In this paper, we propose a channel reservation mechanism referred to as time-based channel reservation algorithm (TCRA). The aim of TCRA is to handle the handover issue in low Earth orbit satellite networks. These systems face an important number of handover attempts due to the high satellite velocity when placed in low orbits. The TCRA scheme uses the deterministic satellite movement pattern to estimate the user residence time in each cell to be crossed. Two versions of the algorithm are proposed depending on whether the network disposes of a positioning system or not. These versions of TCRA allow to guarantee a null handover failure probability for the users. The performance of TCRA (with its two versions) is examined by simulations and compared to the guard channel scheme. The results show the behaviour of the schemes and their performance in terms of new call and handover blocking probabilities.