Views: 14 Author: Site Editor Publish Time: 2020-01-03 Origin: Site
With the continuous maturity of LTE network technology, the enthusiasm for building LTE networks around the world is also getting higher and higher. In addition to large operators, LTE networks are also increasingly favored by private network users. Users in various industries such as energy, public transportation, military, and education have also begun to consider using LTE to build their own dedicated communication networks and create exclusive services.
Figure 1 describes a scenario in which the energy extraction industry uses LTE networks for video surveillance. These enterprises generally have many operating areas or other high-risk operating areas located in deserted or deserted places such as the Gobi. They install video capture devices to monitor the operating areas in these areas. A mobile terminal is installed at each point, and multiple high-definition cameras are connected. The collected high-definition video is transmitted to the control center through a dedicated LTE / EPC network. This LTE network is generally composed of several macro stations or dozens of small base stations, and the number of simultaneous access terminals is generally less than 100.
These private network users generally have the following characteristics.
● Small network scale: Generally, the capacity is only a few hundred or several thousand users, and the larger scale also has tens of thousands of users;
● Simple network architecture: It is basically a set of core network equipment plus several base stations to form a network;
● Limited equipment room conditions: Many users do not have professional telecommunications equipment rooms, and the space in the equipment room is often small;
● Sensitive to construction cost: Most users bear equipment costs of tens of millions without starting, and hope that the construction cost of the entire network can be controlled in the range of two to three million yuan or even lower;
● Simple operation and maintenance: Most private network users lack professional telecommunications knowledge and hope that the daily maintenance of network equipment is as simple as possible.
Unlike large telecommunications operator networks, private network users need miniaturized, highly integrated, and low-cost EPC core network equipment to provide them with services
The EPC core network is located between the LTE base station eNB and the service network, and mainly implements a series of management such as access, mobility, and sessions for LTE users. The EPC core network mainly includes 4 network elements: MME, HSS, SGW, and PGW. The functions of each network element are as follows:
● MME (Mobility Management Entity) provides the main control, mobility management, security control, and session management functions of the LTE access network.
● SGW (Serving Gateway) is responsible for transmitting, forwarding, and routing switching of LTE user data.
● Packet Data Network Gateway (PGW) manages the connection between mobile terminal equipment and external packet data networks, and is mainly responsible for terminal IP address allocation and egress routing of user service data. In addition, it also serves as an anchor point inside the mobile network, which remains unchanged during the user's movement to ensure the continuity of business.
● HSS (Home Subscriber Server, Home Subscriber Server) is responsible for the management of subscriber subscription data and authentication information.