WIRELESS HOME AUTOMATION

Following table provides links to useful  RF  converters and calculators. It include aggregate noise figure  calculator , circular waveguide lowest cutoff frequency frequency calculator, dBm to dBW converter, dBm to Watt  converter , Watt to dBm converter, microstrip line impedance calculator, PI attenuator resistance value calculator, Power Divider output port value calculator, rectangular waveguide cut off frequency calculator, return loss to VSWR converter, Skin depth calculator, Strip line impedance calculator, T attenuator resitances calculator, RF Exposure calculator, RF Field Strength, RF Transformer calculator, TEM wavelength calculator, waveguide breakdown power, planar resistance calculator, interdigital capacitance, spiral inductance calculator, circular and rectangular cavity resonator calculators, plane wave calculator, reflex klystron calculator, slotline calculator, magnetron, reflection coefficient, Time Domain Reflectometry length, TWT, Tunnel diode, varactor diode

z-wave frame structure   As shown in the fig-1,  z-wave frame  consists of a preamble part, SOF(Start of Frame), Frame data and EOF(End of Frame) symbol. The data part is manchester codes or NRZ coded based on data rate. MAC layer controls the RF spectrum. Data part comes from the upper layers and z-wave frame as mentioned in formed at the MAC/PHY layers. After this is done the z-wave frame as depicted is transmitted by the RF antenna after necessary radio frequency conversion as desired using RF Transceiver. For details on z-wave frame structure as well as various z-wave MAC layer frame types, Read more . z-wave protocol stack The  z-wave protocol stack  consists of PHY layer, MAC layer, Transport layer, Network layer and application layer. Other than servicing their peers all the layers have their own tasks.  Read more . z-wave Physical layer(zwave PHY) The  z-wave Physical layer  takes care of preamble insertion in the z-wave frame. It takes care of modulation and demod

Z-wave technology based devices operates in ISM band. It is developed for low bandwidth data communication applications such as security sensors, home automation, alarms etc. The following section mentions frequencies used in z-wave. It uses 868.42 MHz in Europe and 908.42MHz in USA. Following table-1 mentions basic features of z-wave technology widely used in IoT(Internet of Things) due to low power and low data rate. Z-wave protocol is developed by Sigma Designs, Inc. including encryption. Open source implementation of Z-Wave protocol stack known as open-zwave is also available but it does not support security layer. Z-wave PHY and MAC layer specifications are defined in ITU-T G.9959 standard. Specification z-wave support Standard ITU-T G.9959 (PHY and MAC) RF Frequency Range 868.42 MHz in Europe, 908.42 MHz in US Data rate 9.6, 40, 100 Kbps Maximum Nodes 232 Architecture Master and slave in mesh mode MAC layer CSMA/CA RF PHY modulation FSK (for 9.6kbps and 40 kbps), GFSK