Wireless devices will generally be shipped with a default SSID (service set identifier) that will be identical on the same product shipped to others from this products manufacturer. In order to secure your wireless network making it more difficult for others to connect, its a good idea to change the SSID to something different and also turn off the "broadcast SSID" feature if possible. You can also configure the device to only allow connections from certain MAC (factory burned in addresses for the Network Interface Card) addresses which belong to your devices and will be unique if the device supports this capability.