Ns is a discrete event simulator targeted at networking research. Ns provides substantial support for simulation of TCP, routing, and multicast protocols over wired and wireless (local and satellite) networks.

正交幅度调制，即QAM。现有的协议，如802.11b无线以太网（Wi-Fi）协议和数字视频广播（DVB）协议都使用了64-QAM调制。-Quadrature amplitude modulation, i.e. QAM. Existing protocols, such as 802.11b wireless Ethernet (Wi-Fi) protocol, and Digital Video Broadcasting (DVB) protocols are used in 64-QAM m

Although many localization protocols have been proposed for wireless sensor networks in a three dimensional topology, the demand to further improve the accuracy of node positioning method make it necessary to design and develop new localization a