# US 2019/0174357 A1 · Electronic device and method for controlling the electronic device for joint transmission thereof > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0174357 A1 - Document ID: US20190174357A1 - Status: Published application - Kind: A1 - Application number: 16/013,392 - Filed: 2018-06-20 - Published: 2019-06-06 - Earliest claimed: 2017-12-05 - Assignees: Samsung Electronics Co., Ltd. - Applicants: Samsung Electronics Co., Ltd. - Inventors: Min-gyu LEE - Web page: https://patentgrep.com/patent/US20190174357A1 ## CPC - H04W 28/16: Central resource management; Negotiation of resources or communication parameters, e.g. negotiating bandwidth or QoS [Quality of Service] - H04B 7/024: Co-operative use of antennas of several sites, e.g. in co-ordinated multipoint or co-operative multiple-input multiple-output [MIMO] systems - H04B 7/0639: {Using selective indices, e.g. of a codebook, e.g. pre-distortion matrix index [PMI] or for beam selection} - H04B 7/0837: {using pre-detection combining (H04B7/0868 takes precedence)} - H04L 1/0003: {by switching between different modulation schemes} - H04L 1/0009: {by adapting the channel coding (H04L1/1812 takes precedence)} - H04L 1/0025: {Transmission of mode-switching indication} - H04W 48/20: Selecting an access point - H04W 88/08: Access point devices - H04W 92/20: between access points - H04W 74/0816: with collision avoidance - H04W 88/12: Access point controller devices - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) - H04B: TRANSMISSION - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract A control method of an electronic device for performing joint transmission is provided. The control method includes searching for access points (APs) to retrieve a plurality of APs, determining a modulation and coding scheme (MCS) for data transmission based on a signal strength of at least two APs among the plurality of APs, determining the at least two APs as candidate APs for joint transmission by comparing a joint transmission gain time according to the determined MCS and a synchronization time for the at least two APs to perform joint transmission, transmitting information about the candidate APs to an AP control device, and performing data communication with joint APs, which are determined to perform joint transmission by the AP control device, among the candidate APs. ## Claims ### Claim 1 A control method of an electronic device for performing joint transmission, the method comprising: searching for access points (APs) to retrieve a plurality of APs; determining a modulation and coding scheme (MCS) for data transmission based on a signal strength of at least two APs among the plurality of APs; determining the at least two APs as candidate APs for joint transmission by comparing a joint transmission gain time according to the determined MCS and a synchronization time for the at least two APs to perform joint transmission; transmitting information about the candidate APs to an AP control device; and performing data communication with joint APs, which are determined to perform joint transmission by the AP control device, among the candidate APs. ### Claim 2 (depends on 1) The method as claimed in claim 1, wherein the determining of the at least two APs as candidate APs further comprises: determining APs to which the electronic device is accessible among the plurality of APs; and determining the at least two APs as the candidate APs based on a signal strength among the APs to which the electronic device is accessible. ### Claim 3 (depends on 2) The method as claimed in claim 2, wherein the determining of the at least two APs as candidate APs further comprises: obtaining a time at which data is received from the at least two APs; and identifying the synchronization time for the at least two APs based on a difference in time at which the data is received. ### Claim 4 (depends on 3) The method as claimed in claim 3, wherein the determining of the at least two APs as candidate APs further comprises: determining the MCS based on a signal strength of the at least two APs; calculating a first data reception time at which a predetermined size of data is received based on the determined MCS; calculating the joint transmission gain time by calculating a difference between the first data reception time and a second data reception time at which the predetermined size of data is received from an AP having a strongest signal strength; and in response to the joint transmission gain time being greater than the synchronization time, determining the at least two APs as the candidate APs. ### Claim 5 (depends on 4) The method as claimed in claim 4, further comprising: in response to the at least two APs being determined as the candidate APs, adding the at least two APs and a new AP; determining a new MCS for data transmission based on a signal strength of the at least two APs and the new AP; and determining the at least two APs and the new AP as candidate APs for joint transmission by comparing a joint transmission gain time and a synchronization time for the at least two APs and the new AP to perform joint transmission based on the new MCS. ### Claim 6 (depends on 1) The method as claimed in claim 1, wherein the information about the candidate APs includes identification information related to at least one candidate AP set, synchronization time information of the at least one candidate AP set, and MCS information corresponding to the at least one candidate AP set. ### Claim 7 (depends on 6) The method as claimed in claim 6, wherein one of the at least one candidate AP set is determined as a joint AP by the AP control device based on a network situation. ### Claim 8 (depends on 7) The method as claimed in claim 7, wherein the