Java Technology for the Wireless Industry (JTWI) Frequently Asked Questions


Technology for the Wireless Industry (JTWI)
Frequently Asked Questions

Q. What is the purpose of JTWI (JSR 185)?
A. The goal of JTWI (JSR 185) is to clarify how the various technologies associated with the Java 2 Platform, Micro Edition (J2ME) Connected Limited Device Configuration (CLDC) and Mobile Information Device Profile (MIDP) work together to form a complete Java runtime environment that enables the deployment of end-to-end solutions on mobile phones and other mobile information devices.

Q. What functionality is being covered in JTWI?
A. The initial JTWI specification will define a Java runtime environment for mobile devices based on CLDC 1.0 (JSR 30), MIDP 2.0 (JSR 118), WMA 1.0 (JSR 120), and MMAPI (JSR 135) where applicable. An integrated reference implementation and TCK bundle will be provided for the described technologies. Subsequent versions of the JTWI roadmap and specification will incorporate additional technologies defined through the Java Community Process (JCP) program.

Q. How is JTWI different from the individual technologies listed above?
A. The JTWI specification is not meant to replace the specifications that it refers to and that are already being defined through the JCP. What the JTWI specification will define, which is not within the scope of any existing JSR, is how the various technologies associated with CLDC and MIDP work together to form a complete Java runtime environment for mobile devices. In addition, the JTWI expert group will provide advice to the JCP ME Executive Committee and other relevant standards bodies and consortiums in the wireless industry with regards to issues related to any of these JSRs.

Q. Can the JTWI JSR refer to any other JSRs not listed currently as a technology in section 3 (contributions)?
A. Future versions of the JTWI roadmap and specification may refer to other JSRs not listed here, provided the JSR 185 expert group deems that the referenced JSR fulfills required criteria regarding architectural fit with the technologies already chosen for JTWI, and provides consistent licensing terms for the specification, reference implementation (RI) and technology compatibility kit (TCK).

Q. Will the JTWI JSR mandate which wireless-related JSRs can be filed?
A. The JTWI JSR can promote certain JSRs, but will not prohibit other JSRs to be filed through the JCP. It is up to the J2ME, J2EE and J2SE JCP Executive Committees to decide whether specific JSRs will be accepted for development. However, the JTWI expert group represents the parties who are essential to providing a consistent architecture and platform for wireless clients, and therefore wish to promote certain JSRs. A consistent wireless client platform, with consistent access terms to it will benefit the developer community, device manufacturers and service providers.

Q. What are the target devices for JSR 185?
A. JSR 185 is targeted at mobile phones and other mobile devices, including PDAs and communicators.

Q. When will the JSR 185 specification, RI, and TCK be available?
A. Once a JSR is approved for development, it takes on average 6 to 9 months for a specification, RI and TCK to be delivered. However, it is up to the expert group to propose a schedule after agreeing on the set of features that will be addressed by the specification. The first versions of the JTWI specification, RI, and TCK are expected to be finalized in the second quarter of 2003.

Q. When will the first devices supporting JSR 185 be commercially available?
A. On mass-market handsets, most software components, including the Java runtime environment, must be embedded in ROM at manufacturing time. Once the final specification, RI, and TCK are available, device manufacturers have to create optimized implementations of JSR 185 targeted at specific chip sets and operating systems. We expect the first JTWI compliant devices to be commercially available in the fall of 2003.

Q. What companies are endorsing this effort?
A. Several of the leading handset manufacturers and wireless operators in the world are forming the initial expert group for this JSR together with Sun Microsystems and other software providers. The entire list of expert group members can be found on the JCP web site.

Q. Where can I find more details about the JTWI JSR?
A. The full text of the JTWI JSR proposal can be found on the JCP web site at The initial version of the JTWI road map is available at

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