TAXONOMY FOR MOBILE TERMINALS A Selective Classification Scheme Gunther Schiefer and Michael Decker Institute of Applied Informatics and Formal Description Method, University Karlsruhe (TH), 76128 Karlsruhe, Germany Keywords: Simple Phone, Feature Phone, Smartphone, Handheld, Web-Tablet, Netbook, Mobile PC, Tablet-PC, classification, mobile Terminal. Abstract: There is a great number of different types of mobile computing devices like cellular phones, Handhelds and notebooks. However in literature so far there is no common accepted definition for these terminal types. Es- pecially the term “Smartphone” is used for very different types of mobile phones. In our article we therefore propose a comprehensive taxonomy for mobile terminals that clearly distinguishes between different classes of terminals. 1 MOBILE TERMINALS is that mobile computing is a rather new technology so a market consolidation like that for personal desk- Everyday life without mobile terminals is almost top computers didn't take place yet. There are also unthinkable. With the increasing use of them for a many application scenarios for mobile computers multiplicity of tasks the equipment variants increase with different requirements so it is necessary to have likewise. At present the most popular mobile termi- mobile terminals especially developed for individual nals with the highest penetrations rates are mobile fields of applications. To get an impression of the great variety of mobile terminals one can refer to the phones and Feature Phones. According to Kuhn 1 (Kuhn, 2004) a mobile terminal is a portable com- WURFL project which assembles a profile database puter-assisted communication system with inde- with information about capabilities of different mo- pendent data processing capacity, which can com- bile terminals: the file comprehends over 5.000 municate as endpoint of a wireless connection with different profiles. Some software products for mo- other IT-systems. “Independent data processing bile terminals are available in customized versions for several hundred types of mobile terminals, e.g. capacity” means that the mobile terminal is equipped 2 with random access memory (RAM), a central proc- “Yahoo!Go” a mobile applications that provides essing unit (CPU) (this implies programmability), access to services like e-mail, news, weather fore- own network-independent power supply (battery) casts and maps. and the possibility to directly interact with human Nevertheless we can identify distinct classes of users by providing means for data input (e.g. keys, mobile terminals with common characteristics. microphone, touchscreen) as well data output (e.g. display, light emitting diodes, speaker). Thus radio frequency identity tags (RFID), Smartcard etc. are 2 CLASSES OF TERMINALS not mobile terminals in the sense of the above defi- nition because they don’t dispose over an independ- Within the range of the mobile terminals there are a ent power supply and a user interface. Computers number of different types. They differ in the charac- integrated into machines (e.g. vending machines, teristics listed above. There are different approaches machines in factories) are also not considered as to divide the terminals into different classes (see for mobile terminals because a human user can’t carry example (Noesekabel and Lehner, 2002), (Meier, them along. 2002) or (Roth, 2005)). The borders between the Mobile terminals differ particularly with regard to their size, their use and their performance for the 1 http://wurfl.sourceforge.net/ execution of mobile applications. One reason for this 2 http://mobile.yahoo.com/go 255 Schiefer G. and Decker M. (2008). TAXONOMY FOR MOBILE TERMINALS - A Selective Classification Scheme. In Proceedings of the International Conference on e-Business, pages 255-258 DOI: 10.5220/0001911502550258 Copyright c SciTePress ICE-B 2008 - International Conference on e-Business Mobile terminals In narrow sense In broad sense Wireless mobile Board- Mobile phones Smartcards Computer computer Simple Feature Smart Mobile Internet Mobile Handhelds Phones Phones Phones Devices Standard PC Tablet-PC Subnotebooks Figure 1: Classification tree of mobile terminals. different terminal classes are seen differently by regarded in our classification (see also Figure 1) different authors and are often not clear. For exam- have the ability for bidirectional wireless communi- ple according to Brome and Zeman (Brome and cation and have an independent power in the form of Zeman, 2008) and Canalys (Canalys.com, 2004) the an accumulator. Hereby the often vague defined classification into Feature Phone and Smartphone is term Smartphone will be clearly separated from determined by whether additional software is exe- Feature Phone and Handheld. cuted directly by the operating system or by a run- time environment like Java ME. On the one hand 2.1 Mobile Standard PC this distinction isn’t obvious, on the other hand there are terminals which can do both. The wireless mobile standard computers include Mobile terminals can differ in the following cri- laptops/notebooks, subnotebooks (also called net- teria (list is not complete): books) and Tablet-PC (including ultra mobile PC (UMPC)). Subnotebook is the name for a particu- • Size and weight larly small and light notebook, whose equipment is • Input modes very similar to those in a full notebook, however has • Output modes no optical drives (CD/DVD-ROM-drive) and a • Performance smaller keyboard. An UMPC is a Tablet-PC which • Kind of usage is maximally 8 inches large, weighs maximally • Communication capabilities 900 grams and has a display with a resolution of at • Type of operating system least 800x480 pixels; Keyboards can be attached • Expandability externally. On these terminals the conventional desktop operating systems (Linux, Windows) can be Some of these characteristics can be used to dis- used as well as the compatible software packages tinguish classes of terminals from each other. The like office suites. Substantial distinguishing features following section gives criteria for the classification are the size of chassis and display, the weight, the of mobile terminals into distinct classes without the need to do a deepened technical analysis. All classes 256 TAXONOMY FOR MOBILE TERMINALS - A Selective Classification Scheme integrated peripherals (e.g. optical Drive included) sion modules. Handhelds usually have a touch- and the operation kind of the terminals. sensitive display and can be used with a pen (or the Notebooks with wireless communication capa- fingers), or they have a text keyboard and navigation bilities are mobile terminals according to definition keys for it. Increasingly there are terminals which given above. However in the following considera- can be operated through both of them. Terminals are tions we won’t focus on them because our article is only classified as Handheld if they cannot communi- more concerned with smaller and lighter terminals cate in communication networks for mobile teleph- that can be used by a walking or standing user. ony like GSM or UMTS. Notebooks usually need a „stand space“ like a table or someone’s lap. Tablet PCs on the other hand are a 2.4 Smartphones special subclass of the mobile standard computers, because they have a touch-sensitive display and The term “Smartphone” designates a combination of therefore can be used while standing with only one Feature Phone (see below) and Handheld with usu- hand so they can be operated without a stand space. ally somewhat smaller dimensions, smaller display and partly reduced function range in comparison to 2.2 Mobile Internet Devices the Handheld. They form their own class. On the one hand mobile computers which have the characteris- Beside the mobile standard PC there is a terminal tics of Handhelds and the ability to communication class “Mobile Internet Devices” (MID) (also called over mobile telephony networks and have almost Web-Tablet or mobile Thin Client) with similar everywhere and „seamless“3 connection to the Inter- equipment and display size, however clearly reduced net belong to this class. On the other hand portable function range and normally no mechanical drives. radio terminals with the characteristics of Feature Characteristically these terminals are equipped like Phones that have extended input modes belong to Handhelds (see below) with an operating system in this class, too. The extended input mode can be the read-only memory (ROM) and are immediately provided by a touch-sensitive display (which can be ready for use after switching them on. Their function used with the fingers or a pen) or a complete text range is similar to the Handhelds and they are keyboard. mainly used for browsing the web and as client for terminal server sessions. They depend mostly on a 2.5 Feature Phones constant wireless network connection for the fulfil- ment of their tasks. The Web-Tablets (like the Tablet Feature Phones are mobile phones (see below) with PC) can be operated through a touch-sensitive dis- usually somewhat larger display and extended func- play, the mobile Thin Clients usually through a tion range. The primary use purpose of the Feature keyboard. Phones lies in mobile communication, which in- cludes both the voice communication and text-based 2.3 Handhelds communication (SMS, MMS, e-mail etc.). For this terminal class the ability for wireless data communi- Handhelds are small computers, which — like the cation over the mobile communications networks name already suggest — can be held in one hand. (e.g. GPRS or UMTS) and the absence of the ex- They are called often also Personal Digital Assistant tended input modes are characteristic. These are (PDA). Historically these were originated from the limited to a number keyboard and a few additional pure organizers, which could be predominantly used keys. Particularly terminals which support not only for personal information management (PIM) appli- the GSM standard but also UMTS are equipped with cations like calendar, address book or personal a Web browser and software to play back multime- notes. Today's Handhelds have clearly higher per- dia contents. On these terminals the user can install formance and are usually equipped with multimedia additional software.