iMode - Basic Concepts
i-Mode phones have a special i-mode button for the user to access the start menu. There are more plenty of official sites, which are linked to DoCoMo's i-mode portal page and DoCoMo's billing services.
An i-mode users pay for both sent and received data. There are operators, who are charging their customers with additional charges on a monthly subscription basis for premium services and a variety of discount plans also exist; for example, family discount and flat packet plans for unlimited transfer of data at a fixed monthly charge.
NTT DoCoMo takes care of all the contents and operations of all official i-mode sites, most of which are commercial. These official sites are accessed through DoCoMo's i-mode menu, but in many cases official sites can also be accessed from mobile phones by typing the URL or through the use of QR code (a barcode).
There are essentially four main components that are required for the i-Mode service. They are as follows:
A cellular phone capable of voice and packet communication and with a browser installed.
A packet network.
An i-mode server.
Following picture depicts a very broad overview of i-mode concept: