Extreme Tech- Hong Kong Protestors Turn to Mesh Networks

Hong Kong protesters turn to mesh networks to evade China’s censorship

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• By Sebastian Anthony on September 30, 2014 at 8:29 am
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The rather cramped streets of Hong Kong are currently lined with tens of thousands of people — the Umbrella Revolution. They are mostly students and members of Occupy Central, who are protesting for a fully democratic election process during the Hong Kong 2017 leadership election. The Chinese government, as always, has blocked and censored a number of social media sites so that mainland China can’t see what’s going on in Hong Kong. If the protest continues, the authorities might turn to more drastic measures — such as cutting Hong Kong’s internet connection, or turning off the cellular networks. The Hong Kong protesters won’t be so easily thwarted, however: They are already using a mesh networking app called FireChat, which allows the protesters to communicate freely without any kind of centralized cellular or WiFi network. Clearly, the Umbrella Revolution is in it for the long haul.

On August 31 2014, the Chinese government dictated that the next Chief Executive of Hong Kong (the prime minister) must be supportive of the National People’s Congress (the main Chinese parliament). In effect, the Chinese government dictated that all candidates who run for the position of Chief Executive would be pre-vetted, to make sure they don’t cause too much trouble. This upset the pro-democracy camp in Hong Kong, which obviously wanted a completely free and open election — and thus, the Occupy Central with Love and Peace (OCLP) organization was formed. The plan: A massive non-violent display of civil disobedience in Hong Kong’s Central district. A sit-in on a grand scale.

Starting September 28, Central has been filled with tens of thousands of protesters. Chinese riot police have tried to rout the non-violent protesters with tear gas, pepper spray, and some baton use, but the protesters haven’t budged; as you can see in the photos and videos throughout this story, the Central region of Hong Kong is still completely packed. (The name “Umbrella Revolution” stems from the fact that many of the protesters are using umbrellas to protect against the midday sun and the tear gas.) The Chinese government don’t seem to know what to do. They’ve resorted to the usual tactic of censoring Weibo (a Chinese micro-blogging service), Instagram, and other social media networks, to ensure that dissidence doesn’t spread to mainland China. I’m sure the Great Firewall of China is working overtime right now, to stop any website or document that mentions Hong Kong from getting into the country.

But the Occupy Central protest continues — and if other Occupy protests are anything to go by, downtown Hong Kong could be occupied for weeks and months to come. There are certainly some more drastic measures available to the Chinese government, such as cutting off Hong Kong’s internet access entirely or turning off cellular networks in the Central region, but will they use them?

This Umbrella Revolutionist has not one but two umbrellas to fend off the tear gas

Mesh networks to the rescue

FireChat on iOS

In the last few months, Android and iOS have started to see the arrival of mesh networking apps — apps that can use Bluetooth and WiFi to create a local, decentralized network of smartphones (or tablets). If you want technical details of how mesh networking works, read our detailed explainer. In short, though, mesh networking allows anyone using the app to talk to anyone else using the app — as long as there are other app users in the middle, keeping the route open. Obviously, as more people connect, the mesh network becomes more and more resilient. (The internet itself started off as a mesh network, incidentally.)

The Hong Kong protesters are using a mesh networking app called FireChat. The app isn’t of much use in normal circumstances, but the developer says it was downloaded 100,000 times between Sunday and Monday in Hong Kong. FireChat was also used by protesters in Taiwan this spring, due to weak cellular coverage — and it’s also being used in Iraq, where the government is blocking internet access in an attempt to restrict ISIS’s communication channels.

The Occupy Central Hong Kong protet, in Causeway Bay [Image credit: Citobun]

Occupy Central protest in Hong Kong, near Tamar [Image credit: Citobun]

In Hong Kong, where internet access and cellular connectivity is still going strong, FireChat isn’t of much use — though it is a good way for the leadership of Occupy Central/Umbrella Revolution to minimize any chance of intelligence agencies listening to their communications. If the authorities do cut off internet or cell access, then FireChat suddenly becomes a very good way of keeping everyone up to date. FireChat itself doesn’t solve the no-internet-access problem, though — for that, someone in the mesh network would need to provide a satellite uplink, or some other alternate route to the global internet.

Despite the decentralized nature of FireChat, I think such a network could still be shut down by the use of radio jammers. FireChat creates a mesh network via Bluetooth and WiFi — both of which use very standardized, well-known frequency blocks (2.4GHz and 5GHz). If the Chinese government so wished, it would not be hard to blanket the Central region of Hong Kong with jamming radio waves at those frequencies. But that’s another topic for another day. Hopefully the government’s response to the Umbrella Revolution doesn’t escalate to that point…

With tomorrow — Wednesday, October 1 — being the Chinese National Day, tonight will be a crucial moment for the Umbrella Revolution. It is expected that Hong Kong’s police will try to clear the streets in preparation for the national holiday, so that the usual festivities can take place. The protesters, on the other hand, aren’t ready to leave. It’s going to be an interesting 24 hours.
Now read: How to watch hacking, and cyberwarfare between the USA and China, in real time

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• mobile computing
• smartphones
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• ios
• networks
• wireless communications
• china