Apparatus and method for making measurements in mobile telecommunications system user equipment
View Patent ↗A method and apparatus for selecting cells in a mobile telecommunications system, the system comprising a network of a plurality of cells of a Universal Mobile Telecommunications Systems (UMTS) and a network of a plurality of cells of a second Radio Access Technology (RAT), the method comprising, at a user equipment device: when in UMTS mode, flagging in a neighbouring cell list stored on the user equipment device information for a cell of a second RAT which is known to be unsuitable for selection. Information from the neighbouring cell list information for the flagged cell may be removed, in particular for a limited period of time.
1. A method of selecting cells by a user equipment device (UE), the UE configured to be operable in a mobile telecommunications system comprising Universal Mobile Telecommunications Systems (UMTS) cells and second Radio Access Technology (RAT) cells, the method comprising:
flagging, in a neighbouring cell list and when in UMTS mode, information for a cell of a second RAT which is known to be unsuitable for selection, further including a specified time period during which said cell will not be selected.
2. The method according to claim 1 , further comprising removing for the time period from the neighbouring cell list information for the flagged cell.
3. The method according to claim 2 , further comprising restoring the information relating to the flagged cell upon expiry of the time period.
4. The method of claim 1 further comprising: generating measurement data for the cells in the neighbouring cell list; identifying from the measurement data a cell which meets a cell selection criterion; determining whether the identified cell is a cell of the second RAT; and, when the identified cell is determined to be a cell of the second RAT, determining whether the identified cell is suitable for selection and, when the identified cell is deemed not suitable, removing the identified cell from the neighbouring cell list.
5. The method according to claim 4 further comprising re-initiating the generating measurement data step for the cells in the neighbouring cell list step with the omission of the flagged cell.
6. The method according to claim 4 , further comprising storing the measurement data in an order relative to the meeting of the cell selection criterion.
7. The method according to claim 1 further comprising adding the flagged cell to a list of cells known to be barred.
8. The method according to claim 1 wherein the flagged cell is known to be not suitable for selection from information generated from previous attempts at cell selection.
9. The method of claim 1 further comprising: identifying a second cell of the second RAT in the neighbouring cell list which meets a cell selection criterion.
10. The method according to claim 9 , wherein the step of identifying a second cell which meets a cell selection criterion comprises identifying a cell which best meets the cell selection criterion.
11. The method according to claim 10 , further comprising, when the cell which best meets the cell selection criterion is not suitable for selection, determining whether a cell which next best meets the selection criterion is suitable for selection.
12. A user equipment device (UE) configured for use in a telecommunications system comprising a network of Universal Mobile Telecommunications System cells and at least one other Radio Access Technology (RAT) cell comprising:
a processor and memory, the UE being operable to: when in UMTS mode, flag entries in a neighbouring cell list that correspond to a second RAT further including a specified time period for each flagged entry, each flagged entry and its associated time period configured to allow the UE to not select the flagged entry during pendancy of the time period.
13. The UE of claim 12 further operable to remove flagged cells from the neighbouring cell list.
14. The UE of claim 13 further operable to restore cell information to the neighbouring cell list upon expiry of the time period.