Very Low Bit Rate Vocoder Released.

Low bit rates would allow audio over low bandwidth mesh networks.

The CMX608 and CMX618 are flexible, high integration, high performance, half-duplex RALCWI (Robust Advanced Low Complexity Waveform Interpolation) Vocoders, offering near toll quality voice at very low bit rates. A Forward Error Correction (FEC) engine provides optimum performance in real life applications. The RALCWI Vocoder comprises four independent functions which are selectable by the host: Voice Encoder, FEC Encoder, Voice Decoder and FEC Decoder.

In encode mode, the voice encoder uses a 20ms voice frame size with 3 programmable bit rates: 2050bps, 2400bps or 2750bps. The optional FEC encoder performs channel coding of the encoded voice (2050bps, 2400bps or 2750bps, depending on the selected mode) and forms an encoded, interleaved bitstream of 3600bps (216 bits per 60ms packet or 288 bits per 80ms packet). The FEC operation utilises a packet of either 3 or 4 x 20ms Vocoder frames to provide optimum error correction performance.

Source: CML Microcircuits.

Simulation Tool Comparison Matrix.
Table comparing simulation tools for Wireless Sensor Networks (WSN).

Source: CReating Ubiqutius Intelligent Sensing.

ZigBee video Doorbell.

The article 32-bit processors have a place in low-power, low-bandwidth ZigBee designs shows an example application of building a Video-Doorbell System, built with Analog Devices Blackfin processor.

The example doorbell mentions the uses the JPEG format for video. JPEG has patent licensing issues when used in embedded devices. I would avoid JPEG in my own designs, which they do by using more advance codecs in the doorbell.

...While standard low-bit-rate video encoding is an easy task for today's media processors, it does pose challenges to low-bit-rate ZigBee networks. The most bandwidth-efficient media codecs are the most computationally intensive. The nominal rate of the underlying IEEE 802.15.4 standard is 250 kbps. Because of the CSMA/CA architecture, the realistic maximum is on the order of half the nominal rate. In practice, one can expect to achieve upwards of 60 kbps with large packet sizes in a low-frills configuration without security. With network bandwidth of this order, a good-quality VGA-sized JPEG image can be transmitted every second. One way to increase the frame-rate when transmitting images over a low-bit-rate link like ZigBee is to implement a more advanced codec that yields a higher compression ratio than JPEG...

Source: EDN Magazine.

Building Wireless Sensor Networks (WNS).
"Wireless sensor networks (WSNs) dramatically reduce the cost of installing and commissioning instrumentation in industrial facilities. More instrumentation means better visibility into operational and environmental variables that affect overall uptime, safety, and compliance.

WSNs connect critical processes and assets with the systems or experts that can interpret the data or take immediate action. At the end of the day, operational teams with more visibility into their processes can prevent unplanned shutdowns, increase efficiency, and keep workers safe...

...Time Synchronized Mesh Protocol (TSMP) provides a mechanism for WSN intelligence. By defining how a wireless node utilizes radio spectra, joins a network, establishes redundancy and communicates with neighbors, TSMP forms a solid foundation for WSN applications.

TSMP Overview TSMP is a media access and networking protocol that is designed specifically for low power, low-bandwidth reliable networking. Current TSMP implementations operate in the 2.4 GHz ISM band on IEEE 802.15.4 radios and in the 900 MHz ISM band on proprietary radios..."

The article continues with practicle tips on how to design the network for operation after installation, not just after start up.

Source: Robert Shear, Dust Networks, Courtesy of Industrial Control Designline, via embedded.com.

Speech via IEEE 802.15.4.
Jennic's new IEEE 802.15.4 voice reference design enables secure full duplex transmission of speech with long battery life for use in point to point and large wireless sensor networks (WSN).

Source: Jennic Press Release.

Sorting out ZigBee power options.
...ZigBee's RF power specification comes from IEEE 802.15.4, which specifies a minimum power output rating of 1 mW, with no specified maximum. The de facto 100 mW "high power" level relates to the European limit of 100 mW EIRP, including antenna gain...

...100 mW radios offer an indoor range of around 300 feet (100 m) and an outdoor line-of-site range of about 4000 feet (1200 m). The much longer ranges make these products suitable for industrial applications in large factory settings and in outdoor installations, where nodes are often at intervals that cannot be spanned by unamplified ZigBee radios...

Source: Wireless Net Design Line.

Ezurio pushes Bluetooth range to 1 km.
LONDON: Wireless chip and module specialist Ezurio has pushed out the boundaries of Bluetooth with a module that gives the short-range wireless protocol a range of 1 km.

Source: E.E. Times Europe, by John Walko.

Introduction to Bluetooth Ultra Low Power.
Bluetooth's ULP (ultra low power) mode is expected to consume about 10% to 25% of the power of normal Bluetooth operation, which opens to the door to networking with small, battery operated devices and sensors.

Source: Wireless Net Design Line.

IEEE Publication, New Second Edition of Low-Rate Wireless Personal Area Networks: Enabling Wireless Sensors with IEEE 802.15.4tm.
Low-Rate Wireless Personal Area Networks: Enabling Wireless Sensors with IEEE 802.15.4 (Second Edition)
2006/Softcover/180pp
ISBN: 0-7381-4977-2

This book will be an update to the existing book with the title Low-Rate Wireless Personal Area Networks - Enabling Wireless Sensors with IEEE 802.15.4 by Josť Gutierrez, Edgar Callaway, and Raymond Barrett.

The book will introduce the reader to the concept of low-rate wireless personal area networks based on the newly revised IEEE Std 802.15.4-2006, which includes the amendment IEEE 802.15.4b, its application, as well as implementation and system design consideration.
Wibree Radio Technology/Ultra low power Bluetooth.

Wibree is intended for ultra low power applications, which is now being referred to as Ultra low power Bluetooth technology, due to the merging with the Bluetooth SIG.

Wibree is a new interoperable radio technology for small devices. It can be built into products such as watches, wireless keyboards, gaming and sports sensors, which can then connect to host devices such as mobile phones and personal computers. It is essential the missing link between small devices and mobile devices/personal computers.
Bluetooth Body Area Network.

Single chip "wire replacement" based on Bluetooth from National Semiconductor, will be released later this year. It is currently under Non-Disclosure to get the data sheets. Samples are available. Should work well as a Body Area Network.

Passive Optical Networking.
Freescale has introduced the industry's first voice-enabled gigabit passive optical networking (GPON) system-on-chip (SoC).
ONE-NET Protocol  is now available from http://www.one-net.info/.
"ONE-NET is an open design standard for low power wireless optimized for residential and small business control applications. The ONE-NET wireless standard is specifically optimized for very low power, very low cost and very good security. ONE-NET can be implemented with a variety of off the shelf wireless transceivers and microcontrollers."

Download Paper: IC9496.pdf

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