1 WAP and the Future
1 WAP and the Future
In this chapter…
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WAP
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Cellular Network Standards
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New Possibilities
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Always and Everywhere
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T
his chapter concentrates on new techniques such as WAP and GPRS. Benefits of
these techniques and the possibilities they offer to current and future users are described. Thanks to these techniques, everyone will be able to access the Internet from
mobile telephones, organizers, or other mobile equipment. Via Internet, a wide range
of other services will be accessible. Also, related technologies like EDGE, UMTS
Bluetooth, and mobile positioning are explained.
WAP......................................................................
Specially Designed for Mobile
Communication
Wireless Application Protocol (WAP) is a standardized protocol that enables an application to be set up between a mobile telephone and a server. This enables Internet access, as well as use of other applications. The mobile user (Figure 1.1) can access
information and applications on the Internet or on his or her company’s Intranet.
This was already possible before the introduction of WAP. A user who has access to a laptop or organizer can connect to Internet via mobile telephone. The user
calls into an Internet service provider via a mobile phone in exactly the same way that
Figure 1.1
Example of a WAP-enabled phone: the Ericsson R320.
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WAP
he or she would do via a fixed telephone line. The user’s interface is identical, but the
speed is considerably slower. The bandwidth of a GSM connection is 9.6 kbit per second compared to the 56.6 or 64 kbit per second maximum provided by a fixed PSTN
or ISDN telephone network. The GSM connection will be disconnected more often
and give more transmission faults than a connection via a fixed telephone network because it is a radio connection.
The Internet is a simple and efficient method of delivering services to millions of
PC users. WAP was specially developed to make the convenience of the Internet available to mobile users without the need for a laptop. This means that WAP takes into account the following limitations of the mobile terminal and the mobile connection:
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Low bandwidth. Mobile networks have a lower bandwidth than fixed networks. This leads to lower performance. WAP minimizes traffic over the
mobile network, enabling better performance. The WAP protocol eliminates unnecessary information, enabling only about half the quantity of
data that is needed by a standard HTTP/TCP/IP stack to deliver the same
content.
Long delays. Mobile networks have longer delays than fixed networks due
to the lower data speed. For the user this means a long wait before a reaction to his or her action. WAP minimizes the number of question-and-answer sessions between the mobile appliance and the WAP device.
Poor connection stability. Mobile networks can be unavailable to the user
for shorter or longer periods, for example, due to limited capacity or
breakdown in radio contact. WAP minimizes the effects of signal failure
by maintaining the logical session intact. Also, specific lost data can be resent on a selective basis.
Limited screen size. Mobile terminals (even PDAs) have a small screen
compared to a desktop. The size of the human hand will always limit
screen size, even with the arrival of slightly bigger handhelds. WAP takes
account of the small screen by breaking the total interaction with the user
up into small parts (the so-called cards) that can be shown on small
screens. Examples of interactions are text screens, lists of options, input
fields, or combinations of these.
Limited input possibilities. Mobile terminals have a small keyboard for
data input. This is clearly much more difficult to use than the QWERTY
keyboard on a PC. Text as well as numbers can be input with WAP, but input will generally be limited.
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WAP and the Future
Limited memory and processor capacity. Mobile terminals have very limited memory and processing speed compared to PCs. This is true for working memory and space for programs that the manufacturer puts in the
terminal. WAP needs little memory or processing speed.
Limited battery capacity. Access to mobile services increases the use of
the radio interface and with it the consumption of power. WAP restricts the
use of bandwidth and thus also the battery consumption.
The WAP standard has been developed within the WAP Forum and it is being
further developed and extended. WAP is an initiative from Unwired Planet (now
Openwave), Nokia, Ericsson, and Motorola. By 2001 more than 600 companies were
members of the WAP Forum. Among these companies are mobile operators with more
than 100 million subscribers, and suppliers of mobile terminals and Personal Digital
Assistants representing over 90 percent of the global handset market. WAP Forum
also represents all other relevant parties like vendors of SIM cards, hardware and software, and also banks, Internet portals, car suppliers, Internet service providers, and
consultancy companies. The WAP Forum (www.wapforum.org) develops new WAP
standards specifications and certifies WAP products to improve interoperability of the
many different WAP-related products.
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OPENWAVE, THE FOUNDER OF WAP
When the broadband hype broke out in Silicon Valley at the end of
1994, Alain Rossmann, the founder of what is now Openwave, set himself the goal of making the Internet accessible via mobile telephones. In
spite of all the limitations of a small device, Rossmann saw the value of
Internet on the cellular: You always have it with you. He also foresaw a
mass market. In 1996, AT&T was the first company to step into the mobile Internet world with the introduction of PocketNet. The product did
not take off in the mass market, mainly because there were only a few
types of large, heavy devices available. In the business market, numerous
applications developed for transportation and logistics are still in use.
In 1997, in order to break into the fast-growing global mass market
for mobile telephony, Openwave (then called Unwired Planet) decided to
share its technological lead with dominant mobile telecom suppliers Ericsson, Nokia, and Motorola with the aim of making its technology the de
facto standard. The WAP Forum was born. This “new economy” decision
was certainly good for Unwired Planet. The WAP Forum developed into
the industrial platform for mobile Internet. Unwired Planet changed its
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WAP
name to Phone.com. Phone.com itself has a developers forum where
more than 100,000 developers are registered. The Phone.com microbrowser has been licensed to more than 20 mobile telephone suppliers
and is used by Motorola, Alcatel, Panasonic, Siemens, and Samsung,
among others. The French Vodafone daughter, SFR, was the first European mobile operator to take the plunge. In March 1999, [email protected] saw
the light, as part of a mobile telephone package for small businesses.
[email protected] was based on Phone.com’s own HDML programming language, the basis for WAP’s WML.
Phone.com’s application for a stock market offering in June 1999
gave financial room for expansion. Sales offices have now been opened
in all important mobile markets. Also, Phone.com has carried out a number of acquisitions. They have bought Apion to serve the European operator market, @motion to add mobile speech recognition, Paragon for
synchronization products for synchronization of PDAs and mobile telephones with the most important organizer platforms, and Onebox for
unified messaging. These acquisitions have enabled Phone.com to expand its gateway product with personalization modules, telephony applications, and Intranet applications. Also, Phone.com has released a
separate synchronization product under the name FoneSync Essentials
(www.fonesync.com). This product enables synchronization of the most
important organizer platforms (e.g., Microsoft, Lotus) with a whole range
of types of mobile telephones and PDAs.
In November 2000, Phone.com and Software.com, a developer of Internet infrastructure software for communications service providers, merged,
adding a broad range of messaging products to the Phone.com portfolio.
The merged company was called Openwave and it currently serves mobile
operators in Asia, Europe, and the U.S. In the Japanese market—the biggest
and most advanced mobile Internet market at the moment—Openwave has
IDO and KDDI as customers. With i-mode, Japanese market leader NTT
DoCoMo has developed its own WAP variant (see the section “Japanese
Competition for WAP?”). Openwave claims to be the worldwide leader of
open Internet-based communication infrastructure software and applications with more than 80 mobile operator customers like Vodafone Mannesmann (Germany), Telecom Italia, Sprint, and British Telecom.
The first commercial WAP services were based on the WAP 1.1 standard, issued
in June 1999. The first commercial services were launched at the end of 1999 (minfo
from KPN Mobile premiered on November 25, 1999). Prior to WAP 1.1, a number of
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mobile operators carried out a pilot with WAP 1.0. WAP 1.1 deviates somewhat from
the WAP 1.0 standard and equipment based on WAP 1.0 cannot be used for services
that are based on WAP 1.1. The Siemens S25 handset used a WAP 1.0 browser that
was not compatible with any WAP service.
The WAP 1.2 specifications were approved in June 2000. The first commercial
services based on WAP 1.2 were introduced early 2001. WAP 1.2 is backward-compatible with WAP 1.1. This means that WAP 1.1 handsets work with WAP 1.2-based
services. WAP 1.2 provided several technical enhancements of WAP 1.1 functionality
and a range of new functionality—SMS push services, end-to-end security using the
SIM card (or another smart card), and integration of voice telephony services. The
characteristics of the new functionality will be explained later.
WAP 2.0—released in Summer 2001—incorporates TCP/IP and xHTML into
the WAP standard, offering programmers the facility to develop an application for
both fixed and wireless Internet at once. WAP 2.0 also anticipates the upcoming faster
networks and services, solving earlier stumbling blocks like security, personalization,
and provisioning. WAP 2.0 should also be backward-compatible with WAP 1.x.
The WAP Building Blocks
In many respects WAP resembles the Internet. An example is the manner in which interaction takes place. With WAP the user also has a browser at his or her disposal, enabling a request for an Internet address to be entered. This request is transferred to a
WAP gateway via a mobile connection. This gateway sends the information request on
to the WAP server. The server sends the required information back via the gateway.
The gateway sends it back to the mobile phone over the mobile connection.
The WAP building blocks (Figure 1.2) are:
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the WAP client (the browser in the mobile telephone)
the WAP gateway
the server
supporting services
networks
protocols
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WAP
Client
WAP Gateway/Proxy
WSP Request (URL)
WAP
User
Agents
HTTP Request (URL)
Encoders
and
Decoders
Wireless
Network
WAP
Protocol
Stack
Origin Server
WSP Response
(binary WML)
CGI
Scripts
etc.
