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CN (Core Network)

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A core network (CN) is the central part of a telecommunications network that provides connectivity between different access networks, such as mobile, fixed-line, and broadband. The CN is responsible for routing voice, data, and multimedia traffic between different networks and enabling the end-to-end delivery of services.

In this article, we will discuss the key components of the CN, their functions, and the technologies used in the CN.

Key Components of the Core Network

  1. Mobility Management Entity (MME): The Mobility Management Entity (MME) is a key component of the CN in LTE (Long-Term Evolution) networks. The MME provides authentication, authorization, and mobility management for mobile devices. When a mobile device connects to an LTE network, the MME assigns an IP address to the device and tracks its location. The MME also controls the handover of a mobile device from one base station to another as the device moves through the network.
  2. Serving Gateway (SGW) : The Serving Gateway (SGW) is responsible for routing user data between the base station and the core network in LTE networks. When a user sends data, the data is routed through the SGW to the appropriate destination. The SGW also manages the allocation of radio resources for user data transmission.
  3. Packet Data Network Gateway (PDN-GW): The Packet Data Network Gateway (PDN-GW) is responsible for routing user data between the core network and external networks, such as the internet or private networks. When a user sends data to an external network, the data is routed through the PDN-GW to the appropriate destination. The PDN-GW also manages the allocation of IP addresses to mobile devices.
  4. Home Subscriber Server (HSS) : The Home Subscriber Server (HSS) is a database that stores information about subscribers, such as their phone numbers, service plans, and authentication credentials. When a mobile device connects to the network, the HSS provides the authentication and authorization information to the MME to verify the subscriber's identity and authorize access to the network.
  5. Policy and Charging Rules Function (PCRF) : The Policy and Charging Rules Function (PCRF) is responsible for controlling the quality of service (QoS) and charging for network services. The PCRF determines the QoS for different types of network traffic, such as voice or data, and allocates network resources accordingly. The PCRF also determines the charges for network services based on the subscriber's service plan and usage.

Functions of the Core Network

  1. Authentication and Authorization : The CN provides authentication and authorization for mobile devices to access the network. When a mobile device connects to the network, the CN verifies the subscriber's identity and authorizes access to the network based on the subscriber's service plan.
  2. Routing : The CN is responsible for routing traffic between different networks, such as mobile, fixed-line, and broadband. The CN routes traffic based on the destination address and the type of traffic, such as voice or data.
  3. Quality of Service (QoS) : The CN is responsible for ensuring the quality of service (QoS) for different types of network traffic, such as voice or data. The CN allocates network resources, such as bandwidth and radio resources, to ensure that high-priority traffic receives the necessary resources to maintain QoS.
  4. Charging : The CN is responsible for charging subscribers for network services based on their service plans and usage. The CN determines the charges for network services based on the subscriber's usage and service plan.

Technologies Used in the Core Network

  1. Internet Protocol (IP) : The core network uses IP to route traffic between different networks and to allocate IP addresses to mobile devices. IP is a widely used protocol for network communication and enables the delivery of data, voice, and multimedia content over the network.
  2. Virtual Private Network (VPN) : A Virtual Private Network (VPN) is a technology used to create a secure and private connection between two networks over the public internet. In the CN, VPNs are used to connect mobile devices to private networks, such as corporate networks or government networks, securely.
  3. Quality of Service (QoS) : Management Quality of Service (QoS) management is a technology used to ensure the delivery of high-quality network services. In the CN, QoS management is used to allocate network resources, such as bandwidth and radio resources, to ensure that high-priority traffic, such as voice calls or emergency services, receives the necessary resources to maintain QoS.
  4. Multimedia Messaging Service (MMS): Multimedia Messaging Service (MMS) is a technology used to send multimedia content, such as images and videos, over mobile networks. In the CN, MMS is used to enable the delivery of multimedia content between mobile devices and external networks, such as the internet or private networks.
  5. Voice over IP (VoIP): Voice over IP (VoIP) is a technology used to enable voice communication over IP networks. In the CN, VoIP is used to enable voice calls between mobile devices and external networks, such as fixed-line networks or other mobile networks.
  6. Long-Term Evolution (LTE) :Long-Term Evolution (LTE) is a technology used to provide high-speed data communication over mobile networks. LTE enables the delivery of high-quality video streaming, gaming, and other multimedia content over mobile networks. The CN uses LTE to provide high-speed data communication and to enable the delivery of multimedia content to mobile devices.

Conclusion

In conclusion, the core network (CN) is a critical component of a telecommunications network that provides connectivity between different access networks and enables the end-to-end delivery of services. The CN is responsible for authentication, routing, quality of service, and charging for network services. The key components of the CN include the Mobility Management Entity (MME), Serving Gateway (SGW), Packet Data Network Gateway (PDN-GW), Home Subscriber Server (HSS), and Policy and Charging Rules Function (PCRF). The CN uses technologies such as IP, VPN, QoS management, MMS, VoIP, and LTE to enable the delivery of high-quality network services.