Walmart has announced the launch of Walmart Family Mobile, a post-paid plan without a contract or multi-year commitment. The service will be provided by T-Mobile over its nationwide network, and will be sold by Walmart in nearly 2,500 stores starting Sept. 20.

The first line of service will cost $45 per month, and each additional line is $25 per month. Every line has Unlimited Talk & Text.

Family Mobile includes Data plans as well. Activated accounts come with a free preloaded 100MB WebPakTM  for internet usage. Once that 100 MB is used up, customers will have to pay additional fees to continue using data services. Pricing will run $10 for 200 MB, $25 for 500 MB, or $40 for 1 GB.

Walmart Family Mobile phones include Samsung, Motorola and Nokia, phones with the Android Operating System, QWERTY keyboard, touch screens and other features.

With this new alliance T-Mobile may lose some (market) share on T-Mobile branded (service) but expects to take share from other competitors.

Walmart's move also opens possibility of future 4G LTE based data plans when the comercial LTE networks are available, well it certainly fits Harbinger Capital Venture's wholesale LTE network plan.