Apparatus, computer programs and methods for enabling filtering of neighbor cells or frequencies
View Patent ↗A serving cell sends to user equipments (UEs) indications of frequency bands supported by neighbor cells/frequencies, at least one individual neighbor cell/frequency supporting a plurality of frequency bands. The neighbor cells/frequencies are filtered by the UE to retain only those that are indicated to support a frequency band or frequency bands which are also supported by the UE. The sent indications comprise, for each respective neighbor cell/frequency, one absolute radio frequency channel number (ARFCN) associated with the respective neighbor cell/frequency and the frequency band or bands associated with the respective neighbor cell/frequency. Examples are given of various system information blocks for sending the frequency band indications to the UE. In one embodiment they are arranged in an information element IE having an entry for each of the neighbor cells/frequencies and a list of frequency bands for each entry.
1. An apparatus comprising:
a processing system comprising at least one processor and a computer-readable memory storing a program, in which the processing system is constructed and arranged to cause the apparatus at least to:
obtain frequency bands supported by neighbor cells, in which there is at least one individual neighbor cell which supports a plurality of frequency bands; and
send to user equipments indications of the frequency bands associated with the respective neighbor cells that support them, including the plurality of frequency bands supported by the at least one individual neighbor cell;
wherein the indications of the frequency bands comprise, for at least the one individual neighbor cell:
one absolute radio frequency channel number (ARFCN) associated with the at least one individual neighbor cell; and
the plurality of frequency bands associated with the at least one individual neighbor cell,
wherein for the at least one individual neighbor cell, the indicated one ARFCN and the plurality of frequency bands are such that at least one other ARFCN can be derived therefrom.
2. The apparatus according to claim 1 , in which the indications are sent to the user equipments in system information broadcast by the apparatus which comprises a serving cell, and the at least one individual neighbor cell is a neighbor cell to the serving cell.
3. The apparatus according to claim 2 , in which the system information comprises at least one of system information block types 11 , 11 bis, 12 , 19 and 3 .
4. The apparatus according to claim 2 , wherein the serving cell is at least one of:
a node B in a universal mobile telecommunications system (UMTS), and
an evolved node B in an evolved universal terrestrial radio access network (EUTRAN).
5. The apparatus according to claim 1 , in which the processing system is constructed and arranged to cause the apparatus to send to the user equipments the indications by:
arranging the indications in an information element having an entry for each of the neighbor cells and a list of frequency bands for each entry; and
sending the information element in system information.
6. The apparatus according to claim 1 , in which the processing system is constructed and arranged to cause the apparatus to send to the user equipments the indications by:
arranging the indications in an information element having an index and one or more associated frequency bands, in which a value of the index indicates that one or more of the neighbor cells referred to by the index belongs to the one or more frequency bands associated with the index; and
sending the information element in system information.
7. The apparatus according to claim 1 , wherein each of the neighbor cells supports a plurality of frequency bands.
8. A method comprising:
obtaining frequency bands supported by neighbor cells, in which there is at least one individual neighbor cell which supports a plurality of frequency bands; and
sending to user equipments indications of the frequency bands associated with the respective neighbor cells that support them, including the plurality of frequency bands supported by the at least one individual neighbor cell;
wherein the indications of the frequency bands comprise, for at least the one individual neighbor cell:
only one absolute radio frequency channel number (ARFCN) associated with the at least one individual neighbor cell; and
the plurality of frequency bands associated with the at least one individual neighbor cell,
wherein for the at least one individual neighbor cell, the indicated one ARFCN and the plurality of frequency bands are such that at least one other ARFCN can be derived therefrom.
9. The method according to claim 8 , in which the indications are sent to the user equipments in broadcast system information, and the at least one individual neighbor cell is a neighbor cell to a serving cell executing the method.
10. The method according to claim 9 , in which the system information comprises at least one of system information block types 11 , 11 bis, 12 , 19 and 3 .
11. The method according to claim 9 , wherein the serving cell is at least one of:
a node B in a universal mobile telecommunications system (UMTS), and
an evolved node B in an evolved universal terrestrial radio access network (EUTRAN).
12. The method according to claim 8 , in which sending to the user equipments the indications comprises:
arranging the indications in an information element having an entry for each of the neighbor cells and a list of frequency bands for each entry; and
sending the information element in system information.
13. The method according to claim 8 , in which sending to the user equipments the indications comprises:
arranging the indications in an information element having an index and one or more associated frequency bands, in which a value of the index indicates that one or more of the neighbor cells referred to by the index belongs to the one or more frequency bands associated with the index; and
sending the information element in system information.
14. The method according to claim 8 , wherein each of the neighbor cells supports a plurality of frequency bands.
15. A memory tangibly storing a computer program that is executable by at least one processor, in which the computer program comprises:
code for obtaining frequency bands supported by neighbor cells, in which there is at least one individual neighbor cell which supports a plurality of frequency bands; and
code for sending to user equipments indications of the frequency bands associated with the respective neighbor cells that support them, including the plurality of frequency bands supported by the at least one individual neighbor cell;
wherein the indications of the frequency bands comprise, for at least the one individual neighbor cell:
only one absolute radio frequency channel number (ARFCN) associated with the respective neighbor cell; and
the plurality of frequency bands associated with the at least one individual neighbor cell,
wherein for the at least one individual neighbor cell, the indicated one ARFCN and the plurality of frequency bands are such that at least one other ARFCN can be derived therefrom.
16. The memory according to claim 15 , in which the code for sending causes the indications to be sent to the user equipments in broadcast system information, and the at least one individual neighbor cell is a neighbor cell to a serving cell executing the method.
17. The memory according to claim 16 , in which the system information comprises at least one of system information block types 11 , 11 bis, 12 , 19 and 3 .
18. The memory according to claim 15 , in which the code for sending operates to:
arrange the indications in an information element having an entry for each of the neighbor cells and a list of frequency bands for each entry; and
send the information element in system information.
19. The memory according to claim 15 , in which the code for sending operates to:
arrange the indications in an information element having an index and one or more associated frequency bands, in which a value of the index indicates that one or more of the neighbor cells referred to by the index belongs to the one or more frequency bands associated with the index; and
send the information element in system information.
20. The memory according to claim 15 , wherein each of the neighbor cells supports a plurality of frequency bands.