By Olivier Beaujard
The benefits of AMR begin with the operational advantages of eliminating physical meter reading activities. By collecting up-to-date consumption data directly into enterprise databases, billing can become faster, more accurate and individually tailored. Activities including managing peak consumption, identifying faults in the infrastructure, planning preventive maintenance and detecting meter tampering and other frauds are also improved. More advanced AMR systems will take advantage of direct, two-way, broadband communications to deliver and manage sophisticated emerging services such as load shaping and demand pool management.
TECHNICAL AND PRACTICAL REQUIREMENTS
The basic functions of an AMR-enabled meter are to: continuously measure the energy quantity used; store the related consumption data; and transmit the data at regular intervals to a back-end server. Designers typically achieve this by connecting AMR equipment to a cellular GSM/ CDMA/wireless network, requiring integration of a suitable GSM/CDMA stack either on a companion module or running on the main AMR processor. Other requirements include short range wireless connectivity over ZigBee or Bluetooth for local reading and configuration, as well as M-Bus connectivity for wired communication with other networked meters.
AMR developers require a fast and convenient way to implement these capabilities, for example using plug-ins as are provided with the Wavecom Open AT development environment.
RUGGED M2M AND SAFER SUBSCRIBER VERIFICATION
As adoption of AMR increases, a more robust and secure solution to subscriber identification will become a key requirement. Current technologies from the mobile phone domain include the Subscriber Identification Module (SIM) card mandated in the GSM standard and the Re-Useable Identification Module (R-UIM) used by some CDMA cellular networks. The typical SIM device is a plastic card inserted in a carrier on the board. This can often fall short of the rigorous demands imposed by AMR subsystems and applications such as vehicle telematics, for example. Failure of the card when exposed to extremes of temperature, humidity and vibration are of particular concern. In addition, the possible removal and fraudulent use of the SIM card needs to be addressed.
An improved solution is required to overcome these challenges. We here propose one that also helps developers simplify inventory management, streamline management of cellular subscriptions, combat theft of SIMs, and reduce the risk of disconnected devices.
Wavecom was the first M2M supplier to meet these demands and deliver an inherently robust and reliable solution by demonstrating a technology that fully embeds the SIM function at chip level. Wavecom’s inSIM solution combines a state-of-the-art SIM card die, which meets all security standards applicable to plastic SIM cards, in the same package as the wireless microprocessor. Advanced capabilities that proved difficult to achieve using alternative approaches, such as post-delivery subscription allocation and provision for subscription transfer, met their match in Wavecom’s inSIM technology. By solving these challenges, Wavecom inSIM will enable many industrial applications including AMR to embed reliable and rugged remote M2M capabilities that are able to withstand harsh usage over an extended period.
LIFETIME MANAGEMENT - AT A DISTANCE!
A common characteristic of AMR applications is that equipment is likely to be deployed in the field for periods of 10 years or more. The ability to upgrade both the application and the GSM firmware at minimal cost throughout this period is therefore an important feature of a suitable AMR solution. Remote upgrades are the route. The Wavecom Open AT environment supports three different download strategies, allowing independent upgrades of either the application or the GSM firmware, or both.
INCREASING DEMANDS GOING FORWARD
AMR is ready to enable a steady stream of improvements for utility companies. One goal for the short to medium term is to eliminate the small weaknesses of traditional M2M architectures. Benefits will accrue for AMR subsystem developers by improving the reliability of lifetime management and overcoming the vulnerability of conventional SIM cards to failure and fraudulent use.
Investment into open development environments, more accurate and lower cost over-the-air upgrade and error correction, and higher integration within the wireless processor that Wavecom continues to make provide solutions to these challenges. These likewise shorten the development cycle and help AMR and other designers satisfy key functionality and performance requirements.