**San Diego Gas & Electric (SDG&E) - A Unique Case in US Mobile Networking** San Diego Gas & Electric (SDG&E), while primarily known as a public utility providing energy services in San Diego County, California, also operates a private mobile network for its critical infrastructure. This network is identified by Mobile Country Code (MCC) 313, representing the United States, and Mobile Network Code (MNC) 470. Unlike major commercial mobile network operators like Verizon (MCC 311), AT&T (MCC 310), and T-Mobile (MCC 310), SDG&E's network isn't intended for public consumption. Instead, it facilitates reliable communication and data transmission for grid management, smart meters, and field operations, ensuring a resilient and responsive energy grid across its service territory in Southern California. The network leverages wireless technology to enable real-time monitoring and control, a crucial aspect of modern utility infrastructure. The decision for SDG&E to establish its own mobile network highlights the increasing importance of dedicated, secure communication channels within critical infrastructure. While commercial networks offer broad coverage, factors such as network congestion during peak hours and dependence on external providers prompted SDG&E to invest in a private network solution tailored to its specific needs. This approach provides greater control over network performance, security, and reliability – paramount considerations for maintaining a stable energy supply. This approach is becoming increasingly popular in North America & Caribbean, with many utility companies implementing similar infrastructures. It also allows for specialized applications like automatic meter reading and fault detection, ultimately contributing to a more efficient and reliable energy distribution system for the residents and businesses within San Diego County.