Wireless Mesh Networks/Printable version


Wireless Mesh Networks

The current, editable version of this book is available in Wikibooks, the open-content textbooks collection, at
https://en.wikibooks.org/wiki/Wireless_Mesh_Networks

Permission is granted to copy, distribute, and/or modify this document under the terms of the Creative Commons Attribution-ShareAlike 3.0 License.

Acknowledgements

Several people have been instrumental in allowing this project to be completed. We would like to thank the following people for contributing to this book:

  1.   kgrr (discuss · email · contribs · logs · count) Initial outline


(please feel free to contribute and add yourself here)


Introduction

Introduction

edit

Wireless networks nowadays are part of our everyday life, as witnessed by several features: the number of cell (mobile) phone subscriptions reached 7.3 billion in 2014.[1], short-range radio technologies such as WiFi and Blue-tooth are widespread as well as radio frequency IDs (RFIDs).

In a search on Google for “next generation wireless network,” top hits mostly refer to evolutions of the cellular technology collectively named 4G, including technologies such as LTE (Long-Term Evolution), LTE Advanced, etc. These technologies are essentially aimed at improving quality of service (QoS) in cellular networks, especially that which concerns data services, which are expected to play an increasing role in connected world. The improvements are mostly obtained through advancements in the physical and medium access layer of the network protocol stack, for example, through extensive use of multi antenna systems, while the overall architecture of the cellular network is mostly unchanged. Thus, forthcoming 4G networks can be considered as an evolution of the well-established cellular network concept.

On the other hand, the class of networks (ad hoc networks, mesh networks, wireless sensor networks, vehicular networks, and opportunistic networks) that we collectively call next generation wireless networks are characterized by very different features compared to cellular networks:

  • Cellular networks rely heavily on a wired, very expensive communication infrastructure – the network of cellular base stations – to perform communication; on the contrary, next generation wireless networks are characterized by a lightweight – or even absent – infrastructure.
  • Cellular networks are based on the use of relatively long wireless links,with typical communication ranges in the order of up to a few kilometers; on the contrary, next generation wireless networks use short-range – in the order of a few tenths of meters, or hundreds of meters at most – wireless links.
  • Cellular networks rely heavily on the presence of several centralization points, where servers are used for optimizing resource allocation and coordinate radio channel access between the different users in a cell and in adjacent cells; on the contrary, in next generation wireless networks, centralization points are typically lacking, and most network functionalities must be realized in a fully distributed, self-coordinated environment.
  • Cellular networks are single-hop wireless networks, since a mobile terminal directly communicates with a base station in the vicinity; on the contrary, next generation wireless networks typically make extensive use of multi-hop communications to compensate for the short radio range and increase coverage.
Header text Cellular network Wireless mesh network
Infrastructure Yes No, lightweight
Radio range ≤ 2km ≤ 300m
Centralization points Yes Mostly no
Type of communication Single-hop Multi-hop
Radio channel access Coordinated Mostly uncoordinated

It is then evident that the class of emerging short-range wireless networks mentioned above displays striking differences with respect to traditional cellular networks, and that the design and realization of a network of this class entails defining brand-new network architectures and networking solutions spanning the entire network protocol stack. This explains our choice of naming the emergent class of short-range, multi-hop, decentralized wireless networks “next generation wireless networks.” Unless stated otherwise, in the remainder of this Wikibook we will use the term next generation wireless network exclusively to refer to a member of the class of short-range, multi-hop,decentralized wireless networks

What it is actually ?

edit

Wireless mesh network is a multi-hop, peer-to-peer wireless network in which mesh nodes connect with redundant interconnections and cooperate with one another to route packets inside the network.[2]

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 other nodes.

