1. Buffer chip for driving external input signals applied to a multi-rank dual inline memory module to a predetermined number N of memory chips mounted on a printed circuit board of said dual inline memory module, wherein the buffer chip comprises stacked register dies each having several signal drivers, wherein at least two signal drivers are connected in parallel to drive an external input signal to said memory chips.
2. Buffer chip according to claim 1 wherein the buffer chip is a command and address bus buffer chip for driving command and address signals to said memory chips.
3. Buffer chip according to claim 1 wherein the buffer chip is located in the center of the printed circuit board of said dual inline memory module.
4. Buffer chip according to claim 1 wherein the memory chips are DRAMs.
5. Buffer chip according to claim 1 wherein the buffer chip is operated at a system clock rate.
6. Buffer chip according to claim 1 wherein the number of stacked register dies integrated within the buffer chip corresponds to the number of memory dies integrated within each memory chip.
7. Buffer chip according to claim 1 wherein the buffer chip further comprises a phase locked loop to which an external clock signal is applied.
8. Buffer chip according to claim 1 wherein two signal drivers are connected in parallel to form a die driver element pair.
9. Buffer chip according to claim 1 wherein the signal drivers which are connected in parallel are provided on the same register die of said buffer chip.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A method for allowing a femto base station to perform beaconing in a wireless communication system, the method comprising:
obtaining a System Information Block (SIB) message of a neighbor macro base station transmitted to a terminal by the neighbor macro base station;
adding information of the femto base station to the obtained SIB message of the macro base station and updating the same;
transmitting the updated SIB message to the terminal;
adding information indicating existence of the updated SIB message to an indication message; and
transmitting the indication message to the terminal,
wherein the obtained SIB message comprises a SIB 5 message, and
wherein the adding of information indicating existence of the updated SIB message to the indication message comprises:
obtaining a SIB 1 message of the macro base station transmitted by the macro base station to the terminal; and
adding information indicating existence of the updated SIB 5 message to the obtained SIB 1 message of the macro base station as the indication message and updating the same,
wherein the transmitting of the indication message to the terminal comprises transmitting the updated SIB 1 message as the indication message to the terminal.
2. The method of claim 1, wherein the wireless communication system comprises a Long Term Evolution (LTE) system.
3. The method of claim 1, wherein the information of the femto base station comprises at least one of a center frequency of the femto base station and a Physical Cell IDentifier (PCID) of the femto base station.
4. The method of claim 1, wherein the SIB message is transmitted to the terminal according to scheduling information of the macro base station at a frequency of the macro base station.
5. The method of claim 1, wherein the adding of information indicating existence of the updated SIB message to the indication message further comprises:
adding information indicating existence of the updated SIB 5 message to a paging message as the indication message and updating the same; and
wherein the transmitting of the indication message to the terminal comprises transmitting the updated paging message as the indication message to the terminal.
6. The method of claim 1, further comprising:
searching for a neighbor macro base station; and
when a plurality of macro base stations are found, performing time-sharing on the plurality of found macro base stations.
7. The method of claim 1, wherein the femto base station uses a center frequency different from a center frequency of the macro base station.
8. An apparatus for allowing a femto base station to perform beaconing in a wireless communication system, the apparatus comprising:
a reception modem configured to obtain a System Information Block (SIB) message of a neighbor macro base station transmitted to a terminal by the neighbor macro base station;
a message generator configured to add information of the femto base station to the obtained SIB message of the macro base station and update the same; and
a transmission modem configured to transmit the updated SIB message to the terminal,
wherein the message generator is further configured to add information indicating existence of the updated SIB message to an indication message,
wherein the transmission modem is further configured to transmit the indication message to the terminal,
wherein the obtained SIB message comprises a SIB 5 message,
wherein the reception modem is further configured to obtain a SIB 1 message of the macro base station transmitted by the macro base station to the terminal,
wherein the message generator is further configured to add information indicating existence of the updated SIB 5 message to the obtained SIB 1 message of the macro base station as the indication message and update the same, and
wherein the transmission modem is further configured to transmit the updated SIB 1 message as the indication message to the terminal.
9. The apparatus of claim 8, wherein the wireless communication system comprises a Long Term Evolution (LTE) system.
10. The apparatus of claim 8, wherein the information of the femto base station comprises at least one of a center frequency of the femto base station and a Physical Cell IDentifier (PCID) of the femto base station.
11. The apparatus of claim 8, wherein the SIB message is transmitted to the terminal according to scheduling information of the macro base station at a frequency of the macro base station.
12. The apparatus of claim 8, wherein the message generator is further configured to add information indicating existence of the updated SIB 5 message to a paging message as the indication message and update the same, and
wherein the transmission modem is further configured to transmit the updated paging message as the indication message to the terminal.
13. The apparatus of claim 8, further comprising a controller configured to search for a neighbor macro base station, and, when a plurality of macro base stations are found, configured to perform time-sharing on the plurality of found macro base stations.
14. The apparatus of claim 8, wherein the femto base station is configured to use a center frequency different from a center frequency of the macro base station.