Dynamic and Mobile GIS: Investigating Changes in Space and Time - Chapter 2

Chapter 2 Opportunities in Mobile GIS Qingquan Li State Key Laboratory of Information Engineering in Surveying, Mapping and Remote Sensing, Wuhan University, P. R. China 2.1 Introduction Mobile information technology has emerged from a combination of the Internet and wireless communication. This combination provides information services via mobile terminals—anywhere and at anytime. Mobile GIS, itself, comes into being whenever mobile information services and GIS are combined. Mobile GIS has the following characteristics: 1. Mobility. Mobile GIS can operate on many kinds of mobile terminals that offer mobile information services to users through the interaction of wireless communication and remote servers. This makes GI constantly available for those such as field personnel, maintenance operatives, etc. who are always on the move. 2. Dynamic and operating in real time. As a service system, a mobile GIS responds to users’ requirements and provides dynamic and current information about, for example, accidents, travel status and traffic jams. 3. Supports applications. In daily life, more than 80% of available information relates to spatial position; the geographic information resource is abundant and dispersed. Analysing this information and serving dispersed applications is the core task of mobile GIS. 4. Depends on location information. To provide mobile services, mobile GIS requires knowledge of the location of users, in real time. 5. Diverse mobile terminal technologies. There are various classes of terminals, including mobile computers, personal digital assistants (PDAs), mobile telephones, beep pagers and vehicle terminal devices. Furthermore, because of different manufacturers, different technologies and the fact that both spatial and non-spatial information is transmitted to and from terminals, technological diversity is further augmented. Therefore, the arrival of mobile GIS can be considered to be GIS’s ‘new age’. Because of the above characteristics, mobile GIS builds up the professional, commercial and public service GIS sectors by integrating modern mobile communication technologies and GIS technology. It has changed the GIS application scene, bringing into being new application fields and adding value to otherwise routine services. __________________________________________________________________________________________ Dynamic and Mobile GIS: Investigating Changes in Space and Time. Edited by Jane Drummond, Roland Billen, Elsa João and David Forrest. © 2006 Taylor & Francis © 2007 by Taylor & Francis Group, LLC 20 Dynamic and Mobile GIS: Investigating Changes in Space and Time This chapter starts by assessing, in Section 2.2, the development of relevant technologies (wireless communication, mobile positioning, mobile terminal technology and the emergence of mobile GIS). The applications of dynamic and mobile GIS are then presented in Section 2.3 and Section 2.4 introduces market opportunities. Finally, Section 2.5 addresses future research and conclusions are drawn in Section 2.6. 2.2 The development of related technologies Several technologies now contribute to the development of dynamic and mobile GIS. These are briefly introduced in the following sections, prior to discussing the emergence of mobile GIS, from Web GIS, in Section 2.2.4. 2.2.1 Wireless communication technology At present, spatial information transmission is a key technological requirement for mobile GIS. By using wireless communication, the connection between mobile terminals and spatial servers on the Internet, is enabled. Current mobile communication networks include: the first generation mobile communication system (TACS and AMPS are similar mobile cellular telecommunication systems; typical terminals are trunked telephones and cordless telephones); the second generation mobile communication network (the digital cellular system characterised by narrow-band digital technology, such as GSM, IS54 DAMPS, and IS95 CDMA); and 2.5G systems (including GPRS and CDMA). Third generation mobile communication systems (CDMA2000, WCDMA and TD-SCDMA) are now developing fast (Hasan and Lu, 2003; Haung and Ho, 2005) Digital cellular systems, including 2G and 2.5G mobile communication systems, which serve as the main communication platform for mobile GIS, cannot support large-volume spatial information services, so it is necessary to reduce the quantity of spatial data displayed on hand-held or pocket devices. The prominent design characteristics of 3G mobile communication is that information communication and transmission be possible ‘anyway, anywhere, anytime’. The rate of mobile multi-media communications via satellite is 96 KB per second, which is twice the rate of current 2 and 2.5G mobile communication systems. Within 3G systems, the rate of data delivery is 144 KB per second when mobile terminals move at the speed of a normal vehicle, 384 KB per second when sitting or walking outdoors and 2 MB/second when based indoors (Choi et al., 2000; 3GPP2, 2002; Li et al., 2002; Casademont et al., 2004). Because the service quality of 3G can be comparable to that of