Internet
Protocol
Conversion
HTTP Response (WML)
WML
WML Script
WAP
Protocols
Internet
Protocols
Figure 1.2
WAP architecture and building blocks.
WAP Client
To make use of a WAP service, the user must have a mobile device that is equipped for
WAP. Such a phone is equipped with a WAP microbrowser, which fulfills navigation
and presentation functions just like Internet browsers on a PC. The navigation function enables the user to request information by entering an Internet address. The
browser receives information from the Internet address and presents this to the mobile
user. In addition, the browser is equipped with functionality that makes integration of
telephone services possible.
Just as there are various suppliers of Internet browsers, there are also several
suppliers of WAP browsers. At present, the biggest browser suppliers are Openwave,
Nokia, and Ericsson. Nokia and Ericsson developed the browser mainly for their own
equipment. Openwave supplies licenses to Motorola, Alcatel, and Mitsubishi, among
others. Microsoft also supplies a WAP browser, Microsoft Mobile Explorer, that is
used in Sony handsets, among others. Each type of browser presents the information
in its own way, depending on the screen size of the apparatus concerned, but not every
type of browser supports the same set of facilities. Most suppliers offer a toolkit en-
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abling information suppliers to produce services and then to see how the service will
appear on equipment using the browser concerned. Unfortunately, additional testing
on the specific equipment concerned is often also required, because the toolkit may
not work in exactly the same way as the browser on the cellular phone. The large diversity between browsers can mean that, just as on the Internet, an information supplier must present an application in a number of different ways.
WAP Gateway and Server
The WAP gateway routes information requests from the WAP browser or client to an
application server. This application server can be reached via the Internet, but can also
be in the same domain as the gateway. The latter is often the situation when a company acquires its own gateway. This has a direct connection with the company’s application server (for example, the Intranet server). The information from the application
server (the answer to the request) will be decoded by the gateway and sent to the
browser. Coding and decoding take place in order to reduce the number of packages
that must be sent over the mobile network.
WAP makes use of the same address model as that used for the Internet: Uniform Resource Locators (URLs). The information sought via the WAP browser can
thus be found on a server via familiar protocols.
Another possible function of a WAP gateway is a proxy function. Information
from the World Wide Web is regularly collected and stored in the WAP gateway server. When the mobile user requests this information, it can be sent directly to the user
from the WAP gateway, without collecting it from the Internet. A proxy function is
only useful for sites that do not change frequently. Current information can be better
obtained directly from the Internet. Some gateways can also translate (x)HTML into
WML (Wireless Markup Language, to be further explained in this chapter) and the
other way around. This can be useful for information providers who then only need to
make their information available in HTML. Some gateways can also be used for NTT
DoCoMo’s i-mode services offering cHTML in addition to WML. The gateway can
be connected to available databases with supporting services.
Supporting Services
The first commercial launches resulted in several additional requirements. Mobile operators needed additional development to offer their customers WAP services. At KPN
Mobile, we decided to build an automated provisioning tool using SMS to download
initial settings for every type of phone. This was required to lower startup barriers for
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WAP
users without burdening customer care and shops. Also, security and personal profiling requirements resulted in additional investments and undesired propriety solutions.
WAP 2.0 incorporates supporting services, including PKI portals, personal profile standards (UAProf), and provisioning facilities. PKI portals enable end-to-end secure applications, because handsets can initiate creation of public key certificates.
UAProf supports retrieval of personal profiles by applications to personalize services
to a high degree, without the need for a user profile for every individual application.
The provision facilities provide operators a nimble facility for a range of WAP phones
instead of a facility dedicated to one type of phone or vendor.
Networks and Protocols
WAP is a protocol that is bearer-network independent. That means that WAP can be
used with all common network standards like GSM, CDMA, and PDC. WAP also
works with both SMS (Short Message Service) and with a GSM data connection, but
it’s also suitable for (future) bearers, such as GPRS (General Packet Radio Services)
and 3G. The most relevant issue regarding the different networks is the use of circuitswitched networks or packet-switched networks. Packet switching (offered by GPRS
and the Japanese i-mode bearer, PDC-P) improves the user experience. The features
of the current and future bearers will be covered later in this chapter.
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SMS: SHORT MESSAGE SERVICE
The cellular telephone offers various data communication options. In
addition to “normal” data transfer with a speed of 9.6 kbits, use can also
be made of Short Message Service (SMS). Text messages with a maximum
length of 160 characters can be sent and received via a cellular phone. Every GSM phone is suitable for sending and receiving SMS messages. A help
desk worker can also send SMS messages via a PC with special software or
via the Internet. Requesting information about traffic jams, share prices, or
the weather is no longer a novelty—this has been possible since 1996 using SMS. Company-specific SMS applications have been built to facilitate
communication between the office and staff in, for example, the transportation sector or for companies with traveling mechanics.
In spite of these options, the breakthrough of SMS did not take place
in Western Europe until the end of 1999. A number of reasons lie behind
this late breakthrough:
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• Mobile operators have given priority to simplifying the mobile
telephony proposition, with the aim of increasing sales. In
marketing communication, SMS has remained secondary to
speech.
• Until the end of 1999, sending SMS messages with prepaid
phones was not possible. This meant that many, often younger
consumers could not use SMS.
• The first cellular users saw an envelope on their screen—the sign
for a new SMS message on most phones—as an icon for new
voice mail messages.
• The telephone number of the SMS exchange had to be
preprogrammed in the phone before an SMS message could be
sent.
• The cost of sending SMS messages is relatively high.
Many users find composing SMS messages on their cellular phones
too complex. Chatboards and predictive text input can make this simpler.
Remembering a keyword, inputting, and sending to a specific number to
receive news or a file message 160 characters long is asking a lot of the
user.
Because cellular operators now aggressively promote SMS and it is
also within the reach of a young user group, there has been enormous
growth in SMS traffic, from 2 billion messages per month worldwide at
the end of 1999 to a total of 14 billion messages per month at the end
of 2000, and a steady monthly growth rate of 10 to 15 percent. Nokia
even predicts 100 billion messages in December 2003. During a popular
German TV show, Jede Sekunde zahlt (Every Second Counts), viewers
were asked to react to questions by sending an SMS message. The SMS
system, specially designed by SMS vendor and market leader CMG, handled more than 1.2 million messages in 30 minutes. The use of SMS in
Japan quadrupled following the introduction of package-switched networks similar to GPRS. This is a signal that SMS traffic will continue to
grow after introduction of GPRS networks to the rest of the world.
The success of SMS has led to the development of EMS (Enhanced
Mobile Messaging) and, later on, MMS (Multimedia Mobile Messaging).
New functionality like audio and video clips, photographs, and images
are added to SMS. MMS is expected to become a mass market service for
mobile operators.
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WAP
Communication between the WAP gateway and the server takes place via the Internet and the usual protocols. For communication over mobile networks, Wireless Session Protocol (WSP), a binary version of HTTP, is used. To guarantee expandability as
well as scalability and flexibility, WAP is set up in five layers. This layered architecture
offers other services the possibility of making use of the WAP features, without these
services having to be specified in the WAP Forum. The several layers are:
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Application layer, or Wireless Application Environment
Session layer, or Wireless Session Protocol
Transaction layer, or Wireless Transaction Protocol
Security layer, or Wireless Transport Layer Security
Transport layer, or Wireless Datagram Protocol
In Figure 1.3, the WAP protocol stack is shown in relation to the Internet protocols.
A detailed description of the WAP protocols is outside the scope of this book.
The interested reader can consult the WAP specifications at www.wapforum.org. We
Internet
Wireless Application Protocol (WAP)
HTML
JavaScript
Wireless Application Environment (WAE)
Wireless Session Protocol (WSP)
HTTP
Wireless Transaction Protocol (WTP)
TLS–SSL
TCP/IP
UDP/IP
Wireless Transport Layer Security (WTLS)
Wireless Datagram Protocol
(WDP)
WCMP
User Datagram Protocol
(UDP)
Bearers
SMS
USSD
GPRS
CSD
CDPD
Figure 1.3
WAP protocol stack in relation to the Internet protocol stack.
R-DATA
Etc.
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will go deeper into the application layer, as this forms the foundation for building
WAP services and in particular the layout language, the scripting, and the telephony
application. The security layer will also be detailed because of the importance of security for payment functionality, for example.
Wireless Markup Language
Services made up in Hypertext Markup Language (HTML)—the language that is used
for the layout of Internet pages on the World Wide Web—do not take sufficient account of specific circumstances that arise in a mobile environment. That is why WML
was developed. WML is the mobile variation of HTML. A WML file is called a deck.
This deck is made up of cards. A card prescribes how the interaction with the user will
appear. Only one card at a time can be displayed on the mobile telephone screen. The
following interactions are possible with WAP 1.1:
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Text. Text is displayed.
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Links. Just like with standard Internet, one or more links can be shown on
a screen. Clicking a link causes the display of another card. This card can
be from the same deck. The card comes from a different WML deck if the
user clicks on a link to another WML site.
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Selection. A selection can be made from a series of options.
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Soft buttons. The developer can program functions to run from soft buttons. Every modern device has at least one soft button or menu button.
Images. An image is displayed.
Flash screen. With this option a screen is displayed to the user for a period
of 1 to 5 seconds, after which the following screen (new card) is displayed.
