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By Mark Wilcox, Campus Web Administrator

Beware the Wireless

I recently spoke at the SIGS/101 Communications JavaPlus conference in San Jose, CA. One of the most interesting discussions I sat in on was about the future of Java and wireless devices. There is a significant revolution going on with wireless overseas, primarily because standard telephone access (and thus Internet access) is more expensive and in many cases, less reliable than it is in the US.

The reason wireless was brought up at a Java conference was because there is a version of Java that has been modified for these 'micro-devices' which include Cell-phones, palm-type computers and devices that fit somewhere in the middle of these two. This version of Java called J2ME (Java 2 Micro-Edition) is a reduced sub-set of the standard Java environment designed for the limited amount of memory and disk space these systems typically have.

Some interesting observations came out of this discussion:

  1. Moore's law on computing (computer power doubles every 18 months) applies even to micro-devices. The newest cell-phones are shipping with 8 MB of RAM and 40 MHZ CPUs. Yes these are tiny compared to your PC with 800 MHZ CPUs and a gigabyte or more of RAM, but these devices are the equivalent to the most powerful desktops in 1990. Some of these manufactures are now shipping with the full standard Java desktop edition on a cell-phone!

  2. As computers have grown more powerful and functional, the available bandwidth grows more limited. You think 28.8 modems are slow, try a wireless connection.

  3. We need to rethink transactions. Transactions are the process we use to maintain data integrity in a multi-step computational process. What transactions allow programmers to do is to treat a series of steps (for example withdrawing money out of your bank account) as a single operation. If any of the steps fails (you lose power during the withdrawal), the system reverts back to the way it was before any of the steps were completed. In typical client-server applications, losing a connection and causing a rollback are fairly rare because of the quality of the network. In a wireless environment, we might lose the connection at any moment (you go out of range, drive into a tunnel, lose battery power etc.) or the connection could easily be garbled. We now must build our applications to learn to handle these situations. Quite a challenge!

Until next time.

Mark