The mobile users on board vehicles often experience low quality of service due to the vehicular penetration effect, especially at the cell edges. The so-called mobile-cells are installed inside public transport vehicles to serve the commuters. On one end, the mobile-cells have a wireless backhaul connection with the nearest base station, and on the other, they connect wirelessly to the in-vehicle users over access links. This paper integrates the mobile-cells within the cellular networks by reusing their sub-channels. Firstly, this paper proposes an algorithm that allows spectrum sharing for access-link with out-of-vehicle cellular users or MC's backhaul-links. Secondly, it proposes a scheme for controlling the transmit power over the access link to mitigate interference to the backhaul-link, while maintaining high link quality for in-vehicle users.