Anyone know which mobile service offers the best 3G coverage for a good price?

China Unicom may be your best choice.

If you're bringing in a phone from another country, China Unicom is probably the only carrier that will work for 3G service. Reception is spotty in a lot of the city, and basically nonexistent in much of the countryside.

China Mobile has much better reception and coverage, but its 3G standard only works with 3G phones specifically made for that network. You can slap one of their SIM cards into an international 3G phone, but you will only get 2G/Edge.

I don't know about China Telecom

Unicom uses 3G-wcdma. Telecom uses 3G-CDMA (no "w"). Mobile uses 3G-TDSCDMA - the Chinese standard. At the moment Unicom offers the most reliable high speed data (internet) 3G service but as noted - coverage is spotty - but its the same in most cities. For voice - Mobile is still number 1 on it's ancient GSM/GPRS 2.5/2.75G service - but data speeds are SLOW - but acceptable for simple internet browsing (minus FLASH).

it is just my personal experience.

if you travel interstates/inter-regions a lot, china telecom is the best in coverage and stability. a China Telecom CNY100/month business plan allows 60 hour on the net with no data limit. as a supplement, if you ever go to hong kong, you could purchase a China Unicom 3G plan there for HKD$130/month, with that you could access the internet in china,free from the 'China Great Wall.' the access uses proxy in hong kong instead bypassing the 'Great Wall,' accessing overseas sites is 'almost instant.'

i used china mobile before in shanghai, shenzhen and guangxi, it's stability drove me crazy, signal dropping off in random to be useful. i dont know if China Mobile has improved since.

There are 3 networks and they all use different technologies.

China Unicom - WCDMA/UMTS/HSPA/GSM(GPRS) - This is the standard used all over the world and China Unicom offers it on the 2100MHz frequency used in Europe. (N.B. AT&T and T-mobile in the USA also use WCDMA but at total different frequencies to Europe so make sure your phone is compatible). I used Unicom in Kunming for about a year and the coverage is not the best. It will work outside everywhere but occasionally you may lose the signal indoors. It seems much better in Beijing so perhaps it will improve in Kunming in the not too distant future. With HSPA the network is capable of download speeds of up to 21Mbps although this is never going to happen. I think it advertises 7Mbps in Kunming, you'll be lucky if you get anywhere close but it is faster than all the other networks (including fixed line ADSL). If you can't get a 3G signal China Unicom uses GPRS (slower than China Mobile's EDGE) for 2G data.

China Mobile - They have the largest 2G network and the best coverage. However for 3G they've adopted a homegrown technology called TD-SCDMA and there aren't a great deal of handsets compatible although this is changing. If you do get a TD-SCDMA handset and want to take it outside China make sure its internal radio can also use GSM as TD-SCDMA doesn't exist outside China at all. China Mobile has upgraded its 2G data service from GPRS to EDGE in most areas so when you're not using 3G you'll use a much faster 2G data service than you can on China Unicom.

China Telecom - China Telecom uses CDMA for 2G and CDMA2000/EVDO for 3G. This technology is not used in most of the world but is used by 2 major networks in the USA. Apparently coverage is pretty good but again you'll need to get a compatible handset of which there are fewer available than for GSM/WCDMA. Now the interesting part is that rejected_goods mentioned 60 hours with no data limit. For some types of phone that might make sense and be a good deal but for most smartphones this won't work. For example, my iphone is constantly connected to the internet if I enable push mail, even with it disabled it is connected most of the time. I may not consume more than 100 to 200MB of data per month but I am definately connected for much more than 60 hours. Until China Telecom start charging for data rather than connection time it isn't a viable option for many types of handset.

Plus CDMA (including CDMA2000/ EVDO) doesn't allow for voice and data at the same time so if you're in the middle of downloading a file while you get a phonecall it'll cancel your download. I'm not sure about TD-SCDMA but WCDMA (ie, Unicom) supports data and voice simultaneously).

I just bought a China Telecom 3G card to use with a Huawei wireless modem, and I can't configure it for my Macbook (running OS X 10.6.4.) Anybody know how to do this? It looks like I need at least an APN and telephone number.

i am using china telcom 3g but i use windows not a Mac

the windows setup is as follow,

use PPP protocol
Dial : #777
user name: ctnet@mycdma.cn
password: vnet.mobi

i hope that might help for mac users.

just talked to a mate using a mac.

apple menu-> system preferences -> Network -> select the ext. modem
from the pop-up menu choose Add Configuration
then enter the CT default account name: ctnet@mycdma.cn and default password: vnet.mobi and the default dial up number : #777. bingo.

one tip, change the dns configuration to OpenDNS's instead of using CT's DNS
OpenDNS is as follow,
208.67.222.222 primary and 208.67.220.220