4. Mobile stations joined forces with Ericsson, Nokia, and Motorola to form a new joint venture called Symbian [12], with the aim of There are numerous mobile stations available in the establishing EPOC as the de facto operating system for market today. Table 2 lists some major mobile station mobile stations specifications, although several table entries may not be complete as some of the information is classified as 5. Mobile middleware confidential due to business considerations The term middleware refers to the software layer Vendor Processor between the operating system and the distributed System RAM/ROM applications that interact via a the networks. It translates 206 MHz Intel ompaq iPAQ MS Pocket strongarM 64MB/32 requests from mobile stations to a host computer and H3870 PC2002 adapts content from the host to the mobile station [ll] 32-bit RIsC 32-bit ARM9 6MB/8 Communicator OS 5.1. WAP and i-mode 33 MHZ Palm os Palm 1705 Motorola 8 MB/4 MB According to an article in Eurotechnology. com [ 3] 4.1 Dragonball vZ 60% of the worlds wireless internet users were using i- 66 MHZ mode, 39% were using WAP, and 1% were using Palm SONY Clie Motorola 16MB/8 middleware. Table 3 compares i-mode and WAP and PEG-NR7OV details of the middleware follow Toshiba e74 MS Pocket 400 MHz Intel 64 MB/32 WAP PC2002 Developer WAP Forum ITT DoCoMo Table 2. Some major mobile stations Function A complete mobile Internet service CHTML (Compact 4. 1. Operating systems WAP Gateway TCP/P modifications Although a wide range of mobile stations are available in the market, the operating systems, the core of mobile Key Features Weible adopted and I High at d easy to DS, Pocket PC, and Symbian Os Palm OS. The plain vanilla design of the Palm OS [9] Table 3. Two major kinds of mobile middleware has resulted in a long battery life, approximately twice that of its rivals. Palm was slower to add color features WAP (Wireless Application Protocol). WAP is an advantages of battery life, size, and weight. Palm OS 5, wireless devices to easy at allows mobile users with than its competitors because of their reluctance to lose its open, global specification tha which runs an ARM processor (TI OMAP1510), has a information and services instantly [14]. It is a very high-resolution (320x320) color screen. 16 MB of flexible sta memory, built in voice recorder, directional pad, built-in include CDPD, CDMA, GSM, PDC, PHS, TDMA, Bluetooth, and media playback capability(MP3/OGG/ FLEX, ReFLEX, IDEN, TETRA, DECT, DataTAC WAV), complete with speaker and headphone jack. Mobitex, and GRPS. It is supported by most operating Pocket pc. In 1996. microsoft launched Windows systems and was specifically engineered for mobile CE, a version of the Microsoft Windows operating system stations include Palm OS, EPOC, Windows CE, FLEXOS that is being used in a variety of embedded products from oS/9, and JavaoS. The most important technology mobile stations to ialized industrial controller and applied by WAP is probably the WAP Gateway, which is consumer electronic devices. However, it was not well mainly responsible for interfaces between the Internet and received primarily because of battery-hungry hardware the network. It functions as follows--requests from and limitations in the operating system. To solve these mobile stations are sent as a URL through the network to problems, Microsoft introduces Pocket PC [10], which the WAP Gateway; responses a whle static offers far more computing power than Windows CE server to the WaP Gateway in HTML and are then Symbian OS. EPOC16 from Psion Software is a 16- translated in WmL and sent to the mobile stations bit version of the operating system that has been available i-mode. i-mode [5] is the full-color, always-on, and eve packet-switched Internet service for cellular phones stations: EPOC32 is a 32-bit open operating system that offered by NTT DoCoMo. With i-mode, cellular phone supports preemptive multitasking. In mid-1998. Psion users get easy access to more than 60,000 Internet sites, as Proceedings of the 23 rd International Conference on Distributed Computing Systems Workshops(ICDCSw03 SOCIETY 0-7695-1921-003$1700@2003lEEE4. Mobile Stations There are numerous mobile stations available in the market today. Table 2 lists some major mobile station specifications, although several table entries may not be complete as some of the