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homeRF standard

Like 802.11, HomeRF uses the license-free ISM band, but in the slightly restricted frequency range from 2.404 GHz to 2.478 GHz, and works with the frequency hopping method (FHSS). The HomeRF standard provides for 75 frequency bands with a maximum bandwidth of 1 MHz.

In voice transmission, HomeRF distinguishes itself from other WLAN systems by its high quality. HomeRF uses TDMA/TDD for the transmission of time-critical information, such as for voice transmission and streaming media. For the transmission of time-uncritical data, IP data packets are transported as wireless Ethernet, which uses CSMA/CA as the access method. As a result, voice transmission takes place as isochronous transmission with minimal latency.

Characteristics of HomeRF

Characteristics of HomeRF

A HomeRF frame has a duration of 20 ms, which corresponds to the hop frequency rate of 50 frequency hops per second. It consists of several TDMA timeslots and time intervals for CSMA/CA. The duration of the time intervals is not fixed, but depends on whether voice channels are enabled. In the first version, the transmission rate was 1.6 Mbit/s, resulting in a user data rate of about 600 kbit/s. This data rate is reduced depending on the time intervals. This data rate is reduced depending on the number of active TDMA channels.

Version 2.0 of HomeRF with 3 MHz and 5 MHz channels brings it to a data rate of 10 Mbps. A further increase in the data rate to 20 Mbit/s is planned. This data rate is to be achieved by means of frequency shift ke ying (FSK) with four frequencies, 4-FSK, or with linear modulation methods.

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Englisch: homeRF standard
Updated at: 27.09.2004
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