# Integration of LTE 230 and LTE 1800 in Power Wireless Private Networks
## 3 Integration of the Core Network  
Figure 3 shows the structure of the traditional core network and access network that are used in current commercial LTE networks. Since LTE 230 is based on the LTE system and its core network is nearly the same as that for the public LTE network (except for the details of non-access protocols), we can integrate these two systems' core network hardware to reduce the cost and make the management easy.  
Firstly, let us review the traditional core network, especially the functionality of each component. The network between base stations and the devices is called the access network and is wirelessly connected. The remaining is called the core network, which is always wire connected. In the current core network, control and transmission separation is used to increase the adaptivity to different kinds of transmission services. In the control plan, the mobility management entity (MME) is mainly used to manage the mobility of the access devices, and the home site home subscriber server (HSS) is used to manage the registration and original information of users [17].  
In the data plane or user plane, there are the service gateway and packet gateway. The service gateway (S-GW) is a node connecting the access network to the core network. It acts as a mobility anchor when access devices move between base stations, as well as a mobility anchor for other 3 GPP technologies. The collection of information and statistics necessary for charging is also handled by the S-GW [17].  
The packet gateway (P-GW) connects the core network to the Internet. It manages the IP allocation of the access devices and the quality of service enforcement according to the policy controlled by the policy and charging rules function (PCRF). The P-GW is also the mobility anchor for non-3 GPP radio-access technologies to connect to the core network [17].  
As shown in Figure 4, the core network integration controller includes an S1-MME access controller and separator and an S1-U access controller. These two access controllers and the separator module are accessed to enhance the interaction ability of the dual-band base station control signal and data transmission ability. The general ideas are as follows.  
(1) The MME function is realized by the LTE 230 and LTE 1800 core network, and the SGW/PGW adopts an independent protocol stack.  
(2) SGW/PGW adds a transmission separator and router controller to distinguish different user equipment (UE) categories and carry out different protocol stack branch processing.  
(3) Access devices and base stations of different modes are distinguished and identified during access. Independent logic branches are used to deal with devices and base stations of different modes. The control signals of different modes are sent to different protocol stacks through the access controller and separator.  
Figure 3: The structure of the traditional LTE system.  
(4) The uplink and downlink service data are sent to the related protocol stack to complete transmission with the help of the transmission separator and router controller in the integrated S-P/GW.