Boost and Virgin are owned by Sprint, which run on the Sprint CDMA network. There's no GSM network for any of them. Verizon is the other carrier with a separate CDMA network. T-Mobile and AT&T each have their own GSM networks.
ETD means that the Eustachian tube is blocked or does not open properly. Air cannot then get into the middle ear. Therefore, the air pressure on the outer side of the eardrum becomes greater than the air pressure in the middle ear. This pushes the eardrum inward.
The eustachian (auditory) tube drains fluid from the middle ear into the throat (pharynx) behind the nose. Ear Conditions. Earache: Pain in the ear can have many causes. Some of these are serious, some are not serious. Otitis media (middle ear inflammation