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Bluetooth HOGP: HID over GATT Profile Explained

By RF Wireless Expert Team

According to Bluetooth Core Specification, HOGP is an example of an application level profile that operates external to the Core Specification itself, residing on the Bluetooth Host. Because HOGP is an application profile, its deep technical workings are defined in a separate Bluetooth SIG profile specification rather than bluetooth Core Specification. However, by combining the architectural rules of GATT (Generic Attribute Profile) defined in bluetooth specification with standard industry knowledge, here is an explanation of what HOGP is and how it works.

What is HID over GATT Profile (HOGP)?

HOGP stands for Human Interface Device over Generic Attribute Profile.

It is the standard Bluetooth Low Energy (BLE) profile used to connect input devices such as keyboards, mice, remote controls and gaming gamepads to a host device (like a smartphone, PC, tablet, or smart TV).

Before BLE, these devices used the classic Bluetooth “HID Profile.” When BLE was introduced to save power, the Bluetooth SIG created HOGP to allow these devices to operate over BLE, taking advantage of BLE’s extreme energy efficiency so that a wireless mouse or keyboard could run for months or years on a single battery.

How HOGP Works (The GATT Connection)

As explained in the Core Specification, BLE organizes data using the GATT hierarchy of Profiles, Services, Characteristics, and Descriptors. HOGP translates traditional USB HID data structures into this GATT format.

When an HOGP mouse connects to a PC, it acts as a GATT Server, and the PC acts as the GATT Client. Here is how the data is structured:

  1. HID Service (The Category): The mouse exposes a specific “HID Service” to the PC.

  2. Report Map Characteristic (The Blueprint): Inside the service, there is a “Report Map.” This tells the PC exactly how to interpret the data it is about to receive (e.g. “The first byte of data I send you will represent mouse clicks, and the next two bytes will represent X and Y axis movement”).

  3. Report Characteristic (The Actual Data): This is where the actual keystrokes or mouse movements are stored.

  4. GATT Notifications (The Power Saver): Instead of the PC constantly polling the mouse and asking, “Did you move yet?” (which wastes battery), HOGP utilizes GATT Notifications. The PC configures a Client Characteristic Configuration Descriptor (CCCD) on the mouse. Now, the mouse remains completely silent and asleep until you move it. The instant you move the mouse, it “Notifies” the PC and pushes the new X/Y coordinates, then goes back to sleep.

Why HOGP is Important

  • Extreme Battery Life: Because HOGP leverages BLE and GATT Notifications, input devices spend the vast majority of their time in a deep sleep state, drastically extending battery life compared to Classic Bluetooth HID devices.

  • Driverless Compatibility: HOGP is natively supported by almost all modern operating systems (Windows, macOS, iOS, Android, Linux). When an OS sees an HOGP device, it already knows how to read the GATT Report Map, meaning you don’t have to install custom drivers for basic keyboards and mice to work.

  • Fast Reconnection: Because of BLE’s fast connection mechanisms (detailed in the Core Spec’s GAP and Link Layer procedures), an HOGP keyboard can wake up from sleep and reconnect to a PC almost instantly when you press a key, resulting in little to no noticeable latency for the user.

References & Further Reading

  1. Bluetooth SIG : Bluetooth Core Specification Version 6.3, May 5, 2026.
  2. Bluetooth SIG : Bluetooth Technology Overview

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