A powerline adapter is a plug-in device that carries network data over a building's existing electrical wiring. You use at least two: one plugged into a socket near the router and connected with an Ethernet cable, and another in a distant room, offering an Ethernet port or Wi-Fi there.
Why it matters
It provides a wired-style link where running a cable is impractical and Wi-Fi signal is weak, such as through thick walls. Advertised speeds are theoretical maximums; real throughput depends on wiring quality, distance, the circuit breaker layout and electrical noise. Devices such as phone chargers, heaters or power strips with surge filters can interfere.
Adapters on the same circuit generally work better than ones that cross different breaker panels. Data is encrypted between paired adapters, and a pairing button sets the shared key.
Example
A home office has no Wi-Fi coverage. You plug one adapter beside the router, one in the office, and pair them. A speed test over the link shows 80 Mbit/s on a "600 Mbit/s" labeled kit, which is a normal result for older wiring.
Common mistakes
- Plugging adapters into a surge-protected extension lead, which can filter out the signal.
- Mixing incompatible standards and expecting top speed.
- Assuming it will outperform a proper Ethernet cable.
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