Information Handing with Mobile Client using Web Services: a ...

Columbia International Publishing Journal of Advanced Internet of Things (2013) 1: 1-18 doi:10.7726/jait.2013.1001

Research Article

Information Handing with Mobile Client using Web Services: a Disconnected Approach Kamran Ahsan1*, Nadeem Mahmood2, and Adnan Nadeem1 Received 17 November 2012; Published online 15 December 2012 © The author(s) 2012. Published with open access at www.uscip.org

Abstract Mobile computing plays a significant role in providing efficiency and effectiveness for profitable and nonprofit organizations. Large organizations have always dealt with multiple operations simultaneously for the running and smooth delivery of their organizational goals. The healthcare sector’s operational behavior is the same as business organizations due to critical information handling and the complex functioning of their services. The logistics, emergency services, patients’ needs, hospital management, doctors’ priorities for providing smooth service delivery, case taking and decisions about patients at any time are the main issues across the health sector. In this era, the stakeholders of the healthcare sector want instant information about their patients while they are on the move. Mobile devices for providing instant information on the need from anywhere are the best solution for paramedical staff. The purpose of this study is to explore the mobile technology applications in conjunction with communication through web services and application development within healthcare. The study considers client-server technology that will support mobile data access in terms of web services and the SOAP protocol using the interoperable database filing mechanism of XML. Keywords: Information onto mobile; Web services; Mobile communication; Information and communication technology; Healthcare critical information handling

1. Introduction Information is normally provided from a central source onto a mobile device, whether it is requested by the user or pushed on to the mobile device due to some trigger implemented on the central source. In this central source, the database records can be handled on a server machine. This is generally known as client-server communication for mobile devices (Hac and Liu, 1998; Tolia et al., 2007). The following questions arise in respect of the user: who is requesting the information? How can anyone request particular information? What information does the ______________________________________________________________________________________________________________________________ *Corresponding e-mail: [email protected] 1* Federal Urdu University of Arts, Science and Technology 1 2 University of Karachi

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application provide to the different types of users? How and when can the different levels of users interact with the system to update the information? etc. (Sun, 2012). Several technologies can be used to determine the user device capabilities and to customize the information according to the application, services and user environment (Sun, 2012). The modern database environment has the ability to store huge amounts of information in an efficient manner and to provide quick and reliable access to the rapid life-style users of the system (Lauzac, 2002). Sometimes, to perform the day-to-day operations, the mobile device needs to contact the central body (organization) or any shared central server, or information may be rendered from a distributed network environment. The second aspect of handling user needs in the best way is by transferring the requested information in the shortest possible time (Archie, 1979). It is accepted that the information should be complete, relevant, reliable, correct, timely, and so on. Time units vary from situation to situation and in different environments, but nowadays in this fast, mobile and demanding era it can be argued that information should be provided on the spot when and where requested. So, in a business environment where business/application logic and data/information are present most of the time in a central source, such as on the server, it should be available for the decision-making process to users on mobile devices. In the case of a patients’ care environment, healthcare professionals want their patients’ records instantly on their mobile devices or PDAs, especially for the most sensitive patients, which may be in emergency, ICU (intensive care unit) or CCU (cardiac care unit). Therefore, an integrated environment is required to provide accessibility to patients’ data on mobile devices to relevant stakeholders, and this research focuses on important issues pertaining to the development of mobile-based information systems for patients’ care.

2. Application Motivation The research aim is to provide a study of different mobile technology communication media and the use of mobile technology in healthcare. In this research, the idea will develop by including the different technology working and background knowledge and their suitability of use in healthcare units, especially in ICU, where the information is usually more crucial. Usage of mobile devices and applications in healthcare units will be supported through critical information handling technology, and an in-depth study is carried out for client-server communication in conjunction with mobile devices. Further, the client-server communication study will go into the working of the web services and their facilitation for client application and then how the server application can be integrated to use the same database on the server that is available to the client. The idea will be further supported by designing and implementing an application for a client mobile device as a proof of concept.

3. Methodology An evaluation methodology is used in this research project because this project is concerned with the evaluation of different schemes of database communication with mobile devices. There are various communication technologies that are available for implementation; however, at least one will be selected for implementation. This selection is dependent on the various available resources’ efficiency level, the usages and needs within the ICU (Intensive Care Unit), and the database 2

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efficiency and suitability within the given mobile scenario and constraints. There are certain constraints associated with the use of a mobile device, such as limited functionality, small screen, data security and less power and network traffic typically associated with the database software and application. The second reason for selecting the evaluation methodology in the research project is that there are various communication modes and methods of mobile communication available for interaction between the database server and devices (Jing, 1999; Logan et al., 2007). Evaluation is within the given scenario of the ICU (Intensive Care Unit) and then selection of the technology to be used for communication, which should be suitable for paramedical staff use and feasible for the ICU settings.

