Gracias por la pronta respuesta, no instale ningun driver a ubuntu solo dejé que lo reconociera sola y los resultados que obtuve con los comandos que me dijiste son los siguientes:
Mi tarjeta de red wifi es wlan2
root@fran-desktop:/# lsusb
Bus 005 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 004 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 003 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 002 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 001 Device 002: ID 0bda:8187 Realtek Semiconductor Corp. RTL8187 Wireless Adapter
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
root@fran-desktop:/# iwlist wlan2 txpower
wlan2 unknown transmit-power information.
Current Tx-Power=20 dBm (100 mW)
root@fran-desktop:/# iwconfig wlan2
wlan2 IEEE 802.11bg ESSID:"el_essid"
Mode:Managed Frequency:2.437 GHz Access Point: 00:22:44:55:0A:DD
Bit Rate=6 Mb/s Tx-Power=20 dBm
Retry long limit:7 RTS thr:off Fragment thr:off
Encryption key:7869-6F6D-61
Power Management:off
Link Quality=49/70 Signal level=-61 dBm
Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0
Tx excessive retries:0 Invalid misc:0 Missed beacon:0
Mi tarjeta de red wifi es wlan2
root@fran-desktop:/# lsusb
Bus 005 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 004 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 003 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 002 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 001 Device 002: ID 0bda:8187 Realtek Semiconductor Corp. RTL8187 Wireless Adapter
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
root@fran-desktop:/# iwlist wlan2 txpower
wlan2 unknown transmit-power information.
Current Tx-Power=20 dBm (100 mW)
root@fran-desktop:/# iwconfig wlan2
wlan2 IEEE 802.11bg ESSID:"el_essid"
Mode:Managed Frequency:2.437 GHz Access Point: 00:22:44:55:0A:DD
Bit Rate=6 Mb/s Tx-Power=20 dBm
Retry long limit:7 RTS thr:off Fragment thr:off
Encryption key:7869-6F6D-61
Power Management:off
Link Quality=49/70 Signal level=-61 dBm
Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0
Tx excessive retries:0 Invalid misc:0 Missed beacon:0