Nodes are programmed with algorithms that tells them how to interact within the mesh network. The packets that carries informations 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. .[3] There are two types of mesh network which are partial mesh and also full mesh. Partial mesh is mesh where not all the nodes are connected to each other meanwhile the full mesh is mesh where all the nodes are connected to each other

References

edit
  1. Pramis, Joshua (February 28, 2013). "Number of mobile phones to exceed world population by 2014". Digital Trends. Retrieved 8th March 2014. {{cite web}}: Check date values in: |accessdate= (help)
  2. "How Wireless Mesh Networks Work". How Stuff Works. Retrieved 8th March 2014. {{cite web}}: Check date values in: |accessdate= (help)
  3. "How Wireless Mesh Networks Work" (PDF). Motorola. Motorola. Retrieved 8th March 2014. {{cite web}}: Check date values in: |accessdate= (help)
  1. USENIX 2003 Annual Technical Conference, FREENIX Track — Paper "Building a Wireless Community Network in the Netherlands"
  2. "The innovation journey of wifi" authors Wolter Lemstra, Vic Hayes, John Groenewegen, Technische Universiteit Delft, The Netherlands Cambridge University Press 2010 ISBN:9780521199711


Mesh network basics

Mesh network basics

edit

What is a Mesh Network?

edit

A mesh network is a multiple path and multiple hop area wide network that are ideal for outdoor deployment. The mesh network consists of wireless networking devices (known as nodes)connecting within the range of the network nodes. Hence, it will form a decentralized networking as each node will only need to extend its own wireless range up to next node only. Each nodes are consistently communicating with each other in the local mesh network and are responsible for acting as a gateway for the packets to travel inside the mesh network.

A wireless mesh network have 3 characteristic of autonomic system which are

  • Self forming / self organizing
  • Self healing
  • Self optimization
  • Multi hop

Self-forming / Self-organizing

edit

New nodes joining the mesh network are transparently supported because meshing functions such as neighbours discovery and topology learning are implemented. Wireless routers rapidly detect the presence of new paths, thus enhancing the overall performance and coverage


The picture above shows the mesh networking self forming ability.

[1] A new node joins the mesh network
[2] Surrounding node are alerted to the new node presence and configuring on the fly to provide optimized routing for the packets
[3] The new node are accepted in the mesh network

Self-healing

edit

A node may leave a mesh network due to unexpected circumstances such as failure in the networking devices, natural disaster/man made disaster and such.Therefore ,the mesh network are inherently designed to be more robust and resilient. There are many ways to do this such as make it a multi-path for packets to travel from one nodes to another (the amount of connections between 2 nodes is 2 or more) , decentralized connections and redundancy.


The picture above shows the mesh networking self healing ability

[1] One of the nodes in the mesh network are showing intermittent failures
[2] Surrounding nodes connected to the intermittent failing nodes are re-configuring to respond to the failing node
[3] The failing node when offline but the mesh network is still operating without downtime

Self Optimization

edit

The mesh network have the self optimization to enlarge the mesh coverage as large as possible, to minimizes the interferences and also to maximizes the bandwidth capacity of the mesh network.

Multi-hop

edit

Multi-hop connectivity allows several devices to access the network at once by relying on other mesh nodes without affecting the overall network performance. It will guarantees larger coverage zones and an enhancement of the network capacity. In fact, line-of-sight constraint no longer matters because the intermediate nodes relay the information to their neighbors on short wireless links using a reduced power transmission.



The picture above shows the multi-hop of mesh network in progress.
[1] Node A want to access to the node D
[2] Node A sends wireless transmission links to nearby nodes
[3] Node B & node E forming link with node A
[4] Node E already found the node D forming mesh connection A-E-D
[5] Node B is still searching for node D but find node C instead
[6]Node C already found the node D forming mesh connection A-B-C-D

Mesh vs. Point to Multi-point

edit

Reliability

edit

In a classic wireless network, each node monitors that path between itself and an additional node. These networks are configured in a hierarchical fashion that ensures that each node uses a single connection path. The drawback to this approach is its lack of failure protection. If a node fails, the dedicated link is lost and the endpoint is unreachable until service is restored.

The establishment of multiple connection paths is a logical answer to this problem. Unfortunately, classic nodes lack the intelligent technology to select from alternate transmission paths.

Developers studied the idea of adding intelligence to each node to solve this problem. Such intelligence would track each available communication path and would logically select the best route. Added together, the multiplicity of nodes would create a mesh. This mesh would eliminate single points of failure. If one link went down,other network nodes would be alerted and could select an alternative node path. The design's self-healing nature would ensure that the network continued to operate. User access would be maintained as would productivity levels.

