Apparatus, and method, for implementing detection of system information changes in universal mobile telecommunications systems
View Patent ↗In a mobile telecommunications system comprising a network of a plurality of cells and at least one user equipment device, the user equipment is arranged, when the user equipment re-configures itself to enter a new state or performs cell reselection, to read broadcast system information and, when the broadcast system information indicates a change in system information, to update the system information of the user equipment device.
1. A method for enabling configuration changes in a user equipment device, the method comprising a telecommunications network:
broadcasting a system information change notification a first time to notify a device of the intent to change system information; and
broadcasting at least one repeat of the system information change notification in a Transmission Time Interval (TTI) that occurs before the system change is implemented.
2. A method according to claim 1 wherein when the system information change notification is sent in a PAGING TYPE 1 /SYSTEM INFORMATION CHANGE INDICATION message.
3. A method according to claim 1 wherein, when the device is in Cell_FACH, the system information change notification is sent as an Information Element (IE) “BCCH modification info” contained in a SYSTEM INFORMATION CHANGE INDICATION message transmitted on the Broadcast control channel (BCCH) mapped on at least one Forward Access Channel (FACH) on every Secondary CCPCH in the cell.
4. A method according to claim 1 wherein the network repeats the system information change notification after a time period comparable with the maximum time for the device to configure the PCH/FACH channel after reading system information prior to selecting the cell.
5. A method according to claim 4 wherein the time period is around 500 ms.
6. A method according to claim 1 wherein the network repeats the system information change notification up to the time the change occurs.
7. A method according to claim 1 wherein the network broadcasts the repeat of the system information change notification at a time close to the intended change in the system information.
8. A method according to claim 7 wherein the network sends the repeat of the system information change notification in a time interval prior to the time at which the system information is to be changed.
9. A method according to claim 1 wherein the repeat is sent in the TTI (X−1) immediately before the TTI (X) in which the system information is to be changed.
10. A method according to claim 1 wherein the repeat is sent in a TTI (X−n) before the TTI (X) in which the system information is to be changed, where the TTI (X−n) represents a TTI to which the particular device will listen by default.
11. A method according to claim 1 wherein if the system information change notification is set for a deferred time, the network broadcasts at least one repeat of the system information change notification to notify a device of the intent to change system information, the repeat of the system information change notification being sent within a period relative to the deferred time.
12. A method according to claim 1 wherein the network broadcasts the repeat of the system information change notification at a predetermined time selected from:
within one frame before the frame in which the system change is to be implemented;
within 10 frames before;
within 100 frames before;
within 1000 frames before;
within 4000 frames before.
13. A telecommunications network element for enabling configuration changes in a user equipment device, the telecommunications network element being arranged to:
broadcast a system information change notification a first time to notify a device of the intent to change system information; and
broadcast at least one repeat of the system information change notification in a Transmission Time Interval (TTI) that occurs before the system change is to be implemented.