WMBus connectivity option for a product

I'm looking for help for my project : Adding WMbus communication option for our utility water meter product. The scope includes the following: 1. Developing and testing and delivering WMBus stack for meter in C 2. Should be able to support various WMBus communication modes 3. Also check the possibility of running in sniff mode, waiting for the request from data reader application (data concentrator / mobile reading device) and send requested data when request received.