Translation of RIL_PreferredNetworkType terminology to human speak?

[In Android's source code, I see](https://android.googlesource.com/platform/hardware/ril/+/master/include/telephony/ril.h) typedef enum { PREF_NET_TYPE_GSM_WCDMA = 0, /* GSM/WCDMA (WCDMA preferred) */ PREF_NET_TYPE_GSM_ONLY = 1, /* GSM only */ PREF_NET_TYPE_WCDMA = 2, /* WCDMA */ PREF_NET_TYPE_GSM_WCDMA_AUTO = 3, /* GSM/WCDMA (auto mode, according to PRL) */ PREF_NET_TYPE_CDMA_EVDO_AUTO = 4, /* CDMA and EvDo (auto mode, according to PRL) */ PREF_NET_TYPE_CDMA_ONLY = 5, /* CDMA only */ PREF_NET_TYPE_EVDO_ONLY = 6, /* EvDo only */ PREF_NET_TYPE_GSM_WCDMA_CDMA_EVDO_AUTO = 7, /* GSM/WCDMA, CDMA, and EvDo (auto mode, according to PRL) */ PREF_NET_TYPE_LTE_CDMA_EVDO = 8, /* LTE, CDMA and EvDo */ PREF_NET_TYPE_LTE_GSM_WCDMA = 9, /* LTE, GSM/WCDMA */ PREF_NET_TYPE_LTE_CMDA_EVDO_GSM_WCDMA = 10, /* LTE, CDMA, EvDo, GSM/WCDMA */ PREF_NET_TYPE_LTE_ONLY = 11, /* LTE only */ PREF_NET_TYPE_LTE_WCDMA = 12, /* LTE/WCDMA */ PREF_NET_TYPE_TD_SCDMA_ONLY = 13, /* TD-SCDMA only */ PREF_NET_TYPE_TD_SCDMA_WCDMA = 14, /* TD-SCDMA and WCDMA */ PREF_NET_TYPE_TD_SCDMA_LTE = 15, /* TD-SCDMA and LTE */ PREF_NET_TYPE_TD_SCDMA_GSM = 16, /* TD-SCDMA and GSM */ PREF_NET_TYPE_TD_SCDMA_GSM_LTE = 17, /* TD-SCDMA,GSM and LTE */ PREF_NET_TYPE_TD_SCDMA_GSM_WCDMA = 18, /* TD-SCDMA, GSM/WCDMA */ PREF_NET_TYPE_TD_SCDMA_WCDMA_LTE = 19, /* TD-SCDMA, WCDMA and LTE */ PREF_NET_TYPE_TD_SCDMA_GSM_WCDMA_LTE = 20, /* TD-SCDMA, GSM/WCDMA and LTE */ PREF_NET_TYPE_TD_SCDMA_GSM_WCDMA_CDMA_EVDO_AUTO = 21, /* TD-SCDMA, GSM/WCDMA, CDMA and EvDo */ PREF_NET_TYPE_TD_SCDMA_LTE_CDMA_EVDO_GSM_WCDMA = 22 /* TD-SCDMA, LTE, CDMA, EvDo GSM/WCDMA */ } RIL_PreferredNetworkType; The problem is, I don't know what the terminology maps to. "LTE" is obviously just 4G LTE, but what are TD-SCDMA, WCDMA, and EvDo? I'm assuming at least some of them must map to 2G (GPRS), 2G (EDGE), 3G, "3.9G" (HSPA+), but which is which? And which ones are actually CDMA (Sprint, Verizon, etc.) rather than GSM? (I'm a little confused because it seems GSM LTE phones also have modes like WCDMA?)