PUSH TECHNOLOGIES: THE FAVOURABLE FUTURE
COMMUNICATION TECHNOLOGY?
Nun Zameera Zakaria
Department of Electronics and Computer Science
University of Southampton
nzz104@ecs.soton.ac.uk
http:// www.ecs.soton.ac.uk/~nzz104
ABSTRACT
Information overload makes it more and more
difficult to get the right information at the right time.
The traditional hunt and gather methods, i.e. the pull
technology is becoming a limit for more efficient use
of the Web. Push technology is expected to have a
relevant role to maintain a competitive edge in
today’s world as decisions need to be based on the
most current information. This technology also
ushers in a new generation of information sharing
capabilities, which dramatically improve the usability
of existing applications. By applying the push
technology it is possible to generate an effective
delivery of information to the user. In addition, the
possibility of making the Internet accessible via
handheld devices has generated an important
opportunity for push services. This paper introduces
the concept of readily available push technology
and explores the architectures, together with the
mobile technologies that support push based
services.
Thus, how will the students find out what
information is available, then locate it, analyse it and
make it meaningful?
Trecordi and Verticale stated in their paper that
information sharing in the Internet is currently based
in two information retrieval paradigms, namely the
pull and the push. According to the pull paradigm, a
user enters a request that is sent to a server, and
the server answers by sending a webpage (the
response) to the user. The processes can be shown
from Figure 1(a) where a user has to perform a
search repeatedly by searching for each website in
order to get the particular information required. In
contrast, the push paradigm as presented in Figure
1(b) allows the user to express their interest in
receiving information related to subjects of interest
by subscribing to an informational delivery channel
[25].
Keywords
Push technology, WAP push, mobile, alerts.
1. INTRODUCTION
In this era, students for example, have relied on the
web to find all sorts of information, from
entertainment such as music, videos to news that
happens all around the world. As described by
Käpylä, Niemi, and Lehtola, Internet and World
Wide Web (WWW) serve acquisition and
distribution of information very widely at the moment
[11]. However, the massive amount of information
available on the Internet might reduce their chances
of getting the right information.
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th
4 Annual Multimedia Systems, Electronics and Computer
Science, University of Southampton
© 2003 Electronics and Computer Science, University of
Southampton
(a)
(b)
Figure 1: The diagrams show a comparison of
pull and push technology (adapted from WAP
Push Architectural Overview [26])
According to Käpylä, Niemi, and Lehtola, new
information delivery model (i.e. push technology) is
important as the size and complexity of the Web
increases [11]. Furthermore, this technology helps
users to alleviate problems such as information
overload and low bandwidth while using the
Internet. With the continuing explosive growth of the
WWW and the Internet, there are many
opportunities for push technology to enhance data
dissemination.
The rest of the paper is organized as follows.
Section 2 will discuss the overview of the
technology, followed by the relationship of push and
alerts. Section 4 and 5 present the reasons of being
mobile and the relevant frameworks. Finally, section
6 and 7 discuss the limitations and future work of
the technology, followed by the conclusion in
section 8.
2. WHAT IS PUSH?
Push technologies are not new. Although the
terminology is relatively new, push technologies
have been around for over a decade. According to
Berghel, the phrases “push technology” and “pushphase technology” were recognised in 1996-97 [2].
This technology gives users more authority over the
content they receive as the subscribed content is
being delivered, rather than retrieved. Malan,
Jahanian and Subramaniam pointed out in their
paper that the original push technology is electronic
mail as email needs to be pushed from publisher to
subscribers through mailing lists [14]. Even though
email systems may not be as rich as most push
solutions however, emails are believed to continue
on evolving in the future.
A person who creates a webpage may believe the
page contains interesting data; however it may have
no appeal to anyone else, so it is treated as an
unwanted message by other users. This unwanted
message is described by Windrom and Swann as
noise [27]. The noise and network congestion are
making it hard for websites to attract visitors and
keep them coming back [5]. According to Chin, push
technology can be used to make information more
accessible for the user by closing the gap between
the time information made available and the time a
user retrieves it [3], which will then reduce the
above problems. Moreover, push is relatively
passive and requiring little human interaction. This
conforms to what Polese has reported in
BusinessWeek (1997) as saying, ''People want their
computers to be as easy as their television’’ [5]. The
statement proves to suit the push behaviours as
push features allow users to receive fast information
in easy steps. Researches have shown that the
features of push are:
• information is delivered to the users in real time
• assist in minimising or eliminating laborious
searching requirements
• dramatically reducing the
searching for information
time
wasted
in
• uses filtering, indexing and directory services to
manage information overload. [8, 11]
According to Collins, push can also be useful in
Intranet environment where it allows automatic
transfer of information between users in the same
organisation [4]. Microsoft TechNet in chapter 6
shows two examples of the push concept that are
implemented in the corporate intranet using the
integration of Windows 98 and Internet Explorer 4,
which are the Active Desktop and Active Channels.
