ETSI Lower Band Channel Selection Guide

There are different standards that regulate the use of UHF RFID throughout the world. The three main regulations are: FCC, ETSI Lower band, and ETSI Upper band. Whilst the protocol remains the same, the frequency and technique to communicate with the tag are different. Here is a summary of the three main regulations:

  Standard Name Primary Regions of Operation Frequency Range R-->T Technique Max Radiated Power
FCC FCC part 15.247 & 15.249 North America 902-928 MHz FHSS 4W EIRP
ETSI Lower EN 302 208-2 v2.1.1 Europe 865-868 MHz 4 channel plan 2W ERP
ETSI Upper EN 302 208 v3.2.0 Europe 915-921 MHz 3 channel plan 4W ERP

 

This article describes the best practices for selecting channels when operating in the ETSI Lower band (865 MHz - 868 MHz).

For ETSI Lower band, there are 4 transmit channels available (hence the name “four channel plan”) where the reader can transmit the maximum allowable power from the antenna (namely 2W ERP, 33dBm).

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Due to having significantly less channels, less power and less bandwidth per channel than in FCC regions, applications designed for ETSI regions often have to consider channel selection.

Here are some basic best practice tips:

1. Ensure you’re using the correct channels; use all four channels whenever you can; but this is not always possible due to other readers transmitting in close proximity; (if using ItemTest to test your reader, select “Use Specified Frequencies” in "Frequency Settings (ETSI Only)" section and select all 4 channels, as shown below)

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See also: Selecting Specific Channels Using ETSI Regulations

2. If you have more than one reader in close proximity that will be operating at the same time then use alternate output channels as follows;
Reader A: channel 4 (865.7 MHz) and channel 7 (866.3 MHz)
Reader B: channel 10 (866.9 MHz) and channel 13 (867.5 MHz)
ETSI1ChannelSelection.jpg

Red bands: Reader A
Blue bands: Reader B

This can be important for times when two readers are used to create a portal or when two dock door portals are in close proximity. When readers are actively transmitting, if this separation of channels is not designed into the system there is a 25% chance that they will be transmitting at the same time; thereby increasing the chances of interference; and with it the chances of not reading tags.

3. Considerations if you have to use a single channel; ETSI regulations dictate that it is only permitted to transmit on a single channel for a certain period of time. 4 seconds if tags are being read and only one second if no tags are being read... if this happens then the reader must stop transmitting for a period of 100 ms. The reader ensures it complies with the regulations automatically, therefore, it’s important, where possible, to ensure more than one channel is selected.

If you have more than two active readers in close proximity; careful consideration must be given to the design of the system. Which channels to use, separation of antennas, angle of antennas and how operation of the reader is triggered are all variables that can affect the operation of the RFID solution. Please also see this post to learn how to select specific channels when using ETSI readers: Selecting Specific Channels Using ETSI Regulations

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