AT&T will roll out its 3G MicroCell nationwide beginning in mid-April, with new markets activating in cities across the continental U.S. for the next several months.

AT&T 3G MicroCell allows residential customers to route wireless phone calls and data connections (or sessions) across a home broadband connection. This solution is designed to benefit customers who live in homes that have coverage impediments that consistently interrupt wireless spectrum, such as dense wall and roof construction or unfavorable terrain.

AT&T says the 3G MicroCell is the only femtocell to support both 3G data and voice services. Developed in conjunction with Cisco and in a public trial in select markets since September, AT&T 3G MicroCell will be available for $149.99.

Consumers with AT&T 3G MicroCell will be able to activate the device the same day it is purchased, thanks to self-install instructions. Technical support is available for customers who need it.

Consumers manage AT&T 3G MicroCell though their online MyWireless account. Through this online management, only those phones chosen by the customer may use the MicroCell. Customers may define up to 10 lines to have access and up to four may operate on it simultaneously. Minutes used through the MicroCell affect only the account of the phone making the call — there is no requirement to purchase separate service for the 3G MicroCell.

In addition, AT&T will offer a companion rate plan option for MicroCell customers – especially customers on Family Talk plans – who want to supplement their existing voice plans. For $19.99 a month, individual or Family Talk customers can make unlimited calls through a 3G MicroCell, without using minutes in their monthly wireless voice plan.

Consumers who select 3G MicroCell calling plans at purchase are also eligible to receive a $100 mail-in-rebate toward the purchase of AT&T 3G MicroCell – effectively making the device about $50. Customers who also purchase a new line of broadband service with AT&T (DSL or U-verse 1.5MB or higher) are also eligible for $50 via mail-in-rebate — effectively making the device about $100. If a customer is eligible for both rebate options, the customer will be able to get the device for $0, after a mail-in rebate.