Analyzing Zone-Based Registration under 2-Step Paging in Mobile Communication Network

In this study, we have considered zone-based registration (ZBR), which is the most widely adopted type in mobile communication networks. Based on a performance comparison between one-zone-based registration (1ZR) and two-zone-based registration (2ZR), 2ZR is known to be superior to 1ZR in most cases. However, the existing studies on the comparison of 1ZR and 2ZR have a critical problem: The basic assumption in 1ZR is that the entire zone is paged simultaneously when a call arrives, whereas, in 2ZR, the zone is paged by two steps. With these different paging schemes, a proper comparison cannot be made. Therefore, in this study, we analyzed the performance of 1ZR by adopting 2-step paging (2SP) such as 2ZR for a proper performance comparison under equivalent conditions. This study also presents an analytical model of assigning paging areas under 2SP in 1ZR when the zone consists of multiple cells. Considering the mobility characteristics assumed in the previous studies on 2ZR, we have presented the mobility model for movement among cells in a zone, obtained the steady-state probability of each cell by using the Markov chain model to calculate the paging cost under 2SP, and ultimately calculated the total signaling cost. Through various numerical results, it was observed that, when 1ZR also adopts 2SP such as 2ZR, 1ZR can be superior to 2ZR in many cases. In conclusion, by adopting 2SP in both 1ZR and 2ZR, it would be possible to reduce the total signaling cost by selecting the better 1ZR and 2ZR while considering traffic changes.