FRITZ!Box 3390 Service - Knowledge Base

FRITZ!Box 3390 Service

Slow wireless connections (low throughput)

The throughput of the wireless connection (WiFi) established by a wireless device (such as a computer, smartphone, tablet) connected to the FRITZ!Box is lower than the throughput supported by the wireless standard. As a result, data is only transmitted very slowly, for example when downloading files from the Internet.

1 Checking which wireless standards the wireless device supports

  • Consult the corresponding manual or the manufacturer directly to find out which wireless standards the device supports and the maximum throughput it can establish wireless connections with.

    Note:FRITZ!WLAN Stick N supports 802.11n/g/b/a (802.11n with 300 Mbit/s gross),
    FRITZ!WLAN Stick N 2.4 supports 802.11n/g/b (802.11n with 150 Mbit/s gross),
    FRITZ!WLAN Stick supports 802.11n/g/b (802.11n with 150 Mbit/s gross).

2 Determining the user throughput of the wireless connection

The user throughput of the wireless standard being used determines the speed at which data is transmitted over wireless connections. The user throughput is significantly lower than the throughput given for wireless standards since a large part of it is required to establish and control the wireless connection.

  • Determine the user throughput for wireless connections according to the standard being used by your wireless device:
    Wireless standardData streams /
    Channel bandwidth
    Throughput up toUser throughput up to
    802.11n 3 / 40 MHz 450 Mbit/s 200 Mbit/s
    2 / 40 MHz 300 Mbit/s 150 Mbit/s
    1 / 40 MHz 150 Mbit/s 75 Mbit/s
    3 / 20 MHz 195 Mbit/s 90 Mbit/s
    2 / 20 MHz 130 Mbit/s 60 Mbit/s
    1 / 20 MHz 65 Mbit/s 30 Mbit/s
    802.11g - 54 Mbit/s 25 Mbit/s
    802.11b - 11 Mbit/s 5 Mbit/s
    802.11a - 54 Mbit/s 25 Mbit/s
    Table: Throughput rates according to wireless standard

    Important:In the case of wireless standard 802.11n, the maximum throughput depends on the number of data streams and the channel bandwidth. In the factory settings, the FRITZ!Box uses radio channels that are 40 MHz wide.

If the data throughput of the wireless device is almost as high as the user throughput for the wireless connection, there is no problem.

3 Optimizing slow wireless connections

Perform the following step if the throughput of the wireless device is significantly lower than the user throughput for the wireless connection: