https://devzone.nordicsemi.com/f/nordic-q-a/54705/in-beacon-why-128-bit-uuid-is-requiredIn Beacon Why UUID is required ? Where exactly it will be useful ? I understand Major value Minor values , company identifiers values . it will difference the beacon location wise , floor wise, which manufacturer company . but why 128 bit UUID requireden-USTelligent Community 13Thu, 21 Nov 2019 16:11:57 GMThttps://devzone.nordicsemi.com/thread/221396?ContentTypeID=1Thu, 21 Nov 2019 16:11:57 GMT137ad170-7792-4731-bb38-c0d22fbe4515:09dbc868-9bfe-47fd-8e1c-745bc25b9d24Heidi<p>Hi!</p> <p>The 128-bit UUID is required whenever you are making your own custom services and characteristics.&nbsp;<span>It looks something like this: 4A98xxxx-1CC4-E7C1-C757-F1267DD021E8 and is called the “base UUID”. The four x’s represent a field where you will insert your own 16-bit IDs for your custom services and characteristics and use them just like a predefined UUID.</span></p> <p><span>Since the only 16-bit UUIDs you can transmit are the predefined Bluetooth SIG UUIDs, and the beacon example doesn&#39;t use any of those services, it transmits the 128-bit UUID.&nbsp;</span></p> <p><span>Please see <a href="https://devzone.nordicsemi.com/nordic/short-range-guides/b/bluetooth-low-energy/posts/ble-services-a-beginners-tutorial">this tutorial</a>&nbsp;for more information about BLE Services.&nbsp;</span></p> <p><span>Best regards,</span></p> <p><span>Heidi</span></p> <p></p><div style="clear:both;"></div>