Availability and Reliability of Core Networks (4G/5G) From a Deployment Standpoint

4G LTE core networks or service based 5G core networks may be created as a set of virtual network functions (VNFs) i.e., network service (NS). The NS can be deployed with the use of cloud computing platform. A virtual machine (VM) with specialized software is denoted as VNF. In this present work, via mathematical modelling, we derive the NS availability considering the placement of core network nodes in a single virtual machine (SVM) as well as in multiple virtual machines (MVM). We consider the failure perspective of host node, VMs, and core network nodes in the availability analysis. We also look at NS reliability in terms of the placement of VNFs of NS in SVM as well as in MVM. After that, we examine the availability and reliability of SVM based NS and MVM based NS. Then, we compare the availability as well as the reliability considering SVM based NS and MVM based NS. Comparison results show that an SVM based NS deployment can lead to a more than 14% gain in availability and more than 100% gain in reliability with respect to an MVM based NS deployment.