Radio measurements in cellular telecommunication systems

A method comprising:

• measuring, at a mobile terminal, a radio signal from a cell of a cellular telecommunications network on which the mobile terminal is camped;
• performing a mobility assessment of the mobile terminal within the cell and determining, based on the mobility assessment, that the mobile terminal is either fast moving or slow moving;
• applying a filter to the radio signal measurement to generate a filter output, the filter being:
• a fast filter if the mobile terminal has been determined to be fast moving, or
• a slow filter if the mobile terminal has been determined to be slow moving;
• and
• comparing the filter output to a radio signal threshold value to determine whether or not to trigger a mobility related event, the radio signal threshold value being dependent upon the mobility assessment of the mobile terminal.

A mobile terminal comprising:

• means for measuring a radio signal of a cell at the mobile terminal;
• means for performing a mobility assessment of the mobile terminal within the cell and determining, based on the mobility assessment, that the mobile terminal is either fast moving or slow moving;
• means for calculating an average value of a plurality of radio signal measurements of the cell over a time period, the time period being equal to:
• a first predetermined length of time if the mobile terminal has been determined to be fast moving, or
• a second predetermined length of time if the mobile terminal has been determined to be slow moving, the second predetermined length of time being longer than the first predetermined length of time;
• and
• means for comparing the calculated average value to a radio signal threshold value to determine whether or not to trigger a mobility related event, the radio signal threshold value being dependent upon the mobility assessment of the mobile terminal.

A cellular telecommunications network comprising:

• means for receiving measurements of a radio signal of a cell at a mobile terminal;
• means for performing a mobility assessment of the mobile terminal within the cell and determining, based on the mobility assessment, that the mobile terminal is either fast moving or slow moving;
• means for calculating an average value of a plurality of radio signal measurements of the cell over a time period, the time period being equal to:
• a first predetermined length of time if the mobile terminal has been determined to be fast moving, or
• a second predetermined length of time if the mobile terminal has been determined to be slow moving, the second predetermined length of time being longer than the first predetermined length of time;
• and
• means for comparing the calculated average value to a radio signal threshold value to determine whether or not to trigger a mobility related event, the radio signal threshold value being dependent upon the mobility assessment of the mobile terminal.

A mobile terminal comprising:

• means for measuring a radio signal from a cell at the mobile terminal;
• means for performing a mobility assessment of the mobile terminal within the cell and determining, based on the mobility assessment, that the mobile terminal is either fast moving or slow moving;
• means for applying a filter to the radio signal measurement to generate a filter output, the filter being:
• a fast filter if the mobile terminal has been determined to be fast moving, or
• a slow filter if the mobile terminal has been determined to be slow moving;
• and
• means for comparing the filter output to a radio signal threshold value to determine whether or not to trigger a mobility related event in a cellular telecommunications network, the radio signal threshold value being dependent upon the mobility assessment of the mobile terminal.

A cellular telecommunications network comprising:

• means for measuring a radio signal from a cell at a mobile terminal;
• means for performing a mobility assessment of the mobile terminal within the cell and determining, based on the mobility assessment, that the mobile terminal is either fast moving or slow moving;
• means for applying a filter to the radio signal measurement to generate a filter output, the filter being:
• a fast filter if the mobile terminal has been determined to be fast moving, or
• a slow filter if the mobile terminal has been determined to be slow moving;
• and
• means for comparing the filter output to an a radio signal threshold value to determine whether or not to trigger a mobility related event in the network.