Today, the concept of intelligent mesh networks is a reality. Mesh is an increasingly applied network topology as researchers improve and enhance it, and businesses deploy and utilize it. Mesh has become the technology of choice for applications as diverse as securing military perimeters to regulating product flow down factory assembly lines to facilitating the intelligent navigation of one's morning commute.

Redundancy

edit

Coverage

edit
edit

Access

edit

Backhaul

edit

Access/Backhaul shared

edit

References

edit

Motivation

Motivation

edit

Below are listed of several reasons on why the "hacktivist" are keen on developing the mesh network technology

Digital Divide

edit

In rural area, there are often lack of Internet access. There are few projects in the world that tries to bridge the digital divide in the rural area.

(1) (India) SARI (Sustainable Access in Rural Area)

Mesh network created India to let the rural India have access to Internet [1]

(2) (India) Aravind Teleophthalmology Kiosk

Mesh network created to let the patients self diagnosed himself in a kiosk and send the results to the doctors who maybe hundreds of kilometer away

[2]

(3) (Tibet) Dharamsala Wireless Mesh Network

In remote northern India region of Dharamsala where the Internet connection is patchy and unreliable, a group of networking experts helped the local people to set up the network.Using recycled PC parts and materials for antenna, they managed to connect over 2000 devices to the mesh networks itself.

[3]

(4) (Nepal) Nepal Wireless

In remote mountain of Nangi ,Mahabir Pun uses TV relay dishes to connect to Internet using the relays of mesh network. In May 2002, with help of university students, the Internet signal from Pokhara is sending Internet signal to Mohare

[4]

Service Provider

edit

(1) (South Africa) Mesh Potato by Village Telco

Mesh Potato is the wifi based mesh network services that provided data and free voice call to anyone in the network [5]

(2) (Germany) BBNG / Citizen Broadband Network Company

In a population of few hundreds people, a small village Löwenstedt decided to take the slow patchy Internet connections by building their own Internet mesh network

[6]

(3) (United States) DBUIA / Doe Bay Internet User Associations

A group of neighbours frustrated by the Century Link patchy internet connections decided to establish their own Internet network

[7]

Public Service

edit

[8]

[9]

Hobbyist

edit

(1) (Greece)Free sharing culture inside the Greece community

[10]

(2) (Wall Street) Occupy Wall Street - Freedom Tower

The Internet we knew is under huge surveillance by NSA and now the Freedom tower is creating the other Internet which will provide freedom

[11]

Inside of Facility

edit

References

edit


How many radios?

How many radios?

edit

Meshes can be built with nodes that have a single radio, two radios and multiple radios. The number of radios in mesh nodes depends on the throughput and latency demands of the mesh network.[1]

Single radio wireless mesh nodes are low cost, but are limited by latency and scalability. The single radio node has take turns providing client access and transport to the network. The node is forced to store and forward and thus introduces latency.



Dual-radio wireless mesh nodes enhance the scalability and capacity of the wireless mesh network. One radio is used for client access and the other radio provides transport. Since the radios operate independently on two different frequencies, one radio can send while the other one is receiving. This reduces the latency from the access link to the transport link. However, when one node is relaying from one node to the next, a two radio node still needs to store and forward, which introduces latency.


Three or More

edit

A multi-radio wireless mesh node solves the latency problem for both the access link and the transport link. Multi-radio wireless nodes perform with very low latency and work well with real-time applications such as multimedia, voice and video applications. Because the throughput is related to throughput, multi-radio nodes address high density coverage areas, and can be used to aggregate traffic from single- and dual-radio wireless mesh nodes.


Sample Deployments

edit

[2]

Colgate University [3]

References

edit
  1. "Solving the Wireless Mesh Multi-Hop Dilemma" (PDF).
  2. "When everything just meshes" (PDF). Cabling Connection. Feb/March 2006. {{cite web}}: Check date values in: |date= (help)
  3. "Colgate Brushes with Mesh Network". Alanat News. may 11, 2007. {{cite web}}: Check date values in: |date= (help)


Transport

Transport

edit

802.11a Wi-Fi

edit

802.11bg Wi-Fi

edit

802.16 WIMAX

edit

ZigBee

edit

ZigBee does not incorporate electric power lines into its technology therefore it is all wireless. ZigBee is very efficient, it can send up to 128 kilobits at a range of 250 feet. It is expected to be seen every from smoke detectors in your house to medical sensing devices. The best part is that it can function for a long time, on inexpensive batteries. Z-Wave also consists solely of wireless technology which is power efficient. It can send about 127 kilobits per second to a range of 100 feet. When you compare you would notice that Z-Wave and Insteon are very much similar. The only difference is that Insteon used electric power cables and Z-Wave doesn't.

