A mobile phone supporting a fixed-mobile convergence (FMC) network environment has attracted much interest from customers, because it enables users to access to both wired and wireless network with a single mobile phone. This paper presents loosely-coupled Embedded System Architecture for an FMC mobile handset. The main idea of the approach is to separate components execution for the mobile station to make them running over independent processor. This allows enhancing the overall voice quality and to decrease the coupling and complexity of the system. The paper presented a server-assisted call management algorithm as a case study to enhance the support of call in FMC. A bridging system is also presented. In order to illustrate the motivation of lc-ESA, we evaluate our approach by measuring the average mean opinion score (MOS), and mouth-to-ear (M2E) delay.