Since mobile traffic has been increased tremendously due to popularization of high-end mobile devices, many mobile carriers and smartphone manufacturers have put their best effort on solving the capacity problem. Small cell is introduced as an idea for the solution, and various mobile carriers have installed small cells to provide more bandwidth to areas that have too much traffic to be handled by single cell tower. In this paper, we state a problem that is an extended version of current capacity problem, and argue that the problem cannot be solved by installing small cells only. Therefore, we propose the concept of Personal Area Cell (PAC) that is portable and able to perform multi-hop transmissions. In order to justify the proposed problem and solution, a traffic model is designed and simulated. The simulation results show that small cell based network is inefficient when population and traffic of each cell are changed over time while PAC adopted network is cost-efficient and adaptive to such the change.