Problems with wireless coection. Lubuntu 14.04

I just installed Lubuntu 14.04 two days ago. The problem I have is that my my wifi does not work properly. It works for some minutes but after a while it begins being slow until the coection is lost. The problem is in the software because I am able to coect from another computer with Kubuntu and with my cellphone and everything works just fine there.

I have this information:

*-network
descrição: Interface sem fio
produto: RTL8723BE PCIe Wireless Network Adapter
fabricante: Realtek Semiconductor Co., Ltd.
ID físico: 0
informações do barramento: pci@0000:02:00.0
nome lógico: wlan0
versão: 00
serial: a8:a7:95:ab:d4:2f
largura: 64 bits
clock: 33MHz
capacidades: pm msi pciexpress bus_master cap_list etheet physical wireless
configuração: broadcast=yes driver=rtl8723be driverversion=4.2.0-30-generic firmware=N/A ip=192.168.1.104 latency=0 link=yes multicast=yes wireless=IEEE 802.11bgn
recursos: irq:19 porta de E/S:1000(tamanho=256) memória:91000000-91003fff

My computer is an HP with 2GB or Ram and 32 in the hard disk. 64 bits.

I hope someone can help me!

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