The current situation is such that it is difficult for drugs to reach posterior tissues of an eyeball, such as choroid and retina, with the result that treating diseases in such regions is difficult. Firstly, when the wireless communication system starts to operate from a standby mode, a state signal is transmitted from the wireless communication system to the PDA. In addition, both network based mobility and UE based mobility mechanisms are supported to allow a UE supporting dual stack mobility access to a network supporting only one of IPv4 or IPv6.