In the Press

Weightless-P Standard is Designed for High Performance, Low Power, 2-Way Communication for IoT

posted: Tuesday 11th August 2015

Weightless was unveiled over two years ago, as a new standards for IoT leveraging “white space” spectrum, previously used by analog TV broadcasts, for free M2M / IoT communication using low power (10 years battery life) and cost-efficient hardware ($2 hardware) offering a range of 5 to 10 km. Development kits and base stations were scheduled for Q2 2014, but there’s either been some delays or they are only available to Weightless members, as you need to register to get notified once hardware becomes available.

WeightlessThe Weightless SIG (Special Interest Group) has not stopped working on the standard as there are now three Weightless standards: Weightless-W (using White band spectrum), Weightless-N (sub-GHz spectrum), and and newly announced Weightless-P offering similar features as 3GPP carrier grade solutions, but at lower costs and lower power consumption.

The key features of Weightless-P are shown below:

Excellent capacity and scalability for IoT deployment

FDMA+TDMA in 12.5kHz narrow band channels offer optimal capacity for uplink-dominated traffic from a very large number of devices with moderate payload sizes

Operates over the whole range of license-exempt sub-GHz ISM/SRD bands for global deployment: 169/433/470/780/868/915/923MHz

Flexible channel assignment for frequency re-use in large-scale deployments

Adaptive data rate from 200bps to 100kbps to optimise radio resource usage depending on device link quality

Transmit power control for both downlink and uplink to reduce interference and maximize network capacity

Time-synchronised base stations for efficient radio resource scheduling and utilisation

Bidirectional

Supports both network-originated and device-originated traffic

Paging capability

Low latency in both uplink and downlink

Fast network acquisition

Forward Error Correction (FEC)

Automatic Retransmission Request (ARQ)

Adaptive Channel Coding (ACC)

Handover, Roaming, Cell re-selection

Long range

Lower data rates with channel coding provide similar link budget to other LPWAN technologies

2km in urban environment

Industrial-grade reliability

Fully acknowledged communications

Auto-retransmission upon failure

Frequency and time synchronisation

Supports narrowband channels (12.5KHz) with frequency hopping for robustness to multi-path and narrowband interference

Channel coding

Supports licensed spectrum operation

Ultra-low energy consumption

GMSK and offset-QPSK modulation for optimal power amplifier efficiency

Interference-immune offset-QPSK modulation using Spread Spectrum for improved link quality in busy radio environments

Transmit power up to 17dBm to allow operation from coin cell batteries

Adaptive transmit power and data rate to maximize battery-life

Power consumption in idle state when stationary below 100uW (vs 3mW for the best cellular technologies)

Secure and efficient networking

Authentication to the network

AES-128/256 encryption

Radio resource management and scheduling across the overall network to ensure quality-of-service to all devices

Support for over-the-air firmware upgrade and security key negotiation or replacement

Fast network acquisition and frequency/time synchronization

Low cost and complexity

Using standard GMSK and offset-QPSK modulation channels ensures broad availability of hardware and no dependency on a single vendor

Compared to UNB, narrowband operation is less sensitive to frequency offset and drift, allowing the use of lower cost, lower power XOs or DCXOs instead of TCXOs

Maximal transmit power of 17dBm allows for integrated power amplifier

Open standard

Brings the reliability and performance of cellular technologies at a fraction of the cost by avoiding any legacy or backward-compatibility concerns

Ensures interoperability between the manufacturers

Provides for multi-vendor support to stimulate ongoing innovation and minimize end user costs

Royalty free IP minimizes production costs

Hardware for the new Weightless-P standard will be available in Q1 2016.

You may wonder about the differences between Weightless-W/-N/-P and which one you should use for your IoT project. The Interest group published a table comparing the three standards.

  Weightless-N Weightless-P Weightless-W
Directionality 1-way 2-way 2-way
Feature set Simple Full Extensive
Range 5km+ 2km+ 5km+
Battery life 10 years 3-8 years 3-5 years
Terminal cost Very low Low Low-medium
Network cost Very low Medium Medium

 

So if one way communication is suitable, go with Weightless-N, if the “white-space” spectrum is available in your country go with Weightless-W, and otherwise you may want to select Weightless-P for high performance 2-way communications.

You can find some information on all three royalty-free  standards on Weightless technical information page. But if you want access to the full specifications for your project(s), you’ll need to become a Weightless members with membership starting at 900 GBP (~$1400) per year for “associate” members.