fixed systems, it can fit well with cellular, cordless, satellite, PSTN, Internet or IP/data networks; that is 3G provides globally seamless coverage with roaming terminals. Thus 3G mobile communication systems will work effectively for even large-volume spatial information transmission. Mobile IPv6 technology in a 4G mobile network is able to support advanced position and location based services using Internet Protocol (IP) to combine different radio access networks. Radio Access Network (RAN) consists of physical entities that manage radio resources and provide users with a mechanism to access © 2007 by Taylor & Francis Group, LLC 2. Opportunities in Mobile GIS 21 both core and packet-switched network services; furthermore, RAN can be adapted to maintain real-time network services via the mobile Internet (Bravo, 2004). The development of wireless Internet technology offers new ways for the transmissions required by mobile GIS. The continuing improvement of wireless access technology, such as WAP, i-Mode, SMS/MMS and so on, provides an excellent communication platform for the development of mobile GIS. 2.2.2 Mobile positioning technology Generally speaking, mobile positioning technology can be presented as three classes: network-based, terminal-based, and integrated technology. The first includes COO (cell of origin) positioning, TOA (time of arrival), AOA (angle of arrival), TDOA (time difference of arrival), and E-OTD (enhanced-observed time difference) positioning technologies. The second includes the Global Positioning System (GPS). The third includes wireless Assisted-GPS (A-GPS) and combines the positioning function of mobile terminals with functions of the network. In A-GPS and GPS, GPS receiving modules (receivers) must be added to mobile terminals, and thus the receiving antenna will be altered. However, terminals do not, themselves fully determine the position information, they only transfer information received from the GPS to the wireless communication network. The network’s positioning servers then calculate the receiver’s position and return it to the mobile terminal. 2.2.3 Mobile terminal technology Mobile terminals are responsible for communication with users and for retrieval of spatial information. User terminals include hand-held computers, personal digital assistants (PDAs), mobile phones, intelligent watches, vehicle computers and so on. Terminal devices may deploy many kinds of embedded operating systems (the operating system running in a terminal), such as the embedded Windows system (WinCE), VxWorks, Palm OS, EPOC, uC/OS-II, the embedded Linux system, the QNX system and so on. Microsoft’s WinCE, which is designed for a platform with limited resources, provides multi-thread, full priority and multi-task services. VxWorks is characterised by extensive intertask communications and synchronization facilities, a high-performing multi-tasking kernel and a user friendly development environment; it can be deployed in different terminals fulfilling tasks varying from anti-lock brake systems to space exploration. Palm OS is another embedded operating system commonly deployed in PDAs, which is compatible with a variety of hardware, its program execution is efficient, it supports many third-party manufacturer and software applications and has low resource consumption. The hardware devices that the Palm OS supports include smart-phones, hand-helds, multi-media devices, game players, industrial, scientific and educational tools. The Palm OS system offers features such as compatibility with Microsoft Windows and other major enterprise standards; multi-tasking, multi-threading; memory protection; support for more memory and larger screens; industry standards-based security; extensible communication and multi-media frameworks capable of handling multiple connections simultaneously. EPOC © 2007 by Taylor & Francis Group, LLC 22 Dynamic and Mobile GIS: Investigating Changes in Space and Time (reputedly an acronym for ‘Electronic Piece of Cheese’) is the PDA operating system produced by Symbian, a joint venture between Psion, Nokia, Ericsson, Motorola and Panasonic. EPOC is a three-tier system consisting of a base, middleware and an EIKON GUI. EPOC`s third-party support is certainly as extensive as that for Windows CE. EPOC has enormous potential and its PDAs remain a very popular choice in the UK and Europe. WinEpoc is a powerful Windows-like desktop for Symbian/EPOC-equipped pocket computers. It provides a familiar workplace allowing intuitive control without losing any advantages of the powerful EPOC operating system. µC/OS-II (pronounced: ‘micro C O S version 2’) is a portable, ROMable, pre-emptive, real-time and multi-tasking kernel. The execution time for almost every service provided by µC/OS-II is both deterministic and constant. µC/OS-II allows the user to: create and manage up to 63 tasks, delete tasks, change the priority of tasks; suspend and resume tasks; create and manage binary or counting semaphores; delay tasks for an integral number of time periods (‘ticks’), or for a user-specified number of hours, minutes, seconds and milliseconds; lock/unlock the scheduler; create and manage fixed-sized memory blocks and send messages from an ISR or a task to other tasks. The embedded Linux system is an open system available from many different suppliers, and it supports POSIX, an industry-standard program application interface, as well as standard, open interfaces for networking and graphics. Developers are protected from dependency on a single vendor`s future directions and successes because their applications can easily be moved to Linux systems from multiple suppliers, as well as to other UNIX and compatible systems. All these embedded operating systems provide not only system and hardware support for mobile services, but also facilitate an applications development environment for mobile terminals. 