我一直遇到 Wi-Fi 问题。以前我的无线连接没有问题，但我的笔记本电脑在一天内多次断开连接。但现在我可以看到所有的 Wi-Fi 网络，我尝试连接但每次都连接失败。我的笔记本电脑是 Dell Inspiron，装有 Ubuntu 14.04。我大约 3 个月前重新安装了 Ubuntu，但重新安装后 Wi-Fi 没有任何问题。我尝试重新安装驱动程序，但毫无帮助。
iwconfig wlan0命令输出
wlan0
IEEE 802.11abgn ESSID:"WiFi #9"
Mode:Managed Frequency:2.412 GHz Access Point:74:D0:2B:5B:0A:F0
Bit Rate=65 Mb/s Tx-Power=22dBm
Retry long limit:7 RTS thr:off Fragment thr:off
Power Management:off
Link Quality=16/70 Signal level=-94 dBm
Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid flag:0
Tx excessive retries:169 Invalid misc:35 Missed beacon:0
lspci -nnk | grep -iA2 net; uname -r command结果
06:00.0 Network controller [0280]: Intel Corporation Wireless 3160 [8086:08b3] (rev 83)
Subsystem: Intel Corporation Dual Band Wireless Ac 3160 [8086: 8470]
Kernel driver in use: iwlwifi
07:00.0 Ethernet controller [0200]: Realtek Semiconductor Co., Ltd. RTL8101/2/6E PCI Express Fast/Gigabit Ethernet controller [10ec:8136] (rev 07)
Subsystem: Dell Device [1028:06b0]
Kernel driver in use: r8169
3.13.0-141-generic
编辑：
nmcli dev wifi list命令输出
SSID BSSID MODE FREQ RATE SIGNAL SECURITY ACTIVE
'TOTOLINK N300RT' 78:44:76:C3:85:F0 Infrastructure 2412 MHz 54 MB/s 25 WPA WPA2 no
'netis_5G_D1520D' E4:BE:ED:D1:52:12 Infrastructure 5220 MHz 54 MB/s 22 WPA WPA2 no
'WiFi #9' 74:D0:2B:5B:0A:F0 Infrastructure 2462 MHz 54 MB/s 22 WPA2 no
'HOME' 78:44:76:C4:C5:B4 Infrastructure 2412 MHz 54 MB/s 17 WPA2 no
'Vanechka' E4:BE:ED:D1:52:0D Infrastructure 2437 MHz 54 MB/s 17 WPA WPA2 no