A person may be a carrier of a disease, such as Streptococcus in the throat, without exhibiting any symptoms. Depending on the disease, the person may or may not be contagious during the incubation period.During clinical latency, an infection is subclinical. With respect to viral infections, in clinical latency the virus is actively replicating. person may be a carrier of a disease, such as Streptococcus in the throat, without exhibiting any symptoms. Depending on the disease, the person may or may not be contagious during the incubation period.
The first commercial deployment in North America of camera phones was in 2002. The Sprint wireless carriers deployed over 1 million camera phone manufactured by Sanyo and launched by the PictureMail infrastructure (Sha-Mail in English) developed and managed by LightSurf.
Handsets that could be used in a vehicle had been developed prior to Martin Cooperâs phone, but his was the first usable truly portable mobile telephone. Cooper made mobile phone history in April 1973 when he made the first ever call on a handheld mobile phone. 1  Japan became the first country to have a city-wide commercial cellular mobile phone network in 1979.  The Nordic Mobile Telephone (NMT) system launched in Denmark, Norway, Sweden and Finland in 1981.