Input. The user can be requested to input data. This might be only numbers, only text, or a combination of text and numbers.
Regarding layout, there are a few possibilities. The text can be made larger or
smaller, bold, or italic using tags. The text can also be left- or right-aligned or centered. Some browsers can display tables. Also, small pictures, called wireless bitmaps,
can be one of the options. Examples and tips for the design of your own WAP page are
given in Appendix A.
In addition, WML supports soft buttons. These buttons at the bottom of the
screen can have their identity changed and you can trigger an action by clicking on
them. The left button, Options, is standard and enables options such as Back to homepage and To bookmarks. The right button is often Back, taking the user back to the
previous screen.
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WAP
WML can also handle Events. This is necessary for use with telephone services,
for example, if the user has an incoming call.
Considering the limited graphical and interaction possibilities, it is important that
the information provider presents the data as concisely as possible. After all, reading
long pieces of text on a mobile telephone is not easy. Also, the amount of input from
the user must be limited as much as possible, because typing data with the keyboard of
a cellular telephone is also not easy. Suppliers of WAP telephones are doing their best
to make surfing as simple as possible. On the Nokia 7110, there is a NaviRoller™ to
enable easy scrolling through text and easy clicking on links (see Figure 1.4). Ericsson
has a touch screen on the R380. Links can be easily clicked using a pen.
Figure 1.4
The NaviRoller™ of the Nokia 7110.
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JAPANESE COMPETITION FOR WAP?
The Japanese market for mobile Internet is the biggest and most advanced in the world. Since April 1999, Japanese mobile operators have
offered mobile access to Internet services. NTT DoCoMo is easily the market leader, with more than 7.5 million mobile Internet users by the end
of June 2000 and up to 19 million users by the end of January 2001.
More than 90 percent of new subscribers start using i-mode (see Figure
1.5). Competitors IDO and J-phone are quite successful marketing WAP
services, too. They have been offering WAP services with platforms delivered by U.S. company Openwave. IDO’s WAP service, named EZweb,
was launched in April 1999. After a slow start, the subscriber base grew
to more than 3 million by mid-2000, adding 1 million subscribers during
the last 2 months. At that moment, one in three IDO customers used
their mobile phones for WAP services.
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NTT DoCoMo uses Compact HTML (cHTML), a subset of HTML, rather
than WML for its i-mode service. This makes WML-based converters unnecessary and it is thus even easier to build mobile Internet sites. Midway
through 2000, 15,000 Web sites had been developed in cHTML and at the
end of January 2001, 38,000 sites were available. All these sites are especially for NTT DoCoMo customers. At the same time there were about
10,000 WAP sites from more than 95 different countries. In June 2000,
Logica was the first to introduce a gateway (the m-WorldGate) that supports cHTML as a markup language in addition to WML. Also, different
browsers are needed and thus a separate mobile device.
cHTML devices in Japan support,
among other things, possibilities not supported by the current WAP phones, such as
color pictures, GIF animations, and the
downloading of ring tones of MIDI quality
(see Figure 1.6). Handsets equipped with
cHTML will become available in the European market. These will be suitable for both
GSM and GPRS. It could be that cHTML will
eventually oust WML as the primary markup
Figure 1.5
language for mobile Internet telephones.
Email via i-mode.
Since early 2000, in view of the development of WAP services in Europe and the acceptance of WAP as a standard,
it could also be that the opportunities for cHTML as an alternative for WAP
lie mainly outside Europe. Coexistence is the other alternative. NTT DoCoMo has already announced it will support WAP 2.0. standards as well.
DoCoMo also has announced that they would like to export i-mode.
Figure 1.6
Japanese phones.
Another difference between WAP
and NTT DoCoMo’s i-mode in Japan is that instead of a GSM network as carrier, PDC-P is used.
PDC-P networks have the same
data speed as GSM networks, but
already offer billing for the
amount of sent data instead of
connection time and “always-on”
functionality. More details about
networks and their features are
described in the next paragraph.
In mid-2000, DoCoMo implement-
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WAP
ed Java and Japan is the first country in the world launching 3G services
in 2001. Japan is approximately two years ahead of Europe in data
speed. Success will be achieved thanks to the content available. The content available in Japan is only partly usable in Europe. DoCoMo, with its
service concept and experience with millions of mobile Internet users,
has a know-how advantage over Europe. After all, the Japanese succeeded in marketing this brand new concept very well. NTT DoCoMo bundled new phones and a broad range of easy-to-use services for
acceptable prices. KPN Mobile, as a DoCoMo partner, will make use of
this. There is more information about the services offered by i-mode in
Chapter 5.
WML Script
WML Script makes it possible to improve services that have been written in WML. It
can add specific intelligence to a service, such as calculating logical and conditional
functions. WML Script can, for example, be used for validating the user’s input. Without the use of WML Script, validation must be done in the server and that means a
question-and-answer session over the network. With WML Script, a local function can
also be used in the mobile device, for example, a telephone function.
Telephony Services within WAP
Wireless Telephony Application (WTA) is also defined in the WAP standard (see Figure 1.7). WTA is an environment that makes it possible to use telephone services. The
WTAI (Wireless Telephony Application Interface) offers a collection of telephony-related functions in a mobile telephone that can be activated with WML or WML Script.
These are functions related to a call, such as making, breaking, or putting a call on
hold. Functions for handling text messages or for the control of the telephone directory in the device can also be activated using WTAI.
Because the real-time behavior of a service is very important for telephone services, it is possible to save specific WTA services in the device. This enables the device to react directly to “events” because it does not first have to refer to a server via
the network. Typical events are incoming calls, breaking off a call, and answering a
call. The WTA services that are stored in the device can react to these events immediately. The user can receive an indication about the event, (for example, a new voice
mail message), and is given the opportunity to start an accompanying service. A user
who receives a voice mail indication can choose to listen to this message immediately
or save it for later.
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WML
HTML
WAP
Proxy
Web
Server
WML
WML
Wireless
Network
HTML
Filter
WAP Proxy
WML
WML
WTA
Server
Figure 1.7
The WAP infrastructure with WTA server.
Content Billing
During the emergence of the Internet virtually all information was free. Attempts have
been made with varying success to obtain payment for information, by means of a
subscription, for example. In many cases access to the restricted Internet site is part of
a bigger picture. In this way, subscribers to a magazine can receive access to the archives of the magazine via the Internet plus some additional services. Bank customers
sometimes have to pay to access their account via the Internet. The WAP standard has
no facilities for billing customers via the mobile bill or the prepaid account, so operators develop their own facilities, depending on the business model they choose to offer. A few mobile operators offer information suppliers payment facilities if the
information is supplied via WAP. minfo from KPN Mobile gives information suppliers the facility to ask a maximum of around $1 per day (or per successful information
request) to be included on the mobile invoice. NTT DoCoMo has also developed billing services for 1,200 “recognized” sites to charge end users via their mobile phone
bill for using the service.
Other mobile operators buy information for a fixed sum and charge for this information within the tariff for the GSM connection. A fixed tariff is charged irrespective of the value of the information. A third possibility is that the information is
sponsored by advertising income.
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MOBILE INSTANT MESSAGING
In a mobile environment, messaging applications are very important.
The success that SMS and email notification services already had before
WAP was introduced proved this. The WAP 2.0 framework facilitates
building messaging applications in different content formats, including
images, audio, video, animation, and all kinds of data records.
Another development in this area is the instant messaging standards
war that is being fought at the moment against America Online (AOL).
Instant messaging makes it possible to see which of your friends are online, so that you can send them a short message, sound, or picture. This
is an excellent example of a WTA “killer app.” With ICQ (I seek you) and
Instant Messenger (over 20 million active users), AOL controls this market
of more than 1 billion messages per day. Yahoo! and Microsoft’s instant
messaging programs each have more than 10 million active users using
the fixed Internet. The different programs are not interoperable, so most
heavy users use more than one program. Tegic is the inventor of T9 software, which makes it possible to send simpler messages from a mobile
telephone. Tegic—acquired by AOL—has developed a mobile ICQ. Customers can ICQ with a friend regardless of whether they are using a fixed
or mobile Internet device. On top of this, AOL has integrated SMS in its
ICQ window. The WAP 2.0 framework includes facilities to support multimedia messaging, including email and instant messaging programs on
WAP handsets.
Security
Security is very important with all types of services that include banking and payment, regardless of the medium used. The following aspects are important:
•
Identification. Who is the user of the service? How can the user be recognized?
•
Authentication. Are the users really who they say they are? The same is of
course equally valid for the service supplier.
•
•
Authorization. Is the user authorized to make use of this service?
•
Integrity. Is the information secure from alteration during exchange?
Confidentiality. Is the information being exchanged secure from being
read by unauthorized persons?
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WAP and the Future
Irrefutability. Is it impossible for the participating parties to negate the
transaction or part of it?
In the WAP Forum, Wireless Transport Layer Security (WTLS) has been developed. WTLS looks after the following security components:
•
Encryption. The transmitted data is encoded between the browser and the
WAP gateway, so that the confidentiality of the information transfer can be
guaranteed.
•
Data integrity. The data that is received by the browser or the gateway is
controlled by control bits to ensure that it is the same as that sent by the
gateway to the browser.
•
Authentication. Authenticity of server and client is guaranteed by digital
certification. In the WAP 1.1 standard, only server authenticity is provided.
WAP 1.2 extends this to the clients.