Both provide true web integration with desktops and
customizable information delivery architecture [15].
Active Desktop
• provide a single metaphor
for accessing content of
application on a corporate
intranet or WWW.
Active Channels
• a web site that automatically
delivers content to the user
on a regular schedule
An example of push in the intranet environment
might be an automatic notification of events, where
the financial managers could be alerted if the
shares prices drop below a certain level. This
increases the accessibility for the managers to find,
receive and organize information and applications
that they need. From Figure 2, the red arrows
(pointed to the server) represent the clients
subscribing to particular pages on the company
server while the blue arrows (pointed to the client)
represent that the server delivering changed pages
to the clients.
Figure 2: Overview of push technology in
Intranet environment (adapted from Microsoft
TechNet [15])
Really Simple Syndication (RSS) is another form of
push services. British Broadcasting Corporation
(BBC) website for example has implemented the
RSS toolbar so that the users will be able to
subscribe to any information available on its web. In
return, the users will be automatically notified when
the subscribed pages have added new content.
According to Kendall and Christopher [5], this type
of service will bring another fundamental way of
communicating to the Net and helps to promote
information that merrily slips across channels.
In iAnywhere Solutions Inc. article, alerts are “often
delivered to a companion device such as an SMScapable mobile phone” [10]. It is believed that with
the increasing use of Internet and mobile
communications amongst users, it is important to
assist in accelerating the speed of information to be
shared. Although alerts often will not contain a
large amount of information, they help to notify the
recipient immediately that vital new information is
available. The recipient can then take action to the
alert, which often means checking email, browsing
to a Web site or placing a phone call.
Figure 3 shows the availability of RSS options
on the BBC website which the users can
subscribe (taken from BBC website [1])
Figure 5 shows the connection of push and
alerts system
Figure 4 shows the pop-up window confirming
upon subscription on the chosen RSS option
(taken from BBC website [1])
Based on Figure 3 and Figure 4, RSS is described
by Notepage, Inc. as a simple concept which aids to
increase the visibility of the information. Using the
RSS, users are allowed to:
Figure 5 shows the alerts capabilities of reminding
the user of the latest information that is available on
subscribed channels. In order for the user to access
the alerts system, one has to subscribe to the
appropriate services. There are various alerts
services available (Figure 6), such as alerts onto the
desktop screen or to portable devices (PDAs or
mobile phones).
• receive the information in real-time
• scanning through
information
the
headlines
of
the
• categorise the information by theme [17]
3. PUSH AND ALERTS
Although
email
has
been
an
effective
communication tool since the very early days, there
is still opportunity to use the email to become more
effective in communication information exchange.
This is because, relying on end users to manually
initiate synchronization with the server is often
unrealistic, and increase probability that the end
user will get the information after it is too late to act
upon [10]. For example, email is used as a primary
communication mechanism between lecturers and
students. If a lecturer sends an important email to a
student, but the student forgets to synchronize
his/her email for a few hours, it may be too late to
send a timely reply. The student may then appear
unresponsive to his lecturer. Similarly, if mobile
users do not receive email messages as they arrive,
they may miss vital information. Hence, alerts
function is important to notify an individual of new
information.
Figure 6 shows some examples of alert’s
services available on the BBC website [1]
Using the pull method, a user might not know when
there is a change in the status of the information.
Thus, alerts services can be considered highly
important in our daily lives, especially when pushing
alerts improves the efficiency of Web based
information distribution [11].
4. WHY PUSH TO MOBILE?
Over recent years, the importance of mobile phones
as a tool of personal communication has gradually
increased. Unlike PCs, mobile devices provide
continual contact and connectivity as a mobile
phone can be taken anywhere, and the user will not
be restricted by the availability of a computer.
