Internet Wifi caindo [RESOLVIDO]

Bom dia Pessoal.
Socorro.
Estou com o seguinte problema:
Esses dias tive um problema na minha internet e usei o comando pppoeconf para tentar configurar uma vpn, depois disso a indicação de cabo de rede (eth0) não aparece mais.. sem problemas.. consigo trabalhar tranquilamente com o cabo conectado, hoje estou em um local que só tenho rede sem fio.
O wifi está caindo muito, já fiz algumas pesquisas e tentei algumas coisas, mas ainda não consegui identificar o problema, o wifi cai o tempo todo no note (sempre usei sem problemas) e no celular está ok.

O que já percebi é o seguinte, quando a internet cai, eu estou usando o comando sudo /etc/init.d/networking restart, enquanto o comando está sendo executado a internet fica ok.. assim que o comando é concluido a internet cai.

Alguma dica ?

Obrigado a todos.

1-qual linux vc stá usando? poste saida do comando: lsb_release -a
2-qual sua placa wifi? poste saida do comando: lspci

cristiano@cristiano-Latitude-E6510:~$ lsb_release -a
LSB Version: core-2.0-ia32:core-2.0-noarch:core-3.0-ia32:core-3.0-noarch:core-3.1-ia32:core-3.1-noarch:core-3.2-ia32:core-3.2-noarch:core-4.0-ia32:core-4.0-noarch:core-4.1-ia32:core-4.1-noarch:cxx-3.0-ia32:cxx-3.0-noarch:cxx-3.1-ia32:cxx-3.1-noarch:cxx-3.2-ia32:cxx-3.2-noarch:cxx-4.0-ia32:cxx-4.0-noarch:cxx-4.1-ia32:cxx-4.1-noarch:desktop-3.1-ia32:desktop-3.1-noarch:desktop-3.2-ia32:desktop-3.2-noarch:desktop-4.0-ia32:desktop-4.0-noarch:desktop-4.1-ia32:desktop-4.1-noarch:graphics-2.0-ia32:graphics-2.0-noarch:graphics-3.0-ia32:graphics-3.0-noarch:graphics-3.1-ia32:graphics-3.1-noarch:graphics-3.2-ia32:graphics-3.2-noarch:graphics-4.0-ia32:graphics-4.0-noarch:graphics-4.1-ia32:graphics-4.1-noarch:languages-3.2-ia32:languages-3.2-noarch:languages-4.0-ia32:languages-4.0-noarch:languages-4.1-ia32:languages-4.1-noarch:multimedia-3.2-ia32:multimedia-3.2-noarch:multimedia-4.0-ia32:multimedia-4.0-noarch:multimedia-4.1-ia32:multimedia-4.1-noarch:printing-3.2-ia32:printing-3.2-noarch:printing-4.0-ia32:printing-4.0-noarch:printing-4.1-ia32:printing-4.1-noarch:qt4-3.1-ia32:qt4-3.1-noarch:security-4.0-ia32:security-4.0-noarch:security-4.1-ia32:security-4.1-noarch
Distributor ID: Ubuntu
Description: Ubuntu 15.04
Release: 15.04
Codename: vivid
cristiano@cristiano-Latitude-E6510:~$ lspci
00:00.0 Host bridge: Intel Corporation Core Processor DRAM Controller (rev 02)
00:01.0 PCI bridge: Intel Corporation Core Processor PCI Express x16 Root Port (rev 02)
00:19.0 Ethernet controller: Intel Corporation 82577LM Gigabit Network Connection (rev 05)
00:1a.0 USB controller: Intel Corporation 5 Series/3400 Series Chipset USB2 Enhanced Host Controller (rev 05)
00:1b.0 Audio device: Intel Corporation 5 Series/3400 Series Chipset High Definition Audio (rev 05)
00:1c.0 PCI bridge: Intel Corporation 5 Series/3400 Series Chipset PCI Express Root Port 1 (rev 05)
00:1c.1 PCI bridge: Intel Corporation 5 Series/3400 Series Chipset PCI Express Root Port 2 (rev 05)
00:1c.2 PCI bridge: Intel Corporation 5 Series/3400 Series Chipset PCI Express Root Port 3 (rev 05)
00:1c.3 PCI bridge: Intel Corporation 5 Series/3400 Series Chipset PCI Express Root Port 4 (rev 05)
00:1d.0 USB controller: Intel Corporation 5 Series/3400 Series Chipset USB2 Enhanced Host Controller (rev 05)
00:1e.0 PCI bridge: Intel Corporation 82801 Mobile PCI Bridge (rev a5)
00:1f.0 ISA bridge: Intel Corporation Mobile 5 Series Chipset LPC Interface Controller (rev 05)
00:1f.2 RAID bus controller: Intel Corporation 82801 Mobile SATA Controller [RAID mode] (rev 05)
00:1f.3 SMBus: Intel Corporation 5 Series/3400 Series Chipset SMBus Controller (rev 05)
00:1f.6 Signal processing controller: Intel Corporation 5 Series/3400 Series Chipset Thermal Subsystem (rev 05)
01:00.0 VGA compatible controller: NVIDIA Corporation GT218M [NVS 3100M] (rev a2)
01:00.1 Audio device: NVIDIA Corporation High Definition Audio Controller (rev a1)
03:00.0 Network controller: Intel Corporation Centrino Advanced-N 6200 (rev 35)
04:00.0 CardBus bridge: Ricoh Co Ltd CardBus bridge (rev 02)
04:00.1 SD Host controller: Ricoh Co Ltd MMC/SD Host Controller (rev 03)
04:00.4 FireWire (IEEE 1394): Ricoh Co Ltd R5C832 PCIe IEEE 1394 Controller (rev 03)
3f:00.0 Host bridge: Intel Corporation Core Processor QuickPath Architecture Generic Non-core Registers (rev 02)
3f:00.1 Host bridge: Intel Corporation Core Processor QuickPath Architecture System Address Decoder (rev 02)
3f:02.0 Host bridge: Intel Corporation Core Processor QPI Link 0 (rev 02)
3f:02.1 Host bridge: Intel Corporation 1st Generation Core Processor QPI Physical 0 (rev 02)
3f:02.2 Host bridge: Intel Corporation 1st Generation Core Processor Reserved (rev 02)
3f:02.3 Host bridge: Intel Corporation 1st Generation Core Processor Reserved (rev 02

Seu Linux é o Ubuntu-15.04 e sua wifi é uma Intel Corporation Centrino Advanced-N 6200
Por acaso vc testou dvd ou pendrive do Ubuntu-14.04 para ver se esse problema persiste?
Vc já viu esta dica?
http://askubuntu.com/questions/538764/centrino-advanced-n-6200-dell-studio-1569-slow-internet

Boa tarde Clodoaldo.
Obrigado pela ajuda.
Acho que consegui resolver o problema.
Apaguei todo o conteúdo do arquivo /etc/network/interfaces
Após isso já estou conectado desde as 12:00

Valeu.

Problema resolvido com:

Apaguei todo o conteúdo do arquivo /etc/network/interfaces