Serval Mesh Extender

Current Version

See Second-Generation Mesh Extender for details about the current version of the Mesh Extender.

Motivation

Difficulties with Ad Hoc Wi-Fi

Ad Hoc Wi-Fi is problematic on many Android phones, requiring a custom ROM to use. Interoperability problems also exist between various Ad Hoc Wi-Fi firmware. Ad Hoc Wi-Fi also has higher energy requirements compared with “managed” Wi-Fi.

Increasing Range

Wi-Fi in general has limited range, in particular on mobile telephones that lack substantial antenna. Experience suggests maximum range of 100m - 170m outdoors and 10m - 30m indoors. This means that almost every dwelling would require a mesh node to allow connection across an urban or peri-rural setting. For rural settings Wi-Fi simply fails, regardless of the uptake because dwellings are more distant than the maximum achievable range. Therefore, the Mesh Extender incorporates a longer-range UHF packet radio (and the option to connect to a variety of external radios).

Unskilled Deployment

Another vital characteristic is to ensure that Mesh Extenders installation consists simply of turning the device on: There should be no aiming of antennae, network configuration or other skilled tasks required. This ensures that the product can be easily and effectively used by anyone who has need.

Also, aiming is impossible for a portable device is simply not possible. This is one reason why aimed long-shot Wi-Fi is not a solution.

Concept

As Wi-Fi is not a complete solution, we wish to allow the use of other radio interfaces to connect devices. Also, for nearby devices, we wish to provide a Wi-Fi Access Point, so that energy consumption of the mesh nodes can be minimised.

Thus we wish to make a small device, that is a Wi-Fi AP, and also allows the use of a variety of other radio interface to provide longer-range and more energy efficient mesh networking. The device could also offer an HTML interface to the mesh, so that devices lacking the Serval Mesh software could still participate, and potentially download the Serval Mesh software if so desired.

Prototyping Attic

The following describe other hardware platforms and development threads we have explored. See the above section for the most relevant material.

Prototyping on TP-LINK MR3020 - This is our 2nd generation prototype developed during our crowd-funding campaign in 2013.

Building Serval DNA for OpenWRT

How to extract an openwrt file

Comparison of power consumption of various hardware options

Resources for using the HopeRF RFM22/23B/BP UHF Radio Modules

Prototyping on TP-LINK WR703N / Mesh Potato 2.0 - This is the 1st generation prototype

Prototyping on OLinuXino A13 + ATH9k Wi-Fi Module - Another prototype we considered, but are not currently pursuing.

Prototyping on OLinuXino iMX233 + TP-LINK WR721N/722N - Another planned prototype that has been cancelled for now.

Prototyping on MK808B Android stick-PC - This was a planned 2nd generation prototype that has been cancelled.

Resources for running Dragino and similar devices on solar power

NLnet Foundation Grant Tracking


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