information is classified as confidential due to business considerations. Vendor & Device Operating System Processor Installed RAM/ROM Compaq iPAQ H3870 MS Pocket PC 2002 206 MHz Intel StrongARM 32-bit RISC 64 MB/32 MB Nokia 9290 Communicator Symbian OS 32-bit ARM9 RISC 16 MB/8 MB Palm i705 Palm OS 4.1 33 MHz Motorola Dragonball VZ 8 MB/4 MB SONY Clie PEG-NR70V Palm OS 4.1 66 MHz Motorola Dragonball Super VZ 16 MB/8 MB Toshiba E740 MS Pocket PC 2002 400 MHz Intel PXA250 64 MB/32 MB Table 2. Some major mobile stations 4.1. Operating systems Although a wide range of mobile stations are available in the market, the operating systems, the core of mobile stations, are dominated by just three major brands: Palm OS, Pocket PC, and Symbian OS. Palm OS. The plain vanilla design of the Palm OS [9] has resulted in a long battery life, approximately twice that of its rivals. Palm was slower to add color features than its competitors because of their reluctance to lose its advantages of battery life, size, and weight. Palm OS 5, which runs an ARM processor (TI OMAP1510), has a high-resolution (320×320) color screen, 16 MB of memory, built in voice recorder, directional pad, built-in Bluetooth, and media playback capability (MP3/OGG/ WAV), complete with speaker and headphone jack. Pocket PC. In 1996, Microsoft launched Windows CE, a version of the Microsoft Windows operating system that is being used in a variety of embedded products from mobile stations to specialized industrial controller and consumer electronic devices. However, it was not well received primarily because of battery-hungry hardware and limitations in the operating system. To solve these problems, Microsoft introduces Pocket PC [10], which offers far more computing power than Windows CE. Symbian OS. EPOC16 from Psion Software is a 16- bit version of the operating system that has been available for several years and is embedded in many mobile stations; EPOC32 is a 32-bit open operating system that supports preemptive multitasking. In mid-1998, Psion joined forces with Ericsson, Nokia, and Motorola to form a new joint venture called Symbian [12], with the aim of establishing EPOC as the de facto operating system for mobile stations. 5. Mobile Middleware The term middleware refers to the software layer between the operating system and the distributed applications that interact via the networks. It translates requests from mobile stations to a host computer and adapts content from the host to the mobile station [11]. 5.1. WAP and i-mode According to an article in Eurotechnology.com [3], 60% of the world’s wireless Internet users were using i￾mode, 39% were using WAP, and 1% were using Palm middleware. Table 3 compares i-mode and WAP and details of the middleware follow. WAP i-mode Developer WAP Forum NTT DoCoMo Function A protocol A complete mobile Internet service Host Language WML (Wireless Markup Language) CHTML (Compact HTML) Major Technology WAP Gateway TCP/IP modifications Key Features Widely adopted and flexible Highest number of users and easy to use Table 3. Two major kinds of mobile middleware WAP (Wireless Application Protocol). WAP is an open, global specification that allows mobile users with wireless devices to easily access and interact with information and services instantly [14]. It is a very flexible standard including most wireless networks, which include CDPD, CDMA, GSM, PDC, PHS, TDMA, FLEX, ReFLEX, iDEN, TETRA, DECT, DataTAC, Mobitex, and GRPS. It is supported by most operating systems and was specifically engineered for mobile stations include Palm OS, EPOC, Windows CE, FLEXOS, OS/9, and JavaOS. The most important technology applied by WAP is probably the WAP Gateway, which is mainly responsible for interfaces between the Internet and the network. It functions as follows—requests from mobile stations are sent as a URL through the network to the WAP Gateway; responses are sent from the Web server to the WAP Gateway in HTML and are then translated in WML and sent to the mobile stations. i-mode. i-mode [5] is the full-color, always-on, and packet-switched Internet service for cellular phones offered by NTT DoCoMo. With i-mode, cellular phone users get easy access to more than 60,000 Internet sites, as Proceedings of the 23 rd International Conference on Distributed Computing Systems Workshops (ICDCSW’03) 0-7695-1921-0/03 $17.00 © 2003 IEEE