This functionality gives the assurance that the information sent has not been manipulated by a third party, that privacy is safeguarded, that the author of a message can
be identified, and that both parties cannot deny that they have exchanged information.
Nevertheless, this is still not sufficient for high-security applications. WTLS
only looks after security between the browser and the WAP gateway. This means that
there is no end-to-end security between the client (the browser on the mobile telephone) and the application. After all, the security between the WAP gateway and the
application server is not defined by WTLS. The connection between the WAP gateway
and the application server can be the Internet, but use can also be made of HTTP-S (an
encoded channel on the Internet), ISDN, or a fixed line. Safe applications can be made
using the latter connection, where, thanks to the security of the GSM network, a higher security level can often be reached than with the analog dialing of a server.
The WAP Forum has accepted proposals to take up the Wireless Identity Module
(WIM) in the WAP standard (WAP 1.2) to achieve end-to-end security. WIM is used
for performing WTLS and application-level security functions. Information concerning user identification and authorization often requires sensitive data (keys). The keys
and the operations involving these keys can be stored and handled in the WIM. To realize the required level of security (tamper resistance), physical hardware protection is
used. Mobile phones and PDAs do not reach this security level. Smartcards (e.g., SIM
cards placed in every GSM phone) are suitable to perform the WIM functionality. The
SIM (Subscriber Identity Module) is the smart card that must be placed in a GSM device to enable the user to access GSM services. The SIM ensures the unique identity
of the GSM network user. WIM enables extra security due to RSA signing, private key
decryption, and storage of certificates for user, server, and applications.
19
WAP
An application uses WIM for signing and unwrapping of a key. The private key
will never leave the WIM and the operations are generic, so any application can make
use of the facilities provided by WIM. Signing may be used for authentication, signing of documents, and confirmation of transactions. The user may be asked to enter a
Personal Identification Number (PIN) for every signature made. Also, the WIM can be
used by the application to calculate a digital signature using the private key.
If an application receives a wrapped key, it will send it to the WIM. WIM deciphers it using the private key and returns the unwrapped key. The application may use
the unwrapped key to decode the attached message.
Existence of WIM on the SIM card has no effect on the GSM functionality. If
the mobile phone does not support WIM, the SIM can be used for GSM purposes
(e.g., making and receiving calls and WAP services not requiring WIM functionality).
WIM will be added to the SIM during the personalization process and by using Over
The Air mechanisms. With WIM as a basis, Nokia, Ericsson, and Motorola have once
again joined forces in a joint venture called Mobile Electronic Transactions (MET),
which will develop an open standard for mobile payments.
Does this mean that safe applications are not possible without WIM? That is not
the case. Secure connections of a GSM device to a WAP gateway with WTLS and
from the WAP gateway to the application server with HTTP-S are already possible
and if the mobile operator becomes familiar with them, various options for payment
are already available. Online bookseller Bruna and online CD vendor Boxman already
offer the option to purchase books and CDs via credit card payment using WAP.
SIM Application Toolkit
The SIM application toolkit (STK) has been developed to make it easier to send SMS
messages. Menu structures can be added to the menu of the mobile telephone using a
new type of SIM card. The advantage of this is that the user does not have to type in or
remember a password. Another advantage of services on the SIM card is that this
technique is adequately secure for bank transactions. STK supports digital signatures
from the SIM card. The disadvantages of SMS remain: the limited message size of
160 characters and the delays that can occur during sending and receiving messages.
For each transaction, several messages must often be sent backward and forward and
this can take considerable time and lead to high costs. The fact is that every message
sent costs money. The programming of menus on existing SIM cards makes extension
or changing of the menu difficult. The SIM card will have to be replaced often. New
JAVA-card 2.1 SIMs promise interoperability between different vendors and an ETSIapproved download standard. This means that applications can be downloaded to the
SIMs through the network without physical return or replacement of the SIM. New
class 3 functionality offers the SIM control over calls and sending of SMS messages.
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WAP and the Future
The SIM is important for a mobile operator because the operator issues the card and
determines the applications on the card. Handsets are often packaged to a SIM by the
outlet. Therefore, the operator does not control type and software release of the handsets. The improved functionality and flexibility of the SIM card opens up new opportunities for operators.
In the Netherlands, most operators use the STK to stimulate use of SMS messages
by offering a customer menus instead. Dutchtone has introduced I mobile. This is a SIM
toolkit application enabling popular services like news, traffic, and stock prices to be accessed easily. BT Mobile’s Telfort has also launched a SIM toolkit application that enables email messages to be read. Both applications have been built to improve the user
interface for SMS information services and not specifically for high-security applications. In the United Kingdom, more than 100,000 customers of Barclays Bank make use
of a SIM toolkit banking application.
WAP via a GSM data link overcomes the 160-character restriction and supports
graphics. The dynamic menu structure makes expansion and alteration of services
possible as well as online interaction without delays. This makes use of services both
simple and direct. Because of the limited penetration of WAP telephones compared to
the 100 percent penetration of SMS, the offering of SMS services could be very attractive over the next two years. In many instances, current SMS users will be the
WAP users of the future. Also, the experience with SMS services gained within the organization is applicable to WAP. With SMS, the need for concise messages is even
greater and topicality and speed are preconditions.
Companies with higher security needs such as banks, can make use of the STK.
STK makes it possible to place extra applications on the SIM card of a mobile telephone. These can be applications to simplify the operation of services such as voice
mail and SMS information services, or programs for mobile banking or electronic signatures. These applications make use of SMS as a carrier. A suitable device is needed
for use of SIM Toolkit. All current devices, including WAP devices, support STK, but
many people have older devices that are not suitable.
In principle, WAP services could start offering the customer all sorts of options
via WAP, but with payment via SIM toolkit. This depends on what operators put on
their SIM cards. At the moment, most SIM cards have very limited memory (8, 16, 32,
or 64 kbit) and therefore cannot support extensive programs. The operator has to
choose which applications are important enough to be placed on the SIM card. Subsequently, for good market penetration of these new SIM cards, it will be necessary that
many of the existing cards be replaced, leading to higher costs for the mobile operator.
It is thus probable that many operators for WAP will wait until WIM is specified and
place this on their cards for new customers. Until then, they will cooperate with banks
and payment services for their existing customers on the basis of SMS.
21
WAP
WAP and USSD
USSD (Unstructured Supplementary Services Data) is another carrier that can be used
for sending messages with a maximum length of 182 characters. USSD, just like
SMS, uses the signaling channel of the GSM network as a carrier. With SMS, every
time there is a message, a channel is reserved. With USSD, a session only starts at the
moment that the user starts to use a USSD service and the radio connection remains
open until the application user finishes the session or until a time-out takes place (if
there is no data transmission for a specific period). This makes USSD seven times
faster than SMS during a session. Nokia is offering a platform where USSD can be
used as a carrier for information services complementary to the SMS services. This
can be interesting, particularly for services that need fast response times, such as chatting. USSD can also be used as a carrier for simple WAP services next to it.
WAP on the SIM Card
WAP on the SIM makes the purchase of a mobile telephone with a WAP browser unnecessary. WAP services can be used via existing devices with a new SIM. The advantage of this solution is that the scarcity of WAP telephones will not prevent the
introduction of WAP services. Also, it is not necessary to replace good devices that do
not have a WAP browser. Another advantage of services on the SIM is that this technique is adequately secure for bank transactions. STK supports digital signatures from
the SIM, enabling end-to-end security to be offered.
WAP on the SIM requires a device that supports the STK. The limited memory
of the SIM has negative consequences for WAP services. The use of graphics is not
possible. The menus cannot be extended and are limited in number and depth (the
number of menu layers). There are also no soft key options or options for building in
intelligence that would make personalization possible.
Implementation of a limited set of WAP functions on the SIM is not interesting
for the innovator. The innovator will not accept a product with restrictions. The remaining interested users become confused—WAP, SIM toolkit, WAP on SIM card,
GPRS, and so on. These users are interested in services based on techniques that will
not become outdated within a year. The implementation of WAP on the SIM has consequences for the mobile operator. The distribution of SIMs to users is neither easy
nor cheap. Besides, the operator must invest in an infrastructure specifically for WAP
on the SIM.
Considering that the shortage of devices is temporary, end-to-end security in the
device for WAP browsers is close, and the service for users, suppliers, and operators
has many drawbacks, it seems that this is a short-term solution for mobile operators.
Virgin is a virtual mobile operator because they make use of the mobile network from
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WAP and the Future
One2One. Virgin does supply SIM cards themselves. As the fifth operator in a market
nearing saturation, a large number of Virgin customers will quit their service with another operator and keep their device. Virgin has offered WAP on the SIM to customers
who wish to use WAP but do not want to purchase a new device. WAP on the SIM
does give parties such as Virgin the possibility of enabling users to call on their own
WAP portal without the device having to be financed.
CELLULAR NETWORK STANDARDS ....................
WAP is designed to work with most known mobile network standards for mobile telephony, two-way paging, and two-way radio. At first this seems rather trivial but it is
not. There’s a variety in standards used by different countries. WAP can be used on the
following networks: GSM, CDMA, CDPD, TDMA, PDC, PHS, Flex, ReFlex, iDEN,
TETRA, DECT, DataTAC, and Mobitex. It’s beyond the scope of this book to describe each standard in detail. We will focus on the main standards for mobile telephony, the main differences, and their upgrades to facilitate mobile Internet services now
and in future networks, often referred to as 3G (third generation).
