In the recent IMS/VoLTE Competitive Assessment, ABI Research rates Ericsson as the overall leader with respect to innovation and implementation. Ericsson’s large cache of IMS and VoLTE patents, industry leadership in interoperability testing, and market share firmly places them in the top position. Closely at their heels are Alcatel-Lucent and Nokia Siemens Networks, both of whom have strong portfolios, and in some aspects are superior. Alcatel-Lucent and Nokia Siemens Networks hold dominant positions at the most demanding, leading wave LTE IMS deployments, and Nokia Siemens Networks is ahead with virtualization technology. Additionally, the Huawei and ZTE unique propositions are noteworthy.