Translation of RIL_PreferredNetworkType terminology to human speak?

Question

In Android's source code, I see

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?)

Answer 1

I figured them out thanks to here and here.

• GSM is 2G (on GSM networks)

• WCDMA is 3G (HSPA)

• CDMA is 2G (on CDMA networks)

• EvDo is 3G (on CDMA networks)

• TD-SCDMA is 3G (UMTS)

• LTE is 4G (LTE)

This PDF (page 16) explains the evolution of the different technologies.

Warning: A lot of this terminology is conflated (e.g. "CDMA" can refer to both the channel access method as well as mobile phone standards, "3G" and "4G" can refer to lots of different things, etc.) so take these with a grain of salt.