新手求解释：NS2中 set dist(5m) 7.69113e-06
问题描述：
新手求解释：NS2中 set dist(5m) 7.69113e-06
# For model 'TwoRayGround'
set dist(5m) 7.69113e-06
set dist(9m) 2.37381e-06
set dist(10m) 1.92278e-06
set dist(11m) 1.58908e-06
set dist(12m) 1.33527e-06
set dist(13m) 1.13774e-06
set dist(14m) 9.81011e-07
set dist(15m) 8.54570e-07
set dist(16m) 7.51087e-07
set dist(20m) 4.80696e-07
set dist(25m) 3.07645e-07
set dist(30m) 2.13643e-07
set dist(35m) 1.56962e-07
set dist(40m) 1.20174e-07
Phy/WirelessPhy set CSThresh_ $dist(25m)
Phy/WirelessPhy set RXThresh_ $dist(25m)
答
这是NS-2提供一种无线传播模型（2径模型,包括直射波和地面反射波）
目前NS2支持三种无线传播模型（Radio Propagation Models）：
free space model
two-ray ground reflection model
shadowing model
后面的小数是指能量,你会发现随着距离的增加能量逐渐衰减!所以dist是距离的缩写!这个模型的数据是固定的,不需要改动!