Mesh Networking: Building, managing, and the works

1
Mesh NetworkingBuilding, managing, and the works

• Suman Banerjee

Wisconsin Wireless and NetworkinG Systems
(WiNGS) Laboratory
2
Mesh in the press

• Outdoor metro meshes
• Many cities, urban downtowns
• A set of mesh points connected to gateways
• Goal provide Internet access to users
• Business model?
• Serve the taxpayer
• Run it as an ISP
• Single expert administrator of the network, and
  homogenous nodes
• But there are other scenarios!

Madison, WI downtown 60 mesh points
3
Scenarios I want to talk about

• Rural networking
• An urban hub connecting a set of villages (say 40
  mile range)
• Goal provide Internet access to users
• Integrate applications Distance education,
  tele-medicine, expert advice
• Cost needs to be low
• Not-so-expert administrator, possibly
  homogeneous nodes
• Indoor (home) meshes
• Extend the notion of home-networking
• HDTV over wireless from set-top box to 2nd floor
  TV
• Phone base unit to handset in kitchen
• Single not-so-expert administrator,
  heterogeneous nodes

4
Rural networking Issues

• Why meshes make sense?
• Can use WiFi (unlicensed)
• Most of equipment is low cost and widely
  available
• Technology is getting there to meet the demands

5
Rural networking Issues

• Start at the very beginning
• How do we deploy a mesh?
• Manage
• How do we monitor and manage it?
• Improve
• If we detect performance problems, what are the
  right changes to make?
• Security
• A perennial problem in any domain

6
Deployment

• Where to place the mesh nodes how many nodes
• such that
• Budget constraints are met
• Good fault tolerance and quality of service

40 km

• 384 Kbps to each village
• Also multicast

7
Deployment

• Parameter choices
• Many possible locations (gt few 100s)
• Candidates for deploying mesh nodes
• Directional nodes vs. omni-directional nodes
• Cost vary depending on nature of antenna systems
  in use
• Interference patterns
• Buildings, other hotspots
• Gateway locations
• Choice of channels in multi-radio nodes

8
Deployment

• Current state-of-the-art
• Manual inspection based human judgement
• Example MadCity broadband uses consultants
• WFI Networks
• Neither cost effective nor scalable

9
Management

• All of the network management headaches that
  occur in enterprise
• Plus
• Those due to multi-hop wireless nature of the
  network
• A control wired backplane does not exist
• Control and data on the same flaky wireless
  interface
• Performance debugging
• User calls up
• Network is too slow at University Ave. and
  Randall St.
• Can we find the bottlenecks?
• Can we detect route mis-configurations?

10
Management

• Current solutions
• Very basic, SNMP based
• Essentially monitoring done by the mesh nodes
  themselves
• Can be extremely inaccurate
• Data is of low fidelity
• Maybe a specialized (low-cost) monitoring
  infrastructure

11
Improve

• How to upgrade the network?
• Where do we deploy new nodes?
• It is possible to spend money and degrade
  performance
• How many nodes?
• What kind of nodes?
• Where do we place them?

12
Security

• Current planned model
• Secure each link
• End-to-end security obtained through composition
  of secure links
• What if a mesh node is compromised?

13
Indoor meshes Issues

• Devices manufactured by different vendors
• TVs, set-top boxes, phones/handsets, etc.
• Interoperability is key
• Should be virtually un-managed
• Things should just work out of the box!
• Security

14
Finally, the applications

• Multi-hop wireless has many interactions that
  reduce end-to-end throughput
• HDTV, voice, tele-medicine requires some QoS
  guarantees
• Wireless links are very diverse and have
  different properties
• Some of the MAC protocols adapt poorly
• How to manage priorities of these traffic on the
  mesh

15
Thanks!

• Suman Banerjee

Wisconsin Wireless and NetworkinG Systems
(WiNGS) Laboratory
16
(No Transcript)