IEEE Std 802.15.4f:2012 pdf free download

IEEE Std 802.15.4f:2012 pdf free download.IEEE Standard for Local and metropolitan area networks一 Part 15.4: Low-Rate Wireless Personal Area Networks (LR-WPANs).
It should be noted that the preamble length is variable between 16 pulses and 128 pulses at the discretion of the implementer. Sixteen pulses have been shown to be sufficient for a wide variety of use cases, but the implementer may desire to improve acquisition performance by increasing the preamble length. however. doing so has three important negative effects on overall system performance. so the choice should be carefully considered. A longer preamble will:
— Risk increasing the packet length beyond 192 pulses. which may require the pulse amplitude to be reduced in order to comply with local IJWB average emission limits.
Increase power consumption in the tag (more pulses transmitted and more processor on-time). Increase tag packet collisions (due to longer packets).
J.2.1.1.2 Extended mode
The extended mode adds rate 14 convolutional code to provide simple forward error correction to the base mode for improved perfonnance in certain circumstances. Additionally, the extended mode allows for a longer preamble (up to 256 pulses) if the implenienter needs to increase acquisition robustness. The encoding scheme is simple to implement in the transmitter, and allows for two different decoding schemes in the receiver.
Since the extended mode packet length is longer than a base mode packet, the signal is likely to become constrained by the regulatory average emission limits for UWB. This requires individual pulse amplitudes to be reduced, which causes a loss in terms of link budget when using a non-coherent receiver. This loss is to be weighed against an expected coding gain of up to 4 dB to detennine whether extended mode has net benefit in any given circumstance.
It can be used stand-alone for non-precision active RFID and data transfer applications or in conjunction with other lEI1 802.15.4 PHYs (e.g.. LRP UWB PI-IY) for control and regulatory compliance. An example of a device that might use the LRP UWII P1W and the MSK PIIY 2450 MHz band together is a small location tracking tag. which is operating in a regulatory domain that prohibits LRP UWI3 transmissions unless the tag is in the vicinity of a fixed reader infrastructure. The reader infrastructure might periodically transmit an ‘OK to transmit signal via the MSK PIIY 2450 MHz band. and the tag would inhibit its LRP UWB transmissions unless it had recently received such a signal.
J.2.3.2 Channel selection and interoperability with other 2.4 GHz services
The MSK PHY 2450 MI-li band is compatible with global regubtions relating to the 2.4 Gui ISM band and offers bidirectional capability with low circuit complexity. lower sidelobes than O-QPSK (leading to improved compatibility with neighboring users of the radio spectrum). and is implemented by commonly available transceiver ICs.