Mobile and PDA (Personal Digital Assistant) Operating Systems
Mobile, portable and handheld devices are improving their digital audio capabilities. The foremost development has been the support for .mp3, .wma digital audio playback capability. This is primarily a playback application and the actual files must be downloaded from a desktop or introduced into the device from flash or compact memory cards. The next step is incorporating support for internet access with stable connection, appropriate bandwidth and high quality streaming media.
Psion runs the Symbian Epoc operating system. The Symbian operating system is also endorsed by Sonyricsson, Nokia, Motorola, Siemwns , Samsung and Panasonic (Sendo is a licensee) which support the operating system as an alternative to MS Windows. Symbian will support RealNetworks audio codec and the streaming protocol RealPlayer Mobile. A Licensee of the Symbian software is allowed to modify it such that a menu interface on one manufacturer’s smartphone may not look the same on another Symbian-based smartphone (Nokia’s version of Symbian, Series 60, is licensed to some of the other smartphone manufacturers).
Palm Pilot runs the Palm OS. The format is also supported by Qualcomm, Handspring, Casio and Sony Clié. This format conserves battery life. The most recent version developed by PalmSource (the software division) is Palm OS 5 (applications written for OS 4.0 should still be supported). The operating system provides for improved security with 128-bit encryption (RC4 and SSL), support for 802.11b wireless interface and improved 16-bit audio playback. OS 5.0 provides very good support for ARM-compliant microprocessors, and renewed support for the Apple / Mac OS platform, particularly OS X.
Palm Pilot OS devices use an application named HotSync to synchronize data transfer with desktop computers running the MS Windows operating system. The program can utilize a serial, USB, Ethernet or 802.11b/Wi-Fi connection to synchronize with the desktop. The advantage with HotSync is that it will also synchronize data from applications installed on the Palm device with the application on the host desktop computer. Synchronization is not automatic and must be initiated by either opening the application on the Palm or opening HotSync.
As of July 2003, Palm divided the software operation from the hardware manufacturing operation. The new Palm software development company is PalmSource. This allows the Palm software platform to evolve separately from sales competition between Palm PDAs and those companies that license the Palm OS for their own brand of PDAs.
Pocket PC 2002 and Pocket PC 2003 is Microsoft’s platform for handheld and mobile devices. The operating system is the revised, embedded 32-bit Windows CE, which runs on the Compaq iPAQ, Hewlett-Packard Jornada, Symbol PPT/PDT, Casio Cassiopeia, Toshiba Genio, and NEC PocketGear handheld devices. The graphical interface is similar to Windows 9x. File Explorer is similar to Windows Explorer and allows one to search for access files on a desktop MS Windows computer. PocketPC also supports Windows Media player. The application installed on the handheld unit is Windows Media Player 7.1, which supports the playback of the .wma audio format on the device (files must be downloaded by cable connection separately). The earlier Windows CE operating system required quite a bit of memory of the device and utilizes quite a bit battery power. The upgrade of the operating system for PocketPC 2002 is, however, of a design geared more toward a business usage. In addition to PocketPC 2002’s support of Windows Media Player, it will also support 802.11b, Bluetooth and wireless data connections (CDPD, GSM/GPRS and CDMA/1XRRT). Pocket Internet Explorer provides very good support for HTML, cHTML and WML and WMLScript. Applications that will run on Windows CE can be written in C++ and VisualBasic. Some present generation mobile telephones run the Pocket PC 2002 Phone Edition platform.
Microsoft Pocket PC 2002 and PC 2003 devices use an application named ActiveSync to synchronize data transfer with desktop computers running the MS Windows operating system. The program can utilize a serial, USB, Ethernet or 802.11b/Wi-Fi connection to synchronize with the desktop. Synchronization is automatic when the device is placed in the sync and charge cradle.
Microsoft has also developed Stinger (based on MS Windows CE) as an operating system for 2.5G and 3G mobile telephones. The application would allow one to download a digital audio file to telephone and then play the file.
Sun Microsystems’ Java OS is also capable of running handheld and wireless devices. For instance, in Japan, i-mode wireless service is Java-based (J phone) and allows the downloading of Java applets that support content delivery, which allows users to view web pages with enhanced graphics on their mobile telephone. The operating system on a PDA is named PersonalJava, but both are versions of Java, known as J2ME (java 2 Micro Edition), that is a reduced code length version specifically designed for portable, mobile devices which have limited power and processing capabilities (however the reduced size does place some restrictions on J2ME’s capabilities and functionality).
Linux is also capable of running on handheld devices. The recently reintroduced Zaurus PDA by Sharp Electronics has Linux as the operating system and applications that are written in Java (the device will stil synchronize with MS Windows-based computers). Linux OS devices tend to installed on units with ARM microprocessors.
Intel’s Integrated Performance Primitives (IPP), while not an operating system is closely associated with the Strong Arm series of microprocessors for handheld devices. IPP are codecs designed for high quality multimedia on handheld devices. IPP will allow digital audio applications access the processor directly for shorter processing time and less power consumption. The architecture will support MS Windows Media.
Similarly, Texas Instruments has integrated RealAudio into the DSP microchip that is installed in several models of handheld telephones. The inclusion of the algorithm will allow the streaming of digital audio compressed in the ReaAudio format to the telephone itself along with similarly equipped PDAs. The Texas Instrument DSP microchip will also support other compression formats and DRM compliant encoding.