A method for a first wireless communication system and a second wireless communication system to share a spectrum resource, wherein the spectrum resource is divided into at least a first section and a second section, the method comprising: - the second wireless communication system using the first section and the second section of the spectrum resource until a first point in time, - the second wireless communication system clearing the first section of the spectrum resource from the first point in time, and - the first wireless communication system using the first section of the spectrum resource from a second point in time, - the second wireless communication system continuing to use the second section of the spectrum resource from the second point in time, wherein the second point in time (T2 is later than the first point in time, - the second wireless communication system clearing, from a third point in time, the second section of the spectrum resource, and - the first wireless communication system using, from a fourth point in time, the first section and the second section of the spectrum resource, wherein the fourth point in time is later than the third point in time. wherein the spectrum resource is divided into at least a first section and a second section, the method comprising: - the second wireless communication system using the first section and the second section of the spectrum resource until a first point in time, - the second wireless communication system clearing the first section of the spectrum resource from the first point in time, and - the first wireless communication system using the first section of the spectrum resource from a second point in time, - the second wireless communication system continuing to use the second section of the spectrum resource from the second point in time, wherein the second point in time (T2 is later than the first point in time, - the second wireless communication system clearing, from a third point in time, the second section of the spectrum resource, and - the first wireless communication system using, from a fourth point in time, the first section and the second section of the spectrum resource, wherein the fourth point in time is later than the third point in time. - the second wireless communication system using the first section and the second section of the spectrum resource until a first point in time, - the second wireless communication system clearing the first section of the spectrum resource from the first point in time, and - the first wireless communication system using the first section of the spectrum resource from a second point in time, - the second wireless communication system continuing to use the second section of the spectrum resource from the second point in time, wherein the second point in time (T2 is later than the first point in time, - the second wireless communication system clearing, from a third point in time, the second section of the spectrum resource, and - the first wireless communication system using, from a fourth point in time, the first section and the second section of the spectrum resource, wherein the fourth point in time is later than the third point in time.