A method of operating a wireless power receiver apparatus comprising one or more radio frequency, RF, transceivers and control circuitry configured to establish a connection with a wireless power transmission system, the method comprising: receiving a signal including a connection invitation message transmitted by a first wireless power transmission system of multiple wireless power transmission systems, wherein each of the multiple wireless power transmission systems includes multiple adaptively-phased RF antennas configured to deliver a coherent power transmission signal to the wireless power receiver apparatus when a wireless power connection is established; processing the signal including the connection invitation to identify attributes associated with the first wireless power transmission system, wherein the processing includes measuring a signal strength of the connection invitation and the attributes include the signal strength of the connection invitation; applying selection criteria to the attributes associated with the first wireless power transmission system and attributes associated with other wireless power transmission systems of the multiple wireless power transmission systems to determine whether to accept the connection invitation, wherein the selection criteria include signal strength threshold values; for each attribute; and in response to determining to accept the connection invitation, directing the one or more RF transceivers of the wireless power receiver apparatus or a wireless device in which the wireless power receiver apparatus is embedded to transmit a response to the connection invitation message, wherein the response indicates an acceptance of the connection invitation message, and establishing a wireless power connection with the first wireless power transmission system subsequent to transmitting the response to the connection invitation message. receiving a signal including a connection invitation message transmitted by a first wireless power transmission system of multiple wireless power transmission systems, wherein each of the multiple wireless power transmission systems includes multiple adaptively-phased RF antennas configured to deliver a coherent power transmission signal to the wireless power receiver apparatus when a wireless power connection is established; processing the signal including the connection invitation to identify attributes associated with the first wireless power transmission system, wherein the processing includes measuring a signal strength of the connection invitation and the attributes include the signal strength of the connection invitation; applying selection criteria to the attributes associated with the first wireless power transmission system and attributes associated with other wireless power transmission systems of the multiple wireless power transmission systems to determine whether to accept the connection invitation, wherein the selection criteria include signal strength threshold values; for each attribute; and in response to determining to accept the connection invitation, directing the one or more RF transceivers of the wireless power receiver apparatus or a wireless device in which the wireless power receiver apparatus is embedded to transmit a response to the connection invitation message, wherein the response indicates an acceptance of the connection invitation message, and establishing a wireless power connection with the first wireless power transmission system subsequent to transmitting the response to the connection invitation message.