layout"><tbody><tr><td>RTL-SDR $50<\/td><td>AirSpy2 $180<\/td><\/tr><tr><td><img src="https:\/\/salemdata.net\/johnpress\/wp-content\/uploads\/2025\/07\/20250731_152053_Thu.png" alt=""><\/td><td><img src="https:\/\/salemdata.net\/johnpress\/wp-content\/uploads\/2025\/07\/20250731_152227_Thu-1.png" alt=""><\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<p class="wp-block-paragraph">Normally, a program or process has exclusive control of a transceiver so you cannot have several processes access the data stream. So what I did is create a small utility which broadcasts the data stream of UDP (<a href="https:\/\/en.wikipedia.org\/wiki\/User_Datagram_Protocol">User Datagram Protocol<\/a>) multicast… very similar to what online broadcasters of multimedia do. This diagram sums up the benefit of leveraging a single stream and making it available to multiple simultaneous users:<\/p>\n\n\n\n<p class="wp-block-paragraph"><\/p>\n\n\n\n<figure class="wp-block-image size-full wp-duotone-unset-1"><img src="https:\/\/salemdata.net\/johnpress\/wp-content\/uploads\/2025\/07\/image.png" alt="" class="wp-image-217"\/><\/figure>\n\n\n\n<p class="wp-block-paragraph">In essence, the tools in iq Multicast act as a “digital splitter” allow an unlimited number of processes to subscribe to the stream.<br>The project is at:<\/p>\n\n\n\n<p class="wp-block-paragraph"><a href="https:\/\/github.com\/jlpoolen\/iq_multicast">https:\/\/github.com\/jlpoolen\/iq_multicast<\/a><\/p>\n\n\n\n<p class="wp-block-paragraph"><\/p>\n<\/div>
\n

I released a tool, iq_multicast<\/strong>, that broadcasts a USB Software Defined Radio (“SDR”) IQ stream. The tools are written in the C programming language. SDRs range from the $50 (kit on Amazon) RTL-SDR to several hundred dollar versions, e.g. HackRF One ($300) and AirSpy2 ($180).<\/p>\n\n\n\n

RTL-SDR $50<\/td>AirSpy2 $180<\/td><\/tr>
\"\"<\/td>\"\"<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

Normally, a program or process has exclusive control of a transceiver so you cannot have several processes access the data stream. So what I did is create a small utility which broadcasts the data stream of UDP (User Datagram Protocol<\/a>) multicast… very similar to what online broadcasters of multimedia do. This diagram sums up the benefit of leveraging a single stream and making it available to multiple simultaneous users:<\/p>\n\n\n\n

<\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n

In essence, the tools in iq Multicast act as a “digital splitter” allow an unlimited number of processes to subscribe to the stream.
The project is at:<\/p>\n\n\n\n

https:\/\/github.com\/jlpoolen\/iq_multicast<\/a><\/p>\n\n\n\n

<\/p>\n<\/div><\/div>","protected":false},"excerpt":{"rendered":"

<p class="wp-block-paragraph">I released a tool,<strong> iq_multicast<\/strong>, that broadcasts a USB Software Defined Radio (“SDR”) IQ stream. The tools are written in the C programming language. SDRs range from the $50 (kit on Amazon) RTL-SDR to several hundred dollar versions, e.g. HackRF One ($300) and AirSpy2 ($180).<\/p> <figure class="wp-block-table"><table class="has-fixed-layout"><tbody><tr><td>RTL-SDR $50<\/td><td>AirSpy2 $180<\/td><\/tr><tr><td><img src="https:\/\/salemdata.net\/johnpress\/wp-content\/uploads\/2025\/07\/20250731_152053_Thu.png" alt=""><\/td><td><img src="https:\/\/salemdata.net\/johnpress\/wp-content\/uploads\/2025\/07\/20250731_152227_Thu-1.png" alt=""><\/td><\/tr><\/tbody><\/table><\/figure> […]<\/p>\n","protected":false},"author":2,"featured_media":217,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_gfmr_meta_descriptions":[],"_gfmr_multilingual_taxonomy_terms":[],"footnotes":""},"categories":[1],"tags":[],"class_list":["post-213","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-uncategorized"],"_links":{"self":[{"href":"https:\/\/salemdata.net\/johnpress\/index.php?rest_route=\/wp\/v2\/posts\/213","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/salemdata.net\/johnpress\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/salemdata.net\/johnpress\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/salemdata.net\/johnpress\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/salemdata.net\/johnpress\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=213"}],"version-history":[{"count":1,"href":"https:\/\/salemdata.net\/johnpress\/index.php?rest_route=\/wp\/v2\/posts\/213\/revisions"}],"predecessor-version":[{"id":218,"href":"https:\/\/salemdata.net\/johnpress\/index.php?rest_route=\/wp\/v2\/posts\/213\/revisions\/218"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/salemdata.net\/johnpress\/index.php?rest_route=\/wp\/v2\/media\/217"}],"wp:attachment":[{"href":"https:\/\/salemdata.net\/johnpress\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=213"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/salemdata.net\/johnpress\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=213"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/salemdata.net\/johnpress\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=213"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}