The Rebirth of Mesh Networks
When thousands of fans come to arenas and stadiums for major events like the Super Bowl, wireless mesh network technology is often out in full force as well, functioning as a reliable means for the venue’s security team to stay in touch at all times.
This technology also surfaces during natural disasters and large-scale emergencies, such as on Sept. 11, 2001, or after the Boston Marathon bombing, when cellular networks face unexpected outages or when the volume of users trying to access the system at the same time exceeds its capacity. Mesh networks can sidestep these problems.
Mesh networks were first deployed by the military 30 years ago to ensure constant communications over rough terrain and in areas where cell tower infrastructure does not exist. These networks let users connect directly to each other, rather than requiring a central hub, internet service provider or phone company.
The network itself is made up of wireless devices, or “nodes,” that are powered by radio-based technology and can talk to each other. Unlike in other kinds of communication networks, these nodes are decentralized, thus they can be added or removed as needed and, if one stops working, the entire network will still continue to function, allowing messages to be transmitted consistently. If online connectivity is required, only one node needs to be connected to the internet to allow all of them to access it. Mesh networks also do not require cable to be laid or expensive cell towers to be built, so they can be set up quickly and at minimal cost.
“When you lose all basic communications in a disaster, people don’t care about watching YouTube, but they do want to be able to send short text messages and say, ‘I’m trapped in a building,’” said Matthew Pearl, an attorney affiliated with the Berkman Center for Internet & Society at Harvard University who has studied emergency-related communication tools. “The design and resilience of mesh networks allow you to do that quickly and with relative ease.”
According to Richard E. Howard, former head of wireless research at Bell Labs and now a research professor at Rutgers University, “From a risk management and reliability point of view, mesh networks can provide connectivity in a hostile or challenging environment as they mitigate the risk of the network being shut down.”
Mesh networks are increasingly being used for more than crisis communication. Companies that require a great deal of mobility in their operations, such as in those in the oil and gas, mining, shipping, trucking and agriculture industries, have learned that wireless mesh networks can ensure reliable communication in quickly changing environments. And for businesses and individuals with privacy or connectivity pricing concerns, local mesh networks offer an alternative to traditional internet communications.
They are also being incorporated into more smart building, agriculture, factory and home systems as a part of the growing Internet of Things, where machines may be in constant communication among themselves to automate services. “Mesh networks are well suited, for lower-bandwidth, Internet of Things-type applications, like a thermometer reading or a report of a security problem in your home,” said Lee Ratliff, principal analyst specializing in connectivity issues at IHS Technology. “But due to bandwidth restrictions, you won’t be sending gigabyte photos across these networks.”
New interest in mesh networks for business and personal use is being fueled by the relentless demand for wireless connectivity and the growing number of smart phones, sensors, monitors, wearables and tablets in use. A March 2015 report from the Global Association of Mobile Operators forecast that the number of unique mobile subscribers in the world will grow from 3.6 billion at the end of 2014 to 4.6 billion by 2020, increasing by 4% each year. It also projects that, by 2020, almost 60% of the global population will subscribe to mobile services. Additionally, Cisco predicts that 15.9 terabytes of mobile data traffic will traverse networks by 2016—a tenfold increase over 2014. As a result, there will be a greater need for wireless and mobile capacity to meet the demand.
Mesh networks may provide a solution. “Mesh networks are a great way to extend cellular systems,” said Jon M. Peha, a professor at Carnegie Mellon University who runs a research lab focused on wireless and broadband networks. “If mobile traffic doubles every year and a half, you can’t double the spectrum every year and a half. You need another way.” He views mesh networks as one of those alternatives, made even more appealing because they are a cost-effective way to serve the fast-growing global market. “With mesh, you don’t have to build another million-dollar cellular tower,” he said.
A number of challenges could hamper more widespread adoption of mesh networks, however. Available spectrum is limited, and power and battery constraints remain an issue. The structure of mesh networks and radio technology makes it difficult, although not impossible, to transmit large data files and video. As networks expand, the latency—the time delay between transmissions—can increase. Network nodes also generally need to have a line of sight with other nodes to allow for connectivity, although some mesh network providers have found ways to overcome this problem with advanced radio technology. Finally, many of the standards for mesh networks are proprietary rather than open, which could hinder future development.
“From a risk management and reliability point of view, mesh networks can provide connectivity in a hostile or challenging environment as they mitigate the risk of the network being shut down.”
Innovation and the Internet of Things
Despite these drawbacks and the failure of past large-scale efforts, mesh networks are making a comeback as startups and smaller firms develop new innovations. João Barros, CEO and co-founder of mesh-networking firm Veniam, said that the need for bandwidth is becoming so great that telecom operators are looking for ways to offload internet traffic from cellular networks. He believes the solution is attaching mesh network systems to vehicles and other moving objects. As they roam, this would create a network with greater scope that can then be enhanced by using cloud computing and analysis tools, allowing for data collected by the network to be utilized in a variety of ways. Barros refers to it as “the Internet of Moving Things.”
A professor of electrical and computer engineering at the University of Porto in Portugal, Barros was able to test his theory on a variety of fleets. Currently, Veniam provides 600 buses and taxis in the city of Porto with mesh networking nodes that are the basis of a seamless swath of Wi-Fi hot spots for public transportation customers and other users in the city.
