  In Onur et al. ["Cooperative density estimation in random wireless ad hoc
networks," IEEE Commun. Lett., vol. 16, no. 3, 269 pp. 331-333, Mar. 2012], two
novel density estimation (DE) approaches in wireless random networks were
introduced by Onur et al., which are carried out respectively in cooperative
and individual fashions. Both of them were derived via the maximum likelihood
(ML) method. However, an implicit but fatal error was made obtaining the
individual DE (I-DE) approach. This letter comments on Onur et al. and points
out the aforementioned error. By investigating the distance order statistics
(DOS) distributions in the random networks, the correct I-DE approach is
presented and discussed. Simulation results also show that the correct I-DE
outperforms the wrong one. More importantly, a new method that can obtain any
univariate or multivariate DOS distribution is demonstrated, which is expected
to be helpful for the study of the wireless communications and networking.
