# US 8,787,908 B2 · Efficient femto discovery protocol using macro synchronization > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,787,908 B2 - Document ID: US8787908B2 - Status: Granted - Kind: B2 - Application number: 13/290,325 - Filed: 2011-11-07 - Published: 2013-05-09 - Granted: 2014-07-22 - Earliest claimed: 2011-11-07 - Assignees: QUALCOMM Incorporated - Applicants: Saurabh Tavildar; Ashwin Sampath - Inventors: Saurabh Tavildar; Ashwin Sampath - Web page: https://patentgrep.com/patent/US8787908B2 ## CPC - H04W 48/12: using downlink control channel - H04W 56/00: Synchronisation arrangements - H04W 84/045: {using private Base Stations, e.g. femto Base Stations, home Node B} - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) ## Abstract A method, a computer program product, and an apparatus are provided in which the apparatus (e.g., a femto cell) receives timing information from a second apparatus (e.g., a macro cell). The apparatus receives a signal from a third apparatus (e.g., a UE) based on the received timing information. The apparatus transmits a broadcast signal based on the received signal. A method, a computer program product, and an apparatus are provided in which the apparatus (e.g., a UE) receives timing information from a second apparatus (e.g., macro cell). The apparatus transmits a signal to a third apparatus (e.g., a femto cell) based on the received timing information. The apparatus receives a broadcast signal from the third apparatus in response to the signal. ## Claims ### Claim 1 A method of operating a femto cell, comprising: receiving timing information from a macro cell; receiving a signal from a user equipment (UE) based on the same timing information received from the macro cell, the signal being a peer discovery signal that identifies the UE; determining whether to transmit a broadcast signal based on the identity of the UE obtained from the peer discovery signal; and transmitting the broadcast signal based on the determination, wherein the broadcast signal comprises synchronization information, timing information, and system information of the femto cell. ### Claim 2 A method of operating a femto cell, comprising: receiving timing information from a macro cell; transmitting a peer discovery signal based on the received timing information, the peer discovery signal identifying the femto cell; receiving a signal from a user equipment (UE) based on the same timing information received from the macro cell, wherein the signal from the UE is a request for the broadcast signal in response to the transmitted peer discovery signal; and transmitting a broadcast signal based on the received signal, wherein the broadcast signal comprises synchronization information, timing information, and system information of the femto cell. ### Claim 3 (depends on 2) The method of claim 2, wherein the peer discovery signal is transmitted with a first periodicity and the broadcast signal is transmitted with a second periodicity greater than the first periodicity. ### Claim 4 A method of a user equipment (UE), comprising: receiving timing information from a macro cell; receiving a peer discovery signal from a femto cell that identifies the femto cell; determining whether to receive a broadcast signal from the femto cell based on the identity of the femto cell; transmitting a signal to the femto cell based on the determination and based on the same timing information received from the macro cell; and receiving the broadcast signal from the femto cell in response to the signal transmitted to the femto cell, wherein the broadcast signal comprises synchronization information, timing information, and system information of the femto cell. ### Claim 5 (depends on 4) The method of claim 4, wherein the transmitted signal is a request for the broadcast signal. ### Claim 6 A method of a user equipment (UE), comprising: receiving timing information from a macro cell; transmitting a signal to a femto cell based on the same timing information received from the macro cell, wherein the transmitted signal is a peer discovery signal that identifies the UE; and receiving a broadcast signal from the femto cell in response to the signal transmitted to the femto cell, wherein the broadcast signal comprises synchronization information, timing information, and system information of the femto cell. ### Claim 7 An apparatus for wireless communication, comprising: means for receiving timing information from a macro cell; means for receiving a signal from a user equipment (UE) based on the same timing information received from the macro cell, the signal being a peer discovery signal that identifies the UE; means for determining whether to transmit a broadcast signal based on the identity of the UE obtained from the peer discovery signal; and means for transmitting the broadcast signal based on the determination, wherein the apparatus is a femto cell and the broadcast signal comprises synchronization information, timing information, and system information of the femto cell. ### Claim 8 An apparatus for wireless communication of a femto cell, comprising: means for receiving timing information from a macro cell; means for transmitting a peer discovery signal based on the received timing information, the peer discovery signal identifying the femto cell; means for receiving a signal from a user equipment (UE) based on the same timing information received from the macro cell, wherein the signal from the UE is a request for the broadcast signal in response to the transmitted peer discovery signal; and means for transmitting a broadcast signal based on the received signal, wherein the broadcast signal comprises synchronization information, timing information, and system information of the femto cell. ### Claim 9 (depends on 8) The apparatus of claim 8, wherein the peer discovery signal is transmitted with a first periodicity and the broadcast signal is transmitted with a second periodicity greater than the first periodicity. ### Claim 10 An apparatus for wireless communication, comprising: means for receiving timing information from a macro cell; means for receiving a peer discovery signal from a femto cell that identifies the femto cell; means for determining whether to receive a broadcast signal from the femto cell based on the identity of the femto cell; means for transmitting a signal to the femto cell based on the determination and based on the same timing information received from the macro cell; and means for receiving the broadcast signal from the femto cell in response to the signal transmitted to the femto cell, wherein the apparatus is a user equipment (UE) and the broadcast signal comprises synchronization information, timing information, and system information of the femto cell. ### Claim 11 (depends on 10) The apparatus of claim 10, wherein the transmitted signal is a request for