I have installed an Asus PCE-N15 wireless adapter on my Ubuntu 14.04 install. It sees and connects easily to Wireless networks, but it only connects at 1Mb/s when connected to my TP-Link TL-WR340G wireless router. My wireless security settings on the router are WPA2-PSK with AES as the security option. The weird thing is that when I connect to my mobile phone hotspot, it connects at full speed and I can browse the internet no problem.

This is the output of nm-tool | more:

NetworkManager Tool

State: connected (global)

- Device: wlan0  [THWIRELESS] --------------------------------------------------
  Type:              802.11 WiFi
  Driver:            rtl8192ce
  State:             connected
  Default:           no
  HW Address:        E0:3F:49:8B:89:82

    Speed:           1 Mb/s

  Wireless Properties
    WEP Encryption:  yes
    WPA Encryption:  yes
    WPA2 Encryption: yes

  Wireless Access Points (* = current AP)
    KK1690:          Infra, 00:1D:0F:F0:2D:3C, Freq 2437 MHz, Rate 54 Mb/s, Strength 40 WPA