  Motivated by improved detection and prediction of temporal holes, we propose
a two stage algorithm to classify the channel access method used by a primary
network. The first stage extends an existing fourth-order cumulant-based
modulation classifier to distinguish between TDMA, OFDMA, and CDMA. The second
stage proposes a novel collision detector using the sample variance of the same
cumulant to detect contention-based channel access methods. Our proposed method
is blind and independent of the received SNR. Simulations show that our
classification of TDMA, OFDMA, and CDMA is robust to network load while
detection of contention outperforms existing methods.
