As Yankee Group analyst Josh Holbrook notes, carriers often lag behind the economic times because they sign their customers to contracts of a year or longer and because demand for voice services is fairly stable. Thus, even if consumers and enterprises are hurting financially, they are unlikely to change their telecom spending habits until well after a recession is already under way.

So when the telcos do start to feel the pinch from the current recession, how will they adapt? Carriers this year have already employed one of the most obvious strategies to save money by cutting jobs. , for instance, last week said that it was going to lay off 8,000 employees, while AT&T has to cut 12,000 workers from its payrolls throughout 2009.

Gartner analyst Tole Hart says that the majority of cuts within the telecom industry are likely to come from telcos' wireline businesses as more consumers switch permanently over to wireless services. Looking at AT&T and Verizon's income statements for 2008 lends support to this view, as both companies experienced significant drops in their wireline operating revenue while showing continued growth in their wireless operating revenue.

Looking beyond layoffs, carriers could also slow planned upgrades to their networks and other big capital projects. For instance, both AT&T and T-Mobile last week that they were planning to focus on upgrading the performance of their 3G High-Speed Packet Access wireless data networks before making a big push to switch over to 4G Long Term Evolution technology. Both companies previously stated that they planned to begin deploying LTE in 2010 with a commercial launch slated for 2011. Even so, Hart says that unless the recession gets significantly worse, he expects the carriers will begin rolling out their 4G systems more or less on schedule, with Verizon leading the way by launching its LTE network commercially in 2010.

"It seems like AT&T might be pushing their commercial deployments back a bit, but Verizon seems to be on track," he says. "LTE networks were always going to start out in big cities and then gradually be built out to more rural areas, so it leaves them with some room to tweak their plans."