## Common ground
All are types of electronic equipment used to support wireless signal transmission or reception, typically installed in fixed locations.
## Options at a glance
**8504.40 – charger base stations**
- **Defining trait:** Designed primarily to charge portable devices via wired or wireless power transfer.
- **Typical examples:** Wireless charging pads for smartphones, electric vehicle charging docks.
- **Best fit when:** The product’s main function is delivering electrical energy to recharge batteries.
**8517.61 – communication base stations**
- **Defining trait:** Used to transmit and receive data signals in mobile networks (e.g., 4G/5G), connecting user devices to a network.
- **Typical examples:** Cellular tower equipment, LTE base stations, Wi-Fi access points with backhaul.
- **Best fit when:** The product enables wireless communication between mobile devices and a central network.
**8526.91 – radio navigational base stations**
- **Defining trait:** Provides positioning or navigation signals (e.g., for aviation, maritime) using radio waves.
- **Typical examples:** GPS ground reference stations, VOR (VHF Omnidirectional Range) beacons.
- **Best fit when:** The product supports location tracking or route guidance via radio signals.
## Key differences
| Feature | 8504.40 (Charger) | 8517.61 (Comm) | 8526.91 (Nav) |
|-----------------------|-------------------|----------------|---------------|
| Primary function | Power delivery | Data transmission | Positioning signal |
| Signal type | Electrical current | Radio data | Radio navigation |
| Typical use case | Device charging | Mobile network access | Aircraft/marine navigation |
## How to choose
- Does it charge electronic devices? → 8504.40
- Is it part of a mobile network (e.g., 5G, LTE)? → 8517.61
- Does it provide location or route guidance via radio signals? → 8526.91
## Overlaps & pitfalls
A base station might combine functions (e.g., a communication base with built-in charging). In such cases, use the **main function** to decide: if signal transmission is primary, choose 8517.61; if power delivery dominates, go for 8504.40. If navigation is central, pick 8526.91. No option is inherently prioritized—choose based on the product’s primary purpose