Data-enabled mobile phones provide a new medium
that allows people to not only make or receive voice
calls, but also communicate in new ways and
access new and old applications and information
anywhere and anytime [18]. One of the factors that
encourage the growth of mobile push is the rapid
development of wireless systems which allow
people to access the Internet from mobile phones,
Personal Data Assistants (PDAs) and smart
phones.
WAP push opens up a new world of possibilities for
mobile Internet services. It is a fundamental
application capability that multiplies the power of the
mobile Internet by enabling new applications and
enhancing existing applications [18]. Also, it brings
to subscribers the information they need and where
they need it most, thus allowing content providers to
bring subscribers back to valuable services again
and again.
4.2 PUSH VENDORS
As a result of the increasing use of data-enabled
mobile phones, it gives an opportunity for push
technology to play a relevant role in the mobile
scenario. With reference to Kendell and Kendell
paper, push allows for newly appealing services
which foresee the distribution of information useful
to mobile users who require on-the-go computer
solutions [13]. Hence, mobile devices will serve as a
great information delivery tool to the user, if
combined with the push behaviours.
4.1 WAP PUSH
The Wireless Application Protocol (WAP) is an
industry wide standard defining a communication
protocol and application environment that allows
users to access Internet contents and services from
mobile phones [22]. By integrating this protocol and
push, WAP push is defined as a mobile technology
that automatically sends information from service
providers to service subscribers [22].
The tremendous growth of Web-enabled portable
devices such as PDAs opens new opportunities for
push-enabled services [18]. As communication
occurs in an asynchronous manner, Chin reported
that “Push will take the frustration out of having to
navigate through a series of menus” [3]. This means
that users no longer have to seek out information as
described by pull paradigm, which requires
numerous searches in order to get specific
information.
In Wired magazine (issue 5.03, 1997), Kelly and
Wolf described WAP push as “information that
cascades, not just through a PC, but across all
forms of communication devices” [12]. When a
compatible mobile device such as a PDA receives a
WAP push message, it allows the user to access
that WAP content. With this technology, handhelds
or portable devices will be able to communicate to
each other in an ad hoc way. This will ensure that
mobile users are up-to-date as email messages that
have been received by a desktop of server mail
system can be transmitted automatically to a PDA.
As reported by Palo Wireless WAP Resource
Centre, WAP push can also be presented as an
SMS message which contains a link to a WAP page
[21].
According to Gerwig, the number of companies
offering technology that sends users Internet or
intranet information without making them click
through thousands of individual links grows
everyday [7]. As a result, it increases the reliability
for users to search for instant information. Based on
paper written by Hauswirth and Jazayeri, there are
several main providers that ventures promise to
manage the complexity of the web by providing data
to users by means of subscription such as [8]:
4.2.1 PointCast
PointCast is both a push system and an information
provider. It is the first company to allow customers
to subscribe to content “channels” that send
information at specific intervals selected by the
user. It pushes selected news and stock quotes into
a user’s machine at prescribed intervals. However,
PointCast allows users to subscribe a limited set of
channels only. Moreover, according to OpenWave
Systems Inc. (December 2001), “The delivery of
messages or data (using PointCast) was limited to
the desktop, so if a user was away from the
desktop, there was no easy way of accessing timecritical information, thus further diminishing the
value of push”[18].
4.2.2 Castanet
Castanet is an advanced push system for
distributing content with specific emphasis on
installing and updating software over the Internet.
The Castanet receiver (tuner) can also be
automatically updated. As Collins stated in his
journal, “What actually happens in most cases is
that the client’s computer will pool the service
provider at user specified periods to see if there is
any new information to receive” [4]. This conformed
to the Castanet services, as the clients pull at
configurable intervals down to 15 minutes, or if
requested.
4.2.3 BackWeb
BackWeb is a highly configurable framework for
information distribution. It comes with a rich set of
supporting applications and authoring tools which
enables users to filter channel data by type and
content.
Kendall proved that the above companies allow
users to select channels and further select the
topics within channels [13]. As a result, the push
technologies providers permit users to work with
information on the web in meaningful ways. By
having the specific information pushed to them, the
users can now feel confident in the information they
are using to make all types of decisions.
available in an efficient manner [13]. According to
Tosi, the push solutions that currently exist in the
mobile network are [24]:
Short Message
Service (SMS)
• maintain
scalability
capability
5. THE PUSH FRAMEWORK
Push allows users to subscribe to any desired
content. When the content is updated, the new
information is then sent to the client so that they
have the most recent updates. From Figure 7, push
is performed in an asynchronous manner, which
means information can be originated by the server
and sent to the client device without a request by
the client.
