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.
The success of the CSFB tests reinforces ZTE’s position on the cutting edge of LTE end-to-end solutions in the industry and the company’s ability to provide a variety of choices for operators. An active advocate of TD-LTE commercialisation, ZTE has launched diversified LTE terminals and products, including data cards, uFi, modules, tablets and smartphones. To date, ZTE has deployed TD-LTE commercial and trial networks for 29 leading operators in 16 countries worldwide.