METHOD FOR INTERFERENCE COORDINATION OF FEMTOCELLS, FEMTOCELL AND USER TERMINAL EQUIPMENT
The present invention proposes a femtocell interference coordination method, a femtocell and a user terminal equipment in a macro-femtocell deployment scenario. The key point of this invention is to stimulate a user terminal of the macrocell to initiate a random access request to a femtocell defined by a “closed subscriber group”. Based on this, the femtocell will know there is a user that can not be detected by the macrocell and then trigger corresponding interference coordination operation to ensure that the user terminal equipment of the macrocell can at least receive information of control channels correctly.
1 . A method for interference coordination by a femtocell, wherein there is at least one user terminal of a macrocell within coverage range of the femtocell, the method comprising:
the femtcell receiving a random access request initiated by the user terminal of the macrocell;
the femtcell estimating path loss between the femtocell and the user terminal of the macrocell; and
the femtcell performing interference coordination to ensure that the user terminal of the macrocell can receive information of control channels correctly.
2 . The method according to claim 1 , wherein the femtocell receiving a random access request initiated by the user terminal of the macrocell further comprises:
synchronizing the user terminal of the macrocell to the femtocell;
the user terminal of the macrocell receiving system information of the femtocell, the system information of the femtocell indicating that the user terminal of the macrocell can access the femtocell; and
the user terminal of the macrocell initiating the random access request to the femtocell.
3 . The method according to claim 1 , wherein the femtocell receiving a random access request initiated by the user terminal of the macrocell further comprises:
updating information settings of “whitelist of closed subscriber groups” of the user terminal of the macrocell to comprise all femtocells that potentially cause interferences to the user terminal of the macrocell;
synchronizing the user terminal of the macrocell to the femtocell; and
the user terminal of the macrocell initiating the random access request to the femtocell.
4 . The method according to claim 1 , wherein the femtocell receiving a random access request initiated by the user terminal of the macrocell further comprises:
synchronizing the user terminal of the macrocell to the femtocell; and
the user terminal of the macrocell receiving an instruction from a user to initiate the random access request to the femtocell.
5 . (canceled)
6 . (canceled)
7 . (canceled)
8 . The method according to claim 1 , wherein the femtocell performs the interference coordination based on power control or time domain resource allocation.
9 . (canceled)
10 . A method for initiating a random access to a femtocell by a user terminal, wherein the user terminal is a user terminal of a macrocell and is located in coverage area of the femtocell, and the user terminal of the macrocell is an unauthorized user terminal for the femtocell, the method comprising:
the user terminal obtaining information allowing initiation of a random access request to the femtocell; and
the user terminal initiating the random access request to the femtocell.
11 . The method according to claim 10 , wherein the user terminal obtaining information allowing initiation of a random access request to the femtocell comprises: the user terminal receiving system information from the femtocell, the system information of the femtocell indicating that the user terminal of the macrocell can access the femtocell.
12 . The method according to claim 10 , wherein the user terminal obtaining information allowing initiation of a random access request to the femtocell comprises: information settings of “whitelist of closed subscriber groups” of the user terminal of the macrocell comprising all femtocells that potentially cause interferences to the user terminal of the macrocell.
13 . The method according to claim 10 , wherein the user terminal obtaining information allowing initiation of a random access request to the femtocell comprises: the user terminal receiving from a user an instruction which instructs the user equipment to initiate the random access request to the femtocell.
14 . (canceled)
15 . (canceled)
16 . A femtocell, wherein there is at least one user terminal of a macrocell within coverage range of the femtocell, the femtocell comprising:
a synchronizing unit configured to receive synchronization information from the user terminal of the macrocell within the coverage range of the femtocell;
a receiving unit configured to receive a random access request initiated by the user terminal of the macrocell;
a path loss estimating unit configured to estimat path loss from the user terminal of the macrocell to the femtocell and path loss from the macrocell to the femtocell; and
an interference coordination unit configured to perform interference coordination to ensure that the user terminal of the macrocell can receive information of control channels correctly.
17 . (canceled)
18 . The femtocell according to claim 16 , wherein the interference coordination unit performs the interference coordination based on power control or time domain resource allocation.
19 . (canceled)
20 . (canceled)
21 . (canceled)
22 . A user terminal equipment, which is within coverage range of a femtocell, the user terminal equipment comprising:
a detecting unit configured to detect whether initiation of a random access request is allowed; and
a random access request initiating unit configured to initiate the random access request to the femtocell when the detecting unit outputs information allowing initiation of a random access request.
23 . The user terminal equipment according to claim 22 , wherein:
the user terminal equipment further comprises a first receiving unit configured to receive system information from the femtocell; and
the detecting unit detects the system information from the femtocell and outputs to the random access request initiating unit the information allowing initiation of a random access request once it detects that the system information from the femtocell indicates that the user terminal of the macrocell can access the femtocell
24 . The user terminal equipment according to claim 22 , wherein:
the user terminal equipment further comprises a closed subscriber group whitelist storage unit configured to store whitelist of closed subscriber groups; and
settings of the closed subscriber group whitelist storage unit is updated to comprise all femtocells that potentially cause interferences to the user terminal of the macrocell; and
when the detecting unit detects that the whitelist of closed subscriber groups includes all femtocells that potentially cause interferences to the user terminal of the macrocell, it outputs to the random access request initiating unit the information allowing initiation of a random access request.
25 . The user terminal equipment according to claim 22 , wherein:
the user terminal equipment further comprises a second receiving unit configured to receive from a user an instruction which instructs the user equipment to initiate the random access request to the femtocell; and
when the detecting unit detects the instruction which instructs the user equipment to initiate the random access request to the femtocell, it outputs to the random access request initiating unit the information allowing initiation of a random access request.
26 . (canceled)
27 . (canceled)