The other chapters of this book often refer to GSM, GPRS, and UMTS because
these are the European standards. With respect to mobile Internet services this is not relevant because of the bearer-independent nature of WAP and its successors.
First-Generation Mobile Networks
One of the first analog standards is called NMT (Nordic Mobile Telephony). NMT
was introduced in 1969 by the four Nordic countries and provided roaming possibilities (using the same mobile phone in a different network). NMT evolved and was
rolled out in Switzerland and the Netherlands as well. Other well-known analog standards are Advanced Mobile Phone Service (AMPS) and Total Access Communications System (TACS) standards. In general, these standards are named first-generation
systems (1G).
Mobile telephony standards are about technologies using available radio spectrum. Different types of cellular systems employ various methods of multiple access.
The traditional analog cellular systems, such as AMPS and TACS, use Frequency Division Multiple Access (FDMA). FDMA channels are defined by a range of radio frequencies, usually expressed in a number of kilohertz (kHz), out of the radio spectrum.
For example, AMPS systems use 30-kHz “slices” of spectrum for each channel.
Narrowband AMPS (NAMPS) requires only 10 kHz per channel. TACS channels are
25 kHz wide. With FDMA, only one subscriber at a time is assigned to a channel. No
other conversations can access this channel until the subscriber’s call is finished, or
Cellular Network Standards
23
until that original call is handed off to a different channel by the system. AMPS is still
in use in the United States. TACS is still in use in European countries like Italy, Spain,
and the United Kingdom with a few million customers. NMT is no longer in use in the
Netherlands, where the spectrum is used for GSM. In the Nordics and other countries,
NMT is still operational but the amount of users is decreasing quickly in favor of the
GSM networks. WAP is not supported by these networks.
Second-Generation Mobile Networks
The next-generation networks have been rolled out in Europe since 1991. The dominant 2G standards are GSM, CDMA, TDMA, and PDC. Starting in the Nordic countries, GSM (Global System for Mobile Communication) has become the dominant
standard. GSM is available in more than 160 countries and offered by more than 400
operators. With about 500 million users globally, GSM had captured about 70 percent
of the wireless market by the first quarter of 2001. GSM is dominant in Europe, the
Middle East, and Africa and is growing strong in Asia Pacific. The second most important second-generation standard is CDMA (Code Division Multiple Access). With
more than 80 million subscribers, it’s dominant in the United States and has a presence in Asia Pacific, the Caribbean, and Latin America as well. Another digital standard, TDMA (Time Division Multiple Access), was used by 61 million subscribers in
North America and Latin America by the end of 2000. TDMA claims to be the most
widely used wireless technology in the Americas. The Japanese developed their own
standard called PDC (Personal Digital Cellular), which is used by NTT DoCoMo and
a few other Asian networks.
TDMA is a common multiple access method employed in new digital cellular
systems. TDMA digital standards include North American Digital Cellular (also
known by its standard number IS-54), GSM, and PDC. TDMA systems commonly
start with a slice of spectrum, referred to as one carrier. Each carrier is then divided
into several time slots or channels. Only one subscriber at a time is assigned to each
channel. No other conversations can access this channel until the subscriber’s call is
finished, or until that original call is handed off to a different channel by the system.
For example, IS-54 systems, designed to coexist with AMPS systems, divide 30 kHz
of spectrum into three channels. PDC divides 25-kHz slices of spectrum into three
channels. GSM systems create eight time-division channels in 200 kHz-wide carriers.
With CDMA, unique digital codes, rather than separate RF frequencies or channels,
are used to differentiate subscribers. The codes are shared by both the mobile phone
and the base station. All users share the same range of radio spectrum.
Interoperability between the different standards is one of the big issues. Using
the same phone and the same SIM card wherever you go becomes common to most
Europeans. Using your GSM phone in other networks (or vice versa) is not that easy.
Different ways of global roaming exist: from having a “world phone” (or a rental
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WAP and the Future
phone while keeping your SIM), which can be used in some American networks, or
another mobile phone. Sometimes it’s possible to keep your own number and receive
the costs on the same bill. In many cases another phone number is required. They all
have two things in common: It’s a hassle and it’s expensive. One of the objectives of
3G is realizing true global roaming. In the meantime, integration takes place to make
global roaming on 2G networks easier by providing multiband (phones that can make
use of different frequencies) and multisystem (phones that can use more than one mobile standard) phones, SIM cards, and roaming agreements.
WAP and 2G Mobile Networks
Most commercial WAP services make use of a data link as bearer, and that is a circuitswitched connection. For a WAP session, a connection is set up that remains open during the whole session. Thus, the connection remains open even when the user is reading or entering data. This is a disadvantage of the circuit-switched data link as carrier.
The other big disadvantage is the 15 to 30 seconds needed to make the connection. In
November 1999, KPN Mobile was the first GSM operator offering services based on
WAP 1.1 services. In the meantime, most other European operators offer WAP services. In about the same period, operators across North America, Korea, and Japan began
launching cdmaOne Internet and information services.
As mentioned before, it is also possible to make use of SMS as a bearer service
in the place of the data link. New WAP menus and information are then collected by
means of SMS messages and input data is sent via SMS. A disadvantage of this option
is that the interaction is certainly not immediate. If the SMS exchange receives a lot of
messages to be sent, a queue of SMS messages develops, causing delays and unreliability. The first WAP implementations, for example, the WAP browser in the Siemens
S25 telephone, could only make use of SMS as the carrier. This was not successful
when it became apparent that most operators made use of circuit-switched data for
connection to the WAP gateway.
With a GSM data link, circuit switching is at the disposal of the user during the
entire connection time. The bandwidth of 9.6 kilobits per second (kbps) is limited and
the time needed to establish the connection is quite long. A few European operators,
such as the German E-Plus, have built facilities into their networks to enable use of a
maximum of four channels simultaneously for data transmission. This technique is
called High Speed Circuit-Switched Data (HSCSD) and makes data speeds of 57.6
kbps possible. Nevertheless, most operators choose GPRS because they do not have
the extra capacity in their networks necessary for a successful HSCSD offering. The
Nokia Communicator 9210 makes use of HSCSD. According to Nokia, every country
has an operator offering HSCSD and high-end users demand proven technology. According to Yankee Group’s estimation, Nokia will miss 85 percent of the market.
Cellular Network Standards
25
2.5-Generation Mobile Networks
The market demand for the full complement of 3G services is not yet quantified. Similarly, spectrum allocation differences across regions and continents make a global 3G
band seem unlikely. Meanwhile, today’s 2G systems are still rolling out. Operators
from all technologies have already invested billions of dollars in state-of-the-art infrastructure. Operators appreciate 3G’s potential, but their financial reality is in today’s
investments in today’s market. The packet-switched carrier services like PDC-P,
CDMA2000, and GPRS overcome the current disadvantages of 2G networks. Because
they are extensions of the second generation, they are often called 2.5 generation
(2.5G) networks.
In contrast to circuit switching, package switching does not make a connection
with a specific capacity that is only for the exclusive use of the user. The information
is placed in packages and these are sent over the network. Packages from various
senders make use of the same transmission line. For speech and other applications
where delay leads to excessive loss of quality, circuit switching with the current GSM
speeds is the best solution. Package switching is ideal for data traffic.
Package switching has the following advantages:
•
•
•
Efficient use of the bandwidth. If no information is transmitted for a short
period with a circuit-switched connection, the open line remains. With
package switching, this bandwidth can be utilized for packages from other
users.
Always online. The user does not have to make a connection every time
that he or she wants to send or receive information. Once the user has
made contact with the server used for sending and receiving data, he or she
can remain online all day and only pay for the actual use made.
Paying for use. With circuit-switched connections, the user is charged on
the basis of the length of time that he or she has made use of the connection, regardless of the quantity of data transmitted. With package-switched
data transmission, it could also be possible to charge on the basis of the
number of bytes sent and received.
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GPRS
General Packet Radio Services (GPRS) is the standard for package switching in GSM networks. GPRS offers higher speeds, thanks to the more efficient use of bandwidth. The expectation is that when introduced, GPRS terminals will provide a speed of 56 kbps in the
direction of the user and 14 kbps from the user to the server. This higher speed, compared
to the 9.6 kbps of the current GSM traffic, offers a broadening of the number of types of
possible applications and improved user friendliness for the current GSM data applications. In the first instance, GPRS seems to be too slow for real-time video and multimedia,
but will enormously stimulate the development and use of WAP services. GPRS is in this
respect not a competitor of WAP, but a complementary technology. To be able to offer
GPRS, operators must adapt their networks. This means considerable investment. Thus,
the British mobile operator Orange paid around $60 million to telecom manufacturer Ericsson to make the Orange network suitable for GPRS. In late Summer 2000, Telstra (Australia) and Smarttone (Hong Kong) introduced GPRS services. During 2001, most
European operators rolled out their GPRS networks. As with WAP, GPRS services might
not meet customers’ expectations. Speeds are often lower than the maximum 56 kbps and
the limited time window of GPRS might restrict companies to invest heavily. Most European operators first introduced their GPRS subscriptions to the corporate market for access
to corporate intranets and applications because of the limited availability of GPRS terminals in 2000 and the first half of 2001 (see Figure 1.8). Another reason for this is that
GPRS is a complex new network technology and most European operators thought it wise
to start experimenting with a limited set of heavy-using clients instead of introducing it to
consumers when the technology is not fully tested.
