Patent ID: 9077444
Filing Date: 2015-07-07
Classification: H04B

Abstract:
1. A method for late entry in asynchronous frequency hopping wireless communications, the method comprising: during a traffic phase of a call, generating a random permutation sequence of frequencies, 1 to N, in a hop set based on data exchanged in a connection establishment phase of the call, wherein the hop set comprises N frequencies; finding a selected preamble frequency in the generated random permutation sequence at which to transmit a late entrant preamble frame for late entrant devices; finding a selected synchronization frequency in the generated random permutation sequence at which to transmit a late entrant synchronization frame associated with the late entrant preamble frame; finding a subsequent frequency in the generated random permutation sequence after the selected preamble frequency, wherein the subsequent frequency is located in the generated random permutation sequence where late entrant devices expect to find the late entrant synchronization frame associated with the late entrant preamble frame relative to the location of the selected preamble frequency in the generated random permutation sequence; switching the subsequent frequency in the generated random permutation sequence with the selected synchronization frequency in the generated random permutation sequence to form a modified random permutation sequence; and transmitting traffic, the late entrant preamble frame, and the late entrant synchronization frame over the frequencies, 1 to N, in accordance with the modified random permutation sequence.