No wifi connection on Ubuntu 13.10

I have a new laptop lenovo thinkpad edge e540 and I have installed ubuntu 13.10 on it, but now I am not able to connect to the internet via wifi. It seems that ubuntu cannot use my wifi card, there is no option in system settings to manage wireless connection at all. Wired connection works. Can anybody help me?

Here is more information concerning the hardware:

* uname -a *

Linux ThinkPad 3.11.0-14-generic #21-Ubuntu SMP Tue Nov 12 17:04:55 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux

* lsb_release *

Distributor ID: Ubuntu
Description:    Ubuntu 13.10
Release:    13.10
Codename:   saucy

* lspci *

04:00.0 Ethernet controller [0200]: Realtek Semiconductor Co., Ltd. RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller [10ec:8168] (rev 10)
Subsystem: Lenovo Device [17aa:5028]
Kernel driver in use: r8169
05:00.0 Network controller [0280]: Realtek Semiconductor Co., Ltd. Device [10ec:b723]
Subsystem: Lenovo Device [17aa:b728]

* lsusb *

Bus 002 Device 002: ID 8087:8000 Intel Corp. 
Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 001 Device 002: ID 8087:8008 Intel Corp. 
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 004 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 003 Device 002: ID 0bda:b728 Realtek Semiconductor Corp. 
Bus 003 Device 004: ID 04f2:b398 Chicony Electronics Co., Ltd 
Bus 003 Device 003: ID 138a:0011 Validity Sensors, Inc. VFS5011 Fingerprint Reader
Bus 003 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

* iwconfig *

* rfkill *

0: hci0: Bluetooth
Soft blocked: no
Hard blocked: no
1: tpacpi_bluetooth_sw: Bluetooth
Soft blocked: no
Hard blocked: no

* nm-tool *

NetworkManager Tool

State: connected (global)

- Device: eth0  [Wired connection 1] -------------------------------------------
  Type:              Wired
  Driver:            r8169
  State:             connected
  Default:           yes
  HW Address:        <MAC address removed>

  Capabilities:
    Carrier Detect:  yes
    Speed:           100 Mb/s

  Wired Properties
    Carrier:         on

  IPv4 Settings:
    Address:         147.231.103.183
    Prefix:          22 (255.255.252.0)
    Gateway:         147.231.100.31

    DNS:             147.231.100.1
    DNS:             195.113.144.233

* NetworkManager.state *

[main]
NetworkingEnabled=true
WirelessEnabled=true
WWANEnabled=true
WimaxEnabled=true

* NetworkManager.conf *

[main]
plugins=ifupdown,keyfile,ofono
dns=dnsmasq

[ifupdown]
managed=false

* interfaces *

# interfaces(5) file used by ifup(8) and ifdown(8)
auto lo
iface lo inet loopback

* resolv.conf *

nameserver 127.0.1.1
search ujf.cas.cz

* blacklist *

[/etc/modprobe.d/blacklist-ath_pci.conf]
blacklist ath_pci

[/etc/modprobe.d/blacklist.conf]
blacklist evbug
blacklist usbmouse
blacklist usbkbd
blacklist eepro100
blacklist de4x5
blacklist eth1394
blacklist snd_intel8x0m
blacklist snd_aw2
blacklist i2c_i801
blacklist prism54
blacklist bcm43xx
blacklist garmin_gps
blacklist asus_acpi
blacklist snd_pcsp
blacklist pcspkr
blacklist amd76x_edac

* udev rules *

# PCI device 0x10ec:0x8168 (r8169)
SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{address}=="<MAC address removed>", ATTR{dev_id}=="0x0", ATTR{type}=="1", KERNEL=="eth*", NAME="eth0"

I suggest you build and try the driver referred to in the second link. With a temporary wired ethernet connection, please open a terminal and do:

sudo apt-get install linux-headers-generic build-essential git
git clone http://github.com/lwfinger/rtl8723be
cd rtl8723be
make
sudo make install
sudo modprobe rtl8723be

This is the first of these devices I've come across so we may need to tweak a bit.

Detach the ethernet. Is it now working?

When a newer kernel version, known as linux-image is installed, after you reboot, you will need to recompile the driver:

cd ~/rtl8723be
make clean
make
sudo make install
sudo modprobe rtl8723be

Please retain the files and these instructions for that time.