Siemens M35 Series Service Manual page 13

4. Wireless Transport Layer Security
WTLS incorporates security features that are based upon the established Transport layer
Security (TLS) protocol standard, that include data integrity checks, privacy on the WAP
Gateway to client leg and authentication.
5. Wireless Datagram Protocol
Allows WAP to be bearer independent by adapting the transport layer of the under-laying
bearer. WDP presents a consistent data format to the higher layer on the WAP stack.