Wap push

Wireless Application Protocol (WAP) is a technical standard for accessing information over a mobile wireless network. A WAP browser is a web browser for mobile devices such as mobile phones that uses the protocol. Before the introduction of WAP, mobile service providers had limited opportunities to offer interactive data services, but needed interactivity to support Internet and Web applications such as:

The Japanese i-mode system offers another major competing wireless data protocol. As of 2013, WAP use has largely disappeared in Europe and the United States. Most modern handset internet browsers now fully support HTML, so do not need to use WAP markup for webpage compatibility, and most of them are no longer able to render and display pages written in WAP.

The WAP standard described a allowing the interoperability of WAP equipment, and software with different network technologies, such as GSM and IS-95 (also known as CDMA).

The bottom-most protocol in the suite, the (WDP), functions as an adaptation layer that makes every data network look a bit like to the upper layers by providing unreliable transport of data with two 16-bit port numbers (origin and destination). All the upper layers view WDP as one and the same protocol, which has several "technical realizations" on top of other "data bearers" such as SMS, USSD, etc. On native IP bearers such as GPRS, UMTS packet-radio service, or on top of a circuit-switched data connection, WDP is in fact exactly UDP.

WTLS, an optional layer, provides a public-key cryptography-based security mechanism similar to TLS.

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Wikipedia