Blackberry BROWSER VERSION 4.7.0 - FUNDAMENTALS GUIDE Podstawy - Strona 31

Przeglądaj online lub pobierz pdf Podstawy dla Oprogramowanie Blackberry BROWSER VERSION 4.7.0 - FUNDAMENTALS GUIDE. Blackberry BROWSER VERSION 4.7.0 - FUNDAMENTALS GUIDE 42 stron.

Drukuj stronę
Fundamentals Guide

Content optimization and delivery

Content optimization by the network gateway

The BlackBerry® MDS Connection Service and the BlackBerry Internet Service Browsing network gateways are specifically
designed to deliver content to the BlackBerry® Browser. To help maximize efficiency and minimize the bandwidth requirements
of content that is sent over the wireless network, these network gateways use optimization techniques unique to the BlackBerry®
Infrastructure.
The BlackBerry MDS Connection Service and the BlackBerry Internet Service Browsing network gateways optimize content in
the following ways:
•
by reading the existing content in the BlackBerry Browser cache to determine if requested content is already stored on the
device
•
by preprocessing requested content and filtering out unsupported or unnecessary markup or resources
•
by converting images into an appropriate format for display on the BlackBerry device, reducing the color depth of images,
and scaling images for display on a small screen size
•
by compressing content for efficient delivery over the wireless network
Some WAP network gateways might optimize content and might convert HTML to XHTML or limit the size of images. WAP network
gateways are not designed for a particular user agent, and therefore cannot offer the same level of optimization for the BlackBerry
Browser as the BlackBerry MDS Connection Service or the BlackBerry Internet Service Browsing network gateways. Content
delivery times are typically slower over WAP network gateways. WAP network gateways do not remove unsupported elements
before they send the content. As a result, the BlackBerry Browser must parse more content on the BlackBerry device, which
increases the time it takes to render the content.

Content transcoding

The BlackBerry® MDS Connection Service and BlackBerry Internet Service Browsing network gateways transcode data into
formats that are more suitable for sending over the wireless network and for rendering in the BlackBerry® Browser.
Data type
markup languages
Description
Markup languages are transcoded in the following ways:
•
HTML and XHTML are simplified and transcoded into a format similar to
WBXML.
•
WML is transcoded into WMLC.
•
SVG is transcoded into PME, a proprietary binary file format that BlackBerry
devices can render.
Content optimization and delivery
4
29