لطفا منتظر باشید ...
14.3 OracleAS Wireless Deployment
OracleAS
Wireless applications can be deployed for many different types of
access, including wireless Internet browser, two-way ASK messaging,
voice, J2ME devices, and delivery of alerts and notifications.
Because of this flexibility, it is desirable to have a single
application delivery via multiple channels. The
Multi-Channel Server is designed
specifically to meet this need.The Multi-Channel Server delivers device-independent content based on
the device's capabilities and ensures compatibility
with new and emerging devices. In effect, the Multi-Channel Server
provides a common interface that eliminates the need for
device-specific applications. It enables the adaptation of text,
images, ring tones, voice grammars, and audio/video streams for each
device type. For example, if an application generates GIF images, and
the device supports only Wireless BitMap (WBMP) format, the
adaptation engine adapts the image to WBMP before it is sent to the
device. The Multi-Channel Server also supports standard markup
languages and provides the XForms engine. Devices are
detected as they make requests. The Multi-Channel Server supports URL
caching and can be deployed within existing portals.Browser-based applications are developed using the OracleAS Wireless
XML or
XHTML languages. Data is accessed
using these applications in a synchronous fashion via wireless
Internet-connected devices. The typical communication protocols used
for deployment include CDMA and 1xRTT; GSM with GPRS and UMTS; CDPD;
Mobitex; and 802.11 a, b, and g.Applications that access data using ASK message protocols via the
Multi-Channel Server can operate in disconnected mode. Messaging
devices used for an ASK application might include two-way pagers,
email clients, instant messaging clients, and mobile phones with SMS.
Once the Multi-Channel Server receives an incoming message, it parses
the message and sends requests to applications via HTTP. OracleAS
Wireless then transforms the content of the response (initially
defined by XHTML tags) and matches it to message services available
on the mobile device.Voice applications respond to requests made via speech or a
phone's keypad. Once a request is recognized at a
voice gateway, the request is sent via HTTP to the Multi-Channel
Server. From there, it is relayed to the appropriate application.
When the application responds, OracleAS Wireless receives it in XML
and transforms it to a user device markup language (commonly
VoiceXML).Rather than deploying to proprietary device interfaces, some
developers prefer to use J2ME as the runtime environment. OracleAS
Wireless makes this possible by extending Web Services to J2ME
devices through a Proxy Server in the J2ME Development Kit.Three OracleAS Wireless components are used to
deliver
alerts and notifications:Data Feeder
Retrieves alert content from a database, file, URL, or other source
Alert Engine
Manages alert subscriptions and triggers
Multi-Channel Server
Formats messages and delivers alerts to specified devices over
appropriate channels
Security
safeguards are crucial to successful mobile application deployment.
In securing your applications, you must ensure the three fundamental
goals of security: privacy, data integrity, and authentication:Privacy
You can ensure the privacy of your mobile applications by
implementing appropriate encryption and decryption of data.
Data integrity
You can ensure data integrity using various forms of digital security.
Authentication
You can ensure authentication using digital certificates.
