《计算机科学导论》课件Unit 6Computer Networks.ppt

3 After reading this chapter, you are supposed tobe able to : OBJECTIVES 4 Personal area network Local area network Metropolitan area network Wide area network Internetwork 6-1 Types of Networks 5 Types of Networks We classify networks by their spanning distance as shown in Figure 6.1. At the top are the personal area networks that supports one person instead of a group. Beyond the personal area networks are longer-range networks. These can be classified as local, metropolitan, and wide area networks, each with increasing scale. Finally, the connection of multiple individual networks is called an internetwork. Without doubt, the worldwide Internet is the best-known (but not the only) example of an internetwork. 6 Types of Networks Figure 6.1 Classification of networks by spanning distance 7 Personal area network A personal area network (PAN) is a technology that let devices communicate with other nearby devices near a single individual, over a short range typically within 10 meters. Personal area networks can be constructed with cables or be wireless. For example, a computer can be connected with its peripherals, or a laptop can be connected with a smart phone or a printer, or a headset can be connected to a mobile phone, using some form of wireless technology. PANs can be wired or wireless. Wired PAN may be linked together using USB and FireWire. Wireless PAN (WPAN) is based on the standard IEEE 802.15 and typically use ANT+, Bluetooth, some infrared connections, ZigBee【紫峰技术〔协议〕】, UWB (Ultra Wideband) 【超宽频】,, RFID (Radio Frequency Identification) 【无线射频识别〔俗称电子标签〕】, 6LoWPAN, or NFC (Near Field Communication) 【近距离无线通信】. 8 Personal area network ANT+ is proprietary wireless sensor network technology used in the collection and transfer of sensor data. It is used in sports watches, workout machines, cycling power meters, fitness equipment, thermometers, speedometers, calorimeters, blood pressure monitors, blood glucose meters, heart rate monitors, position trac