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Replace "Bag Phones" with Cellular IP

An electric company has a number of electric meters with embedded modems. The majority of these meters are connected to standard telephone lines to allow the electric company to dial-in to these meters at regular intervals. For some sites, the electric company has contracted with an integrator to provide analog cellular connections to allow them to dial-in using “bag phones,” analog cellular phones designed for use in remote locations.

The electric company learned the cellular provider is planning to phase out the analog cellular system in favor of digital. This would make the bag phones obsolete. Digi proposed a way for the electric company to continue using cellular for remote meter reading without needing to replace the existing meters.

Digi DialServ is an RJ-11 phone line simulator that, when used in conjunction with Digi cellular gateways, works with both dial-in and dial-out applications by simulating the Telco network. For dial-out, the DialServ sends the phone number to the Digi cellular gateway, which then converts the requested phone number to an IP address (or the phone number can be ignored and data statically directed to an IP address).

If the AMR system polls the meter or dial-in is needed to monitor or change meter settings, a TCP socket connection is opened over the wireless carrier’s IP network to the serial port of the Digi cellular gateway. This serial port then initiates the dial-out to the DialServ, which “calls” the embedded modem of the meter. Once the modems have negotiated and connected, the application will be able to query the meter for its values or allow changes to be made.

The Digi DialServ solution offers the following benefits:

  • The electric company may continue to use its existing software and meters in the field
  • Replacing old phone lines with IP communications allows customers to leverage higher availability, lower-cost networks, while potentially reducing monthly recurring costs related to phone bills
  • Devices using Digi DialServ over high speed IP networks often realize much faster transaction time versus slow dial-up modems

Replacing the bag phone with the Digi DialServ and cellular gateway solution is seamless for the electric company. Customers may continue to use the existing software and meters in the field without significant financial outlays to replace either component.

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Replacing analog cellular phones with cellular IP communications for meter reading

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Utilize an RJ-11 phone line simulator technology to migrate from analog to cellular IP communications for remote meter reading

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