A method and corresponding system is provided to help mitigate the potential quality-of-service degradation associated with fast-moving UEs operating in a network that provides higher-bandwidth frequency channels in some but not all wireless coverage sectors. In accordance with the method, a base station may evaluate a UE's current speed and, when that speed exceeds a threshold speed, the base station may instruct the UE to register on a low-bandwidth channel rather than a higher-bandwidth channel. Registering for service on a low-bandwidth channel instead of a higher-bandwidth channel may help ensure that the UE maintains a consistent quality of service as the UE moves from coverage area to coverage area. Further, the base station may also query nearby base stations to determine whether there exists a sufficient number of base stations that operate on higher-bandwidth channels. If so, the base station may instruct the UE to use a higher-bandwidth channel.