NttDoCoMo:Japan Mobile The carrier is a Japanese telegraph and telephone company cell phone company, and is also is currently one of the world's largest mobile communications companies, and was the first operator to launch commercial 3G services.

NTT is the abbreviation of Nippon Telegraph and Telephone Public Corporation (Japan Telephone and Telegraph Corporation). DoCoMo is the first word in the Over the Mobile Network, and the Japanese pronunciation of "どこも" (Romaji) means "everywhere" in Japanese.

DoCoMo was spun off from the Japanese company Nippon Telegraph and Telephone (NTT) in August 1991, specializing in telecommunications. The Japanese government indirectly holds more than 20% of its shares by NTT. Its main business is FOMA (3G) based mobile communication services. DOCOMO used to provide PHS service, but the service was terminated on January 7, 2008. In addition, the 2G services mova and DoPa stopped accepting new subscribers on November 30, 2008, and will be discontinued on March 31, 2012.December 24, 2010, DOCOMO started to provide mobile services using the 3.9G (LTE-based) method Xi.

NTT DOCOMO is not only the leading mobile operator in Japan, but also plays a significant role in advancing the development of mobile technologies worldwide. It plays a pivotal role in the development of global mobile communications technology. The company has recently announced the Portable SIM, a portable SIM card that will allow future cell phones and tablets to access the Internet without the need to insert a traditional SIM card. The Portable SIM combines Bluetooth, NFC, and SIM technology to extend the functionality of traditional SIM cards.

Docomo says the Portable SIM will be the world's first SIM-like device with both wireless access and authentication, meaning that SIM cards will no longer be standard for cell phone access in the future. Docomo's representatives demonstrated to The Verge how to use the Portable SIM to make phone calls without inserting a SIM card, and how to convert identity information with one click.

Connecting the Portable SIM to a cell phone The caller's identity information can be transferred to the phone by establishing a connection. You can use multiple Portable SIMs, similar to the current dual SIMs, with a private card and a work card; or you can use one Portable SIM for several phones or tablets, and you don't have to remove the card from one device and install it on another device as you did before.

In addition, the Portable SIM can store authentication information for other services, and then the SIM can be used like a master key to unlock all your pre-defined passwords. For example, it can be used as authentication when logging into Amazon, Google; Docomo also plans to implement its compatibility with computer software and eventually apply the technology to electronic PIN locks in cars and homes. If you're worried about security, the Portable SIM authentication process will also be suspended when Bluetooth is disconnected.

The Portable SIM currently on display at Docomo is 8cm long and 4cm wide, about the size of a bank card, and weighs 20g. Docomo will announce details of its plans for the Portable SIM at Mobile Asia Expo 2014, which begins on the 11th.