Despite the growing momentum behind LTE deployments, one of the greatest concerns for established network operators is the legacy of their mature voice networks and their role in the all-IP future. This week, Chinese vendor Huawei trumpeted circuit switched fallback as an opportunity to leverage these legacy networks.

The Chinese manufacturer said Thursday that it has successfully completed a circuit switched (CS) fallback voice call, in a lab environment in Shanghai, demonstrating that operators using Evolved Packet Core to provide pure data services will still be able to leverage their existing 2G network to provide voice services.

Early LTE deployments have not addressed the need for voice services over the new technology. Tommy Ljunggren, SVP and head of system development, mobility services at LTE pioneer TeliaSonera, and one of the Nordic carrier’s leading speakers on its LTE deployment, said that his firm’s 4G launch was easier because the firm, “Focused on data only and not complicated it with voice and voice integration with legacy systems and so on.”

According to the standard solution defined by the 3GPP, CS fallback is considered the preferred solution for the early stages of LTE or EPC network deployment as it allows operators to make full use of their existing networks to protect investments.