FIELD

This invention generally relates to wireless communications and more particularly to rate adaptation in a radio access network.

BACKGROUND

3rd Generation Partnership Project (3GPP) specified a new voice codec named EVS (Enhanced Voice Services). A codec is a device or program that (1) encodes data for transmission and/or storage, and (2) decodes received data for playback, storage, and/or editing. EVS provides high voice quality over a wide range of rates, which allows the low EVS codec rates to still have sufficient quality, and may be used in poor coverage environments and overload scenarios. However, it is still desirable to use the higher codec rates for enhanced audio quality whenever possible. EVS has the flexibility, with a wider rate range and full audio bandwidth, to deliver speech quality that matches other audio inputs, such as stored music, while offering high robustness to delay, jitter, and packet losses.

Radio conditions may also impact the codec mode and codec rate. For example, under poor radio conditions, a lower codec rate may be used to reduce the packet loss, whereas a higher codec rate can be used in good radio conditions to ensure a better user experience. Therefore, a flexible and efficient codec modification mechanism is needed that accounts for the voice codec, network capacity, radio conditions, and user experience.

SUMMARY

A first user equipment (UE) device receives a configuration for a first timer from a base station that is serving the UE device. The first UE device also receives a recommended bitrate from the base station. The recommended bitrate is to be used for a Voice over Long-Term Evolution (VoLTE) call or a Video over Long-Term Evolution (ViLTE) call between the first UE device and a second UE device. The first UE device activates the first timer in accordance with the configuration. The first UE device is prohibited from transmitting a bitrate query to the base station while the first timer is running. Upon receiving a recommended bitrate that is below a Guaranteed Bit Rate for the call between the first UE device and the second UE device, the first UE device stops the first timer and transmits a bitrate query to the base station.

