|
|
|
|
|
 |
- Is this a new radio that I have to evaluate?
- What are licence exempt free bands?
- Is this a new radio that I have to evaluate?
NO. In most cases you will be familiar with the RF "engines" we use. "Easy-Radio" uses well known tried and tested RF "engines" from Circuit Design, LPRS and others. So you don't have to assess the suitability of the radio part for your application.
[Back To Top]
- What are licence exempt free bands?
SRDs or Short Range Devices operate in frequency allocations set aside by local governments. They are generally low output power, typically 10mW and are tightly controlled in terms of frequency accuracy, power output and spurious emissions.
The rules governing these devices have been changing in recent years and a degree of harmonisation now exists between countries, particularly Europe. There are now two harmonised bands for all CEPT countries (EU and beyond). These are 433-4MHz and 868-870MHz. These are "free to air" systems where neither the supplier nor the user has to pay a transmitting licence fee unlike paging companies and mobile services providers.
In order to place a product on the market the maker must demonstrate that they comply with the technical regulations. In Europe this means compliance with the R&TTE Directive, which covers EMC and radio specifications. It is possible to "self-certify" the product complies but many manufacturers continue to use outside Test Houses" to perform this work as they used to under the old regulations (MPT, FTZ etc.) In the USA it is still necessary to carry out official independent tests in order to be approved under the FCC rules.
The most significant bands are as follows:
Frequency range Where used Approx max. power Restrictions
2.40-2.483GHz Worldwide 10mW (up to 200mW - US) virtually none
433.05 - 434.79MHz Europe 10mW No audio, 10% duty cycle
433.05 - 434.79MHz Europe 1mW No audio, up to 100% DC
434.04 - 434.79MHz Europe 10mW No audio, 25KHz channels
433.05 - 434.79MHz SA, Australia, NZ 10mW Check locally
868-870MHz Europe Variable see plan* Variable see plan*
863-865MHz Europe 10mW - audio/speech Max B/W 300KHz
864.8- 865MHz Europe 10mW - audio/speech 50KHz channels
902-928MHz USA/Canada 1mw none
902-928MHz USA/Canada Up to 1W Only frequency hopping systems allowed.
458MHz UK 500mW 25KHz channels
173.225MHz UK 10mW 25KHz channels
40-49MHz Europe 10mW Frequencies vary locally
1.88-1.9GHzDECT Europe 250mW Protocol controlled speech and data
Around 5GHz Worldwide TBA TBA
A document entitled ERC Recommendation 70-03 is available at www.ero.dk. This outlines all the current requirements for Europe. It can be found on their home page entitled "Updated ERC REC 70-03 on Short Range Devices" For the USA rules go to http://www.access.gpo.gov/nara/cfr/waisidx_01/47cfr15_01.html
The most useful sections are from 15.229 to 15.249
If in difficulty please email barry.gillibrand@lprs.co.uk
[Back To Top]
|
|
|
|
|
|
Shopping Cart
