Google Calendar SMS Alert Comes to China


Now Google Calendar users in China can finally enjoy the same SMS alert service as in other countries. Although they mentions China Unicom as the only mobile provider to be supported, I have no problem in registering the service and receiving alerts even I’m a China Mobile subscriber. This alert service is very handy to everyone, as Google Calendar will send you SMS to your mobile phone whenever an event is going to begin.

An interesting tidbit is, they sent the verification code to my mobile phone via HUTCHISON_HK, where HUTCHISON is one of the mobile service providers in Hong Kong. It seems that Google choose neither China Mobile nor China Unicom, the two major mobile providers in China, as their partners.

Combining Google Maps and Google Ditu

Ditu (地圖, 地图) means map in Chinese. China has long been missing from the global Google Maps. Zooming into the China border, only patches of grey blocks are shown, occasionally with blue lines here and there indicating rivers and lakes, and worst of all, maps are just unavailable after you have drilled down deep enough.

Usually this doesn’t pose any problems as Google China serves China maps (and only China maps) at Google 地图, which provides all the functionalities of the global Google Maps website, sans satellite images. This is annoying nevertheless, it’d be the best if users can see maps of China seamlessly when they’re viewing, without jumping out from and then type in another URL just to view some data that’s still backwardly regarded by the Chinese authority as confidential and sensitive.

“Hybrid” mode for China maps is another feature that would be handy to Chinese users. Satellites images are already available but just not being shown on Since hybrid mode requires a special layer of map tiles, specially they have a transparent background so that the satellite images can show through underneath the maps, without post-processing map data provided by Mapabc this is not achievable. By Google’s terms of usage of the map data, processing the maps and then re-distribute is not legal. We can only use some freely redistributable map data such as from

Hooking up with maps from Google China is not difficult, actually that’s much easier than I thought because Google Maps API already have the mechanism to add a new map type for showing custom map data. My proof-of-concept is shown below, press the “Ditu” button at the top right hand corner and you’ll see maps delivered from

Ideally, this “mashup” should best be implemented using the new Google Mapplets, this will give users the best user experience as they only need to add a mapplet and then Google China maps will be embedded to the map window automatically, users are not required to go to this page. But since Google Mapplets doesn’t support adding new map types due to security concerns, this currently is not an option. Frankly, I don’t see there’s any security concerns by supporting new map types.

Don’t be surprised if you notice that the satellite images do not align with the Google China maps, because Google China intentionally shifted the latter to please the Chinese authority. Did it say that the maps are regarded as national security?