Method for Reselections in the Presence of Femto Cells
A method for performing cell reselection in a cellular communication network including determining a first receive power and a first pathloss of a signal from a first cell, determining a second receive power and an upper bound on a second pathloss of a signal from a second cell, and selecting the second cell when the difference between the first path loss and the upper bound on the second path loss is greater than a first threshold and the difference between the first receive power and the second receive power is smaller than a second threshold.
1 . A method in a mobile station to perform cell reselection comprising:
receiving a receive power level range and a corresponding receive power level offset from a first cell;
detecting the presence of a second cell;
determining that the receive power level of the signal from the first cell is within the receive power level range;
selecting the second cell when a sum of a receive power level of the signal from the second cell and the receive power level offset is larger than the receive power level of all other cells.
2 . The method according to claim 1 further comprising:
determining that the sum of the receive power level of the signal from the second cell and the receive power level offset is smaller than or equal to the receive power level of the first cell, and
selecting the first cell.
3 . The method according to claim 1 further comprising:
determining that the receive power level of the signal from the first cell is outside the receive power level range, and
selecting the first cell.
4 . The method according to claim 1 , wherein the receive power level range comprises a receive power level threshold.
5 . The method according to claim 1 , wherein the receive power level range comprises a lower bound receive power level threshold and an upper bound receive power level threshold.
6 . A method in a base station comprising:
receiving a maximum pathloss parameter,
determining a receive power level of a second base station signal, and
setting the transmit power to no more than the receive power level of the second base station signal plus the maximum pathloss parameter.
7 . The method according to claim 6 , wherein the receiving a maximum pathloss parameter comprises receiving the maximum pathloss parameter from the second base station.
8 . The method according to claim 6 , wherein the receiving a maximum pathloss parameter comprises configuring by the network operator the maximum pathloss parameter.
9 . The method according to claim 6 , wherein the determining a receive power level of a second base station signal comprises measuring the receive power level of the second base station signal.
10 . The method according to claim 6 , wherein the determining a receive power level of a second base station signal comprises receiving a measurement report from a mobile station that includes the receive power level of the second base station.
11 . The method according to claim 6 wherein the maximum pathloss parameter corresponds to the maximum allowable coverage size of the base station.
12 . A base station apparatus comprising
a receiver configured to receive a maximum pathloss parameter;
a transceiver configured to communicate with mobile stations;
a controller coupled to the receiver and the transceiver, the controller configured to determine the receive power level of another base station signal; and
the controller further configured to adjust the transmit power to no more than the receive power level of the another base station signal plus the maximum pathloss parameter.
13 . The base station apparatus according to claim 12 , wherein
the receiver configured to receive a maximum pathloss parameter is further configured to receive a signal from at least the another base station, and is further configured to measure the receive power level of the another base station, and
the controller configured to determine the receive power level of the another base station signal is further configured to obtain the receive power level of the another base station signal from the receiver.
14 . The base station apparatus according to claim 12 , wherein
the transceiver configured to communicate with mobile stations is further configured to receive from a mobile station receive power level information of the another base station, and
the controller configured to determine the receive power level of another base station signal is further configured to obtain the receive power level from the transceiver.