john brett vp, marketing & operations mesh and peer-to-peer networks your power. your data. one...
TRANSCRIPT
John BrettVP, Marketing & Operations
MESH ANDPEER-TO-PEER NETWORKS
Your Power. Your Data. One Wireless Network.
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
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