ZTE Completes World-First TD-LTE CSFB Tests

ZTE says that it has completed a series of world-first tests between TD-LTE and 2/3G GSM/UMTS networks using circuit switching fallback (CSFB)

The operations included testing a series of services such as mobile originating calls, mobile terminating calls and short messaging service, or SMS. The tests further reinforce the convergence of TD-LTE and existing networks.

In addition, the tests demonstrate that CSFB is a reliable voice solution on TD-LTE networks. CSFB allows greater call range. When a user on a phone using CSFB that operates on an LTE network initiates a voice call outside the range of a 4G network, the CSFB handset will rapidly "fall back" to available 2/3G networks to complete the call.

This use of existing infrastructure also enables voice services without IMS deployments. It is a single chip voice-implemented solution defined by 3GPP.