你有没有想过如果突然无法连接到互联网(couldn’t connect to the internet)与他人交流，或者无法完成日常任务，你会怎么做？
由于互联网的多种用途，我们大多数人已经开始依赖互联网做很多事情。因此，任何阻碍访问网络和其他在线服务的事情都会使文件共享、购物、流媒体和其他几乎不可能的事情发生。
但是，使用网状消息传递，可以在没有持久托管网络的情况下与他人通信并保持相互连接。
在本文中，我们将帮助您了解什么是网状消息传递、它现在是如何使用的，并解释它是如何工作的。如果您想深入研究不同类型的网络，我们建议您阅读我们的计算机网络(computer networks)指南。
什么是网状消息？
网状(Mesh)消息传递或离网消息传递是一种点对点网络系统，允许用户在不依赖蜂窝或WiFi网络或任何其他政府控制的基础设施的情况下相互联系。
2019 年的香港(Hong Kong)抗议活动就是使用网状消息的一个很好的例子。数十万平民走上街头，举行反送中示威，反对允许政府将犯罪嫌疑人遣返中国(China)的逃犯修正案(anti-extradition demonstrations against the Fugitive Offenders Amendment bill).
抗议活动持续了数周，促使警方使用暴力和侵略性手段来制止这些努力。因此，抗议者需要一种不依赖互联网连接的方式相互交流，以便组织起来并保持安全。
为此，他们使用了FireChat和Bridgefy等离网智能手机应用程序，这些应用程序通过在互联网和运营商基站桅杆之外创建自己的网络来工作。它们主要依赖于两部或多部手机之间存在的WiFi链接或蓝牙。(Bluetooth)
抗议期间，这两款应用仅在香港(Hong Kong)就获得了数千次下载，因为抗议地区的人很多，这使得手机网络完全变慢。
网状消息传递的一些理想用途包括：
- 在地震、洪水、飓风和火灾等灾害期间
- (Jungle)在没有接待的偏远地区进行丛林徒步旅行或团体露营
- 在战区或大规模抗议期间，政府可能会关闭互联网
- 当您的手机上没有移动数据或您的计划已过期时
- 旅行时，您不在同一辆车或飞机上的家人或朋友旁边
网状消息的工作原理(How Mesh Messaging Works)
Mesh消息通过(Mesh)蓝牙(Bluetooth)或 ad hoc WiFi发送数据，类似于您的手机在尝试让家庭安全摄像头或智能设备上网时设置的内容。
该系统的结构使得没有人可以监视或控制您正在进行的对话。通过这种方式，黑客和政府监控机构都无法侵入手机信号塔来阻止通信渠道，关闭您试图用来与他人通信的网站，甚至监听发送给您的互联网服务提供商的任何内容。
用于网状消息传递的应用程序(Apps)不需要传统的在线网络。此外，它们以与下载软件相同的方式在用户之间建立联系，而不是从中央存储库中吸取文件。
如果您的智能手机上安装了网状消息传递应用程序，并且同一地区的许多其他人都拥有相同的应用程序，则更容易互相传递消息，就像接力队传递接力棒一样。但是，传递信息对于将消息发送给其他人的每个人都是不可见的，因此在消息传递时不会被其他人阅读。
网状消息传递的主要工作原理是设备到设备的通信。这利用短距离蓝牙(Bluetooth)连接形成网络并绕过蜂窝或 WiFi 网络(bypass cell or WiFi networks)，以及任何其他政府控制的基础设施。
网状消息传递的主要目的不一定是为了避开政府的雷达，而是为了在连接性较差的区域或没有任何连接形式的偏远地区实现通信。在许多球迷会相互交流的体育场馆的活动中，或者在遭受地震和洪水等自然灾害蹂躏的地方，它也会派上用场，这些自然灾害会破坏手机信号塔和WiFi网络。
网状(Mesh)消息应用程序使用网状网络通过蓝牙(Bluetooth)将用户的设备连接在一起，允许消息从一个设备移动到另一个设备，直到它到达目标人的收件箱。
由于蓝牙的电话到电话的最大范围通常在 100 米左右，因此可以与最远 200 米范围内的其他人进行通信。当两部或多部手机在彼此的范围内时更有效，否则会影响信号强度。
但是，对于更长的距离，您的消息将在最近的用户之间跳转并创建一个网状网络，直到它到达预期的人。例如，电话 A 无法直接连接到电话 C，mesh 消息应用程序会通过电话 B 将消息从 A 退回到 C。
此外，转发消息的人无需在您的联系人列表中或执行任何进一步的操作即可达到您的预期目标。这使得政府或黑客更难关闭它，因为没有可以针对关闭它的单点故障。
网状网络中的用户越多，网状消息传递的效果就越好。
如何使用网状消息应用程序
为了让您了解网状消息传递的工作原理，我们测试了一种流行的离网应用程序Bridgefy，这里有一个关于如何使用它的分步指南。
- 第一步是根据您的手机访问Google Play Store或App Store ，然后下载(App Store)Bridgefy应用程序。对于本指南，我们使用的是Android 9版本的(Android 9)Android智能手机，因此我们将从Google Play Store下载该应用程序。
- 您会在 Bridgefy 下找到两个应用程序：(Bridgefy) Bridgefy -Offline(Bridgefy) Messaging和(Messaging)Bridgefy Alerts(Bridgefy Alerts)。下载Bridgefy-离线消息(Bridgefy-Offline Messaging)选项。
- 接下来，启动应用程序并通过点击新屏幕上的 开始进行设置。(Get Started)
- 通过添加用户名（最好是您的联系人认识您的用户名）完成设置，然后点击完成设置(Complete setup)。
- 在新屏幕中单击下一步(Click Next)，并授予应用程序访问您的位置(Location)设置以使用蓝牙(Bluetooth)通信和您的联系人列表的权限。
- 如果您收到要求您更新位置(Location)设置的弹出窗口，请点击启用(Enable)，然后将位置滑块移至开(On)。点击手机上的返回按钮返回Bridgefy。
- 您现在已准备好使用Bridgefy进行网状消息传递。在聊天(Chats)屏幕中，您会发现两个红色按钮：传播爱(Spread the love)和添加朋友(Add a friend)。您可以使用它们邀请朋友加入Bridgefy或将可能已经使用该应用程序的朋友添加到您的列表中。