• supports Push of a short
message to any mobile
handset (e.g. 160 characters)
standardization,
and
roaming
• limited to simple text without
pictures, audio and video
Multimedia
Message
Service(MMS)
• is a SMS solution extension
• able to transport text, picture,
audio and video
• uses capabilities provided by
WAP, General Packet Radio
Service (GPRS) and 3G to
improve connectivity.
The WAP Push
System
• transports subscribed data to
a
WAP-enabled
handset
without an explicit request
from the client at the time of
delivery.
Figure 7 shows the basic architecture of push
technology (adapted from WAP Push
Architectural Overview [26])
Each of the components on Figure 7 is described as
follows:
Push Clients
• program running on the
workstation
Channels
• a pre-selected website
Push Vendors
• provide channels
Push Servers
• responsible
channels of
clients
for
sending
information to
Although users can subscribe to any channels, the
availability of various channels however, depends
on the push client software. The content of a
channel can be personalised so that the user gets
only the information she/he needs (refer to RSS in
section 2).
In mobile network, push services can be considered
important as they use the limited bandwidth
Figure 9 shows a WAP Push operation (adapted
from OPENWAVE SYSTEM INC. [20])
In order to perform a WAP push operation as shown
in Figure 9, the key components needed are the
Push Initiator (PI), Push Access Protocol (PAP),
Push Proxy Gateway (PPG), Push Over-The-Air
(OTA) Protocol and WAP Push Client. Each of the
components is described as follows [18]:
Push
Initiator
(PI)
• the entity that originates push
content and submits it in a push
request to the PPG for delivery to
the handset
• it uses PAP to deliver content to the
destination
Push
Access
Protocol
Push
Proxy
• assists PI to deliver the content to
the destination
• the access point for pushes from the
Internet to clients
Gateway
(PPG)
• push the message to the mobile
device using the Push OTA Protocol
Push
OTA
Protocol
• assists the PPG to push content
from PPG to the client
WAP
Push
Client
• included in a device that capable of
accepting WAP Push Content
• it hosts applications, such as WAP
browser, that can receive and
process the push content
The flow of the WAP Push operation is explained
below:
PI in the Internet domain contacts a PPG and
delivers content for a destination client using
the Push Access Protocol (PAP)
The PPG then pushes data to a client through
the Push OTA Protocol. At the meantime, the
PPG provides the PI with handset capability
lookup services, thus allowing the PI to select
or format the appropriate content for a
particular mobile.
The WAP Browser receives and processes
the push content.
Exploiting the above architectures, it helps to
ensure fast and effective communication. By using
WAP Push method, information can also be pushed
towards users in a simple and elegant way.
has subscribed to. The ticker can even display the
information while the user works in other
applications. An example of a ticker is Motorola’s
Screen3 technology [16]. With Screen3, content can
be categorised into channels and then delivered to
subscribers via mobile devices. The data
automatically appears along a ticker on the mobile
device home screen, which offers a zero-click
access to contents [9]. As a result, Screen3 makes
it easy for consumer to find and use wireless data
services.
5.1.3 Flash
Flashes are interactive multimedia displays that
proactively alert users to the arrival of content
without interfering with their application. All the user
needs to do is click on a flash, which will then
launch the web browser with the complete article
intact.
From the examples, it is very important for the push
interface to be as simple as possible in order to
ensure flexibility in information sharing and
communications between the content providers and
the users.
6. IS IT WORTH IT?
Dramatic increase of data traffic on the Internet has
made information access periodically difficult to
achieve [11]. Push enables a new level of flexibility
as the user will automatically receive a notification
whenever the information of the subscribed site has
been changed. Hence, push increases the level of
accessibility for users to gain the information
because they no longer have to check their popular
sites from time to time. Of course, the traditional
pull-phase information distribution technologies are
still valid as usable means of distributing data.
These push solutions can thus be complementary.
5.1 USER INTERFACE ASPECTS
As push tries to put fresh content at users’
fingertips, there are varieties of ways for users to
access their information. Even though the methods
of delivery may vary depending on the service, the
most common push interfaces come in the form of
screen saver, ticker and flash [11].
5.1.1 Screen Saver
Some information, such as news could be
presented in the form of a screen saver.
