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Wireless Info Services Need Java Messaging, by Silvano Maffeis

This year will be the genesis of mobile devices and wireless applications. In fact, several European and American carriers have begun rolling out high-speed, packet-oriented wireless networks based on General Packet Radio Service (GPRS) as well as other standards. I've also noticed interesting Java devices based on the Symbian operating system and the J2ME MIDP environment.

The combination of Java-enabled devices and packet-oriented wireless bearers is a compelling catalyst leading to the rapid adoption of "collaborative" and highly interactive applications, delivering the right information (according to our user profile) in real time.

What does this mean to us? Maybe a new type of Internet, based on zillions of gadgets exchanging information via wireless networks!

Such communicators and smart phones will always be on and capable of receiving information in real time. This means a new way of delivering information to the user. Browsing might not be the right model in this mobile world, since your wireless device is able to receive alerts and e-mails at all times. As a user, I don't want to chase or browse for information. I want to receive an alert when something interesting happens .

Reality check. Developing Java applications that connect mobile devices to server applications in a scalable and reliable manner is a challenge. In the wireless world a mobile application must be able to "speak" various protocols and cope with varying bandwidth and loss of network coverage (imagine issuing a stock purchase transaction from your mobile device while driving through a tunnel). Wouldn't it be nice if you could build mobile Java applications on a platform or middleware to take care of those issues?

Building a highly scalable platform to host mobile Java applications isn't easy either. I've been involved in this type of development and the biggest challenge was to devise a communications middleware that copes well with the specific aspects of wireless networks, namely, varying bandwidth, intermittent connectivity, and packet loss. We opted to base our middleware on the messaging paradigm and notably on the Java Message Service (JMS) standard because (1) messaging can deal with intermittent communication links using store-and-forward message delivery, and (2) messaging can hide long communication latencies by transmitting messages in an asynchronous mode (this means the sender of a message doesn't have to wait until the message has reached its destination). Also, messaging middleware can be implemented in a lightweight manner, meaning it can be deployed directly on a mobile device. The wireless JMS is born!

What does this mean? By taking advantage of a wireless-enabled JMS middleware, you can develop mobile applications that deliver information over various wireless bearers, in spite of sudden changes in bandwidth or network coverage. For application developers it truly offers a write-once-go-anywhere possibility irrespective of the bearer. The delivery of information is guaranteed by the JMS store-and-forward message-queuing mechanism, and its timely delivery to large groups of receivers is made possible by the JMS publish-and-subscribe model and by taking advantage of the multicast capabilities of wireless bearers.

This type of JMS middleware acts as a highly versatile bridge between server-side applications running on a J2EE platform and J2ME applications running on a mobile device. If a server application transmits information to a mobile device that's turned off, nothing is lost as the JMS middleware will store and deliver the information automatically and transparently. The same occurs when the device transmits information to a server. The information, which takes the form of messages, is stored on the device and delivered to the server automatically as soon as a wireless connection is physically possible.

What does this solve? The commonality between mobile commerce platforms, wireless financial data feeds, location services, instant messengers, and multiuser games is that they all embody a distributed systems architecture in which various pieces of (Java) code need to communicate by wireless and wireline protocols. JMS has proven viable when complex distributed systems need to be developed and deployed quickly.

As we witness innovative wireless services and applications, a wireless messaging middleware could stand at the vanguard of this revolution!

Author Bio
Dr. Silvano Maffeis is CTO at Softwired (www.JavaMessaging.com), a leading vendor of application-to-application messaging solutions. He is the codeveloper of iBus, a JMS middleware for wireless and wireline systems. [email protected]

 

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