s*******n
发帖数: 730 | 1 att的手机是不是只要有850或者1900就可以用3g（在有对应网络的地方）。而tmo的手
机必须要1700和2100两个都有才能用。
我说的都是umts的频率 | a****l
发帖数: 8211 | 2 I think so.tmobile uses a strange bande which uses one of 1700/2100 for
downlink and one for uplink.so fewer headsets are compatible with tm.
【在 s*******n 的大作中提到】
: att的手机是不是只要有850或者1900就可以用3g（在有对应网络的地方）。而tmo的手
: 机必须要1700和2100两个都有才能用。
: 我说的都是umts的频率
| w**********s
发帖数: 567 | 3
UMTS is designed to operate in 14 paired bands.
In US, ATT use band V(850) and T-Mobile use band IV
(1700) or called AWS. For Band II, the pair frequencey
uses 824-849 as uplink and 869-894 as downlink. Same as band
IV uses 1710-1755 as uplink frequency and 2110-2155 as
downlink frequency.
when you buy an unlock phone, check the specification of the
phone and find out the supported Frequency bands. Usually,
the phone will support multiple bands for UMTS, like I, II,
V, VIII for iphone or I, IV, VIII for some other phones.
【在 a****l 的大作中提到】
: I think so.tmobile uses a strange bande which uses one of 1700/2100 for
: downlink and one for uplink.so fewer headsets are compatible with tm.
| a****l
发帖数: 8211 | 4 one more reminder, also check the 3g coverage of your area. If you are not
in metro area, chances are you don't have 3g coverage at all, then you don't
need to worry about this band issue...
【在 w**********s 的大作中提到】
:
: UMTS is designed to operate in 14 paired bands.
: In US, ATT use band V(850) and T-Mobile use band IV
: (1700) or called AWS. For Band II, the pair frequencey
: uses 824-849 as uplink and 869-894 as downlink. Same as band
: IV uses 1710-1755 as uplink frequency and 2110-2155 as
: downlink frequency.
: when you buy an unlock phone, check the specification of the
: phone and find out the supported Frequency bands. Usually,
: the phone will support multiple bands for UMTS, like I, II,
| c*****e
发帖数: 639 | 5 手机标称上面写的1700和2100之类都是频带的代号，不是真正的使用频谱，
也不是准确的使用频率，只是一个代号。
1700实际是1700MHz左右上行/2100MHz左右下行
2100实际是1900MHz左右上行/2100MHz左右下行
850是850MHz左右上行/850MHz左右下行
1900是1900MHz左右上行/1900MHz左右下行
手机标称上面只要有1700就能用tmobile的3G，因为这个1700是频带的代号，
指的就是用1700上/2100下。
2100不能用在Tmobile的3G上面的。因为2100是一个不同的频带，
1900上/2100下。
欧亚多用2100。ATT用850/1900
【在 s*******n 的大作中提到】
: att的手机是不是只要有850或者1900就可以用3g（在有对应网络的地方）。而tmo的手
: 机必须要1700和2100两个都有才能用。
: 我说的都是umts的频率
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