overall transmission link respectively fig2 shows flowchart 200 which summarizes a threshold selection criterion for reliable rss grouping based on the outage probability constraint according to one embodiment of the present invention as shown in fig2 at step 404 when the signal condition at the bs rss link is good i e a high snr 1 a large threshold value e g u03c5 gt 1 is selected at step 412 so that a larger number of rss form the reliable group this value for threshold value u03c5 is selected because when the signal condition at the bs rss link is good the probability that a greater number of rss are likely to receive a transmitted packet correctly from the bs is high as a result the cooperative diversity gain in the second part of transmission is increased and thus the outage probability is reduced however as shown in step 406 when the signal condition at the bs rss link is weak i e a low snr 1 the threshold value u03c5 is selected according to the channel condition of rss ms link step 406 in particular at step 406 for a high snr 2 a small value for threshold value u03c5 is selected e g u03c5 1 at step.