8. In indoor experiments conducted in 2002, NTT DoCoMo's 4G system demonstrated maximum information bit rates of 100 Mbps for the downlink and 20 Mbps for the uplink. Emerging 4G technology promises to converge wireless access, wireless mobile, wireless local area network (WLAN), and packet-division-multiplexed (PDM) networks. With PDM technology, for example, a single integrated ter- minal using a single global personal number can freely access any wireless air interface. Additionally, PDM radio transmission modules are fully software definable, reconfigurable, and programmable. NTT DoCoMo is currently conducting research into a technology known as variable spreading factor-orthogonal frequency and code division multi- plexing (SF-OFCDM), which has the power to transmit at speeds of up to MODULAR COMPONENTS 100 Mbps outdoors and up to 1 Gbps indoors. Basic functionality has already been verified for this technology and NTT DoCoMo is now involved in actual field experiments. The firm is also building a mobile IP network specifically for packet data that supports seamless service between the company's mobile service and a variety of other networks (such as WLANs) to provide an enhanced online experience with reduced network cost. NTT DoCoMo is also working on an entirely new system concept that will have the power to do away with base stations entirely by allowing terminals to interconnect directly. This company is also investigating versatile mobile networks where base stations will have the ability to install themselves auto- matically to achieve a network that actually thinks for itself. 1.5 MODULAR COMPONENTS As mobile operators race to provide ever more sophisticated and complex services, companies must soon redraw their IT architectures and adopt modular software components in order to market new services quickly and cheaply. For example, many mobile operators find it hard to market their products quickly because of a complex and inflexible IT architecture that forces them to develop many parts of each new p