The great success of the satellite platforms are due mainly to some characteristics related to large bandwidth guaranteed by the use of high-frequency bands that permit the support of: small antenna sizes, making satellite services more pervasive and affordable for millions of commercial and residential end-users; larger system capacity, which is guaranteed by the use of smaller beams thanks to high frequencies, allowing the performance of a cellular-type mechanism, known as frequency reuse, with the capacity of serving more users in the covered area; ubiquitous access, thanks to broadcast nature of satellites and their capacity to reach those areas where other types of telecommunication services are unavailable.  
Thus, the important satellite characteristics of providing an excellent signal quality in a wide coverage propagation are extremely useful in scenarios of natural disasters and make satellite communication very attractive. Moreover, in the context of NGN networks, the use of satellite communication together with 6G wireless technology is able to guarantee high data throughput and channel capacity, making these networks able to improve the QoS provided to mobile users [7]. In this context, the design of an opportunity channel model that is able to model and reproduce high-frequency satellite communication characteristics represents a key factor for the scientific communities that deal with satellite systems [8].  
The main issue typical of these network typologies is the severe signal degradation that is due mainly to atmospheric effects and territory orography. These negative effects are much more evident when working with high frequencies with respect to the use of lower ones. Therefore, negative meteorological conditions such as rain, ice, clouds, and, in general, gas absorption, give rise to a series of phenomena whose study is of fundamental importance in order to be able to deploy satellite networks with optimal performance.  
In this scenario, being conscious of the propagation characteristics of the satellite channel, so as to be able to design a communication system for responding to the new user needs, is of fundamental importance. Thus, adequate knowledge of propagation phenomena is necessary for the performance assessment of these systems. This paper wants to present a comprehensive overview of the most recent developments in satellite channel communications related to mobile services and, in particular, for land mobile satellite (LMS) systems in urban, suburban, and rural environments by presenting all different types of Markov models, from single-state to multi-state models, proposed in the literature from the early 1980s.  
The organization of the paper is as follows: Section 2 presents a brief review of the literature on LMS channel models. Section 3 describes the satellite characteristic fundamentals. Section 4 describes the propagation characteristics and phenomena of LMS communication. The LMS channel models proposed in the literature are provided and  
Figure 1: Mobile satellite system.  
described in Section 5. The paper ends with the future research direction and the concluding remarks provided in Sections 6 and 7, respectively.