This program is a Demo application for BitLevelSMS software library which provides a PC-based user application with access to a mobile phone's Short Message Service (SMS) functionality over serial port, according to ETSI standards: GSM 07.05 (ETS 300 585) "Use of Data Terminal Equipment - Data Circuit terminating; Equipment (DTE - DCE) interface for Short Message Service (SMS) and Cell Broadcast Service (CBS)" and GSM 03.40. "Technical Realization of Short Message Service - Point-to-Point". BitLevelSMS Demo allows the user to: send and receive SMS messages in PDU mode on many GSM mobile phones, including Siemens C35, S25, ME45, Nokia 6610 and others. Interfaces to serial ports COM1-COM8. Supports SEND - RECEIVE - DELETE functions. Decodes sender number and service centre timestamp.