- 如果您点击联系人(Contacts)，您可以在您的联系人列表中看到已经在使用Bridgefy的人员。还有一个共享(Share)按钮，您可以使用它来邀请尚未使用该应用程序的人。
在每个联系人旁边，您可以看到附近可以联系到的人。每个距离您当前位置较近的联系人旁边都会显示一个 带有“范围(In Range)内”字样的红色气泡。
- 点击(Tap)用户名开始向他们发送消息。您还可以通过点击屏幕右下方的红色按钮发送您的位置。
- 点击图钉，然后点击分享我的当前位置(Share My Current Location)（适用于谷歌地图）。
- 当您收到新消息时， Bridgefy(Bridgefy)还会向您发送通知弹出窗口，就像您使用WhatsApp和其他消息传递应用程序一样。
注意(Note)：在测试过程中，我们用手机在大楼里四处走动，并尝试从不同的房间发送消息。我们发现我们无法进行通信，因为我们的消息要么显示一个小计时器图标，指示消息正在等待传递，要么显示重试(Retry)（带有感叹号），指示它们尚未传递或未能发送。
当我们靠近范围时，消息开始一个接一个地传来。所有发送和传递的消息都显示绿色双刻度线，类似于WhatsApp上的蓝色刻度线。
让消息更容易(Make Messaging Easier)
网状(Mesh)消息传递是保护您的隐私同时避免政府监视或在线窥探的好方法。它不会取代您的日常通信，但它肯定会使在繁忙的地方的消息传递更容易，并在互联网不再被使用或信任的情况下提供安全的通信和应对方式。
What Is Mesh Messaging & How Does It Work?
Have you ever thought about what you’d do if suddenly you couldn’t connect to the internet to communicate with others, or get your everyday tasks done?
Most of us have come to rely on the internet for many things because of its many uses. Thus, anything that hinders access to the web and other online services would render things like file sharing, shopping, streaming media and others almost impossible to do.
With mesh messaging though, it’s possible to communicate with others without a persistent managed network and stay connected to each other.
In this article, we’ll be helping you get a grasp of what mesh messaging is, how it’s being used today and explain how it works. If you’d like to delve more into different types of networks, we recommend you give our guide on computer networks a read.
What Is Mesh Messaging?
Mesh messaging or off-the-grid messaging is a peer-to-peer networking system that allows users to contact each other without relying on the cell or WiFi networks, or any other government-controlled infrastructure.
A good example of where mesh messaging has been used is in the Hong Kong protests of 2019. Hundreds of thousands of civilians filled the streets and held anti-extradition demonstrations against the Fugitive Offenders Amendment bill that would allow the government to repatriate suspected criminals to China.
The protests went on for weeks, prompting police to use violent and aggressive means to quash the efforts. Consequently, the protestors needed a way of communicating with one another without depending on an internet connection, so as to organize themselves and stay safe.
To do this, they used off-the-grid smartphone apps like FireChat and Bridgefy, which work by creating their own networks outside the internet and carrier cell masts. They rely mainly on the WiFi link or Bluetooth that exist between two or more phones.
Both apps registered thousands of downloads in Hong Kong alone during the protests because there were lots of people in the protest areas, which made the cell network slow altogether.
