EFFICIENT INFORMATION ACCESS FROM CONSTRAINT

WIRELESS TERMINALS

Exploiting Personalization and Location-Based Services

Hans Weghorn

Faculty for Information Technology, BA-University of Cooperative Education, Rotebühlplatz 41, Stuttgart, Germany

Keywords: Personalization, Wireless Internet, Wireless JAVA, Location-based Services, Information Management

Abstract: Today, the success of data services used from small mobile devices, like digital phones or PDAs, appears

very limited. Different reasons can be identified, which prevent the average customer from broadly using

wireless data services. At first, the user has to deal with very uncomfortable devices in terms of UI

ergonomy, and on the other hand, the costs for wireless data communication are extremely high. These

restrictions can be overcome by employing a system concept, which is built up on two main components: A

personalized display software allows simplifying the information access on the wireless terminal, while an

intermediate agent residing on the Internet takes care of mining the desired contents from the open Web. In

addition to the improved UI handling, this concept offers a reduction of access costs and an increase in

retrieval speed. Real-world experiments with an information system on actual train departures are reported

for measuring and demonstrating the benefit of the described system concept.

1 INTRODUCTION

Up to now, a common use of data services accessed

from mobile terminals could not establish very well.

Due to their broad market distribution, digital

mobile phones for cellular networks would yield a

very interesting platform for data services, e.g.

information retrieval on traffic situation on lanes and

public transportation. Unfortunately, the user of

these devices today faces a couple of constraints,

which prevent a wide acceptance of such wirelessly

accessed data services.

Considering first the handling of mobile devices,

it has to be stated that software tools are usually very

uncomfortable. Most tools do not sufficiently respect

the constraints of small mobile devices

(Johnson, 1998), because the user often has to enter

information, e.g. lengthy Web paths, account

information, or selection information. The costs for

the wireless transfer of data contents represent

another critical aspect. For instance in Germany, a

comparison of the tariffs of land line networks (e.g.

ADSL technology) and cellular phone networks

shows that transferring data amounts wirelessly is

roughly 10

times more expensive.

Furthermore, the wireless data rates are slower in

the order of 10

– 10

. WLAN (Riezenmann, 2002)

seems to be an alternative wireless access

technology, which can overcome these back draws.

Unfortunately, it is not truly feasible for a seamless

information retrieval, because it does not supply

roaming and requires more complicate hardware.

E.g., a laptop computer linked to a WLAN hot spot

is good for reading e-mails in a restaurant or at an

airport terminal, but it cannot conveniently be used

for accessing current departure information on, e.g.,

trains or planes while walking or traveling to the

station or airport.

A system concept, which was developed and

reported during the recent years (Weghorn, 2003;

Weghorn, 2004-1), is presumed to overcome these

restrictions. The concept bases on two components

(Fig. 1): One part is personalized display software

for the wireless terminal, which minimizes the

required inputs from the user and which optimizes

the presentation of the results. And the other part is a

data-mining agent running on a central server on the

Internet, which appropriately collects, examines and

prepares the desired information content for a

transfer to the wireless display terminal, as soon as

the user remotely commands this. Since this system

collects customer specific contents on base of

customized tools, the name C2C was defined for this

mechanism.

223

Weghorn H. (2005).

EFFICIENT INFORMATION ACCESS FROM CONSTRAINT WIRELESS TERMINALS - Exploiting Personalization and Location-Based Services.

In Proceedings of the First International Conference on Web Information Systems and Technologies, pages 223-230

DOI: 10.5220/0001236202230230

 SciTePress

The user interacts with the C2C information

retrieval system through the wireless terminal (Fig.

1). During this, the terminal executes specialized

display software, which directs information queries

to a central service agent residing on the Internet.

The display software has to be constructed in the

following manner:

 The required user input actions have to be

minimized.

 The results have to be output in a reasonable

presentation.

 Preferences of the user (e.g. passwords, account

information) have to be remembered

automatically, or should be editable by the user.

 The terminal software retrieves the desired

information from the Internet agent by its

activation with the appropriate settings and user

preferences

The counterpart to the display tool is the mining

agent. The agent has to be permanently available on

the Internet, and it is in charge of sourcing the

addressed contents – in many cases from the open

Web. For instance, there exist many Web sites,

which provide current information on traffic

situation on highways and other main routes, and

these could be used for a traffic information system.

As other example, a mining agent could be

employed to collect e-mail messages (or concise

parts of it) for a remote display.

