> ## Documentation Index
> Fetch the complete documentation index at: https://docs.bota.dev/llms.txt
> Use this file to discover all available pages before exploring further.

# Cellular Mode

> Operate devices autonomously over 4G — upload, heartbeat, and receive commands without a phone

Cellular Mode allows Bota Pin and Pin Pro devices to operate autonomously over 4G/LTE — uploading recordings, sending heartbeats, and receiving remote commands without a paired mobile phone.

## Why Cellular Mode?

With Bluetooth Sync, recordings transfer from the device to a phone app, which then uploads to the cloud. Cellular upload removes the phone from the equation — the device uploads directly.

**Benefits:**

* No phone needed nearby during or after recording
* Faster time from recording to transcription
* Better for shared devices (clinics, enterprise fleets)
* Enables autonomous, always-on operation

**Ideal for:**

* Medical clinics with shared devices
* Field sales reps without phones nearby
* Remote workers who want instant transcription
* Enterprise deployments with dedicated device fleets

## How It Works

```mermaid theme={null}
sequenceDiagram
    participant D as Device
    participant T as Cellular Network
    participant C as Bota Cloud

    D->>T: Connect via 4G modem
    D->>C: Upload recording to S3
    C-->>D: Upload complete
```

The device makes authenticated HTTPS requests directly to the Bota API using its device token (`dtok_*`) and embedded cellular modem. No phone or Wi-Fi needed.

Network selection, failover, and priority configuration are covered in the [Connectivity](/guides/connectivity) guide.

## Data Usage

Recordings use the OGG Opus codec at 32 kbps. Data consumption is predictable:

| Recording Length | File Size |
| ---------------- | --------- |
| 5 minutes        | \~1.2 MB  |
| 30 minutes       | \~7.2 MB  |
| 1 hour           | \~14.4 MB |

### Daily Data Limits

Set a daily cellular data cap to control costs. When the limit is reached:

* Cellular uploads are blocked for the rest of the day
* Device falls back to WiFi or Bluetooth Sync
* Counter resets at midnight (device local time)

Set `daily_data_limit_mb` to `0` for unlimited cellular data.

## Roaming

By default, cellular uploads are **disabled when roaming** to avoid international data charges.

You can enable roaming uploads per device if needed, but monitor data usage carefully — roaming charges can be significant.

For international travel, consider using **Travel Mode**: disable cellular, enable WiFi only, block roaming. See [Device Management — Presets](/guides/device-management#common-presets).

## Battery Considerations

Cellular uploads consume more power than Bluetooth Sync. Optimize battery life with:

* **Pause on low battery** — Automatically pause uploads when battery drops below threshold
* **Off-peak uploads** — Schedule uploads during overnight hours when the device is likely charging
* **Radio idle timeouts** — Power down the cellular radio after a period of inactivity

These are all configurable via [device settings](/guides/device-management#upload-settings).

## Streaming + Cellular

For long recordings, combine cellular upload with [streaming upload](/guides/streaming-upload) to start uploading chunks while recording continues. This gives you:

* Near real-time transcription over cellular
* Reduced device storage requirements
* Faster time-to-insight

## Authentication

Direct uploads use **device tokens** (`dtok_*`) for authentication. Tokens are:

* Issued when you [bind a device](/api-reference/devices/bind) to an end user
* Bound to a specific device + end user pair
* Automatically refreshed

See [Authentication](/authentication) for details.

## Heartbeat

When connected over 4G, the device automatically sends periodic heartbeats to the Bota API. This keeps the backend informed of the device's status — battery level, storage usage, signal strength, and connectivity state — without any action from the end user or your application.

Heartbeats enable real-time device monitoring through the [Heartbeat API](/api-reference/devices/heartbeat) and power webhook alerts like `device.low_battery` and `device.offline`.

## Related

* [Device Management](/guides/device-management) — Configure connection and upload settings
* [Streaming Upload](/guides/streaming-upload) — Upload chunks while recording
* [Update Device](/api-reference/devices/update) — API reference for device settings
* [Bota Pin](/hardware/pin) — Pin hardware specifications