Some of the ideal uses of mesh messaging include:
- During disasters like earthquakes, floods, hurricanes, and fires among others
- Jungle trekking or group camping in remote areas without reception
- In a war zone or during mass protests where the government is likely to shut down the internet
- When you don’t have mobile data on your phone or your plan expired
- When traveling and you’re not seated next to your family or friends in the same vehicle or plane
How Mesh Messaging Works
Mesh messaging sends data via Bluetooth or ad hoc WiFi similar to what your phone sets up when trying to get a home security camera or smart device online.
The system is structured in such a way that no one can monitor or control the conversations you’ve got going. This way, neither hackers nor government surveillance authorities can tap into cell towers to block the communication channels, pull down websites you’re trying to use to communicate with others, or even listen in on whatever is being beamed to your internet service provider.
Apps used for mesh messaging don’t need traditional online networks. Plus, they make connections between users in the same way torrenting software does, instead of sucking files from a central repository.
If you have a mesh messaging app installed on your smartphone, and many other people in the same area have the same app, it’s easier to pass on messages to each other the way a relay team would pass on a baton. However, the passing on is invisible to everyone sending the message to others so it’s not being read by other people as it moves along.
The main principle at work in mesh messaging is device-to-device communication. This makes use of short-range Bluetooth connections to form a network and bypass cell or WiFi networks, and any other government-controlled infrastructure.
The main purpose for mesh messaging isn’t necessarily to keep off the government radar, but to enable communication in areas with poor connectivity, or remote locations with no form of connectivity. It also comes handy during events in stadiums where many fans would interact with each other, or in places that have been ravaged by natural disasters like earthquakes and floods, which destroy cell towers and WiFi networks.
Mesh messaging apps use the mesh network to link users’ devices together via Bluetooth, allowing the message to move from one device to another until it lands on the intended person’s inbox.
Since Bluetooth’s phone to phone range typically maxes out at around 100 meters, it’s possible to communicate with other people within a range of up to 200 meters. It’s more effective when two or more phones are within range of each other, otherwise the signal strength is affected.
For longer distances though, your message will jump between the nearest user and creates a mesh network until it reaches the intended person. For example, phone A can’t connect directly to phone C, the mesh messaging app will bounce the message from A to C via phone B.
Plus, the people forwarding the message needn’t be in your contacts list or perform any further actions whatsoever for it to reach your intended target. This makes it harder for the government or hackers to shut it down as there’s no single point of failure that can be targeted to shut it down.
The more users in a mesh network, the better mesh messaging works.
How to Use A Mesh Messaging App
For you to understand just how mesh messaging works, we tested one of the popular off-the-grid apps, Bridgefy, and here’s a step-by-step guide on how to use it.
- The first step is to go to Google Play Store or App Store depending on your phone, and download the Bridgefy app. For this guide, we’re using an Android smartphone with Android 9 version, so we’ll download the app from Google Play Store.
- You’ll find two apps listed under Bridgefy: Bridgefy-Offline Messaging and Bridgefy Alerts. Download the Bridgefy-Offline Messaging option.
- Next, launch the app and set it up by tapping Get Started on the new screen.
- Complete the set up by adding a username (preferably one your contacts know you by) and tap Complete setup.
- Click Next in the new screen and give permissions for the app to access your Location settings to use Bluetooth communications, and your Contacts list.
- If you get a popup that requests you to update Location settings, tap Enable, and move the Location slider to On. Hit the return button on your phone to go back to Bridgefy.
- You’re now ready to use Bridgefy for mesh messaging. In the Chats screen, you’ll find two red buttons: Spread the love and Add a friend. You can use them to invite friends to join you on Bridgefy or add a friend to your list who probably already uses the app.
- If you tap on Contacts, you can see the people on your Contacts list who are already using Bridgefy. There’s also a Share button you can use to invite those who aren’t using the app yet.
Next to each contact, you can see who is nearby that you can get in touch with. A red bubble with the words In Range will show besides each contact who is closer to your current location.
- Tap on a user’s name to start sending them messages. You can also send your location by tapping the red button at the lower right side of the screen.
- Tap the pin and then tap Share My Current Location (works with Google Maps).
- Bridgefy also sends you notification pop-ups whenever you receive a new message, just as you’d get with apps like WhatsApp and other messaging apps.
Note: During testing, we moved around the building with our phones and tried sending messages from different rooms. We discovered that we couldn’t communicate as our messages would either show a little timer icon indicating the message is pending delivery, or Retry (with an exclamation mark) indicating they’ve not been delivered or they failed to send.
As we came closer within range, the messages started trickling in one after another. All messages that were sent and delivered show the green double ticks akin to the blue ticks on WhatsApp.
Make Messaging Easier
Mesh messaging is a great way of protecting your privacy while avoiding surveillance by the government or online snoops. It won’t replace your day-to-day communication, but it definitely makes messaging at busy places easier, and offers safe way of communicating and coping if the internet can no longer be used or trusted.