Figure 1.8
Examples of GPRS phones by Sendo (Z100) and Trium (Geo GPRS).
Cellular Network Standards
27
GPRS Terminals, Traditional and New
A GPRS terminal can be a mobile telephone, possibly with a WAP browser. A GPRS
terminal can also be a modem card that fits in the PCMCIA slot of a laptop. Handhelds and palmtops will probably make use of WAP for access to the Internet. Laptops
will remain using traditional HTML Web browsers and their successors for Web
browsing. All types of Web browsing will become much more user friendly with
GPRS because of the higher speed and the fact that it will no longer be necessary to
dial in. Also, new types of GPRS terminals will come onto the market, enabling, for
example, drawings, photos, and moving pictures to be made and exchanged or highquality sound files to be made and subsequently transmitted.
Standard GSM telephones are not suitable for GPRS. Also, mobile telephones
with WAP browsers are unfortunately not suitable for GPRS. Customers have to buy a
new phone. Delay in the introduction of new handsets forced many operators to stick
to commercial pilots longer than they intended to.
PDC-P
PDC-P is a package-switched carrier service developed by the Japanese. It is comparable to GPRS. PDC-P has a minimal dial-in time and the service is always on standby after the customer has dialed in. Use is calculated per amount of data sent and not
per minute. The data speed at 9.6 kbps is lower than GPRS and is the same as the European GSM network without GPRS. PDC-P is used by NTT DoCoMo for its successful i-mode service.
CDMA2000X
The CDMA2000X proposal (also known as Wideband CDMAOne) is merely an extension of CDMAOne. CDMAOne evolution promises operators progress toward
high-speed data in manageable steps: 14.4 kbps is available in CDMAOne already, as
well as 64 kbps. Data rates beyond these are already in trial and are being demonstrated by infrastructure providers. Because CDMA2000 evolution builds on the same
technology framework, operators have the flexibility to upgrade in a cost-effective
manner.
Next in the evolution path is an upgrade that is in the definition phase at this time
within the TIA standards process. Implementing this next phase of CDMAOne, an operator can offer services of 144 kbps on a 1.25 MHz channel on its current system. This
data rate exceeds what’s available to most worldwide Internet consumers today.
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Third-Generation Mobile Networks
Third-generation networks promise the most appealing services, like surfing the Web
quickly with mobile phones and laptops, viewing electronic maps, and transferring
files from PCs.
3G covers the standards EDGE, UMTS (or Wideband CDMA), and
CDMA2000 3x. CDMA2000 3x is an extension of the CDMA2000 technology described in the previous section. CDMA2000 3x and EDGE both use already allocated
spectra. Auctions for the third-generation mobile spectrum have been taking place in
Europe and will be held during 2002 in the United States. The U.S. Federal Communications Commission adopted a Notice of Proposed Rulemaking to explore the possible use of frequency bands below 3 GHz for 3G. The most coveted spectrum is now
used by the U.S. Defense Department for satellite tracking and radio communication.
Sharing spectrum with 3G services would cause interference and moving defense services to other frequencies would be too disruptive. The mobile industry focused on
global consistency of frequency bands, meaning using the same mobile device anywhere. If this cannot be realized, rollouts should be delayed and handset and infrastructure prices will increase. Handsets with networks on various frequencies already
exist and can be improved, so a scarcity of frequency in the United States seems to be
a bigger potential problem if 3G services prove to be successful.
EDGE
EDGE (Enhanced Data Rates for GSM Evolution) is a technique that makes it possible to send at 64 kbps instead of the present 9.6 kbps over a single GSM or TDMA
channel. The expectation is that this technique will be implemented in mobile networks during 2002. The maximum performance for speech and data services can be
extracted from the network when it is used in combination with the packet switching
of GPRS. EDGE creates a migration path for GSM from GPRS to UMTS (Universal
Mobile Telecommunication Services), because the changes to be made will later also
be useful for UMTS. The success of EDGE will be determined by the timely availability of mobile devices (see Figure 1.9) and by the introduction of UMTS. The longer
the UMTS introduction is delayed, the greater the chance that operators will implement EDGE. EDGE can perhaps increase the survival chances of operators that fall by
the wayside during the auction of UMTS licenses. EDGE is standardized within the
ETSI (European Institute for the Standardization of Telecommunication) for GSM
networks and was later taken on by ANSI for CDMA networks in the United States.
The introduction of GPRS and spectrum auctions have resulted in major shifts in
North America and Latin America. The U.S. auctions opened up new spectrum opportunities to GSM and TDMA players. AT&T Wireless announced it was deploying GSM/
Cellular Network Standards
29
Figure 1.9
Prototype of an EDGE phone by Ericsson.
GPRS alongside its existing TDMA network. AT&T previously stuck to a migration from
TDMA to EDGE, but the decision to introduce GSM/GPRS enables the operator to start
large-scale wireless data services by the end of 2001. GSM’s clear path to 3G via GPRS
is an important reason for other TDMA operators to start offering GSM services. Driven
by their European shareholders, El Salvador’s CTE Personal will replace its TDMA network for GSM and Bolivia’s Entel Movil will build a GSM/GPRS network alongside its
TDMA network, and Telcel Mexico will do the same. The development of TDMA via
EDGE is uncertain compared to GSM/GPRS. Credit First Boston announced it may signal the death knell for EDGE, with a diminishing market reducing terminal demand.
UMTS/W-CDMA
The next step in the mobile evolution (see Figure 1.10) is UMTS, which will use new
radio technology with speeds of between 384 kbps and 2 Mbps. The radio technique
that will be applied for this in Europe is Wideband Code Division Multiple Access (WCDMA). With the high speeds offered by UMTS it will be possible to send moving
pictures and a large number of mobile applications will be extensively expanded with
that option. In addition to the new radio part, the UMTS network makes use of the
same circuit- and package-switched exchanges as the GSM network. Mobile operators
who manage to acquire a UMTS license will be able to use the investments they have
made in GSM and GPRS toward UMTS. Acquiring licenses and building networks will
cost the European mobile operators between $275 billion and $350 billion. NTT
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WAP and the Future
Figure 1.10
Evolution from second- to third-generation networks.
DoCoMo was the first mobile operator to introduce 3G during 2001. Its competitors
will follow in 2002, offering NTT DoCoMo the possibility to expand the lead it already
has in mobile Internet. Japanese experience with 3G standard W-CDMA has proven
that the limits of available radio spectrum mean that the technology cannot simultaneously provide data speeds needed for long video and sound transmissions to a large
number of users. Downloading MP3 files takes a long time and might become quite expensive (see Figure 1.11). This is especially the case in densely populated areas.
UMTS offers new mobile capabilities like the following (see Figure 1.12):
•
•
•
•
•
Voice quality comparable to wireline
Multimedia high-speed data connections
User customization, like quality control (treble/bass), enhanced control on
personal voice mail routing, announcements, call forwarding, call screening, and so forth
Personalized mobility services; location-dependent advertising and information services, emergency services, and vehicle navigation
Wireless PSTN and wireless public data network access
31
Cellular Network Standards
3G
(W-CDMA or EDGE)
Enhanced wireless
(adding GPRS, etc.)
Enhanced wireline
(ISDN)
Basic wireline
Email
Web
Photo
Video clip
2G wireless
(GSM/TDMA)
0 10 sec. 1 min.
10 min.
1 hour
Transfer Time
Source: Hadden Telecom Ltd.
Figure 1.11
Transfer time needed to load different applications for UMTS, GPRS, ISDN,
and GSM.
The high investments and the success of the business models NTT DoCoMo introduced with i-mode (see Figure 1.13) will drive operators to open their network for
other parties. The expected growth in voice traffic will not cover the expenses, so data
will be a key revenue driver. Other parties will offer a broad range of applications
combining voice and data over a mobile phone or laptop.
Figure 1.12
Prototypes of UMTS terminals by Sony, Nokia, and Ericsson.
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WAP and the Future
Figure 1.13
NTT DoCoMo advertisement featuring Keiji Tachikawa, President and CEO of
NTT DoCoMo.
..........................................................................................................................................
ERICSSON: THE POWER OF MOBILITY
(By Patrick Blankers, specialist in mobile data communication at Ericsson Telecommunication)
The Internet as it is now is a fantastic phenomenon. It provides access to a worldwide treasure of information, an inestimable quantity of
online services, and a virtual shopping mall for the global economy. The
Internet is at the threshold of a new phase: mobile Internet.
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In contrast to the fixed Internet, mobile Internet can always accompany us. The personal and mobile character of Internet services will certainly change our lives. It will bring us better ways of getting in contact
with our friends, it will be a “wireless purse,” and it will make personal
information accessible—irrespective of time and place. In the near future,
interactive games, music, movie clips, and other forms of entertainment
will be within reach via a pocket terminal.
Positioning is one of the most valuable characteristics of mobile data
services. The GSM network is capable of delivering data that can determine the user’s position. Recently developed techniques make positioning
increasingly more accurate by determining the distance of the user from
three local GSM transmission masts. If the position of the Internet user is
known, a large number of tailor-made information services can be offered.
