JSI, Vol. 5 (1) Aug. 2014. ISSN: 2229 – 5836 1 Journal of Science Information PHYSICAL DATA TRANSMISSION Vijay N. Pawar, Nagesh D. Sawant and *Swapnil Sunil Tandel Shri Jagdish Prasad Jhabarmal Tibrewala University, Rajasthan. *A. C. Patil College of Engineering, Mumbai University, Mumbai. ABSTRACT Early wired communication is known to be more reliable in terms of error but it comes with physical boundary. Modern wireless communication system hasovercome many drawbacks of wired communication systems. Due to its tempting features many systems now a days comes with mobility.But collaborating wireless communication instead of wired comes with a great deal of complexity and to abstain from those up to certain extent designed wireless solution can be used. Designed system have used with weather sensor system with which it transmits attributes of ambience like temperature, light, humidity to the receiving station. The system is request-response based in which after receiving the request from query station node processes it and generates the response and transmits to the query station. INTRODUCTION The various parameters like temperature, pressure. Humidityetc are sensed using suitable transducers. The electrical signal is in analog form. The signal is then converted in digital form using Analog to Digital (ADC) converter. This signal is connected to microcontroller for scanning each parameter after predefined time intervals. This microcontroller is interfaced to a Personal Computer which reads the data and displays it.The same data is sent to the transmitter through the output port of PC i.e. the serial port (RS. 232 port). The transmitter collects the signal and transmits it using either of the following methods: Infrared (IR) Transmitter Radio Frequency (RF) Transmitter The modulated IR / RF signal is transmitted through air. On the other side, the receiver is connected to another PC which collects this signal, demodulates it and sends it to the PC. In this way we can observe the received signal at both the PCs The designed system is request- response based RF system which