Kannel is an open source project to keep an eye on. It is a WAP gateway that supports the bajillion different protocols that fall under WAP. According to the status page, the following protocols/features are working:
- WSP: connection oriented and connectionless modes.
- WML compiler from text to binary form. Supports a number of character sets.
- WMLScript compiler: Converts textual WMLScript source code to a bytecode format.
- WTP: class 0, 1, and 2. Error handling is not very much tested, though.
- WDP: Supports only UDP bearer (GSM data and GPRS), no SMS bearer suppor yet.
- SMS center protocols: CIMD 1.3, CIMD 2.0, SMPP 3.4, UCP/EMI 4.0. Also: SEMA SMS2000 OIS protocol for SMS centers over Radiopad and X.25. These work for SMS gateway, not WAP gateway. Kannel can also use some types of GSM phones and GSM modems as pseudo SMS centers.
This project could lower the bar for entering the WAP field.