Determine mobile network technology(e.g. 2G, 3G, 4G)

SBGetAccurateNetworkReachability

static CTTelephonyNetworkInfo * __telephonyNetworkInfo;
SBNetworkReachability SBGetAccurateNetworkReachability()
{
    SBNetworkReachability reachability = SBGetNetworkReachability();
    if (reachability == SBNetworkReachabilityMobile) {
        if ([[[UIDevice currentDevice] systemVersion] floatValue] >= 7.0f) {
            if (!__telephonyNetworkInfo) {
                __telephonyNetworkInfo = [CTTelephonyNetworkInfo new];
            }
            NSString * radioAccessTechnology = __telephonyNetworkInfo.currentRadioAccessTechnology;
            if ([radioAccessTechnology isEqualToString:CTRadioAccessTechnologyGPRS] ||
                [radioAccessTechnology isEqualToString:CTRadioAccessTechnologyEdge] ||
                [radioAccessTechnology isEqualToString:CTRadioAccessTechnologyCDMA1x])
                reachability = SBNetworkReachabilityMobile2G;
            else if ([radioAccessTechnology isEqualToString:CTRadioAccessTechnologyLTE])
                reachability = SBNetworkReachabilityMobile4G;
            else
                reachability = SBNetworkReachabilityMobile3G;
        } else {
            SCNetworkReachabilityFlags flags;
            SCNetworkReachabilityGetFlags(__reachability, &flags);
            return ((flags & kSCNetworkReachabilityFlagsTransientConnection) == kSCNetworkReachabilityFlagsTransientConnection) ? SBNetworkReachabilityMobile2G : SBNetworkReachabilityMobile3G;
        }
    }
    return reachability;
}