Advanced Metering Infrastructure (AMI)

Advanced Metering Infrastructure (AMI)

Advanced Metering Infrastructure (AMI) is used to automatically collect water/energy meter readings in real time. The systems employ use of radios integrated in meters to communicate data to information management systems via collectors/gateways.

AMI enables continuous two-way communications between the network and metering devices, to accurately measure and collect data that can be used for billing, send customer alerts and notifications, demand-response, and remote service-connections and disconnections.

AMI communication can use:
• Radio frequency (RF) mesh
• RF Point-to-Point (PtP) or Point-to-MultiPoint (PtMP)
• Cellular
• Power line communication (PLC)

(See Rfwel Engineering’s long range communication links capability here)

There is considerable use of Low-power WAN (LPWAN) networks in AMI systems, for example, LoRaWAN®.

A key strength of LPWAN is its ability to support large number of devices per gateway. Depending on the policy applied and the time allowed on the network per device each day, thousands of devices can be supported simultaneously.

AMI sample architecture
 
Some of the issues experienced in wireless AMI networks includes:

• Communication reliability: Due to the ability to connect many nodes to a single network or gateway, interference might arise particularly for unlicensed spectrum.

• Line of Sight (LOS) issues: Although 900 MHz has better penetration than higher unlicensed frequencies, it is more susceptible to signal fading or shadowing caused by hills, valleys, and radio-reflective or radio-absorbing obstructions.

Possible solutions for wireless AMI network Issues

• Use of Mesh networks/mesh radios
Mesh networks can allow self-healing or self-routing providing multiple communication paths for metering interface units (MIU), in case one path fails.

Metering Interface Units in mesh topology

  

• Use external antennas and higher power stations
To improve coverage of 900 MHz gateways consider using external directional high gain antennas. 
For example:

          o Rfwel’s RFWY072712D 12 dBi 900 MHz antenna provides excellent directional gain to compensate for loss from long cable runs and connector losses. Additionally, MYA9306 and T09150Y11206T also offers good gain for 900MHz applications. You can search for other popular 900 MHz antennas here here}

 
900MHz antenna application in AMI wireless networks


           o The Teletronics 12-105 provides up to 26dB transmit gain (also features an automatic gain control for automatic output power control depending on the power input) at 900 MHz. You can search for other 900 MHz amplifiers here.

 
900MHz amplifier application

See example gateway below for AMI application.

 R900 Gateway System
R900 Gateway System: Connects R900 endpoints and transmits to central IMS. See antenna accessories for 900MHz and cellular frequencies.

• Consider cellular:
There is an option to use MIUs with cellular connectivity (NB IoT or LTE M1). With external antenna ports, you can use higher gain antenna to improve signal reception should there be an issue.

Cellular based MIUs

See below other sample AMI equipment.

Enless TX PULSE sample MIU device
 
TX PULSE 600-036 Connects to pulse meters with a dry contact interface or open collector inlet to convert them to a smart meter, pulses are converted and transmitted to gateways via LoRaWAN.

For more on signal improvement solutions or IoT applications, please contact an RFWEL Wireless Specialist.