Wibree

edit

Others

edit

proprietary microwave

Throughput

edit

[1]

References

edit


Operations

Operations

edit

There are few popular protocol operations used in the mesh network. Below are a few popular ones.

  • Babel

http://www.pps.univ-paris-diderot.fr/~jch/software/babel/

  • B.A.T.M.A.N.

http://www.open-mesh.org/projects/open-mesh/wiki

  • L3 and L2
  • BMX

http://bmx6.net/projects/bmx6

  • OLSR

http://olsr.org/


References

edit


Planning Tools

Planning Tools

edit

NetSim

edit

NetSim is a popular tool for wireless network design and planning. The steps would be

Modeling and Simulation: Model the network scenario, and set up the protocol / device parameters. Then run the simulation Visualizing the simulation using the packet animator: This would show the flow of packets, movement of nodes etc Analyzing the results: Study the output statistics and then iterate if required

Motorola Mesh Planner

edit

References

edit


Appendix A - Applicable Standards

Applicable Standards

edit

802.11k

edit

802.11r

edit

802.11s

edit

802.11v

edit

802.16b

edit

802.15d

edit

Appendix B - Known Deployments

Known Deployments

edit

Chandler, AZ

edit

Mesa, AZ

edit

Philadelphia, PA

edit

Rio Rancho, NM

edit

Tempe, AZ

edit

Appendix C - Mesh Timeline

Mesh Timeline

edit

1999

edit

2000

edit

2001

edit

2002

edit

2003

edit

2004

edit

2005

edit

2006

edit

2007

edit

Appendix D - Mesh network vendors

Mesh network vendors

edit

BelAir

edit

Cisco

edit

http://www.cisco.com

Concentris Systems LLC

edit

http://www.concentris-systems.com

Concentris Systems uses open standards wireless mesh networking technology to develop unique solutions that solve real life, challenging problems for rugged and severe-duty applications.

Concentris pioneered the versatile RapidLink network architecture that offers reliable, secure, high performance wireless mesh data networking. Easy to deploy and manage, RapidLink is ideal for situations where conventional data networking techniques are impractical or cost prohibitive.

Concentris Systems is focused upon making other people’s technology work better. The company provides a comprehensive suite of hardware and software products, coupled with training programs and hands-on service, for OEM and System Developer customers. Its toolkit is flexible and intuitive making it possible to create application-specific solutions in a surprisingly short time.

MIT graduate Tareq Hoque founded Concentris Systems. Before Concentris, Hoque was the president of Firetide, a successful early innovator in the field of mesh networking protocol and ad-hoc mesh networking. He was also president of Adtech Inc., the largest contributor to the Spirent Communications group of companies.

Concentris Systems LLC is a small, disadvantaged minority-owned business based in Honolulu, Hawaii.

Firetide

edit

http://www.firetide.com/

Mesh Dynamics

edit

http://www.meshdynamics.com

Incorporated in 2005, MeshDynamics is a privately held, profitable, U.S based corporation. Our headquarters are in Santa Clara, Northern California, USA.

Target Markets: Emerging outdoor enterprise wireless market opportunities such as those in mining, materials processing, military and border security, video surveillance, seismic oil exploration etc., place high demands on the wireless network infrastructure. Beyond data, critical real-time voice and video streams must also be supported, often in motion. Traditional wireless mesh architectures have been unable to support demands of this traffic, and thus have not penetrated these fast-developing markets to date.

Extensive testing by USAF, Battelle and others confirm that MeshDynamics' patented wireless mesh technology provides the highest throughput, low latency, and low jitter demanded by these applications through the use of dynamic channel allocation and a robust tree-based (deterministic and scalable) topology. High quality voice/video transport in demanding underground mine environments some up to 40 hops deep are in operation. No other mesh provider has demonstrated this level of scalability.

