A communication device for wireless communication systems, comprising: one or more processors, configured to determine information of a reference geographical location used for the communication device; and generate, based on the information of the reference geographical location and a current absolute geographical location of the communication device, information of a relative geographical location of the communication device with respect to the reference geographical location; and a communication unit, configured to transmit the information of the relative geographical location to a predetermined communication object wherein, the one or more processors are further configured to calculate a difference value between the current absolute geographical location of the communication device and the reference geographical location, and quantize and encode the difference value to generate the information of the relative geographical location; and a storage unit, configured to store one or more geographical location information quantization tables, and the one or more processors are further configured to quantize and encode the difference value based on a corresponding geographical location information quantization table; wherein the one or more processors are further configured to select the corresponding geographical location information quantization table in accordance with the distance to the reference geographical location and wherein the communication unit is configured to transmit information indicative of the selected geographical location information quantization table with the information of the relative geographical location. one or more processors, configured to determine information of a reference geographical location used for the communication device; and generate, based on the information of the reference geographical location and a current absolute geographical location of the communication device, information of a relative geographical location of the communication device with respect to the reference geographical location; and a communication unit, configured to transmit the information of the relative geographical location to a predetermined communication object wherein, the one or more processors are further configured to calculate a difference value between the current absolute geographical location of the communication device and the reference geographical location, and quantize and encode the difference value to generate the information of the relative geographical location; and a storage unit, configured to store one or more geographical location information quantization tables, and the one or more processors are further configured to quantize and encode the difference value based on a corresponding geographical location information quantization table; wherein the one or more processors are further configured to select the corresponding geographical location information quantization table in accordance with the distance to the reference geographical location and wherein the communication unit is configured to transmit information indicative of the selected geographical location information quantization table with the information of the relative geographical location.