This kind of middleware should be a more

generalized approach than wrapper or mediator

services, which were reported earlier (Mahmoud,

2002; Wang et al., 2003), because in the new

concept here the mining agent sources information

from different sites in parallel, and retrieves by that

a measure of the quality of information (Weghorn,

2004-2). Depending on the situation, the agent can

already decide which information finally should be

the correct one. In the end, the user will receive on

the terminal the desired output together with a

reliability score.

Clearly, for many cases, the user could do the

same actions through WAP browsing manually, but

of course, the automation of these procedure speeds

up the information access, reduces the access costs,

offers the user a very compact and efficient

handling, and allows finally an appropriate display

of the querying results. The fully programmed

solution (instead of the manual use of standard tools

like WAP browsers) allows also to apply compacted

coding schemes on the expensive and slow wireless

data link between the mobile terminal and the

mining agent, which should additionally increase

access speed and the effect of cost saving. In the

reports about the different development stages of the

C2C concept (Weghorn, 2004-1) the investigations

mainly were derived from computer simulations of

the wireless access. A considerable advance of this

research presented in the following sections here is

an extended real-world application for a specific

information access system on public transportation.

2 KEY TECHNOLOGIES FOR

EFFICIENCY IMPROVMENTS

2.1 Personalization

Personalization can be used as key for simplifying

the user handling of wireless terminals. For instance,

if the user wants to access e-mail from a handheld

device, all account information (server settings, user

name and password, filter definitions for mail

retrieval) need to be entered only once into the

terminal software, and these settings can be used

Figure 1: Construction concept of the customized information service

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automatically from this point. After initial

configuration, the user can launch the e-mail

inspection efficiently by pressing only a few buttons

or – depending on the capabilities of the terminal –

even by one single press of a so-called hot key. This

concept renders possible, because handheld devices

usually are treated as personal belongings. This

means that a mobile phone rarely is lent to a

colleague or another person, and hence, the

information on these mobile devices can be

considered as protected contents.

People, who are daily commuting between their

living home and their working place (office, school

place, University, or similar) are also prospective

candidates for using this kind of personalized

information systems, because most societies today

face continuous traffic problems in terms of delays

of public transportation or traffic jams. For a person,

who is using public transportation like trains, the

information query parameters, which have to be

defined once, would be the departure, changing and

destination stations, and probably the kind of train

that is used. Another person, who usually goes by

car to the office, will drive on a certain routing of

roads and highways, and exactly this routing list of

streets will represent the configuration set for an

information query on traffic jams or other traffic

messages.

2.2 Automated Personalization with

Location-based Services

One very recent research topic is the application of

location-based services (Schiller, and Voisard 2004).

This could be used in the here described information

systems as well, since for the commuting sample,

the travel direction changes each day. Hence, the

direction represents also a parameter for the

information collection. Introducing the geographical

location into the information retrieval process,

allows the system automatically detecting the

travelling direction: When a commuting person is

inside or close by the office, the information system

knows implicitly, which station the next departure

place of the daily used train link will be.

Unfortunately, accessing this geographical

information in general will require additional high

efforts, for instance a GPS receiver inside the

handheld terminal. Theoretically, each cellular

phone terminal knows the communication cell,

where it is registered, and this cell, which is

identified by some kind of index value, could be

resolved into a geographical location. How such a

translation process can be implemented is discussed,

e.g., in (Roth, 2003). The inconvenience today in the

software structure of wireless devices is that this cell

broadcast content (its regularly broadcasted

Figure 2: The railway company, which is used for the investigations, provides a Web site, from which departure

tables for all main stations can be downloaded (left browser frame). In parallel to that, also information pages for

WAP download are available, but the herein contained information is reduced for size reasons (right frame). Both

content pages were retrieved at the same time, and as seen in this sample, the WAP service also is not accurate,

because it does not report the information about the delayed train to Munich (“München”)

EFFICIENT INFORMATION ACCESS FROM CONSTRAINT WIRELESS TERMINALS - Exploiting Personalization

and Location-Based Services

225

information, which does not require any retrieval

costs) is not always accessible from add-on wireless

application software. The chance is that all cell

broadcast information will be available in future

through standardized APIs, and then the location-

based concepts can directly help to improve the

described information systems without introducing

new restrictions or requirements.

