Method and arrangement for making a handover decision in a mobile communication system
AssigneeNokia Telecommunications Oy
InventorTomi Vaara
Life of this patent
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Abstract
The invention relates to a method and arrangement for making a handover decision in a mobile communication system of multilayer radio coverage, which comprises measuring at a mobile station (MS) a radio signal transmitted by a base station (BTS) of a microcell, and reporting the measurement results at substantially regular intervals. The invention is characterized by determining a relative speed for the mobile station on the basis of the number and classification of the measurement results received at substantially regular intervals. Mobile stations moving at a speed slower than the relative speed are defined as slow moving and commanded to register in the base station of a suitable microcell (A, B, C).
Claims11
A method for making a handover decision in a mobile communication system comprising at least one microcell, the coverage area of which is at least mainly located within the coverage area of a another cell, said method comprising
- measuring at a mobile station a signal strength of a radio signal transmitted by a base station of a microcell, and reporting the a signal strength measurement results at substantially regular intervals to the mobile communication system,
- comparing each of said reported signal strength measurement results with a preset signal threshold level,
- classifying each of said signal strength measurement results above the threshold level as acceptable and each of said signal strength measurement results below the threshold level or are missing measurement results as unacceptable,
- determining a relative speed for the mobile station on the basis of a relative number of the measurement results classified as acceptable and unacceptable,
- defining a mobile station as a slow moving mobile station, when the determined relative speed of said mobile station is lower than a predetermined relative speed, and
- commanding mobile stations defined as slow moving mobile stations to switch to the, base station of a suitable microcell.
An arrangement for making a handover decision in a mobile communication system comprising at least one microcell the coverage area of which is at least mainly located within the coverage area of another cell, and mobile stations arranged to measure a signal strength of a radio signal transmitted by a base station of at least one microcell and to report the signal strength measurement result at substantially regular intervals, said arrangement comprising:
- first comparison means for classifying the signal strength measurement results received from a mobile station at substantially regular intervals for the base station of each microcell, by classifying each of said signal strength measurement results above the pre-set signal threshold level as a acceptable and each of said signal strength measurement results below the threshold level or are missing measurement results as unacceptable;
- counter means for determining a relative speed of the mobile station by counting a relative number of the signal strength measurement results classified as acceptable and unacceptable for the base station of each microcell and
- second comparison means for comparing the relative speed of the mobile station with a pre-set threshold value and when the threshold value is exceeded, defining the mobile station as a slow moving mobile station, and
- means for commanding a mobile station defined as a slow moving mobile station to switch to the base station of a suitable microcell.
Dependencies are inferred from the claim text.