i-Mode

There are four main components of the i-mode service:

• <Packet Transmission Network>
• <i-mode Compatible Handsets>
• <i-mode Compatible Web sites>
• <i-mode Billing System>

Packet Transmission Network

Source NTT DoCoMo

PDC-P (PDC mobile Packet data communications systems) ‘DoPa’
Leveraging the infrastructure of its PDC network (voice communications network), NTT DoCoMo built a packet data overlay on its PCD network to ensure low-cost and speedy access. The PDC-P (PDC mobile Packet data communications system), commonly referred to ‘DoPa,’ the technology allows for consistent connectivity. Because it does not require the allocation of an exclusive radio channel per user, packet data transmission lets multiple users use a single radio simultaneously. This helps boost network efficiency, while reducing communication costs. DoCoMo’s DoPa provides maximum transmission speed of 28.8 kbps and is compatible with a wide range of Internet protocols such as TCP/IP, from e-mail to remote-LAN access.