Moving into JavaME

The IP Multimedia Subsystem (IMS) involves the evolution of very basic telephone and data exchanges into a modern exchange system, powered by a plethora of high-capacity devices and networking lines. Driven by the recent explosion in internet and highend devices, Java ME, which is installed on billions of devices worldwide, is strategically placed to take advantage of this.

What Is the IMS?

The IMS is an architectural framework that helps with delivering multimedia services that use the Internet Protocol (IP). It was originally defined by the 3GPP (3rd Generation Partnership Project) as a standardized way for wireless mobile devices to distribute internet-based services. However, it is broader now and covers multiple network and media types. The architecture defines a centralized exchange-type of system that advertises its services. End users can connect their devices to this centralized service and gain individual identities. Multi media based messages and data are sent to these identities via pipes that provide for simultaneous transfer of the data. Therefore, instead of an old-style telephone exchange system, which provides for only one kind of media transfer (voice), the IMS can easily handle multiple media transfers simultaneously. This exchange of data can take place between services without a human element present, as in video or audio streaming where an end user consumes the data without needing to have a physical entity present at the other end. The end user is dialing into a service that would have advertised itself previously with its own unique identity. Businessto- business transactions are also possible, as long as individual identities have been established and a connection is possible based on pre-existing criteria and contracts.Identity on an IMS network is established using SIP (RFC 3261—essentially, your

e-mail address) or a “tel” URI (RFC 3966—essentially, your phone number). An end user or service may have multiple such identities, and the user can be reached on one, some, or all of these identities, at the

same time. This is the beauty of an IMS-based system.