An electronic device, which comprises a memory, a processor, and a serial number length adjustment program stored in the memory and operable on the processor is disclosed. The serial number length adjustment program is executed by the processor to implement following functions: performing an angle estimation algorithm on all user equipments (UEs) through a low-frequency band to estimate beam angles of the UEs relative to the electronic device; generating high-frequency band beams of the UEs relative to the electronic device according to the estimated beam angles; and enabling the electronic device to communicate with the UEs according to the generated high-frequency band beams.