MeshDynamics mesh nodes have been installed in demanding applications requiring performance over multiple hops, noise free voice and video and rapid mesh formation with high speed mobility nodes. Applications include: municipal networking, underground mining and industrial, video surveillance, homeland security and public safety.

Nortel

edit

http://www.nortel.com

Proxim

edit

RoamAD

edit

http://www.roamad.com

Sky Pilot

edit

Strix

edit

http://www.strixsystems.com

ClearMesh Networks

edit

http://www.clearmesh.com

Tropos

edit

{chapter stub}

ValuePoint Networks

edit

http://valuepointnet.com


Bibliography


Architectures

edit

Review of three generation of mesh networking architectures http://wireless-straight-talk.blogspot.com/2006/11/talkin-bout-my-generation.html What is Third Generation Mesh?

Performance issues of First and Second Generation Mesh products http://www.google.com/search?q=cache:bMPl1QN_sI0J:www.dailywireless.org/2004/06/28/ugly-truth-about-mesh-networks Ugly Truths About Mesh Networks

Vendors

edit

Locust World An open source mishap offering for community networks as well as commercial offerings >http://www.locustworld.com LocustWorld

RoamAD For a software based approach to open architecture mesh networks for communities or ISPs. RoamAD also offers public safety networks capable of supporting video surveillance and mobile VoIP. http://www.roamad.com RoamAD

Mesh Networks (now Motorola) http://www.wi-fiplanet.com/columns/article.php/961951 http://www.wi-fiplanet.com/news/article.php/3436581

Metro Wi-Fi Deployments

Cambridge

"Municipal Mesh Network Protocols developed at MIT are helping the city of Cambridge to go wireless".

Books

edit

Held, Gilbert Wireless Mesh Networks


Glossary

Glossary

edit

AC Alternating Current

API Application Programming Interface

CA Certificate Authority

CIDR Classless Inter-Domain Routing

DC Direct Current

DHCP Dynamic Host Configuration Protocol

DNS Domain Name System

FCC Federal Communications Commission

GPIO General Purpose Input/Output

GUI Graphical User Interface

HNA Host Network Announcement

I/O Input/Output

ICMP Internet Control Message Protocol

IP Internet Protocol

LED Light Emitting Diode

LOS Line Of Sight

MANET Mobile Ad Hoc Network

MID Mobile Internet Device

MPR Mote Processor Radio

NEMA National Electrical Manufacturers Association

NTP Network Time Protocol

NTSC/PAL National Television System Committee/Phase Altering Line OEM Original Equipment Manufacturer

OLSR Optimized Link State Routing

OLSRD Optimized Link State Routing Daemon

PoE Power Over Ethernet

PTT Push To Talk

PWM Pulse Width Modulation

RP-SMA Reverse Polarity-SubMiniature Version A

RF Radio Frequency

SSID Service Set Identifier

TC Topology Control

TCIP/IP Transmission Control Protocol/Internet Protocol

TOS Type Of Service

USB Universal Serial Bus

UTP Unshielded Twisted Pair

VANET Vehicular Ad Hoc Network

VPN Virtual Private Network

WAN Wide Area Network

WEP Wired Equivalency Privacy

WPA WiFi Protected Access


Index

Index

edit

A

B

C

D

Design Parameters

E

  • Economics
  • Electric Power, Getting Power to the Node

F

G

H

Handoffs, Mobility Handoffs History Highlights How many radios?

I

ISO, What layers does it run on?

J

K

Known Deployments

L

Layers, What layers does it run on? Loops, preventing Topology Control

M

  • Management
  • Mesh network basics
  • Mesh network vendors
  • Mesh routing protocols
  • Mesh Timeline
  • Meshes, Do it yourself Meshes you can build
  • Meshes, Low Cost
  • Meshes, Realtime
  • Meshes, Types of
  • Meshes, Taxonomy
  • Meshes you can build
  • Mobility Handoffs
  • Motivation
  • Mounting Options

N

O

Operations

P

Politics Power, Getting Power to the Node

Q

R

Regulatory RF concerns Routing protocols, mesh

S

Social Impact Standards Applicable Standards

T

Taxonomy of Mesh Types Timeline, Mesh Timeline Tools, Planning Tools, Survey Tools, Testing Topology Control Transport Types of Meshes

U

V

Vendors, Mesh Network Vendors

W

X

Y

Z