More recent communication technologies also

would allow location-based control of information

retrieval. Again for the commuting sample,

Bluetooth communication can be applied for

automatically determining the position of user: In

particular, when the user is inside the office, the fact

that the wearable device is registered in a local

Bluetooth communication cluster can be used as

location measure. For this, no application

communication with the wireless device is required,

but only the presence of the hand held terminal in

the Bluetooth cell has to be detected, which can be

done automatically and periodically from a host

computer inside the office. If the user enters during

the day once the office, this method provides already

a feasible indicator for switching the travelling

direction in the information system. As other

example, an e-mail forwarding concept was reported

already at a time (Weghorn, 2001), when

programming of handheld devices was not available

for cellular phones openly to the market. Today due

to the before described technologies and applicable

development systems like wireless JAVA

programming (Piroumian, 2002), also this

forwarding of important e-mail contents can be

automatically controlled by the before described

location detection mechanisms.

3 SAMPLE SYSTEM FOR TRAIN

DEPARTURE QUERYS

3.1 Information retrieval mechanism

After some prior concept design and simulation of

an information system on train actual departures, an

information access system was developed, which is

truly executable on JAVA-enabled wireless devices

(Piroumian, 2002). The intermediate agent is

implemented as JAVA servlet (Hall, and Parr 2001),

and it handles a query about a certain train

connection route. This tool uses a public Internet

page, which is operated by the railway company

(Fig. 2), and translates the Web coded contents into

a format (Fig. 3) that is feasible for transfer and

display on a wireless terminal (Fig. 3). Depending

on the query parameters, the original information

source will have sizes of 300 kilobytes and more,

which obviously shows that a direct access to this

information by mobile browsing does not make any

sense. Truly, the same railway company operates a

WML page server for WAP access to the

information (Fig. 2), but the contents presented there

are only a fraction of the Web version; in particular,

if the reader doesn’t know the train code, the system

Figure 3: The personalized service filters all connections of interest out of the generalized Web departure table,

which is seen in Fig. 2. The debug mode of the mining agent (left browser frame) shows the intermediate steps of

this analysis, and the result will be displayed by the terminal software part (right frame) of the described

information system

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is more or less worthless, because intermediate train

destinations are not displayed. For a personalized

application, the WAP solution provides the wrong

subset of information, at least for the indicative

sample of daily commuting. Another problem is that

it is obviously working incorrectly (Fig. 2), but this

is not a fundamental problem.

3.2 UI design for the terminal client

The minimization of required inputs is one aim for

the proposed information system. Therefore, the

normal operation mode in the train departure query

application is that after launching the terminal

software, the information retrieval will start

automatically. For overcoming the necessity of an

additional configuration tool, the train query

application starts with a welcome screen, which

dismisses after a defined short time delay (Fig. 4). If

the user doesn’t want to run the default query, the

welcome screen can be interrupted by a keyboard

press. In this case a selection menu will appear next,

and the user can modify the configuration for the

favourite query, or place a manual query. The latter

feature of performing individual queries shall make

the information system more flexible, and it can

casually be of interest, e.g., for use during business

travels. The first launch of the application after its

installation on the terminal requires one special

additional UI mode: During this, the customer is

informed about the regular behaviour of the

information tool, and is then directly switched to the

configuration menu.

The system was tested on six different physical

devices: First, a Palm IIIc PDA computer, and a

Siemens SL45i with B+W display screen belong to

the first generation of JAVA-enabled handheld

devices, which appeared on the market; next, the

devices Erricson T630, Erricson P900, Nokia 6600,

and Siemens SX-1 represent the recent generation on

the market, while the latter three smart phones are

based on the open operating system Symbian

(www.symbian.com). The implementation and the

tests showed that the different phone vendors do

have individual interpretations about the operation

of the standardized JAVA API. Therefore, several

adoptions were required to produce terminal

software, which is sufficiently working on all the

test devices, although the first implementation was

working cleanly in Sun’s simulation environment.

To give samples of this disturbing behaviour,

four of the devices do not display the defined

program icons, which would make the handling

more convenient for the non-technical user. Another

of the devices couldn’t display graphical images,

which were produced with standard UNIX imaging

tools. The alternatively used desktop software

produced images files, which were displayed

Figure 4: UI chart of the information channel on actual train departure times for a certain (personalized) travelling

route. The direction of travelling is determined by a configurable switching time. If the user doesn’t interfere, the

query process proceeds automatically through the direct path between the markers for “start” and “end”. This

sample shows that this kind of application is feasible for a use on simple-styled phones, which are equipped with

small B+W screens only

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correctly on all devices, but the coding length of

these images was bigger, which leads to a waste of

memory on the terminal.

