关于dect射程问题

我们有个产品DECT射程问题想请教下。此产品天线功能参数很好，在空旷地方测试距离很好，可在室内测试距离很差，而把座机放在台面，把座机抬高40mm距离很好，请教大家为什么?怎样解决此问题。此产品用的是line天线。

上面问题，求助高手讨论。

怎没人讨认，是否太简单了。或没人懂。

first you should confirm the ouside range test condition meet 360degree have no dead angle at 300meter. if your longest communcation range only have  just 2-3 fully meet the test condition, your antenna have strong directional repednance. when you sure that your device can fully meet the no direction dependance and then do the inside test. sorry i have the simply chinese font,i shall type in by english