How to know 5G network type from code in iOS?

let networkInfo = CTTelephonyNetworkInfo()
    let carrierType = networkInfo.serviceCurrentRadioAccessTechnology
    guard let carrierTypeName = carrierType?.first?.value else {
        return "UNKNOWN"
    }

    switch carrierTypeName {
    case CTRadioAccessTechnologyGPRS, CTRadioAccessTechnologyEdge, CTRadioAccessTechnologyCDMA1x:
        return "2G"
    case CTRadioAccessTechnologyLTE:
        return "4G"
    default:
        return "3G"
    }