Personalised screen savers keep the user informed
of the latest news or announcements with headlines
that scroll across the screen.
5.1.2 Ticker
A ticker is a moveable, resizable, bar-shaped
window that appears on the screen that scrolls time
sensitive information from channels which the user
According to Kelly and Wolf, “Push media can build
community through the expectation of reliability
[12].” Both believed that there is a huge difference
between having the newspaper delivered to one’s
door every morning and going out to a box down the
street. Home delivery of newspaper is as reassuring
as it is convenient. This means that users can
actually rely on qualified push sources, such as the
BBC to get their content. The experience of such
content providers will make it possible for users to
get high quality information. Therefore, push
technology can assist the user in improving the
timeliness of information delivery and has the
advantage of being flexible [13].
Also, push technology has advantages for both
content providers and end users. In our case, the
content providers might be the university
administration while the end users might be the
students.
For
example,
the
university
accommodation office can provide information to
the students that are staying in halls only. This will
then help to guarantee readership level and provide
mechanisms to understand information usage better
[11]. For content providers, it allows targeting their
information to the audience more directly and
accurately [23]. As a consequence, it reduces the
chance of students that live outside the halls getting
unwanted messages.
Based on Kendall & Kendell research, the push
technology is useful in many different types of
applications. It enables all of the personal
information devices such as palmtops, pagers and
mobile phones to deliver a greater quantity of
customised information in a more personalised
manner. Push is also useful to the end user
because it pre-qualifies appropriate information and
reduces the burden of acquiring data in a large
information flow, hence significantly improves the
response time of accessing content [1, 23].
However, push technologies have not really
overtaken the traditional pull model. As Trecordi and
Verticale reported, “A user may then be flooded by
the unsolicited delivery of data whose value to the
user is far from being guaranteed [25]”, it shows that
the popularity of push technology is loaded by a
number of problems. Although push enables users
to obtain the information that they need as soon as
it is available, it often means having constant
interruption [11]. Though interrupts can take a
user’s focus away from the task at hand, the real
problem is that they are too frequent and generally
unscheduled. In addition, the users might miss
valuable and relevant information as push
eliminates the need for the users to find information
themselves. Franklin and Zdonik argued that even
push allows automation of content, the technology
raises the potential that users receive irrelevant
data while not receiving the information they really
need [6]. As a result, the quality of the received
information becomes strongly dependant on
whoever pushes the information.
Another setback of push mentioned by Berghel is
the difficulty in trying to determine which push
features will remain important as cyberspace
continues to redefine itself [2]. For example,
audio/video streaming via push channels, though in
theory a useful application, fall victim to the
bandwidth-bottleneck problem. Based on Gerwiq’s
judgement, if people had everything pushed to
them, they could end up with copies of entire
Internet sites eating up computer storage. Last but
not least, the push technology cannot replace
‘traditional’ pull communication and may not be
useful in all sectors [11]. It is just another
mechanism to access information.
7. FUTURE WORK
Berghel and Gerwig pointed out in their paper that
the two most popular push environment, Internet
and enterprise content delivery, will likely to
continue to evolve, penetrating even narrower and
more focused target users along the way [2,7].
Based on their judgement, it is expected that there
will be more upgraded versions of push technology
that help refine user requirements in the future. This
will then help content providers to distribute
information to specific and well defined users as a
one-size-fits-all “push for the masses” environment
would drown users in the huge volume of Internet
resources. In the future, push will also complement
both the Web and email by adding a layer of
automated information feeds on top of existing
content, which allows up-to-date information being
delivered to the users. For these reasons alone, the
future of push in some form or other seems secure.
8. CONCLUSION
The paper presents that the heavy traffic on the
Internet has reduced the ability for users to search
for information. However, the push technology is
able to make information more accessible for the
user. Push technology helps to increase the
productivity of many different levels amongst users,
as the fundamental purpose is to timely distribute
data to the users. The technology presented also
plays an important role in continuing convergence of
information in mobile industry. The power of the
mobile push technology can be seen as it allows the
users to receive and react on the relevant
information on time. With the integration of WAP
and push technology, this provides global
accessibility and a wider range of available
services, hence improving the share of information.
Each push technology presented has its own
strength and is better suited for a particular category
of users. It seems that there is a future in the push
technology, although some limitations remain
unsolved at the moment. In conclusion, the way in
which most people search for information on the
Internet, is in need of change.
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[19] (not in use - diagram deleted)
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