我最近买了一台笔记本电脑，并在其上安装了新的 Ubuntu，与 Windows 8 进行双启动。在 Windows 中，我的 wifi 连接非常好，信号一直很高。然而，在我家的同一位置，在 Ubuntu 上，我只能收到 1 或 2 格信号。我试图发布它的号码，但似乎我在 iwconfig 中没有无线扩展
eth0 no wireless extensions.
wlan0 IEEE 802.11abg ESSID:"amiraratoud"
Mode:Managed Frequency:2.412 GHz Access Point: 94:FB:B3:F9:94:2D
Retry short limit:7 RTS thr:off Fragment thr:off
Power Management:on
lo no wireless extensions.
和 lspci 结果：
00:00.0 Host bridge: Intel Corporation Broadwell-U Host Bridge -OPI (rev 09)
00:02.0 VGA compatible controller: Intel Corporation Broadwell-U Integrated Graphics (rev 09)
00:03.0 Audio device: Intel Corporation Broadwell-U Audio Controller (rev 09)
00:04.0 Signal processing controller: Intel Corporation Broadwell-U Camarillo Device (rev 09)
00:14.0 USB controller: Intel Corporation Wildcat Point-LP USB xHCI Controller (rev 03)
00:16.0 Communication controller: Intel Corporation Wildcat Point-LP MEI Controller #1 (rev 03)
00:1b.0 Audio device: Intel Corporation Wildcat Point-LP High Definition Audio Controller (rev 03)
00:1c.0 PCI bridge: Intel Corporation Wildcat Point-LP PCI Express Root Port #1 (rev e3)
00:1c.1 PCI bridge: Intel Corporation Wildcat Point-LP PCI Express Root Port #2 (rev e3)
00:1c.2 PCI bridge: Intel Corporation Wildcat Point-LP PCI Express Root Port #3 (rev e3)
00:1c.3 PCI bridge: Intel Corporation Wildcat Point-LP PCI Express Root Port #4 (rev e3)
00:1c.4 PCI bridge: Intel Corporation Wildcat Point-LP PCI Express Root Port #5 (rev e3)
00:1f.0 ISA bridge: Intel Corporation Wildcat Point-LP LPC Controller (rev 03)
00:1f.2 SATA controller: Intel Corporation Wildcat Point-LP SATA Controller [AHCI Mode] (rev 03)
00:1f.3 SMBus: Intel Corporation Wildcat Point-LP SMBus Controller (rev 03)
08:00.0 Network controller: Broadcom Corporation BCM43142 802.11b/g/n (rev 01)
09:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8101E/RTL8102E PCI Express Fast Ethernet controller (rev 0a)
0a:00.0 3D controller: NVIDIA Corporation Device 1347 (rev a2)
和 lshw 类网络结果：
*-network
description: Wireless interface
product: BCM43142 802.11b/g/n
vendor: Broadcom Corporation
physical id: 0
bus info: pci@0000:08:00.0
logical name: wlan0
version: 01
serial: d8:5d:e2:b8:12:0f
width: 64 bits
clock: 33MHz
capabilities: pm msi pciexpress bus_master cap_list ethernet physical wireless
configuration: broadcast=yes driver=wl0 driverversion=6.30.223.248 (r487574) ip=*.*.*.* latency=0 multicast=yes wireless=IEEE 802.11abg
resources: irq:18 memory:c6100000-c6107fff
*-network
description: Ethernet interface
product: RTL8101E/RTL8102E PCI Express Fast Ethernet controller
vendor: Realtek Semiconductor Co., Ltd.
physical id: 0
bus info: pci@0000:09:00.0
logical name: eth0
version: 0a
serial: 94:57:a5:d6:b7:0f
size: 10Mbit/s
capacity: 100Mbit/s
width: 64 bits
clock: 33MHz
capabilities: pm msi pciexpress msix bus_master cap_list ethernet physical tp mii 10bt 10bt-fd 100bt 100bt-fd autonegotiation
configuration: autonegotiation=on broadcast=yes driver=r8169 driverversion=2.3LK-NAPI duplex=half firmware=rtl8107e-2_0.0.2 02/26/15 latency=0 link=no multicast=yes port=MII speed=10Mbit/s
resources: irq:49 ioport:4000(size=256) memory:c6004000-c6004fff memory:c6000000-c6003fff
