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I'm new to Ubuntu and I've 18.04 installed. Not sure if this is due to faulty installation or something, but I'm having trouble with very slow Wi-Fi speeds and frequent disconnections. Here is a pastebin link to diagnose my issue, important info as follows:

##### kernel ############################

Linux 4.15.0-33-generic #36-Ubuntu SMP Wed Aug 15 16:00:05 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux

Parameters: ro, quiet, splash, vt.handoff=1

##### lspci #############################

08:00.0 Network controller [0280]: Realtek Semiconductor Co., Ltd. RTL8723BE PCIe Wireless Network Adapter [10ec:b723]
    Subsystem: Hewlett-Packard Company RTL8723BE PCIe Wireless Network Adapter [103c:804c]
    Kernel driver in use: rtl8723be

09:00.0 Ethernet controller [0200]: Realtek Semiconductor Co., Ltd. RTL8101/2/6E PCI Express Fast/Gigabit Ethernet controller [10ec:8136] (rev 0a)
    Subsystem: Hewlett-Packard Company RTL810xE PCI Express Fast Ethernet controller [103c:8096]
    Kernel driver in use: r8169

Any help is greatly appreciated. I've started a new project in college and need to use Ubuntu. If it helps, I'm using a HP Pavilion Notebook (M2W75PA#ACJ).

So far, I tried disabling 802.1n band. Unfortunately, it didn't help me much.

pomsky
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notDarkMatter
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    Possible duplicate of Realtek RTL8723BE Wi-Fi incredibly weak, this is to fix weak signal issue with RTL8723BE in general. But you currently have Linux kernel v4.15.0-33 and it seems kernel v4.15.0-33 has a bug, see these: https://askubuntu.com/questions/1069153/wifi-networks-not-found-ubuntu-18-04-with-rtl8723be and https://askubuntu.com/questions/1068826/wifi-doesnt-work-on-ubuntu-18-04-1-lts – pomsky Sep 13 '18 at 14:24
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    Kernel 4.15.0-34 has the same bug, so you can either install rtlwifi-new from github or boot into 4.15.0-32 or older – Jeremy31 Sep 13 '18 at 14:31

1 Answers1

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In your pastebin, we see this:

[/etc/modprobe.d/rtl8723de.conf]
options rtl8723de ant_sel=1

You haven’t any rtl8723de device; yours is an rtl8723be. They are two different devices. Let’s remove the needless file:

sudo rm /etc/modprobe.d/rtl8723de.conf

We also see this:

[/etc/modprobe.d/rtl8723be.conf]
options rtl8723be ant_sel=2
options rtl8723be 11n_disable=1

11n_disable is not an available parameter in the driver rtl8723be. Confirm:

modinfo rtl8723be

Let’s remove the needless declaration:

sudo nano /etc/modprobe.d/rtl8723be.conf

Remove the 11n line so that the file now only contains:

options rtl8723be ant_sel=2

Save (Ctrl+o followed by Enter) and close (Ctrl+x) the text editor.

We also see:

Cell 01 - Address: <MAC '301 Th' [AC1]>
                    Channel:9
                    Frequency:2.452 GHz (Channel 9)
                    Quality=54/70  Signal level=-56 dBm  
                    Encryption key:on
                    ESSID:"301 Th"
                    Bit Rates:1 Mb/s; 2 Mb/s; 5.5 Mb/s; 11 Mb/s; 6 Mb/s
                              9 Mb/s; 12 Mb/s; 18 Mb/s
                    Bit Rates:24 Mb/s; 36 Mb/s; 48 Mb/s; 54 Mb/s
                    Mode:Master
                    Extra:tsf=00000000c8e6d93d
                    Extra: Last beacon: 60ms ago
                    IE: WPA Version 1
                        Group Cipher : CCMP
                        Pairwise Ciphers (1) : CCMP
                        Authentication Suites (1) : PSK
                    IE: IEEE 802.11i/WPA2 Version 1
                        Group Cipher : CCMP
                        Pairwise Ciphers (1) : CCMP
                        Authentication Suites (1) : PSK

I have worked on several cases where removing a space in the name of the SSID improved connectivity. If this is a router for which you have administrative privileges, I suhhest that you rename it to 301Th or 301_Th or some such without a space.

Next, check the settings in the router. WPA2-AES is preferred; not any WPA and WPA2 mixed mode and certainly not TKIP. Second, if your router is capable of N speeds, you may have better connectivity with a channel width of 20 MHz in the 2.4 GHz band instead of automatic 20/40 MHz, although it is likely to affect N speeds. I also have better luck with a fixed channel, either 1, 6 or 11, rather than automatic channel selection. Also, be certain the router is not set to use N speeds only; auto B, G and N is preferred. After making these changes, reboot the router.

Please see this interesting post about the unreliability of auto channel select: https://superuser.com/questions/1311149/why-do-wifi-routers-do-such-a-bad-job-of-channel-selection

Next, I recommend that your regulatory domain be set explicitly. Check yours:

sudo iw reg get

If you get 00, that is a one-size-maybe-fits-all setting. Find yours here: http://en.wikipedia.org/wiki/ISO_3166-1_alpha-2 Then set it temporarily:

sudo iw reg set IS

Of course, substitute your country code if not Iceland. Set it permanently:

sudo nano /etc/default/crda

Change the last line to read:

REGDOMAIN=IS

Proofread carefully, save and close the text editor.

chili555
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  • Thanks! It Worked. I can't thank you enough. But there is one small problem. I seem to get full download speeds (100Mbps) only when I'm sitting right next to the router. The second I move to my room, barely 5ft and behind a wall, the speed drops to 10Kbps. I don't have this problem in Windows 10. Again, thank you for your help. – notDarkMatter Sep 13 '18 at 15:44
  • Please edit the rtl8723be.conf file to show ant_sel=1 , reboot and tell us if there is any improvement. – chili555 Sep 13 '18 at 16:32
  • Hi, it didn't work. So i went ahead and bought a wifi dongle. Now I have no issues. Really appreciate the help. Thank you. – notDarkMatter Sep 18 '18 at 13:31