i-Mode Network System (PDC)

NTT DOCOMO's i-mode service enables users to access a variety of information and exchange email on the Internet through simple operations of the browser installed in mobile terminals. We have developed and configured a PDC mobile packet communications system (PDC-P) that efficiently exchanges information in i-mode formats, and has also newly developed the i-mode server to connect content sites and manage users, as well as the protocol conversion equipment to link the i-mode server with the PDC-P system.

In order to improve communications efficiency and minimize packet communications fees, a data transmission protocol specific to i-mode communications has been developed and is being used under the PDC-P system. And because connections between the i-mode server and the Internet use generic TCP/IP technology, the PDC-P network includes a mobile message packet gateway (M-PGW) to handle conversions between these two protocol formats.

As multiple M-PGW units are deployed within the PDC-P network to provide for traffic load distribution and greater reliability, the network configuration adopts multiple M-PGW connections to each i-mode server. For the connection between a mobile terminal and the M-PGW, moreover, multiple M-PGWs are set up to correspond with any single connection destination number, and the circuit connection is established by sequentially searching and selecting the connection destination from among these multiple M-PGWs in order to distribute the PDC-P network traffic.

Configuration of PDC-P Network

Created 2001/03

Updated 2004/03