For automatically determining the travelling

direction, an additional time parameter is defined

and used in the system. The user can set a time, e.g.

noon, from which the system assumes that the user

will travel home, which means that the departure and

the destination stations are exchanged for the

departure table query. This sample shows how the

requirement for knowing the geographical location

can be overcome. Although this doesn’t represent

always an accurate measure, it will in most cases be

a feasible strategy for replacing the detection of the

geographical location.

With the P900 smart phone it can be

demonstrated how convenient the use of the

proposed information tool can be, because on this

device JAVA applications can be placed for a quick

start on top menu level. The actions for running the

tool are opening first the keyboard cover, and next

pressing with the touch pen the appropriate icon.

Following this, the query launches automatically,

and the user can read after a few seconds delay the

result about the train connections of interest.

3.3 Performance measurements in

phone networks

The train information system was used with different

network operators and networking modes for

investigating the efficiency of the tool. In general, in

Europe data services can be used through the

wireless telephony network (GSM) as traditional

modem connection and with GPRS with enhanced

data communication. Understanding the tariffs of the

different network operators is not straight forward,

and hence the produced costs for the information

retrieval were also measured (Table 1).

In the standard GSM data link, the customer has

to pay for the time duration of the connection, while

with GPRS the customer has to pay theoretically for

the transferred data amount. The latter paying

method was too low for the network operators, and

they invented additional charges for GPRS, some are

billing an extra monthly charge of five Euros for

using GPRS, others bill for each day of use an

additional service charge (e.g. 19 Eurocents). This

all complicates the calculation, what the retrieval of

a dedicate information will cost, but exactly this

confusion may be of strategic business interest for

the network operators. As consequence, it is in

general not possible to specify the precise billing

amount for a single information access, e.g., one

retrieval on train departures.

In summary, it can be derived that running one

information query can in average cost down to 10

Eurocent with GPRS, while with the old modem

connection at least twice this amount is charged. The

required time for retrieving the information is an

important factor for the user handling. With the

GSM standard data link, the entire access will take

approximately one minute. With GPRS the overall

time depends on the fact, whether the mobile

terminal has already registered the GPRS link. In

this mode, most time is consumed for setting up the

data link (~ 15 sec), while the information transfer

from the application takes only a few seconds.

4 CONSIDERATION OF

EXPERIMENTAL RESULTS

4.1 Discussion of benefits for the

customer

For qualifying the benefit of the proposed

information access concept, its handling has to be

compared to alternative methods. Traditionally, one

could use a desktop computer with an Internet

connection or a phone voice service. Due to the

structure of current operating systems, the use of a

desktop computer will consume much more time,

because it has to be booted, the user has then to log

on to the operating system, and afterwards to launch

the Internet connection. After this, the information

retrieval can be invoked, and finally the whole

computer system has to be shut down. This will take

several minutes, and of course, the data terminal is

not wearable. With a laptop computer this process

can be accelerated, but in the end it will also take

considerably longer for accessing the information. In

addition to that, the laptop computer solution is not

conveniently applicable in many situations, e.g.

walking, going by public bus, or driving in a car.

With voice telephony services, it is like there is

no possibility of personalization. Hence, if the user

wants to obtain information about current train

departure, always a voice-controlled navigation

through an access tree will be required, which

consumes time and produces network costs. The

situation is comparable to Web browsing without

bookmark links. Summarizing, it can be stated that

the personalized access is much more efficient than

traditional alternatives, because it can be performed

in almost any situation and it will take one minute or

with the proper configuration only a fraction of a

minute. Each information access typically will cost

around 10 Eurocent, which may be more expensive

than with other systems.

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4.2 Run-time behaviour of J2ME

devices

Besides the above-discussed difficulties with the

operation of J2ME standard UI elements, there arise

also problems with networking on the J2ME-enabled

devices manufactured by different companies. This

applies especially when using the standard GSM

data link instead of the enhanced GPRS mode. On

some devices, a network data link can be established

from the J2ME application, but it cannot be

terminated under application control. It is closed

down only after exiting the JAVA sub menu in the

phone UI. The consequence is that the user is

charged in background additional costs, e.g., when

the results of an information query are displayed,

although no data needs to be transferred any more.

