In the present world is linked in a network to exchanges the data

In the present world is linked in a network to exchanges the data, news and views through Internet . According to World Statistics of specialist about Internet as at December 31st in 2011 there was an estimated 2, 267, 233, 000 Internet users worldwide (Anon., n.d.) . While coming to the Things which can be any object or person which can be distinguishable by the real world. Everyday , every time objects include not only electronic devices .we encounter and consume daily and technologically advanced devices and gadgets, but “things” that we do n’t think of as electronic at all. furniture materials ,food, clothing, and equipment, merchandise and specialized items landmarks , monuments and works of art and all the miscellany of commerce, culture and sophistication (L.M. Goncalves,J.G. Rocha, P.F. Rocha, M.P. Silva, and S. LancerosMendez, 2010).The Internet of Things (IoT) provide users to bring physical objects into the sphere of cyber world.
Near Filed Communication (NFC)
Near Field Communication (NFC) is a set of short range wireless technology at a particular frequency (13.56 MHz), typically requiring a distance of 4 cm. NFC technology helps life easier and more convenient for consumers by making it simple to do transactions, exchange digital data, and connect electronic devices even a touch. Allows intuitive initialization of wireless networks and NFC is complementary to Bluetooth and 802.11 with their long distance capabilities at a distance up to 10 cm. It does not depend on on environment , It does n’t need line of sight and easy and simple connection method. It is first innovated by Philips and Sony companies. Data exchange rate is now days approximately 424 kbps. Power consumption of NFC is under 15ma during the data tranfer.
ZigBee
ZigBee is one of the protocols developed for enhancing the features of wireless sensor networks. ZigBee technology is created by the ZigBee Alliance which is founded in the year 2001. Characteristics of ZigBee are low cost, low data rate, relatively short transmission range, scalability, reliability, flexible protocol design. It is a low power wireless network protocol based on the 802.15.4 standard (Chen, X.-Y. and Jin, Z.-G, 2012). ZigBee has range of around 100 meters and a bandwidth of 250 kbps and the topologies that it works are star, cluster tree and mesh. It is widely used in home automation, digital agriculture, industrial controls, medical monitoring & power systems.
Wireless sensors and smart devices can be controlled by the internet anytime and anywhere with the IoT concept. Wireless sensor networks (WSNs) mostly seen in detecting events and identifying surrounding information. Since sensors which are in wearable devices are powered by portable battery , recharging the batteries of smart devices by home electricity is very hard to achieve. For the most of smart online operations, energy generating studies have been much attention through the researchers. The researchers said that energy generating technologies could be applied in, alarm sensors, smart meters, smoke detectors and remote controls. There will be 25 billions of Internet connected devices by 2020 according to calculations of statistics specialists . Wireless sensors which are included in IoT devices are connected to a network will gather information about the environment from the sensor terminals. A key requirement for IoT and M2M concept is the ability to locate place wireless sensors in any kind of locations to obtain the necessary signals .In spite of above there is another big issue is the battery use and life or the installation of power distribution by the wire network or the time period for the replacement of battery . It is worst that fixing this a problem with 10-20 batteries or huge battery with large capacity . there are lots of people those are concerns about not only initial costs for battery but also the large scale of maintenance costs .Those facts reasoned for spread the studies about the portable energy generation with the smart wearable devices. solar cells, piezoelectric elements, and thermoelectric elements are used as power generating elements to convert vibration, light and heat into electric power, then use that electric power efficiently. IoT based technologies and wireless networks would be produced now because semiconductors have achieved a point between the improving power generating