network situation comprises a number of external electronic devices accessed to a candidate AP, and wherein the AP control device determines the joint APs by excluding APs in rooms in which a guest stays and APs which are accessed to a plurality of other electronic devices from the joint APs. ### Claim 9 (depends on 1) The method as claimed in claim 1, wherein the performing of the data communication comprises: receiving a request to send (RTS) packet including address information related to the joint APs and a duration calculated using an MCS corresponding to the joint APs from the joint APs; and in response to receiving the RTS packet, transmitting a clear to send (CTS) packet including a duration calculated using an MCS corresponding to a reception signal strength of the RTS packet to the joint APs. ### Claim 10 (depends on 9) The method as claimed in claim 9, wherein the RTS packet is transmitted from the joint APs simultaneously based on the synchronization time. ### Claim 11 An electronic device which performs data communication with a plurality of access point (APs) through joint transmission, the electronic device comprising: a communication interface; a processor configured to control the electronic device and be electrically connected with the communication interface; and a memory configured to store instructions that, when executed by the processor, cause the processor to: search for APs to retrieve a plurality of APs, determine a modulation and coding scheme (MCS) for data transmission based on a signal strength of at least two APs among the plurality of APs, determine the at least two APs as candidate APs for joint transmission by comparing a joint transmission gain time according to the determined MCS and a synchronization time for the at least two APs to perform joint transmission, control the communication interface to transmit information about the candidate APs to an AP control device, and control the communication interface to perform data communication with joint APs, which are determined to perform joint transmission by the AP control device, among the candidate APs. ### Claim 12 (depends on 11) The electronic device as claimed in claim 11, wherein the processor is further configured to: determine APs to which the electronic device is accessible among the plurality of APs, and determine the at least two APs as the candidate APs based on a signal strength among the APs to which the electronic device is accessible. ### Claim 13 (depends on 12) The electronic device as claimed in claim 12, wherein the processor is further configured to: obtain a time at which the at least two APs receive data, and identify the synchronization time for the at least two APs based on a difference in time at which the data is received. ### Claim 14 (depends on 13) The electronic device as claimed in claim 13, wherein the processor is further configured to: determine an MCS based on a signal strength of the at least two APs, calculate a first data reception time at which a predetermined size of data is received based on the determined MCS, calculate the joint transmission gain time by calculating a difference between the first data reception time and a second data reception time at which the predetermined size of data is received from an AP having a strongest signal strength, and in response to the joint transmission gain time being greater than the synchronization time, determine the at least two APs as the candidate APs. ### Claim 15 (depends on 14) The electronic device as claimed in claim 14, wherein the processor is further configured to: in response to the at least two APs being determined as the candidate APs, add the at least two APs and a new AP, determine a new MCS for data transmission based on a signal strength of the at least two APs and the new AP, and determine the at least two APs and the new AP as candidate APs for joint transmission by comparing a joint transmission gain time and a synchronization time for the at least two APs and the new AP to perform joint transmission based on the new MCS. ### Claim 16 (depends on 11) The electronic device as claimed in claim 11, wherein the information about the candidate APs includes identification information related to at least one candidate AP set, synchronization time information of the at least one candidate AP set, and MCS information corresponding to the at least one candidate AP set. ### Claim 17 (depends on 16) The electronic device as claimed in claim 16, wherein one of the at least one candidate AP set is determined as a joint AP by the AP control device based on a network situation. ### Claim 18 (depends on 17) The electronic device of claim 17, wherein the network situation comprises a number of external electronic devices accessed to a candidate AP, and wherein the AP control device determines the joint APs by excluding APs in rooms in which a guest stays and APs which are accessed to a plurality of other electronic devices from the joint APs. ### Claim 19 (depends on 11) The electronic device as claimed in claim 11, wherein the processor is further configured to: control the communication interface to receive a request to send (RTS) packet including address information related to the joint APs and a duration calculated using an MCS corresponding to the joint APs from the joint APs, and in response to receiving the RTS packet, control the communication interface to transmit a clear to send (CTS) packet including a duration calculated using an MCS corresponding to a reception signal strength of the RTS packet to the joint APs. ### Claim 20 (depends on 19) The electronic device as claimed in claim 19, wherein the RTS packet is transmitted from the joint APs simultaneously based on the synchronization time.