Engineers at the Harris Corp. RF Communications Division in Rochester, N.Y., are developing a wireless e-mail system for the U.S. Air Force that operates over high-frequency (HF) radio bands. HF is one of the most versatile, yet troublesome communications bands. While it has worldwide reach because it bounces signals off the ionosphere, it is particularly susceptible to static and fading. The Harris system will send high-priority data and imaging traffic messages with stringent enough security for U.S. government agencies. The system, which will use commercial off-the-shelf Windows 95- and NT-based PCs, adjusts to changes in the HF environment using the latest HF modem technology, adaptive transfer techniques, and new network strategies. - J.K.