I have a router that supports bandwidth upto 150Mbps speeds. And my internet plan is for 90 Mbps. And my Wifi router flawlessly delivers me internet speeds of 85-90Mbps.
But the problem is when I have to transfer files across devices on my LAN. Say if I want to transfer a file from my laptop to phone, I get only around 2.7MB/s i.e. around 25Mbps. I have tried it with differet devices but its still the same.
While my WiFi router can deliver me internet speed of 90Mbps, why is the LAN speed capped at 25Mbps?
2 Answers
When you use WIFI for both devices each device is trying to use the limited available WIFI bandwidth. Assuming that its 90 megs in total, available to each device that means only 45megabit is available to each as they are trying to send (on the sending device to the router, and again from the router to the second device) But its worse then that because there will be conflicting times when both devices to send at the same time causing conflicts, dropped packets and slowdowns.
For clarity when talking on a WIFI network (on 802.11n) devices do not communicate directly they communicate via the router/AP.
Were you to connect one or both devices via ethernet or upgrade to 802.11ac you would see improved throughput.
2Wifi or 802.11 is a half-duplex technology, so if you are connected using 150mbps datarate de maximum data throughput is ~80mbps best case scenario. The throughput of course can be affected negatively in many ways when comes down to Wifi
