According to an example, signal transmissions by a first antenna apparatus and a second antenna apparatus connected to a central processing apparatus through an Ethernet switch may be synchronized with respect to each other. An Ethernet packet containing first data and second data may be generated, in which the first antenna apparatus is to wirelessly transmit the first data and the second antenna apparatus is to wirelessly transmit the second data. In addition, the Ethernet packet may be communicated to the Ethernet switch, in which the Ethernet switch includes a first port that is in communication with the first antenna apparatus and a second port that is in communication with the second antenna apparatus, and the Ethernet switch is to communicate the Ethernet packet through the first port and a copy of the Ethernet packet through the second port substantially simultaneously with respect to each other.