Cellular telephone set having a wearable electronic device and a display device is disclosed. Wearable electronic device includes a first processor, a first storage memory, a small display, a small battery pack, a cellular communication module, a first local communication module, a character receiving unit, a first charging circuitry, a motion sensor, and a biosensor configured for generating physiological signals indicating health conditions of user. Display device includes second processor, second storage memory, large display, large battery pack, a second local communication module, a character input unit, video processing unit and second charging circuitry. Wearable electronic device is worn on a wrist of user and capable to perform cellular phone functions by itself without display device. Display device is configured to provide a full QWERTY keyboard to facilitate data entry into wearable electronic device. Display device is capable of charging wearable electronic device when connected in wired or wireless manner.
