A View from Jason Pontin
What Don't I Understand About Meshes?
Here are some initial thoughts about mesh networks. Tell me what I am missing or what I have got wrong. In particular, I would be interested in learning what constitutes a “low-bit” network and what a ‘high-bit” network is in…
Here are some initial thoughts about mesh networks. Tell me what I am missing or what I have got wrong. In particular, I would be interested in learning what constitutes a “low-bit” network and what a ‘high-bit” network is in the context of meshes. Also, who knows about packet radio? Tell me if my description in the “History” section is accurate. Finally, vote for your favorite mesh networking companies (you’re not allowed to nominate your own).
1. HYPERBOLE VS. REALITY. The benefits of any truly disruptive technology are at first exaggerated, but their long-term effects surprise everyone. At the moment, mesh networks are experiencing such a misvaluation. Their promoters cannot describe them without hyperbole; but they will be the mechanism by which information becomes like electricity—invisible and ubiquitous.
2. HISTORY. Mesh networks are not very new: their conceptual lineage dates back to the 1970s and packet radio, a kind of digital data transmission used by amateur radio hackers. But investments by the Department of Defense in more reliable and intelligent networks in the 1990s created a renaissance in interest in meshes; and by 2000, a variety of academic institutions (including MIT’s Media Lab) and associated startups believed that mesh networks would overthrow traditional networking and permit a number of exciting new applications.
3. DEFINITIONS. To see why this is so requires a little effort for anyone unfamiliar with networking. At first acquaintance, a definition seems dry. Mesh networks (sometimes called Mobile Ad Hoc Networks or, even less winningly, MANETs) are local area networks all of whose nodes are mobile and communicate directly with each other through wireless connections. Any device with a radio connection can be part of a mesh (although the phrase is most commonly associated with high bit-rate networks like Wi-Fi). Meshes possess no fixed infrastructure; they have no central control. Meshes have no designated routers: instead, all nodes serve as routers for each other. Data packets are forwarded from node to node in a process that network technologists call “hopping.”
4. BENEFITS. Before dismissing meshes as being mainly of interest to specialists, consider their advantages over existing networks with their hubs and spokes. Meshes are self-healing: if any node fails, another will take its place. They are anonymous: nodes can come and go as they will. They are pervasive: a single node will never encounter dead spots without network coverage because there is always another nearby node. Meshes are cheap, efficient, and simple.
5. DISADVANTAGES. Mesh networks are still developing and therefore are not without faults. At the moment, a mesh will support only a dozen nodes and no more than 3 to 4 wireless hops: they are not very big. Low-bit rate mesh networking has a standard called ZigBee that is supported by around 100 companies, including Motorola, Mitsubishi, Phillips, and Samsung; but high-bit rate communications as yet have no such standard. Most notably, mobile nodes cannot communicate with other nodes “seamlessly” (to use the jargon of the trade): therefore, voice, video, and pervasive gaming are unhappy on meshes.
6. APPLICATIONS. But some of the technologies that meshes will make possible are already emerging. Meshes will allow municipalities to create cheap or free city Wi-Fi networks (dozens of cities are at work in this area; we will be writing about how Philadelphia is building its own mesh in TR’s November issue). Meshes have obvious advantages for police officers and soldiers who want networks that are unbreakable and “horizontal” (see “Instant Networks,” TR, June 2005, and “Communicating in Crisis,” TR, May 2004). Environmental scientists like meshes because they can be used to create low-bit networks of sensors that use little or no power; such sensors can offer researchers continuous environmental data from large geographical areas (see “Casting the Wireless Sensor Net,” TR, July/August 2003). But the most important application of mesh networks will be in what used to be called “pervasive computing”: that is, embedding machine intelligence into ordinary human objects like clothes, consumer electronics, and buildings, and connecting those embedded systems into smart networks.
7. ECONOMICS. The economic impact of mesh networks will be profound. There will be 16.4 billion wireless devices by 2008, according to International Corporation. The Defense Advanced Research Projects Agency estimates that around 8 billion embedded processors are built every year. The only likely way such systems will be connected is through meshes. But their most shocking business implication is this: telecommunications companies do not own them. Meshes diminish the importance of enterprises and organizations who own and manage voice communications backbones.
8. BIOLOGY. But for me, the most intriguing characteristic of mesh networks is their cybernetic quality (see “Cybernought,” TR, June 2005): meshes are self-correcting mechanical systems that possess many of the qualities of biological systems like insect societies. In “AntHocNet: An Adaptive Nature-Inspired Algorithm for Routing in Mobile Ad-Hoc Networks,” a report published by the Dalle Molle Institute for Artificial Intelligence in Manno, Switzerland, Gianni Di Caro et al. describe how Ant colonies can converge to discover the shortest path from their nest to a source of food; just so, they say, mesh networks are adaptive and can display apparently intelligent behavior without awareness. Does this mean that intelligence is an emergent property that does not require consciousness? Write and tell me at email@example.com.
Technorati tags: mesh networks
Become an MIT Technology Review Insider for in-depth analysis and unparalleled perspective.Subscribe today