我必须承认，我并不是 Linux 或技术方面的专家，所以请原谅我问了这么愚蠢的问题。几周前，我在 Lenovo z50-70 上安装了 Ubuntu 15.10。从那时起，我就遇到了 wifi 问题：它显示 PC 已连接，但过了一段时间它就完全不工作了。我必须断开/重新连接才能使其再次工作，这种情况每 15-20 分钟就会发生一次（现在我使用的是 TP-Link 调制解调器）。
$ sudo lshw -C network
*-network
description: Ethernet interface
product: RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller
vendor: Realtek Semiconductor Co., Ltd.
physical id: 0
bus info: pci@0000:01:00.0
logical name: enp1s0
version: 10
serial: 68:f7:28:87:a9:98
size: 10Mbit/s
capacity: 1Gbit/s
width: 64 bits
clock: 33MHz
capabilities: pm msi pciexpress msix vpd bus_master cap_list ethernet physical tp mii 10bt 10bt-fd 100bt 100bt-fd 1000bt 1000bt-fd autonegotiation
configuration: autonegotiation=on broadcast=yes driver=r8169 driverversion=2.3LK-NAPI duplex=half firmware=rtl8168g-3_0.0.1 04/23/13 latency=0 link=no multicast=yes port=MII speed=10Mbit/s
resources: irq:45 ioport:5000(size=256) memory:c3504000-c3504fff memory:c3500000-c3503fff
*-network
description: Wireless interface
product: RTL8723BE PCIe Wireless Network Adapter
vendor: Realtek Semiconductor Co., Ltd.
physical id: 0
bus info: pci@0000:02:00.0
logical name: wlp2s0
version: 00
serial: 2c:33:7a:4b:78:5b
width: 64 bits
clock: 33MHz
capabilities: pm msi pciexpress bus_master cap_list ethernet physical wireless configuration: broadcast=yes driver=rtl8723be driverversion=4.2.0-34-generic firmware=N/A ip=192.168.1.111 latency=0 link=yes multicast=yes wireless=IEEE 802.11bgn
resources: irq:19 ioport:4000(size=256) memory:c3400000-c3403fff
$ iwconfig
wlp2s0 IEEE 802.11bgn ESSID:"Tiscali"
Mode:Managed Frequency:2.412 GHz Access Point: E8:94:F6:0F:AB:8D
Bit Rate=15 Mb/s Tx-Power=20 dBm
Retry short limit:7 RTS thr=2347 B Fragment thr:off Power Management:off Link Quality=56/70 Signal level=-54 dBm
Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0 Tx excessive retries:0 Invalid misc:18 Missed beacon:0 lo no wireless extensions. enp1s0 no wireless extensions.
有什么建议吗？