Tham khảo tài liệu 'smart home systems part 3', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Integrated Wireless Technologies for Smart Homes Applications 21 The protocol stack of Zigbee defines only some functionality in layers on top of the physical and MAC layers which are defined in the IEEE standard. It provides the set of programming tools for the intended market. Furthermore ZigBee technology defines a set of applications profiles to facilitate the development and deployment of ZigBee devices from different manufacturers as shown in Fig. 5 Gislason 2008 . PAN coordinator PANC 2 Reduced Function Device RFD Full Function Device FFDjRouter Fig. 4. Possible ZigBee networking topologies Fig. 5. ZigBee Applications Profiles RFID Radio Frequency Identification RFID describes a system that transmits the identity of an object wirelessly using radio waves Want 2006 . It defines a RFID tag holding information about the object carrying the tag and a RFID reader. The RFID tag transmits signals containing its data when it is scanned by the reader. The RFID tag can be either active or passive where an active tag contains a battery and the passive tag does not have a battery. The passive tag uses the reader s magnetic field and converts it to DC voltage to power up its circuitry. Consequently the passive tags are cheaper and have lower range when compared to active tags. RFID systems can be categorized based on the used frequency ranges. The Low-Frequency LF systems use signals with a frequency between 124-135KHz. The High-Frequency HF systems use a and the Ultra-High-Frequency UHF systems use a frequency between 860-960MHz. In general the LF RFID systems have short reading ranges and lower system costs. In case longer reading range is required HF RFID systems can be used however their cost is higher. 22 Smart Home Systems RFID systems can be used in smart homes where every single object can be connected to the Home Area Network HAN through a virtual wireless address and unique identifier Darianian and Michael 2008 . This can be used to keep .
