# US 2019/0246368 A1 · Synchronized wireless signal transmission by endpoints controlled by a central controller > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0246368 A1 - Document ID: US20190246368A1 - Status: Published application - Kind: A1 - Application number: 16/388,571 - Filed: 2019-04-18 - Published: 2019-08-08 - Earliest claimed: 2017-04-28 - Assignees: Cisco Technology, Inc. - Applicants: Cisco Technology, Inc. - Inventors: Paul J. STAGER; David S. KLOPER; Brian D. HART; Matthew A. SILVERMAN - Web page: https://patentgrep.com/patent/US20190246368A1 ## CPC - H04W 56/0015: {one node acting as a reference for the others} - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) ## Abstract Techniques are disclosed to synchronize wireless signal transmission by endpoints controlled by a central controller. For example, an example method of wireless communication includes receiving, at a first device, over a wired medium between the first device and a second device, a plurality of packets from the second device. Each of the plurality of packets comprises data representative of a portion of a signal corresponding to a wireless medium. The method further includes receiving, at the first device, from the second device over the wired medium a synchronization signal based on a common master clock at the second device. The method further includes synchronizing, at the first device, a local clock of the first device to the common master clock based on the synchronization signal. The method further includes reconstructing the signal corresponding to the wireless medium based on the plurality of packets and the synchronized local clock. ## Claims ### Claim 1 A method of wireless communication comprising: receiving, at a first device, over a wired medium between the first device and a second device, a plurality of packets from the second device, each of the plurality of packets comprising data representative of a portion of a signal corresponding to a wireless medium; receiving, at the first device, from the second device over the wired medium a synchronization signal based on a common master clock at the second device; synchronizing, at the first device, a local clock of the first device to the common master clock based on the synchronization signal; and reconstructing the signal corresponding to the wireless medium based on the plurality of packets and the synchronized local clock. ### Claim 2 (depends on 1) The method of claim 1, wherein the first device comprises an endpoint, the second device comprises a common physical point, the method further comprising: transmitting, over the wireless medium, the reconstructed signal. ### Claim 3 (depends on 1) The method of claim 1, wherein the signal comprises a continuous waveform, and wherein data representative of a portion of the signal comprises at least one of: samples corresponding to the continuous waveform, chips indicative of the samples, CDMA patterns indicative of the samples, OFDM frequency-domain data indicative of the samples, and OFDM data without a cyclic prefix indicative of the samples. ### Claim 4 (depends on 3) The method of claim 3, wherein the samples corresponding to the continuous waveform are generated based on the common master clock, and wherein reconstructing the signal comprises aligning the samples corresponding to the continuous waveform received in the plurality of packets based on the synchronized local clock, the method further comprising: using the synchronized local clock to drive a digital-to-analog converter. ### Claim 5 (depends on 1) The method of claim 1, wherein the synchronization signal comprises a physical layer signal. ### Claim 6 (depends on 1) The method of claim 1, wherein synchronizing the local clock to the common master clock comprises: generating a recovered clock signal based on the synchronization signal; and locking a phase and a frequency of a local oscillator to the recovered clock signal, wherein the locked local oscillator is used as the local clock. ### Claim 7 (depends on 6) The method of claim 6, wherein locking the phase and the frequency of the local oscillator to the recovered clock signal is performed using a slow control loop. ### Claim 8 (depends on 6) The method of claim 6, further comprising receiving a wireless signal from a third device, wherein synchronizing the local clock is further based on receiving the wireless signal. ### Claim 9 (depends on 1) The method of claim 1, wherein synchronizing the local clock to the common master clock comprises resampling a frequency of at least one of a digital to analog converter and an analog to digital converter based on the synchronization signal. ### Claim 10 (depends on 1) The method of claim 1, further comprising: receiving, at the first device, over the wireless medium, a second signal; generating a second plurality of packets based on the synchronized local clock and the second signal; and transmitting to the second device, over the wired medium, the second plurality of packets, wherein the second signal can be reconstructed based on the second plurality of packets and the common master clock. ### Claim 11 (depends on 10) The method of claim 10, wherein generating the second plurality of packets further comprises using the synchronized local clock to drive an analog-to-digital converter. ### Claim 12 A first device for wireless communication comprising: an interface configured to: receive over a wired medium between the first device and a second device, a plurality of packets from the second device, each of the plurality of packets comprising data representative of a portion of a signal corresponding to a wireless medium; receive from the second device over the wired medium a synchronization signal based on a common master clock at the second device; a control loop configured to synchronize a local clock of the first device to the common master clock based on the synchronization signal; and a processor configured to reconstruct the signal corresponding to the wireless medium based on the plurality of packets and the synchronized local clock. ### Claim 13 (depends on 12) The first device of claim 12, wherein the first device comprises an endpoint, the second device comprises a common physical point, and the first device further comprises a transmitter configured to transmit, over the wireless medium, the reconstructed signal. ### Claim 14 (depends on 12) The first device of claim 12, wherein the signal comprises a continuous waveform, and wherein data representative of a portion of the signal comprises at least one of: samples corresponding to the continuous waveform, chips indicative of the samples, CDMA patterns indicative of the samples, OFDM frequency-domain data indicative of the samples, and OFDM data without a cyclic prefix indicative of the samples. ### Claim 15 (depends on 14) The first device of claim 14, wherein the samples corresponding to the continuous waveform are generated based on the common master clock, and wherein reconstructing the signal comprises aligning the samples corresponding to the continuous waveform received in the plurality of packets based on the synchronized local clock. ### Claim 16 (depends on 12) The first device of claim 12, wherein synchronizing the local clock to the common master clock comprises: generating a recovered clock signal based on the synchronization signal; and locking at least one of a phase and a frequency of a local oscillator to the recovered clock signal, wherein the locked local oscillator is used as the local clock. ### Claim 17 (depends on 16) The first device of claim 16, further comprising: a receiver configured to receive a wireless signal from a third device, wherein to synchronize the local clock is further based on receiving the wireless signal. ### Claim 18 (depends on 12) The first device of claim 12, wherein synchronizing the local clock to the common master clock comprises: sampling a frequency of at least one of a digital to analog converter and an analog to digital converter based on the synchronization signal. ### Claim 19 (depends on 12) The first device of claim 12, further comprising: a receiver configured to receive, over the wireless medium, a second signal; wherein the processor is further configured to generate a second plurality of packets comprising data representative of a portion of the second signal based on the synchronized local clock; and wherein the interface is further configured to transmit to the second device, over the wired medium, the second plurality of packets, wherein the second signal can be reconstructed based on the second plurality of packets and the common master clock. ### Claim 20 A first device for wireless communication comprising: means for receiving, over a wired medium between the first device and a second device, a plurality of packets from the second device, each of the plurality of packets comprising data representative of a portion of a signal corresponding to a wireless medium; means for receiving from the second device over the wired medium a synchronization signal based on a common master clock at the second device; means for synchronizing a local clock of the first device to the common master clock based on the synchronization signal; and means for reconstructing the signal corresponding to the wireless medium based on the plurality of packets and the synchronized local clock.