2.2.4 From WebGIS to mobileGIS ‘Dynamic and multi-dimensional GIS is a technology in demand for the 21st century, and therefore it will be a key research direction,’ Bergougnoux has claimed (Bergougnoux, 2000). Using WebGIS technology, no matter at which Internet node users find themselves, they can browse spatial data at their WebGIS site, make thematic maps, and perform many operations such as spatial query and spatial analysis. However, there are problems with WebGIS. For example, it relies on the network environment, needs to transmit large data volumes and its structure does not fit the wireless communication network. With the development of mobile Internet technology, applications of WebGIS in the mobile environment, can, potentially, boom. Compared to traditional GIS, Mobile GIS seems closer to many users’ work situation and will attract, potentially, more user groups. But, due to the very mobility of its terminals, mobile internet provides challenging problems for WebGIS systems with regard to bandwidth, transfer of larger data volumes, increasing expense, response speeds and so on. As a result, Mobile GIS has had to be developed step-by-step, combining the real-time dynamic environment with carriers’ characteristics in a manner to satisfy users’ needs. Nevertheless, Mobile GIS is fast becoming operational with the development © 2007 by Taylor & Francis Group, LLC 2. Opportunities in Mobile GIS 23 of wireless communication, mobile positioning technology, mobile terminals, and the distributed management of spatial data. 2.3 The applications of mobile GIS The basic functions of GIS system are: (i) storage; (ii) processing; (iii) management; (iv) analysis; and (v) displaying spatial information by involving computer-assisted cartography and a spatial database. Considering the requirements in application fields such as urban planning and management, transportation management and environment monitoring, GIS provides the powerful functionality of spatial analysis and decision support. Early applications of GIS in these fields were limited and simple, however, mobile GIS changes the application pattern of GIS so that users can free themselves from desktop computers via mobile terminals. It therefore shortens the distance between GIS applications and users, and, based on the above list of functions, mobile GIS can provide very many more services than static GIS, even when considering the limitations of data volume and unstable communication. Summarising, the characteristics of mobile GIS applications: 1. Reduced hardware configuration requirements of terminal devices. Usually an embedded processor has a small volume memory and low CPU frequency, and supports ‘mini’ peripheral equipment at the mobile terminal device. Compared with desktop computers, the performance of the hardware configuration is much lower, but mobile GIS can still execute the basic GIS functions. 2. Wireless networks as carriers. At present, though the wireless network is used to carry spatial information under conditions of unstable communication and considerable expense, it can be improved with the developing wireless communication systems. 3. It is easy for traditional GIS to manage distributed spatial data via the Internet/Intranet while, for mobile GIS, the management of massive data sets is difficult. As mobile GIS needs real-time information about location, spatial data management should be improved in distributed and dynamic computing environments. 4. Mobile GIS relies on real-time position information. High-quality mobile GIS services can be offered only when the terminals are supported with location information, because most spatial information provided by Mobile GIS relates to users’ current locations. 5. The User Interface must be very user friendly in mobile GIS. Traditional GIS software is designed for professionals, and its operation and interface can be complex. But mobile GIS is oriented to the public, so the operations should be necessarily simpler and with simpler interfaces than traditional GIS because of small display screen of mobile terminals. 6. Location based services (LBS) emerge as pivotal in converting GIS from a professional application to a public service industry. LBS mean easy information provision on the basis of location defined by different kinds of indexing and navigation systems. For example, location based services can be © 2007 by Taylor & Francis Group, LLC ... - tailieumienphi.vn