On the Veniam-powered network, up to 70% of wireless traffic goes through the mesh network, allowing buses and taxi travelers to access the internet for free. In addition, data collected by the mesh network nodes and data-collecting sensors can be processed in the cloud to facilitate analysis and prediction of road, infrastructure and security needs. The firm is now getting ready to launch a vehicular mesh network in Barcelona and is providing its hardware and software to fleet and port operators.
Barros said that using mesh networks rather than pricey cellular networks for security and risk monitoring purposes will help many organizations save money. “For oil field operations, plants with complex operations or airports where real-time communications are important, we believe mesh networks are the best way to ensure real-time communications and lower costs,” he said.
Other companies have also found that the growth of the Internet of Things has dramatically increased the need for mesh networking capabilities. “All these discrete devices—pumps, valves, motors—now need to be connected continuously so that failures can be anticipated and avoided,” said Robert Schena, CEO and co-founder of mesh networking firm Rajant Corp. In the oil and gas industry, he has seen the risks of leaks, failures or regulatory penalties drive firms to turn to mesh networks to improve the reliability of their communication networks.
In response to the increase in data collection by a range of industries, Rajant has developed a new mesh node system that has extra processing power. In lieu of a cloud-based system, the nodes are able to store large quantities of video that can be swiftly consumed and analyzed on site. The new system, Schena said, can help firms better oversee security or operational risks and can also upload large video files for further analysis wirelessly and without human intervention.
Rajant is best known for its kinetic mesh technology, which uses hardware and software to build high-bandwidth mesh networks involving hundreds of radios operating in real-time on vehicles and other mobile machines, serving the military, mining, oil and gas, and transportation industries. According to Schena, kinetic mesh allows for greater adaptability to sudden network changes than other types of networking.
“Mesh networks are a great way to extend cellular systems. If mobile traffic doubles every year and a half, you can’t double the spectrum every year and a half. You need another way.”
Since its launch in 2001, Rajant has incorporated artificial intelligence into systems that allow a mesh network configuration to learn data patterns, manage bandwidth and operate more efficiently. The firm also employs multiple radios in a node to help tackle a range of frequency challenges, eliminating the scaling problems that exist with some mesh networks.
With all the nodes and sensors now operating 24/7 on Rajant-powered mesh networks, Schena sees predictive maintenance as perhaps the greatest benefit. “Instead of waiting for an engine to fail, a valve to break or a catastrophe to occur, you can monitor continuously via the network, reducing maintenance costs,” he said.
Three-year-old startup Open Garden takes the mesh networking concept a step further: Since a mesh structure involves machines talking to each other to create a network, why not try to build one with smartphones, the machines we carry with us all the time?
Taking advantage of a new capability embedded in iPhones, which Apple calls a “Multipeer Connectivity framework,” Open Garden introduced FireChat last year. The app exploits the iPhone’s peer-to-peer function to allow direct communication between iPhone users.
With FireChat, iPhone users can bypass phone or internet service providers and talk directly to each other as long as they have downloaded the app and are in Bluetooth or Wi-Fi range. The result is an instant, off-the-grid mesh network that extends up to 200 feet, where users can exchange text messages and photos among themselves by doing what Open Garden CEO Micha Benoliel calls “crowdsourcing a network.” And if one smartphone is connected to the internet, all others in the network can connect as well.
The FireChat software was updated in July so that users can elect to conduct communications privately or publicly, much like sending a tweet. The firm is also working to introduce hardware called Greenstone that extends the reach of the network and can store up to 1,000 messages.
Five million people have downloaded the FireChat app, Benoliel said, and are using it wherever there are large crowds and cellular networks become congested, such as at concerts, festivals or other gatherings. The app has also become popular with protesters in places where governments have restricted or shut down internet access, such as Egypt, Hong Kong and Taiwan.
“As Google and Facebook look to drones, balloons and satellites to deliver the internet to the world, it’s worth remembering that one of the most powerful pieces in the quest for global internet access isn’t up in the sky, it’s down in our pockets,” Benoliel said. “We can enable connectivity and the creation of instant social networks in places where, normally, you have no connectivity.”
Of course, not everyone is as optimistic about the potential of mesh networks. “It’s easier to understand mesh networks when you view them as an exception vehicle,” said Peter Christy, an analyst at 451 Research. “Mesh networks are great for environments that are rugged and a good alternative when things are intrinsically mobile.” But, due in part to bandwidth limitations, he said they represent a “communications network of last resort.”
Some experts believe cellular network technology has advanced enough that mobile cellular base stations, while expensive, are a better disaster tool than mesh networks, which do not scale well in terms of spectrum and energy use. “Over time, mesh networks will function as a backup technology that you use in cases of disaster and as a way of bootstrapping connectivity in developing regions, but they are limited by bandwidth capacity,” said Vyas Sekar, assistant professor in electrical and computer engineering at Carnegie Mellon University. Therefore, he believes, mesh networks will remain a niche technology.
But others see a bright future for mesh networking technology. “When a disaster strikes and communication towers are blown over, it’s all about being able to quickly and easily establish and maintain a communications network,” said Peter Stanforth, holder of 25 mesh networking-related patents and founder and CEO of Spectrum Bridge, a firm that provides technology to facilitate access to the radio spectrum. “There are going to be a lot more instances of mesh networking out there, in business and the home, but in many cases, we won’t know, realize or even care that it exists, as there continues to be constant innovation in the technology.”