Method in a base station for handling a request from a first user equipment for accessing a service in a radio communications network, the method comprising the steps of: receiving a first wide time interval of an incoming signal, which incoming signal comprises a first signal sent from the first user equipment, the first signal extending along a first narrow time interval being a part of the first wide time interval, the first narrow time interval of the first signal being a possible service access request message or preamble thereof; analysing the incoming signal by searching the first wide time interval; in which analysis it is detected that the first signal is a possible service access request message or preamble thereof, wherein the first signal of the user equipment has a specific energy and wherein the first signal is detected as being a possible service access request message or preamble thereof when the specific energy exceeds a predetermined first threshold value, when searching the first wide time interval in the step of analysing; identifying how the first narrow time interval of the first signal relates to the first wide time interval, which relationship will be the same for subsequent time intervals of the incoming signal comprising the first signal from the first user equipment; receiving a subsequent second wide time interval of the incoming signal, the second wide time interval comprising a second narrow time interval of the first signal, which second narrow time interval is a part of the second wide time interval and which second narrow time interval of the first signal is the possible service access request message or preamble thereof sent again from the first user equipment; wherein the method is further characterized by: analysing the incoming signal by searching the second narrow time interval, which second narrow time interval is found by using the identified knowledge of the relationship between the wide time interval and the narrow time interval in subsequent time intervals of the incoming signal comprising the first signal from the first user equipment. receiving a first wide time interval of an incoming signal, which incoming signal comprises a first signal sent from the first user equipment, the first signal extending along a first narrow time interval being a part of the first wide time interval, the first narrow time interval of the first signal being a possible service access request message or preamble thereof; analysing the incoming signal by searching the first wide time interval; in which analysis it is detected that the first signal is a possible service access request message or preamble thereof, wherein the first signal of the user equipment has a specific energy and wherein the first signal is detected as being a possible service access request message or preamble thereof when the specific energy exceeds a predetermined first threshold value, when searching the first wide time interval in the step of analysing; identifying how the first narrow time interval of the first signal relates to the first wide time interval, which relationship will be the same for subsequent time intervals of the incoming signal comprising the first signal from the first user equipment; receiving a subsequent second wide time interval of the incoming signal, the second wide time interval comprising a second narrow time interval of the first signal, which second narrow time interval is a part of the second wide time interval and which second narrow time interval of the first signal is the possible service access request message or preamble thereof sent again from the first user equipment; analysing the incoming signal by searching the second narrow time interval, which second narrow time interval is found by using the identified knowledge of the relationship between the wide time interval and the narrow time interval in subsequent time intervals of the incoming signal comprising the first signal from the first user equipment.