the broadcast signal. ### Claim 12 An apparatus for wireless communication of a user equipment (UE), comprising: means for receiving timing information from a macro cell; means for transmitting a signal to a femto cell based on the same timing information received from the macro cell, wherein the transmitted signal is a peer discovery signal that identifies the UE; and means for receiving a broadcast signal from the femto cell in response to the signal transmitted to the femto cell, wherein the broadcast signal comprises synchronization information, timing information, and system information of the femto cell. ### Claim 13 An apparatus for wireless communication, comprising: a processing system configured to: receive timing information from a macro cell; receive a signal from a user equipment (UE) based on the same timing information received from the macro cell, the signal being a peer discovery signal that identifies the UE; determine whether to transmit a broadcast signal based on the identity of the UE obtained from the peer discovery signal; and transmit the broadcast signal based on the determination, wherein the apparatus is a femto cell and the broadcast signal comprises synchronization information, timing information, and system information of the femto cell. ### Claim 14 An apparatus for wireless communication of a femto cell, comprising: a processing system configured to: receive timing information from a macro cell; transmit a peer discovery signal based on the received timing information, the peer discovery signal identifying the femto cell; receive a signal from a user equipment (UE) based on the same timing information received from the macro cell, wherein the signal from the UE is a request for the broadcast signal in response to the transmitted peer discovery signal; and transmit a broadcast signal based on the received signal, wherein the broadcast signal comprises synchronization information, timing information, and system information of the femto cell. ### Claim 15 (depends on 14) The apparatus of claim 14, wherein the peer discovery signal is transmitted with a first periodicity and the broadcast signal is transmitted with a second periodicity greater than the first periodicity. ### Claim 16 An apparatus for wireless communication, comprising: a processing system configured to: receive timing information from a macro cell; receive a peer discovery signal from a femto cell that identifies the femto cell; determine whether to receive a broadcast signal from the femto cell based on the identity of the femto cell; transmit a signal to the femto cell based on the determination and based on the same timing information received from the macro cell; and receive the broadcast signal from the femto cell in response to the signal transmitted to the femto cell, wherein the apparatus is a user equipment (UE) and the broadcast signal comprises synchronization information, timing information, and system information of the femto cell. ### Claim 17 (depends on 16) The apparatus of claim 16, wherein the transmitted signal is a request for the broadcast signal. ### Claim 18 An apparatus for wireless communication of a user equipment (UE), comprising: a processing system configured to: receive timing information from a macro cell; transmit a signal to a femto cell based on the same timing information received from the macro cell, wherein the transmitted signal is a peer discovery signal that identifies the UE; and receive a broadcast signal from the femto cell in response to the signal transmitted to the femto cell, wherein the broadcast signal comprises synchronization information, timing information, and system information of the femto cell. ### Claim 19 A computer program product in a femto cell, comprising: a non-transitory computer-readable medium comprising code for: receiving timing information from a macro cell; receiving a signal from a user equipment (UE) based on the same timing information received from the macro cell, the signal being a peer discovery signal that identifies the UE; determining whether to transmit a broadcast signal based on the identity of the UE obtained from the peer discovery signal; and transmitting the broadcast signal based on the determination, wherein the broadcast signal comprises synchronization information, timing information, and system information of the femto cell. ### Claim 20 A computer program product in a femto cell, comprising: a non-transitory computer-readable medium comprising code for: receiving timing information from a macro cell; transmitting a peer discovery signal based on the received timing information, the peer discovery signal identifying the femto cell; receiving a signal from a user equipment (UE) based on the same timing information received from the macro cell, wherein the signal from the UE is a request for the broadcast signal in response to the transmitted peer discovery signal; and transmitting the broadcast signal based on the received signal, wherein the broadcast signal comprises synchronization information, timing information, and system information of the femto cell. ### Claim 21 (depends on 20) The computer program product of claim 20, wherein the peer discovery signal is transmitted with a first periodicity and the broadcast signal is transmitted with a second periodicity greater than the first periodicity. ### Claim 22 A computer program product in a user equipment (UE), comprising: a non-transitory computer-readable medium comprising code for: receiving timing information from a macro cell; receiving a peer discovery signal from a femto cell that identifies the femto cell; determining whether to receive a broadcast signal from the femto cell based on the identity of the femto cell; transmitting a signal to the femto cell based on the determination and based on the same timing information received from the macro cell; and receiving the broadcast signal from the femto cell in response to the signal transmitted to the femto cell, wherein the broadcast signal comprises synchronization information, timing information, and system information of the femto cell. ### Claim 23 (depends on 22) The computer program product of claim 22, wherein the transmitted signal is a request for the broadcast signal. ### Claim 24 A computer program product in a user equipment (UE), comprising: a non-transitory computer-readable medium comprising code for: receiving timing information from a macro cell; transmitting a signal to a femto cell based on the same timing information received from the macro cell, wherein the transmitted signal is a peer discovery signal that identifies the UE; and receiving a broadcast signal from the femto cell in response to the signal transmitted to the femto cell, wherein the broadcast signal comprises synchronization information, timing information, and system information of the femto cell.