Finally revealing its hand in the mobile communications stakes, AT&T Corp will shortly reveal why it was so keen to acquire McCaw Cellular Communications Inc and a string of Personal Communications Services licenses. According to the Wall Street Journal, its aim is to bypass the Baby Bells and launch a local telephone service US-wide using fixed radio links to connect into its long-distance network. The Bells, and other local telephone companies, would then get paid only for delivering calls to their subscribers. Key to the system is an electronic box that would link home telephones directly to the AT&T wireless network. The paper hears the plan could be announced this week, and that AT&T Wireless Systems may charge as little as a $10 flat monthly fee for unlimited local calls from home. The Personal Base Station access box would sell for less than $300.