J2ME Interview Questions and Answers

J2ME – Java 2 Platform Micro Edition. It is targeted at small, standalone or connectable consumer and embedded devices. This technology consists of both a programming language and a software platform. It a highly optimized version of JRE and consists of JVM and a set of APIs suitable for simple runtime environments.

The J2ME Wireless Toolkit is a set of tools that provides developers with an emulation environment, documentation and examples for developing Java applications for small devices. The J2ME WTK is based on the Connected Limited Device Configuration (CLDC) and Mobile Information Device Profile (MIDP) reference implementations, and can be tightly integrated with Forte for Java

The Sun Microsystems (now subsidiary of Oracle) devide java into three editions- J2SE, J2EE, J2ME, each having own software development Kit(SDK) . 1. J2SE- Java 2 Standard Edition. This edition consists of application programming interfaces (APIs) needed to build aJava application or applet. 2. J2EE- Java 2 Enterprise Edition. This edition consists of application programming interfaces (APIs) needed to build a application for access server-side systems. 3. J2ME- Java 2 Micro Edition. This edition consists of application programming interfaces (APIs) needed to build a applications for small computing devices, including wireless Java applications.

802.11 is a group of specifications for wireless networks developed by the Institute of Electrical and Electronics Engineers (IEEE). 802.11 uses the Ethernet protocol and CSMA/CA (carrier sense multiple access with collision avoidance) for path sharing.

Connected Device Configuration (CDC) is a set of tools for developing applications that run on a range of network-connected consumer and embedded devices that support the Java ME CDC application framework. It is a JVM that is highly optimized for resource-constrained devices.

An Application Programming Interface (API) is a set of classes that you can use in your own application. Sometimes called libraries or modules, APIs enable you to write an application without reinventing common pieces of code. For example, a networking API is something your application can use to make network connections, without your ever having to understand the underlying code. 5. What is AMPS

Advanced Mobile Phone Service (AMPS) is a first-generation analog, circuit-switched cellular phone network. Originally operating in the 800 MHz band, service was later expanded to include transmissions in the 1900 MHz band, the VHF range in which most wireless carriers operate. Because AMPS uses analog signals, it cannot transmit digital signals and cannot transport data packets without assistance from newer technologies such as TDMA and CDMA.

A MIDlet is a MID Profile application. A J2ME Midlet’s main class must extends javax.microedition.midlet.MIDlet. This class define three life-cycle notification methods: startApp(), pauseApp(), and destroyApp().

Advanced Mobile Phone Service (AMPS) is a first-generation analog, circuit-switched cellular phone network. Originally operating in the 800 MHz band, service was later expanded to include transmissions in the 1900 MHz band, the VHF range in which most wireless carriers operate. Because AMPS uses analog signals, it cannot transmit digital signals and cannot transport data packets without assistance from newer technologies such as TDMA and CDMA.

Code-Division Multiple Access (CDMA) is a cellular technology widely used in North America. There are currently three CDMA standards: CDMA One, CDMA2000 and W-CDMA. CDMA technology uses UHF 800Mhz-1.9Ghz frequencies and bandwidth ranges from 115Kbs to 2Mbps.

Also know as IS-95, CDMAOne is a 2nd generation wireless technology. Supports speeds from 14.4Kbps to 115K bps.