Page 182 - DCAP512_WAP_AND_WML

WAP & WML

Notes service with respect to throughput, error rate and delays. The WAP protocols are modeled to
substitute for or tolerate these varying levels of service.
Since the WDP layer offers the convergence between the bearer service and the rest of the WDP
stack, the WDP specification lists the bearers that are aided and the techniques used to permit
WAP protocols to run over each bearer. The list of aided bearers will change over time new
bearers being added as the wireless market evolves.
Self Assessment

Fill in the blanks:
5. WAP defines a set of standard components that enable communication between mobile
terminals and ……………………
6. WAP communication protocols enable the communication of …………………… requests
from the mobile terminal to the network web server.
7. The WAP content types and …………………… have been optimized for mass market,
hand-held wireless devices.

8. The protocol gateway translates …………………… from the WAP protocol stack (WSP,
WTP, WTLS, and WDP) to the WWW protocol stack (HTTP and TCP/IP).
9. The …………………… is a general-purpose application environment based on a mixture
of the World Wide Web (WWW) and Mobile Telephony technologies.
10. The Transport layer protocol in the WAP architecture is the ……………………
11. WTLS is a security protocol based upon the industry standard Transport Layer Security
(TLS) protocol, formerly known as ……………………
12. …………………… contains facilities for detecting and rejecting data that is replayed or not
successfully verified.
13. The WAP Transaction Protocol (WTP) layer provides transaction support, adding
…………………… to the datagram service provided by WDP.

12.3 Session Management

In order to tailor your WAP application to a user, you will need to create a software session in
which you can store context information. This session may contain the name of the user and any
data that he generates during his visit, such as items in a shopping cart.
WAP has no support for application sessions built in to its definition. You will have to manually
create them by authenticating the user and tracking his progress. The next few sections will
address how to do this, but it should be remembered that the WML applications should be as
simple as possible to use – you should minimize the information burden you place on the user.
12.3.1 Client Authentication

There are two main ways to authenticate a user for your application: manually in a deck or with
built-in Web server basic authentication. The former requires that you create a user database
with login names and passwords, while the latter requires that you use a user database that your
Web server can access. To create a manual authentication deck, you simply need to ask the user
for his name and password and then pass him on to the deck he wanted originally. This is a very
simple process in most cases. An alternative approach to creating your own authentication
mechanism is the built-in facility in the Web server. This built-in facility is Basic Authentication –
HTTP supplies it in IETF RPC 2617.

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