Wireless mesh networks, an emerging technology, may bring the dream of a seamlessly connected world into reality.

Wireless mesh networks can easily, effectively and wirelessly connect entire cities using inexpensive, existing technology. Traditional networks rely on a small number of wired access points or wireless hotspots to connect users. In a wireless mesh network, the network connection is spread out among dozens or even hundreds of wireless mesh nodes that "talk" to each other to share the network connection across a large area.

Mesh nodes are small radio transmitters that function in the same way as a wireless router. Nodes use the common WiFi standards known as 802.11a, b and g to communicate wirelessly with users, and, more importantly, with each other.

stoplight node
Courtesy Motorola
A node on a streetlight.

Nodes are programmed with software that tells them how to interact within the larger network. Information travels across the network from point A to point B by hopping wirelessly from one mesh node to the next. The nodes automatically choose the quickest and safest path in a process known as dynamic routing.

The biggest advantage of wireless mesh networks -- as opposed to wired or fixed wireless networks -- is that they are truly wireless. Most traditional "wireless" access points still need to be wired to the Internet to broadcast their signal. For large wireless networks, Ethernet cables need to be buried in ceilings and walls and throughout public areas.

In a wireless mesh network, only one node needs to be physically wired to a network connection like a DSL Internet modem. That one wired node then shares its Internet connection wirelessly with all other nodes in its vicinity. Those nodes then share the connection wirelessly with the nodes closest to them. The more nodes, the further the connection spreads, creating a wireless "cloud of connectivity" that can serve a small office or a city of millions.

The Internet: The Original Mesh Network

The Internet is the world's largest mesh network. Information travels across the Internet by being bounced automatically from one router to the next until it reaches its destination. The Internet is often depicted as a "cloud" or "web" of connectivity because of the billions of potential paths across which data can travel.

Wireless mesh networks advantages include:

  • Using fewer wires means it costs less to set up a network, particularly for large areas of coverage.
  • The more nodes you install, the bigger and faster your wireless network becomes.
  • They rely on the same WiFi standards (802.11a, b and g) already in place for most wireless networks.
  • They are convenient where Ethernet wall connections are lacking -- for instance, in outdoor concert venues, warehouses or transportation settings.
  • They are useful for Non-Line-of-Sight (NLoS) network configurations where wireless signals are intermittently blocked. For example, in an amusement park a Ferris wheel occasionally blocks the signal from a wireless access point. If there are dozens or hundreds of other nodes around, the mesh network will adjust to find a clear signal.
  • Mesh networks are "self configuring;" the network automatically incorporates a new node into the existing structure without needing any adjustments by a network administrator.
  • Mesh networks are "self healing," since the network automatically finds the fastest and most reliable paths to send data, even if nodes are blocked or lose their signal.
  • Wireless mesh configurations allow local networks to run faster, because local packets don't have to travel back to a central server.
  • Wireless mesh nodes are easy to install and uninstall, making the network extremely adaptable and expandable as more or less coverage is needed.

In this article, we'll explain how wireless mesh networks work, how they increase network access for a wide variety of industries, and how they might make our dream of a seamlessly connected world come true.