“Where is there a hamburger restaurant in the area?”, “When does the next
bus leave?”, and “How old is the building that I am now standing in front
of?” are all questions that can be answered instantly via mobile Internet access. WAP has been specially developed for such information services. The
examples just given assume that the initiative lies with the GSM user, but
that need not always be the case. With so-called push services, it is the service provider who sends information to the GSM user on its own initiative.
The personalizing of the telephone has already begun with the rise
of GSM. Mobile Internet will really bring personalized information and
entertainment. The mobile terminal is a personal gadget. It gives the Internet user access to personal information wherever he or she might be.
Much of the personal information will be configured via a fixed PC on the
World Wide Web, but will be subsequently requested via a mobile terminal.
Financial transactions form a third aspect of mobile data communication that offers a substantial supplement to the current Web. The GSM terminal can offer important added value to electronic commerce, particularly
concerning security aspects. The security mechanisms in the mobile terminal (for instance, SIM card) will play an important role in identifying the user.
Data to be sent through the ether can be encoded. Payment authorization
can take place via communication with a server. From now on transactions
can take place anywhere: on the street next to the parking meter, by the
soda dispenser, at the door when a parcel is delivered, and so on.
Due to these developments, Ericsson believes that by 2004 there will be
at least 1 billion mobile network users. Of those, around 350 million will
make use of mobile Internet services (see Figure 1.14). The market for mobile data services will therefore grow extremely fast in the coming years—
even faster than the growth that we are now seeing in GSM and the Internet.
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Figure 1.14
Prototype of UMTS terminal by Ericsson.
GPRS (General Packet Radio Services) is an exceedingly important technique in the evolution of mobile Internet services. GPRS offers the GSM network properties such as “always online,” payment per kB, and—not to be
forgotten—higher transmission speeds. The third-generation (3G) networks such as UMTS (Universal Mobile Telecommunications System) will
bring still higher speeds of up to 2 Mbps. With these speeds, sending pictures is no problem and a multitude of new uses will be available.
But wireless communication will go further. Ericsson’s vision is that
eventually all communication cables will be redundant. The global solution for this is Bluetooth. It is a short-distance radio technology that enables all types of apparatus to communicate with each other. The short
reach of the Bluetooth technology (up to 10 yards, and in a later phase
to 100 yards) is specially intended for household applications. Think in
terms of wireless communication between thermostat and server, between PC and ASDL modem, and between keyboard and PC. Bluetooth
was introduced quite recently. In 2005, it is estimated that 900 million
devices (telephones, PCs, household equipment) will be equipped with
a Bluetooth chip.
New Possibilities
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Mobile Internet is very much more than “cable-free” Internet. The
freedom that people experience with GSM on the one hand and with Internet on the other will increase significantly after the two are merged.
Applications that save the busy businessman 15 minutes every day are of
immense value. And that is equally valid for applications that bring fun
and entertainment to the masses. Ericsson’s core activities are the development and building of networks and terminals. Ericsson has decided to
move forward from its leading position in GSM to the 3G world and
therefore is investing a large slice of its R&D budget on the development
of WAP, GPRS, UMTS, and Bluetooth. But it will be the applications that
make new networks and terminals necessary. Therefore, Ericsson is stimulating the development of applications through their own development
and through diverse collaborations with content providers and software
suppliers. The mobile terminal will be the access to the worldwide Internet, and that is the core of “the power of mobility.”
NEW POSSIBILITIES ................................................
Positioning
Many services can deliver extra convenience and added value to the user if the location
of the user is known. Think, for example, about maps and routes to the nearest gas station, bathroom, McDonald’s, or ATM. In addition, it can be relevant for users to know
where others are located. How often do you end up looking for someone in a public
place like an airport, gas station, restaurant, or hall? In the United States, positioning
has been made compulsory for mobile operators to support the alarm number 911.
GSM networks are not developed to give locations of mobile telephones for use in
services. In a GSM network, it is possible to crudely determine where a mobile telephone is located. This method is called cell-ID. The location can be determined most accurately during a call. During a call the location can be established with an accuracy of
between 200 yards and 3 miles. The accuracy depends on the cross-section of the GSM
cell where the user is located. A GSM cell is the reach of a GSM mast. The cells are at
their smallest in those areas where telephone traffic is most dense, for example, around
traffic intersections and in densely populated cities. The reach of a GSM mast and thus
the size of a cell vary due to atmospheric conditions. When the telephone is not in use
but is switched on, the location can be determined at the location area level. In addition
to cell-ID, a number of technologies for positioning are already available or in development: Global Positioning System (GPS), Time of Arrival (TOA), Time Difference of Arrival (TDOA), and Enhanced Observed Time Difference (E-OTD).
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Global Positioning System
GPS is a position-determining system that was developed for
military purposes by order of the U.S. Department of Defense (see Figure 1.15). GPS has an accurate version for authorized users (Precise Positioning System) and a version
available for everyone (Standard Positioning System). SPS
contains an intentionally added fault, making it less accurate.
Differential GPS was developed to correct this defect. The
U.S. Department of Defense can switch off GPS at any time.
GPS is very accurate. The accuracy depends on a number of
factors, such as the angle between the satellites, measured
from the point from where the location must be determined.
Roughly, for Normal GPS (SPS) in 98 percent of cases, accuracy is within 100 yards and in 75 percent within 50 yards.
The accurate GPS version (PPS) is accurate to within 25
yards. Differential GPS is accurate to within 5 yards. The intentional fault was taken out on May 1, 2000, improving accuracy to within a few yards.
Figure 1.15
Combined GPS
and GSM module
designed for the
Handspring Visor.
A disadvantage of GPS is that a clear path is needed to
at least three satellites and this can be a problem in a city. Interference caused by PCs and TVs can also influence the accuracy. A last disadvantage
is that a minimum of 10 seconds and up to half an hour is needed to fix the position,
depending on when the device concerned last used GPS. GPS can be combined with a
mobile telephone by building GPS into the device or by taking up D-GPS in the network. Due to the costs of the equipment and customer-specific requirements, the combination is not yet available for the mass market. GSM and GPS systems are often
built into delivery trucks or automobiles to establish the vehicle’s location in the case
of theft or for navigation.
Triangulation
There are a number of techniques that make use of GSM for positioning. These are
known as triangulation because the measurements of these signals usually take place
from three angles. The best known are Time of Arrival (TOA), Time Difference of Arrival (TDOA), and Enhanced Observed Time Difference (E-OTD). TOA measures
how long it takes a signal to travel from the base station to the mobile telephone or
vice versa. Receivers must be placed on the base station for this. The system works on
all mobile telephones and the location can be found very quickly. If more base stations
measure the TOA of the same cellular telephone, the resulting time differences can be
New Possibilities
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used to calculate differences in distance. TDOA is based on this. Synchronization of
the base stations is essential for this to work. In the case of E-OTD, the mobile telephone measures signals coming from three different base stations. Also here, the base
stations must be synchronized or extra equipment must be installed. Nokia has determined that synchronization is preferable. The location calculations are carried out by
this equipment or by the cellular telephone. In the first case, an adaptation to the software in the mobile telephone is sufficient. In the second case, the mobile telephone’s
processor capability must be expanded. Advantages of this technology are the low
load imposed on the GSM network and the fact that the location is also available when
the device is just switched on. Disadvantages are the adjustments needed to both devices and network, meaning that existing devices cannot make use of this technique.
The synchronization required slows down the positioning, leading to mistakes if the
device is moving at a high speed through the network. All techniques mentioned are
hindered by reflections against buildings. This causes the signal to remain longer in
transit, leading to incorrect location determination. Specific algorithms can eliminate
the effects of reflections. With these, an accuracy of 125 yards is possible in 67 percent of cases.
0804 Measurements Report
Cellpoint has developed an application for the mobile telephone that requires no alterations to the GSM network. The application makes use of an existing management report. This report is sent when the line is open and in other situations it is saved on the
SIM card. These reports actually end up in the wrong place in the GSM network,
causing the information to be not easily available to the service.
Each technology must be judged on the additional investment required in the
network, alterations needed to the mobile telephone, and the required accuracy. Within the telecom world, both operators and suppliers are working on the standardization
of positioning technology. The demand from the U.S. Federal Communications Commission (responsible for the distribution of licenses and the award of frequencies in
the United States) to make positioning compulsory to support the 911 alarm number
service is a key factor here. Also, the possibilities of offering commercial services will
be taken into account.
Without yet being able to say which supplier will provide the dominant positioning technology, it is clear that positioning is a relevant development to support the mobility of the user, with services specifically developed for mobile use. This is not an
option in the normal Internet and is unlikely to quickly become so. Quite apart from
the technological developments, user acceptance is an important condition. Positioning can produce numerous new applications that can offer the user benefits and convenience. Still, users will probably be discerning in their choice of service supplier and
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go for the most trustworthy option. Also, legislation mandates conditions about the
uses of positioning. Later in this book, privacy aspects are covered in detail.
Location-based services are seen as one of the important revenue generators in
the 3G era. Building the right applications and finding the way to offer these services
commercially in a successful way may take some time. Customer acceptance is another important factor. Therefore, most networks will implement location-based services
before the introduction of 3G services. The combination of GPRS and location information can offer application developers enough opportunities to build and market location-based services. The different implementations might restrict the offer to the
home network operators. Customers using other networks—while on vacation or on a
business trip—might find it difficult to use these services, because their own operator
might not be able to offer them outside the home network. These customers must find
and use the services offered by local operators, sometimes in a different language. Location-roaming services will be the next challenge.