4. Mobile Technology In mobile technology environments, the sharing of data is always complicated for various fundamental reasons. These constraints are intrinsic to mobility, and are not just artifacts of current technology (Satyanarayanan et al., 1993). The three main fundamental reasons are: 1. The resources are always poor in mobile environments relative to static environments. The main constraint of mobile technology is the processing speed and reduced memory. The main feasible elements of mobile devices usage are weight, size, and mobility, which make mobile technology implementation more usable over static computation software’s implementation. 2. The probability of damage or loss of the mobile device is higher than workstations locked in offices. The probability of theft for laptops and loss of mobile devices by being stolen is higher than static computers in walled environments. 3. The network conditions may vary from place to place for mobile devices, while the static computer is always connected but cannot move. Mobile equipment can be connected with the network while on the move but is subject to intermittent contact conditions. 4.1 Interoperability The interoperability of the mobile device is useful in the sense that multiple network interfaces maybe available to any device, for example in a laptop that has two interfaces, a CDMA wireless modem and an IEEE 802.11 wireless LANcard, the internet can be accessible through both of these if the application has the capability to adopt both the connections when any one is available and switch to the cheapest one while both are available. This switching is transparent to the user, which gives an easy and high quality experience. An appropriate and feasible use of this technology, for example, would be when the user starts to download the file in a car on a different network connection and transparently switches onto a different network connection while entering into office (Joseph et al., 2004).The same can be applied to the database connection development that interacts with the mobile device, which uses different connections on different time slots, and the database operates smoothly in such a way that there should be consistency without compromising the reliability of the system. The interoperability gives the concept of utilizing both network aspects (wireless LAN and cellular networks) in providing high speed connectivity in wide coverage areas with the support of large numbers of users(Joseph et al., 2004). Interoperability with wireless LANs also helps in relieving the heavy load on cellular networks, especially in crowded regions (Joseph et al., 2004). The load balancing between these connections also increases overall performance and 3

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network throughput. An interoperable system can also support a much larger number of users than any single network (Joseph et al., 2004). This also leads to an increase in revenue in both aspects: a) that users save their resources and also minimize their expense, thereby increasing their revenue and b) that network provider and application handling is also cost-effective in the way that it uses network resources appropriately (Joseph et al., 2004). Table 1 Comparison of GPS, Infrared, GSM and Bluetooth (Mannar, 2004) Transmission Power

Cost of Implementation

Content Delivery

User Location

GPS

Low

Device is expensive

Not possible, apart from the location of the user

Infrared

N/A

Low

High bandwidth available

Device can be used throughout the world Line of site should be maintained

GSM

High (3 Watt)

Moderate

Bluetooth

Low (1m Watt)

Low

Limited type content with speed 14.4 kbps Rich content can be delivered with speed 720 kbps

Mobile Within confined space

Table 1 shows the comparison of some communication technologies available on mobile devices. If a significant number of devices use Bluetooth within one area, and the devices are short range, slow and have conflicting frequency ranges, then consideration should be given when a greater number of devices communicate in the same area, since this can cause low throughput. On other hand, it is a rapidly growing technology and works very efficiently for local wireless environments without being too expensive. It is economical in use for the user, as nowadays most mobile devices are Bluetooth enabled. So, consideration should be made for communication technologies and their feasibility in this research before implementing for a particular scenario (ICU in our case). 4.2 Disconnected Mobile Technology Environments Server applications are important for mobile communication systems as the mobile equipment usually has insufficient memory and power to operate the huge amount of data on their end. So, the disconnected environment is the key enabling technology for mobile computing (Satyanarayanan et al., 1993). A client becomes disconnected with respect to a volume when no server in its VSG is accessible(Satyanarayanan et al., 1993).In the mobile computing environment an involuntary disconnection is easily possible whenever a temporary impediment to communication occurs. The basic cause of a temporary impediment to communication is due to short range signal in underground places, in buildings that are steel framed, and where the line of sight is limited. When the user deliberately operates isolated from the network (due to cost or power reasons), no network facility is available at the location of the mobile device; if this happens it may also become a voluntary disconnection. Whenever a device is disconnected from the network, the mobile device lies on the contents of its cache. Where disconnection happens while running the system, the mobile device should continue 4

