The opinions expressed in this editorial are those of the author and do not necessarily reflect those of Decima Reports. Canada's wireless telecommunications industry could be quite different in a few years as some key regulatory matters and competitive issues come to a head at the same time.In fact, three articles in this issue of Report on Wireless explore the potential changes: the federal government appears open to liberalizing the foreign investment regime; Wi-Fi is gaining momentum; and the wireless operators are likely to be subjected to more copyright fees.One key development, however, is most apparent at Microcell Telecommunications, and that is there was a significant slowdown in subscriber growth last year (see chart in this issue). Microcell lost nearly 50,000 subscribers in 2002. Some analysts may say it's too early to tell if Canada is heading into a period of slower growth indicative of a possible trend, but the steep drop in subscriber additions for 2002 certainly indicates that the wireless operators are finding it harder to lure new people into the wireless world.Carriers are generally performing better financially (except Microcell) and this is evident in higher EBITDA and average revenue per user (ARPU) numbers. The increases, though, aren't entirely due to a greater number of users. The increase in ARPU over the past several quarters, for example, can undoubtedly also be attributed to the switch back to per-minute billing. When the carriers announced their plans to return to per-minute billing, analysts estimated that this could improve ARPU by 10%.But what the industry has done is create an artificial safety blanket upon which it can rely for the next little while. That's not such a bad move, especially during these times when money for infrastructure builds and innovative wireless data offerings is limited, if there's any at all.But if current subscriber growth trends downward - even Microcell projects Canadian wireless growth at only 7% over the next five years - the wireless carriers are going to find it increasingly difficult to squeeze more money out of a flatlining subscriber base.While the carriers can be comforted at least for the time being with their artificially inflated revenue thanks to per-minute billing, one has to wonder what they're going to do down the road when the Canadian wireless market hits saturation.