Relationships between application layer protocols in softswitch are explored in this paper.Two notions, i.e.protocol relationship and protocol grouping, are pro
Two standards for security of WLAN,IEEE 802.11 i and WAPI,are introduced,and some shortcomings of them are pointed out.Based on hash chains technique to constru
Tropospheric Scattering(Troposcatter) and Tropospheric Ducting are two different mechanisms due to in-homogenoueties in the lower part of the Earths atmosphere.