Something important that may be overlooked in the blog post is that for most bands you need licenses to transmit over the air. ISM bands are unlicensed but may come with other limitations (e.g., in some countries regulators require a listen-before-talk mechanism that is not always implemented in cellular stacks).
Something important that may be overlooked in the blog post is that for most bands you need licenses to transmit over the air. ISM bands are unlicensed but may come with other limitations (e.g., in some countries regulators require a listen-before-talk mechanism that is not always implemented in cellular stacks).