During the first wave of the wireless revolution, businesses realized that being out of the office didn’t mean being out of action. BlackBerrys, iPhones, and 3G dongles for laptops let businesspeople stay connected on the move.

But the second wave, ushered in by the development of 4G mobile broadband, will take the mobile revolution indoors. Although consumer excitement over apps and smart phones is high, and has attracted much of the attention of the press, the enterprise will be the first serious consumer of 4G services. Cellular networks and other service providers are preparing services that will arrive at offices with the potential to destroy the last vestiges of wired infrastructure such as desk phones and wired Internet links.

“The first really heavy users of the new network will be business users,” says Lindsay Notwell, executive director leading the rollout of Verizon’s LTE service (LTE stands for Long Term Evolution, a set of standards for future networks). That’s due to launch at the end of 2010, bringing coverage to more than 100 million people. “We’ll be announcing 4G modems first and support for cell phones by mid-2011.”

The firm isn’t building a cell-phone network but a data network, one just as fast as wired links. Notwell claims that when you take your laptop indoors and you’re on LTE service, users shouldn’t notice a difference between wireless and wired performance.

Sprint Nextel has been rolling out its 4G service in major U.S. cities all year, and is now up to 55 cities. That network is based on the WiMAX standard, an alternative to LTE. Bob Azzi, senior vice president for network at Sprint Nextel, claims that his network can offer speeds from three to five megabits per second for downloads—and one or more megabits per second for uploads. “That’s absolutely good enough to replace an enterprise’s T1 [wired] connection,” he adds.

A service that speedy makes new kinds of products possible, says Azzi. The technology should have an impact on the retail industry, for instance. Stores typically need fast networks at checkout counters to look up product information, reference customer data, and process credit cards. “Structuring a store is much easier when you are not constrained by having to get wires to every last place,” he adds. “You can use a wireless 4G modem instead.” In such a scenario, salespeople could rove around stores with tablets to help customers and process transactions. Or they could move their fully connected cash registers into the great outdoors, he adds, for events in parks or other outdoor venues.

Sprint is also working on the idea of packaging a set of 4G modems and other hardware into an off-the-shelf “office in a box.” “It would contain everything you needed to set up a new branch and connect it up,” says Azzi. One consequence might be the appearance of “pop-up” offices that can perform just like a more established location. For example, a firm that offers tax preparation services could rapidly set up an office to help a client on a deadline. “In the case of a natural disaster, an insurance firm could drop in a fully powered claims office very simply and quickly,” says Azzi.

But carriers will be hard-pressed to deliver on the promise of fast, tether-free connectivity in all kinds of environments. There are doubts that networks can keep pace with the demand for wireless data, a demand that’s growing 55 percent annually in North America, says ABI Research. And when people get access to more bandwidth, their appetite grows. According to Sprint, users of its first WiMAX capable phone—the EVO 4G—typically tripled their data usage.

The research firm Infinetics predicts that by 2013, there will be more North Americans connecting to the Internet via mobile broadband than via any other form of access—with enterprises expected to account for much of the demand.

Many in the industry think that making wireless competitive with wired will require as much business innovation as it will engineering. For instance, can wireless carriers charge enough to make pricey rollouts worthwhile? The era of flat pricing for wireless data already looks to be ending, and the next step might involve asking customers to pay for different tiers of service depending on their data demands.

Such a strategy could run counter to net-neutrality legislation that would mandate networks to treat all data packets the same. That was one of the motivations for Verizon’s recent controversial pact with Google advocating for different regulations for wired and wireless connections. Ultimately, net neutrality policy may become the biggest practical distinction between wired and wireless connections.