Phase II is the RN configuration phase. Let U be the number of RNs associated with a given ES. The first step is for the ES to receive USER_POS packets from each RN. This takes 0.677 * U seconds.
The next step is to determine the optimum direction of the beams in order to form a connection with the RNs. This algorithm execution is a linear function of the number of RNs, which takes seconds where is a constant. The algorithm is currently implemented in MatLab and takes approximately 7.5 seconds to obtain reasonable convergence of the beam direction to connect with four RNs.
The final step in Phase II is to generate a table of complex weights for antenna beamforming and download this table to the hardware. This is a function of the number of elements in the antenna array, , the number of beams, B, and the number of bits per symbol, M. tables are created with entries per table. This takes on the order of 2 seconds with 4 beams and 8 elements using QPSK on an OSF1 V4.0 386 Dec Alpha workstation.
The entire beamform and table generation module must be repeated for every combination of transmitting RNs. A different table is used depending on which RNs are currently transmitting data. The complete time for Phase II is shown in Equation 2.