PC / AV

ZigBee Solutions
Renesas-developed ZigBee and IEEE802.15.4 MAC Protocol Stacks Let Customers Select the Best Microcomputers

The ZigBee international-standard wireless network technology is intended for short-range, low-data-rate communications and uses IEEE802.15.4 as its physical layer. An important feature of products that support this standard is low power consumption—to the extent that when they are powered from an AA battery, they are expected to run for months or years without a battery replacement. A new Renesas ZigBee/IEEE802.15.4 MAC solution with proprietary protocol stacks we developed in-house can support a broad selection of our microcomputers, giving our customers multiple system design options. This solution is included in an evaluation kit that speeds the development of new ZigBee based products.

The specifications of the ZigBee international standard, finalized in late 2004 by the 180+ member ZigBee Alliance, define an up-and-coming technology for short-range radio communications. ZigBee is a type of personal area network (PAN). It is a complete, open global standard for monitoring and control that is characterized by low cost, low power consumption, simplicity, and a moderate data rate. ZigBee uses IEEE802.15.4 as the MAC/PHY layer, enabling excellent performance in low signal-to-noise ratio (SNR) environments for very robust communication.

The ZigBee standard can be used in a wide span of applications because it supports a number of different network topologies: star configurations, tree configurations, and full mesh configurations. Networks are easy to install and commission. Maximum communication speed is up to 250kbps for the 2.4GHz band, depending on operating conditions. Reliability is excellent, speed is more than adequate for many applications, and security features can be implemented. The fact that a ZigBee device can operate from an AA battery for several months to several years is particularly important. It means that the device need not be connected to an AC power line, so it can be installed anywhere. Moreover, if the device is certified to be compliant to the standard, it will interoperate seamlessly with other certified devices.

The characteristics and advantages of the ZigBee standard favor its adoption in air conditioning control, lighting control, distribution management, home automation, instrumentation, maintenance, safety, security, wireless sensor networks (WSNs), and more. The future for this wireless standard is expected to be very bright.

Helping to drive the adoption of ZigBee technology

The semiconductor business of Mitsubishi Electric, part of the merger that formed Renesas, recognized the potential of ZigBee technology years ago and became a founding member of the ZigBee Alliance. The company promoted the standard since its inception and was an early adopter of it. After the merger, Renesas, in turn, became a participant in the standards process and we are one of the driving forces behind ZigBee.

We are also playing an active role in ZigBee SIG-Japan, which was established in September 2005 to encourage the adoption of ZigBee and further develop the specification. Renesas is the founding leader of the organization, and our personnel currently occupy the positions of leader of the technical working group and sub-leader of the marketing working group.

Close involvement in the activities of the ZigBee Alliance, ZigBee SIG-Japan, and other organizations has enabled Renesas to be among the first to provide ZigBee and IEEE802.15.4 solutions that support the latest standards. Today, we continue to work on providing further short-range wireless communication solutions that can take advantage of the many features and network functions of ZigBee technology.

To enable customers to get a head start on developing ZigBee based products, we now offer attractive solutions for wireless network designs and are working to expand this product line. Those solutions include a ZigBee protocol stack and a separate IEEE 802.15.4 MAC protocol stack that Renesas has developed in-house.

Our ZigBee protocol stack solution has already received certification as a ZigBee Compliant Platform from the ZigBee Alliance. As a result, system engineers can select the optimum MCU from the expanding variety of microcomputers that support those protocol stacks (see Figure 1). Moreover, we offer an evaluation kit that simplifies the task of testing simple ZigBee networks. The kit includes sample software and test circuit boards with a sniffer tool (see Figure 2).

Currently, ZigBee solutions are available for the M16C family of microcomputers. More will become available soon when our protocol stacks are ported to other Renesas microcomputer families. Also, because the Renesas MAC solution is a separate product, we offer it to customers that require the MAC/PHY layer only.