Synchronization
According to Durlacher Research, synchronization is the process of maintaining identical applications or data where the user wants it. A calendar application user will
want to regularly synchronize the calendar on his or her Personal Digital Assistant
(PDA) or cellular phone with the calendar on his or her company network, so that the
information is always up to date. Synchronization is crucial for mobile Internet, because there will be a need for both Web-based and local applications on a PC or a mobile device. The limited penetration of PDAs in the business environment has given
the lucky owner of a PDA synchronization problems up to now. As soon as increased
productivity is a certainty, companies will equip many employees with PDAs. The
PDAs will then have access to intranet, enterprise resource planning, customer relationship management applications, and the current Microsoft or Lotus office environment. Such applications require the presence of local data. The absence of mobile
coverage will be an argument for synchronization in many countries. Within buildings
and in isolated areas, synchronization will be important. Also, business travelers who
work regularly during their flights will need to synchronize their calendar, email, and
files after arrival.
Speech Technology
At first glance, speech technology appears to be a competitive development. This is
because the user communicates by speech instead of via a screen. The reverse is really true. When it is possible to approach a central database in various different ways,
the value of the whole will only increase. Manufacturers are developing software that
New Possibilities
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will enable information from the same XML source file to be accessed via speech as
well as via WAP. The World Wide Web Consortium has accepted VoiceXML 1.0 as a
standard for speech-controlled Internet use. This will enable the application of interactive voice response systems on the Internet to rapidly gain momentum. Applications are being developed that will convert speech and pictures. These speech
technologies will certainly be combined with WAP in the near future. Chapter 2 deals
with this in more detail.
Bluetooth
Bluetooth is a technology for wireless communication. The Bluetooth consortium was
set up with the aim of enabling many types of apparatus to communicate with each
other via wireless means. Bluetooth is intended for a wide range of computing and
telecommunications devices, such as PDAs, laptops, cellular telephones, and cameras,
but also printers, faxes, and video recorders. Bluetooth promises connectivity without
the need for cables or proprietary software interfaces. The devices must not be more
than 10 yards apart. Using an amplifier, this reach can be increased to 100 yards.
Bluetooth has been developed for speech and data. The speed will increase over the
coming years, also making transport of video possible.
Ericsson invented Bluetooth technology. In 1998, Ericsson, together with IBM,
Intel, Nokia, and Toshiba, set up the Bluetooth Special Interest Group to further develop Bluetooth. Version 1.0 of the standard was set down in 1999. Ericsson has made
the technology available license-free to develop a wider market than just mobile telephony. In the meantime, more than 2,000 suppliers have said that they will make use
of this technology.
Bluetooth will be a handy solution for numerous situations. For example, a cellular telephone equipped with Bluetooth will be able to call out at home via the normal
telephone line (lower tariffs). En route it can be used via the mobile network and will be
able to operate as a sort of walkie-talkie if it is within reach of another Bluetoothequipped device. Teachers have a lot to look forward to in the future, as pupils will be
able to whisper not only to those sitting next to them, but to everyone in the class.
Bluetooth is also a welcome addition for computer users. With a laptop you
will be able to reach the Internet from anywhere, regardless of whether you use a mobile telephone, the LAN, or your PSTN/ISDN or ADSL connection. Users can go
with what is easiest and cheapest at the time. During a meeting, participants with a
laptop or PDA will be able to exchange documents and electronic business cards automatically. Also, the perpetual irritation of having to synchronize all types of electronic calendars will be history. The desktop computer, the mobile telephone, the
PDA, and the laptop will synchronize automatically once they are within reach of
each other. The combination of Bluetooth with WAP makes a cellular telephone a
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universal remote control. WAP applications for granting access and controlling all
types of apparatus will be within reach.
In 2000, Ericsson introduced Bluetooth accessories because they did not expect that users would replace their GSM telephones or PDA right away. A big advantage of Bluetooth compared to infrared is that an unbroken line of sight is no
longer needed. The organizer in the hand can communicate with the mobile telephone in the briefcase. Much is expected of the wireless headset (see Figure 1.16).
This can be connected to the cellular telephone in your back pocket or purse or to a
normal telephone. Thus, you will be able to keep your hands free for driving, writing, or other activities. Also, payment in shops could be easier when your cellular
phone can act as a digital billfold. Ericsson is also expecting much from their Cordless Screenphone (HS210), a writing pad with a touchscreen.
Figure 1.16
Ericsson Bluetooth headset and phone.
Always and Everywhere
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Bluetooth faces competition from the following technologies:
•
Microsoft’s Universal Plug and Play (UPnP) supported by 3Com, HP, GE,
and IBM is a competitive standard that is also aimed at PCs, PC peripherals, PDAs, and cellular telephones.
•
•
Jini from Sun, Sony, Cisco, Motorola, and Oracle. Jini is based on Java.
HAVi (Home Audio/Video interoperability), supported by Sony, Philips,
Sun, Pioneer, and Sharp. The focus of these technologies is interoperability between digital audio and video apparatus such as cable modems, settop speakers, and Internet televisions.
The division between these groups and the contribution that many of the supporters of competing technologies give to Bluetooth suggests that, although the battle
is not won, Bluetooth has a good chance of evolving into the standard.
The expectation was that the first devices with Bluetooth would appear in the
market in the spring of 2000, as extensions to existing mobile telephones, notebooks,
or digital cameras. Intel was to deliver the first Bluetooth chips at the end of 1999, but
delays in delivery forced suppliers to come onto the market later. The price of the
Bluetooth chip was still very high at the end of 1999 ($35) and $25 near the end of
2000. The chip must eventually cost around $5 to enable production of affordable
Bluetooth devices. The risk is, of course, that a chicken-and-egg situation will arise,
because the price will only go lower when a specific production quantity has been
achieved and this will not be reached because of the high price. Another old standard
for wireless communication is currently implemented by some notebook producers:
802.11B. Apple has implemented this standard in most of its products because it is
cheaper, more reliable, and can be used over longer distances.
In spite of this, research bureau IDC expects that in 2005 some 2.8 billion devices worldwide will be equipped with Bluetooth, split evenly between mobile devices
and “fixed” apparatus such as computers, faxes, videos, and printers. Ericsson estimates that in 2002, 100 million mobile telephones will be equipped with Bluetooth.
ALWAYS AND EVERYWHERE ..................................
At the beginning of this chapter, the question was posed whether, now that the first
WAP services have been introduced, is this hype or a revolutionary new technique.
When and how you will have access to information over the whole world meets a fundamental demand. Still, WAP is not the first facility that enables access to information
at all times and locations. Laptops with a GSM connection or a special communica-
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tions device have offered this for a while. Why will WAP, in combination with GPRS,
be a success, whereas the earlier-named access techniques were not?
Standards
The main advantage of WAP is that it is a standard that is supported by all parties in
the chain, from mobile customer to information, and it is wholly developed for mobile communication. Mobile equipment suppliers such as Nokia, Ericsson, Motorola,
Samsung, Alcatel, and many others offer devices with a WAP browser. All mobile
operators have launched a WAP service or are working hard to introduce one. In addition, there are also other parties, independent of the mobile operators, such as
banks and portals, who offer services via their WAP gateways. It is relatively simple
for providers of information and services to make services using WML. It is also important for these parties that their information or services are available to a wide
group of users. With the wide support for the standard and the larger potential target
group (not only users with an expensive laptop or communicator), it seems that this
will be possible with WAP. The initial scarcity of WAP devices is also over, enabling
the target group to get hold of the necessary devices. We expect that with the forecast
growth in bandwidth, a need for more functionality within WAP will arise, particularly in the graphics area, for example, color and moving pictures. It is expected that
the WAP standard will be extended to accommodate this in the future. The industry
might also decide to move to another markup language, such as cHTML. As long as
the standard is continuously supported by the whole industry, an important barrier to
the growth of mobile Internet will be removed. After all, uncertainty about standards
leads to much wasted energy by manufacturers and hesitance among consumers.
Sharpened Service Offerings
In contrast to other means of mobile access to the Internet, WAP services are focused
on the mobile situation. Service suppliers make their products especially for the mobile situation, thus taking into account the limited bandwidth and the limitations of the
cellular telephone. The user receives faster access to the information that is relevant
for him or her.
Complementary Technologies and
Possibilities
Because it is an open standard, WAP will benefit from the development of complementary technologies and facilities. Compared to WAP, SMS is an inferior user interface. As a push medium, SMS can give users the option to have their attention drawn
Always and Everywhere
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to files, new email, appointments, stock prices, and sports results. Technically even offers from a supermarket that the user is driving past are possible via SMS. The question is, does everyone want that? In this respect, SMS is supplementary to WAP. The
SIM toolkit is complementary in that it can provide end-to-end security, enabling the
user to make simpler and safer use of M-commerce. The combination of WAP with
faster carrier services, such as GPRS and later UMTS, will increase user friendliness
and the speed of information transfer. The integration of positioning and alliances like
Symbian and Bluetooth will cause an enormous increase in the number of available
applications and ease of use. Positioning will stimulate the personalizing of services.
Symbian will speed the development of mobile Internet handsets. Bluetooth will make
interaction with nearby equipment and use of a mobile telephone as a universal remote control possible. The more applications that become available, the faster that
both the use and the number of users will grow.
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