Hi,
Cisco's Content Transformation Engine was one of the first appliance-based solution on the market to deliver web-based applications to a variety of devices including Cisco IP Phones, Wireless Application Protocol (WAP) phones, personal digital assistants (PDAs).
Content transformation technology helps customers transparently optimize Web content for users accessing information with a variety of mobile or wired devices such as WAP PDAs, cell phones, Research in Motion (RIM) devices, or even Cisco IP phones.
The Content Services Gateway (CSG) provides the capability to examine the mobile wireless and wireline IP datastream beyond the IP and TCP/UDP headers so as to enable billing based on the content being provided to the end user and hence supports billing for the new wireless data services.
For details refer:
http://www.cisco.com/en/US/products/sw/wirelssw/ps779/products_white_paper09186a0080088853.shtml
http://www.cisco.com/pcgi-bin/Support/browse/psp_view.pl?p=Hardware:CTE1400