VoLTE Call's
In normal LTE networks, the users are sent to legacy CS networks (2G/3G) via CSFB mechanism whenever they have to make a voice call. CSFB is a good solution and it has evolved alot but still it takes longer time. The alternate solution is to have the voice session over LTE which is known as VoLTE (Voice over LTE). A VoLTE call is much quicker to setup as there is no fall back required to another RAT and also it has a better quality due to more bandwidth and advanced features. However, VoLTE is basically a PS call and it has its own challenges. VoLTE Call Setup Success Rate, Call Drop Rate and Quality are major issues that operators face after enabling VoLTE. In this article, I will explain the VoLTE basics along with capacity planning and dimensioning VoLTE Call Setup Traditionally, a VoLTE user attachs to the LTE network using both QCI-9 and QCI-5. QCI-9 is the default bearer for data while QCI-5 acts as the default bearer for voice and it carries SIP signaling. When a call n