John BrettVP, Marketing & Operations

 

MESH ANDPEER-TO-PEER NETWORKS

                                                               Your Power. Your Data. One Wireless Network.

• What is a mesh network?

• Pros & cons

• Accessing mesh networks

• Examples

Agenda

Typical network topologies

Bus Ring

Star Tree

Mesh network

• Mesh can be full or partial• Built-in redundancy• Wireless advantage

• Inexpensive to connect• Broadcast capability

Utility networks are hybrid Mesh LAN + WAN

• Nodes in the network (endpoints) can forward information traffic that is not intended for the node

• Multiple redundant communications paths throughout the network

• Self configuring – adding new endpoints is plug-and-play

• Self healing – human intervention is not required for re-routing messages around failed endpoints

Key characteristics

Advantages Built in redundancy

- Multiple comm. paths

Simple flexibility- Adapts to environment

The more, the better Easy to deploy

- If self configuring

Robust- If self healing

Pros & cons

Disadvantages

× Redundant data traffic

× Interference- Typically using shared frequencies (e.g. 900 MHz)

× Requires a backhaul

Things to examine when assessing mesh

and peer-to-peer networks

Provisos

Eh?

Typical LAN ranges: 500 feet to 1,500 feet Daisy-chaining (multi-hops) can extend range

Range

Function of link budget• Transmit power

• Receiver sensitivity

• Antenna pattern

• Path loss

• Range will vary at different orientations to the meter

• Function of:• Inherent antenna pattern• Large chunk of metal in meter

next to antenna• Building siding material

• Pattern is relevant for both transmission and reception

Antenna

Objective: make antenna– Omni-directional– Immune to external factors

• Range will vary at different orientations to the meter

• A shared frequency system (e.g. 900 MHz) will see interference- Interference is transient in nature- Systems are designed to operate in a shared frequency environment- Robust system will cope with it

Interference

• Spread spectrum

Interference, cont’d

Direct Sequence Transmission

Frequency

Po

wer

Frequency Hopping Transmission

Frequency

Po

wer

• Find out:• Are adjacent frequency bands filtered out? (e.g.

paging above 928 MHz)• What is the error correction performance for a

single packet transmission?- i.e. What percentage of a single packet

transmission can be lost without losing the information?

• How many mesh networks can operate concurrently within earshot of each other?

Interference, cont’d

Backhaul / WAN - Star

Star

• Point-to-Point- Talk with one LAN at a time

• Typical for public networks (wired and cellular)- Ready to deploy- Coverage questionable in rural environments (cellular)- Ongoing service fees

Backhaul / WAN - Bus

Bus

• Point-to-multipoint- Broadcast capability

• May be a private network- More capital investment- Tailored for your service territory- No service fees

Example:Rural hilly terrain

• Self configuring- choose the best path

• Self-healing- Seek alternate path in event primary path fails

• Multi-hop- Improves economics- Daisy-chains around obstacles

Collector

ExampleUrbanTownship

• Self-configuring- LANs automatically build

• Self-healing- Multiple redundancies

• Flexible- Easy to add future devices

Collectors

 

                                                               

Your Power. Your Data. One Wireless Network.

www.tantalus.com