BLE Advertisment channels


Bluetooth Low Energy (BLE) is a wireless communication technology that is gaining widespread adoption in various industries. BLE is a popular choice for Internet of Things (IoT) devices, as it allows for low-power communication over short distances. One of the key features of BLE is its advertisement channels, which enable devices to broadcast information about themselves to other devices.


BLE advertisement channels are a method of communication that allows BLE devices to broadcast information about themselves to other devices without the need for a connection. There are three advertisement channels available in BLE:

  • Channel 37 (2402 – 2480 MHz)
  • Channel 38 (2404 – 2480 MHz)
  • Channel 39 (2406 – 2480 MHz)

Each channel has a specific frequency range and can be used for advertising different types of information.


BLE advertisement channels work by allowing devices to send packets of data at regular intervals. These packets can contain information about the device, such as its name, services it offers, or other data that can be used to identify it. Other devices that are listening on the same advertisement channel can receive these packets and use the information contained within them to establish a connection with the advertising device.

The following pictures are screenshots of the Ekahau AI Pro software while the Sidekick was connected to it. They provide a view of spectrum activity when BLE advertisement channels are in use. The first picture shows the spectrum density, which clearly displays the location of the three BLE advertisement channels. The second picture shows the utilization of these BLE advertisement channels over time. In our case, their utilization is quite busy as we are using them for location purposes.


There are no issues when running vBLE alongside 2.4 GHz WiFi. Our Radio Resource Management automatically chooses channels 1, 6, and 11 on WiFi to avoid any interference between the BLE signals being transmitted simultaneously.

BLE transmits on advertising channels 37, 38, and 39 with signals being only 2 MHz wide. These channels are located between the common WiFi channels 1, 6, and 11. This avoids interference with WiFi channels in the 2.4 GHz range. See the link below for a visual of radio signals in the 2.4 GHz range. (Source:


There are several advantages to using BLE advertisement channels, including:

  • Low power consumption: BLE advertisement channels use very little power, making them ideal for battery-powered devices.
  • Easy to implement: Implementing BLE advertisement channels is relatively simple and requires minimal hardware.
  • No connection required: Devices can broadcast information without the need for a connection, making it easier to discover other devices in the vicinity.
  • Fast discovery: BLE advertisement channels can be used to quickly discover nearby devices without the need for complex scanning algorithms.


BLE advertisement channels are an essential part of the BLE protocol, allowing devices to broadcast information about themselves to other devices. They offer several advantages over traditional connection-based communication methods, including low power consumption, ease of implementation, and fast discovery. As the popularity of BLE continues to grow, it is likely that we will see more devices using advertisement channels to communicate with each other.

Post by Amin Sedighfar

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