New pushAll but gone from the wireless market since about 2001, Nortel Networks on Monday announced a new effort to sell high-end wireless networking equipment to telephone carriers and medium-size to large businesses. Nortel is selling access points, based on chips from Atheros Communications, that allow for the use of two different kinds of wireless networks: one built around the common 802.11b standard, and a second using 802.11a, which is five times faster. Users can jump back and forth between the different types of networks. Nortel is also providing a network switch that adds security measures to these networks, such as needing a password to log on. And the company is selling radios for both laptops and personal digital assistants, according to Nortel Networks spokesman Pat Cooper. Prices of the Nortel equipment were not disclosed Monday. Starting in 1999, Nortel devoted a small part of its business plans to the more secure and manageable Wi-Fi equipment used by businesses and telephone providers. A couple years later, though, it all but phased out Wi-Fi, and since then, rivals Cisco, Lucent and Proxim have taken the market lead. Nortel is ratcheting up efforts just as wireless carriers like AT&T Wireless and T-Mobile are building subscription Wi-Fi networks and businesses are adding wireless networks in their offices, Cooper said. "Wireless LANs are getting much more important for businesses and service providers," said Greg Collins, director at market analyst Dell'Oro Group. Businesses are a key target area for Nortel, In-Stat/MDR analyst Allen Nogee said. Nogee said a growing number of networking companies are trying to take advantage of the business market by offering companies entire Wi-Fi systems, from laptop cards to the hardware needed to manage the setups. Before, these same businesses had to rely on smaller players selling smaller networks, Nogee said. "Some companies lost grip on what they had out there," Nogee said. Ben Charny writes for CNET News.com.