Methods for closing down the physical layer

connection, which are available in the standard

JAVA system, are missing in J2ME. Interestingly,

this kind of operation is present in Sun’s sample

implementation for Palm OS handheld computers,

and it seems to be inherited by other devices. Even

worth appears the fact that some newer devices are

incapable at all of establishing a HTTP connection

with the standard data link. These devices are

working well with GPRS, but it depends on the

phone contract, whether GPRS mode is available.

For cost control reasons, and for reliability reasons

the recommendation for a non-technical customer

can only be using J2ME data networking only with

GPRS.

In general, the data networking configuration is

non-trivial, and therefore most devices are delivered

today with all possible configurations for the

different network operators. Unfortunately, it can be

observed that on some devices these settings

interfere with each other, and in the end there were

several cases detected, for which the data

networking was non-functional. After removing the

unusable configurations, these devices started

working correctly, but form this experience it can be

derived that also in GPRS mode non-expert

customers might be incapable of using the

information access software due to general

constraints of the device handling

4.3 SW engineering and XML coding

of contents

The original approach of the concept was that low

level coding (= binary exchange of information

contents) should improve the overall performance of

the wireless information system. From the

experiments (Table 1), it can be deducted that this is

not fully true, because in particular the transfer of

the content in the data communication consumes

only a small fraction of the overall access time.

Hence, coding the data packet according to

established software engineering philosophies (in

particular in XML: Bradley, 1998) would be

acceptable with GPRS for the transfer time and costs

as long as the content packet size remains in the

order of one kilobyte. Despite these measurement

results, there arises still some impact of inefficiency

on the terminal side, since XML coded contents will

require a more complicate parsing in the wireless

software part. Of course, this can be obtained by

using standard library packages (Setiawan, 2001),

but this will increase considerably the code size of

the handheld application.

On the other hand, thinking forward of PUSH

technologies (Ortiz, 2003), XML coding of contents

still is not recommended, because an SMS, which

can be used for this technology, will not be capable

of carrying that content size.

Table 1: Representative measurements of information access time and costs for different networking modes

Experiment

no.

Network

Operator

Mode Open URL Time for

content transfer

Costs Remarks

1 T-Mobile GPRS 9,2 sec 31 ms 19 ct

2 T-Mobile GPRS 3,5 sec <1 ms 19 ct

3.1 T-Mobile GPRS 16,28 sec

<1 ms

3.2 T-Mobile GPRS 3,00 sec <1 ms

3.3 T-Mobile GPRS 3,39 sec 15 ms

3.4 T-Mobile GPRS 3,44 sec 31 ms

28 ct

one

GPRS

session

4 Vodaphone

GSM std

22,25 sec

7564 ms 19 ct

5 Vodaphone

GSM std

17,56 sec

5377 ms 19 ct

6 Vodaphone

GSM std

20,96 sec

5146 ms 35 ct

7.1 T-Mobile GPRS 9,70 sec 31 ms

7.2 T-Mobile GPRS 3,11 sec <1 ms

28 ct

one GPRS

session

8.1 Vodaphone

GSM std

20,87 sec

6770 ms 35 ct

8.2 T-Mobile GPRS 3,47 sec <1 ms

n/a

8.3 T-Mobile GPRS 3,50 sec 140 ms n/a

performed

at the same

time

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5 CONCLUSION

A new information access system for truly mobile

access was conceptually designed and developed

during the recent years. In our former investigations

on this, the concept, which shall customers provide

an efficient and convenient access, was tested and

developed mainly on base of simulations. The

advance of the work presented here is the

application of the information retrieval system in

true networks under real conditions. On base of

these experiments, it can be derived that the claimed

properties, like increased access speed and improved

handling, can be achieved with the proposed kind of

information access structure.

Future work will stepwise regard quality of

information by means of AI, and it shall further aim

to reduce the information access costs, e.g. by

applying AI controlled proactive PUSH

mechanisms. Although the wireless JAVA platform

defines a standard API, the experience with true

devices is that it is not a straightforward task to

develop applications, which are running truly

sufficiently on all devices. Extra effort is required

for achieving this, and therefore alternative

technologies, e.g. C++-based software on Symbian

devices, shall be investigated in future for obtaining

best overall performance.

Also the application fields shall be expanded.

Besides information on public transportation and car

traffic, we are working in actual projects on weather

channels for a customized retrieval of local recent

information and forecasts. Furthermore, we are

currently investigating how Web service technology

(Aleksy and Gitzel, 2004) can contribute to an

improvement of the described information access

systems.

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