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to operate smoothly and every stage of the program must ensure that the critical object always resides in the cache, especially at the time of disconnection. The programs that need network connections on the mobile device must consider the disconnection behavior and perform the reintegration stage when the reconnection of the mobile device with the network occurs. The resynchronization of the mobile device cache with the network server data should occur automatically when the device receives good quality signals. On reconnection, the device enters the reintegration state and resynchronizes its cache (Satyanarayanan et al., 1993). On the other hand, during the period of disconnection from the network, the capacity of the emulation state of the mobile device remains in operation for the duration of disconnection. This is a good approach for program implementation for a mobile device. When the programmer implements this mechanism and uses caching to meet these expectations, and when the cache meets these expectations, it is said to be in equilibrium (Satyanarayanan et al., 1993). The intelligent program can be implemented on the client’s mobile for the purpose of smooth working within the application program, in a fully or partially disconnected environment (Noble et al., 1998). The client monitors resources such as bandwidth, CPU cycles, and battery power and decides how to best exploit them. For example, when high-bandwidth connectivity is lost due to a radio shadow, the client detects the change and reacts to it (Noble et al., 1998). The application program in the disconnected environment should be capable of beginning to conserve bandwidth by lowering the frame rate and using the degraded versions of the large data frame, and when the device emerges from the radio shadow, the application should detect the improvement in the bandwidth and revert to its original behavior (Noble et al., 1998). Although the user is aware of changing application behavior during his walk, he does not have to initiate adaptation or be involved in its details. Rather, he can delegate these decisions to the client, confident that reasonable tradeoffs will be made (Noble et al., 1998). When the mobile clients have not synchronized data, they are depending on the servers for continuous support because of the intermittent nature of the mobile networks. In this situation or scenario, mobile clients must be capable of operating in the disconnected environment for some period of time, depending on the critical need of the synchronized data. This program implementation eliminates the other system, which assumes constant connectivity (Terry et al., 1995). While such systems provide interesting in-building or campus-area solutions, they do not apply to wider use (Terry et al., 1995). Programs fully supporting the disconnected environment behavior can take advantage of the connectivity whenever possible to the mobile client (Terry et al., 1995). Both the commercial and research worlds have turned to this often-connected model for applications such as package tracking, the Coda File System, and Bayou. These systems use bandwidth when it is available, but can cope with disconnection when it is not (Terry et al., 1995). When the clients cannot contact any of the servers while there is one or more server or access point then the disconnected term is usually used for the communication with these types of clients. In such a case, the implementation of the file system through an XML file system, which can handle the data with the layer of abstraction, or other simple file system methods in which the read/write operation can be performed on the cache files, which is usually used for faster response time. The management of such files in the cache is another issue and the program can set the priorities according to the importance and support within the limits of memory and power that remains in the cache in anticipation of unexpected disconnections (Noble and Satyanarayanan, 1995). During disconnected operation, updates are persistently logged by the system, using a variety of 5

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optimizations to reduce resource consumption. For example, if a file is created, renamed, and later deleted, none of those records need to be saved; it is as if none of the operations ever happened. When connectivity is re-established, the program should replay these updates at the servers through reintegration (Noble and Satyanarayanan, 1995). Upon reconnection, each file is suspect and must be revalidated. On a LAN, this overhead is less; it can be expensive on a slower network. The intermittent connectivity typical of wireless networks exacerbates this problem (Kistler and Satyanarayanan, 1992). In the low-bandwidth situation, the cost of revalidation is obviously very high. The system can maintain two types of validation systems: the callback can update on the individual files and on the full volumes. If the volume is coherent with the servers then the volume callback is needed, but the client needs the version stamp for that particular volume for any given time instance. The system should behave with the increment of the time stamp with every change in the file of a particular volume (Kistler and Satyanarayanan, 1992). On slow networks, the use of volume stamps dramatically reduces the time for validation after reconnection (Kistler and Satyanarayanan, 1992). The mobile client can use the network in two ways, either synchronously or asynchronously. In both cases, the application program in the disconnected mobile environment should be capable of queuing and holding the requests for later processing (Chang et al., 1997). On re-establishment of the communication connection, the operation should be performed automatically in the background of the program queue. This approach may be productive for the person using the mobile application software. This approach can be implemented through XML dynamic file systems, which can handle the data on the client side rather than each and every request going to the server. For this purpose, two-process implementations are often used for handling the smooth running of the mobile application software, one process handling the foreground interrupt from the user and fulfilling the user request from the XML file by querying the file within the device and the other process running the thread for automatic updating and synchronizing of the XML file from server(Chang et al., 1997). 4.3 Temporal Data and Mobile Computing Systems Another important aspect is handling of temporal data for mobile computing systems. Most of the mobile database applications involve time-varying data (Burney et al., 2010a) and require frequent updates due to their dynamic nature. Some examples are flight information, last-traded stock prices, news updates, patient condition, bank account balance, as well as traffic and weather updates. Hence, we assume that the data items in the database are used to record the instantaneous values of the objects in the external environment. The rapid change and updates in the database states may lead to database inconsistency. To solve this issue there is a need to develop a temporal ontology (Mahmoodet al., 2012) for mobile computing systems. We must distinguish between different characteristics and behaviors of timerelated attributes (Burney et al., 2010a) and group them on the basis of the change in the data item. There are applications where the change or update transactions are not very frequent, such as news management or weather situation, but there are applications where changes are very rapid, e.g. stock prices. The change in the external data has to be managed and can be time-stamped, which can be further categorized as valid or transaction time stamp (Burney et al., 2010a). Similarly, object values are either augmented with time points or time intervals. For example, that thunder storms may last for two hours (1700 to 1500) GMT is an example of a time interval. Time granularities (Burney et al., 2010b) for mobile computing applications are also very important due 6

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to the dynamic nature of the data and different domain applications. For example, updates for traffic pattern to a mobile client may be required every hour, whereas weather forecasts for next five to ten hours are quite enough for mobile clients. In real-time databases, the mobile clients receive continuous updates from database servers for changes in data items. There is always a time delay in retrieving the data from the database server to the mobile client application due to various reasons, e.g. bandwidth issues or cached data. Time is usually modeled as a distinct linearly ordered pair (T,