According to the statistics and prediction of some institutions, the mobile radio communication services will increase dramatically in the next ten years. Especially, the requirement of the services which happened indoor will be the main increasing part, which will be much more than 50 percent of the total service. Although there are various technologies for the indoor coverage, like wireless local area network (WLAN) and femtocell, all of them are still facing challenges to satisfy the increasing requirements. Therefore, developing new technologies and upgrading the existing systems for indoor services are urgent issues not only at present but also in the future. The study on indoor propagation characteristics, as an indispensable and fundamental step, is of great importance. So the indoor propagation characteristics will be discussed in detail in this chapter.
Indoor propagation characteristics have been widely studied over the world since the 1990s. Lots of field measurements were carried out in various indoor environments, such as offices, factories, houses, and so on. Meanwhile, standardization organizations and research institutions have also defined several indoor channel models for different applicant purposes, as summarized in Table 3.1. International mobile telecommunication–advanced (IMT-A) system, also known as ...