Specifications

ETSI
Final draft ETSI EN 300 328 V1.8.1 (2012
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4.3.1.2.2 Limit
For non-adaptive FHSS equipment, the Duty Cycle shall be equal to or less than the maximum value declared by the
supplier. In addition, the maximum Tx-sequence time shall be 5 ms while the minimum Tx-gap time shall be 5 ms.
4.3.1.2.3 Conformance
The conformance tests for this requirement are (part of the procedure) defined in clause 5.3.2.
4.3.1.3 Dwell time, Minimum Frequency Occupation and Hopping Sequence
These requirements apply to all types of frequency hopping equipment.
4.3.1.3.1 Definition
The Dwell Time is the time that a particular hopping frequency would be occupied by the transmitter during a single
hop. The equipment itself is not required to transmit on this hopping frequency during the Dwell Time.
The Minimum Frequency Occupation Time is the minimum time each hopping frequency shall be occupied within a
given period.
The Hopping Sequence of a Frequency Hopping system is the unrepeated pattern of the hopping frequencies used by
the equipment.
4.3.1.3.2 Limit
4.3.1.3.2.1 Non-adaptive frequency hopping systems
The accumulated Dwell Time on any hopping frequency shall not be greater than 15 ms within any period of 15 ms
multiplied by the minimum number of hopping frequencies (N) that have to be used. Non-adaptive medical devices
requiring reverse compatibility with other medical devices placed on the market when earlier versions of the present
document were harmonised, are allowed to have an operating mode in which the maximum dwell time is 400 ms.
The hopping sequence(s) shall contain at least N hopping frequencies where N is 15 or 15 divided by the minimum
Hopping Frequency Separation in MHz, whichever is the greater.
The Minimum Frequency Occupation Time shall be equal to one dwell time within a period not exceeding four times
the product of the dwell time per hop and the number of hopping frequencies in use.
4.3.1.3.2.2 Adaptive frequency hopping systems
Adaptive Frequency Hopping systems shall be capable of operating over a minimum of 70 % of the band specified in
clause 1.
The maximum accumulated dwell time on any hopping frequency shall be 400 ms within any period of 400 ms
multiplied by the minimum number of hopping frequencies (N) that have to be used.
The hopping sequence(s) shall contain at least N hopping frequencies at all times, where N is 15 or 15 divided by the
minimum Hopping Frequency Separation in MHz, whichever is the greater.
The Minimum Frequency Occupation Time shall be equal to one dwell time within a period not exceeding four times
the product of the dwell time per hop and the number of hopping frequencies in use.
4.3.1.3.3 Other Requirements
Frequency Hopping equipment shall transmit on a minimum of two hopping frequencies.
For non-Adaptive Frequency Hopping equipment, when not transmitting on a hopping frequency, the equipment has to
occupy that frequency for the duration of the typical dwell time.
For Adaptive Frequency Hopping systems using LBT based DAA, if a signal is detected during the CCA, these systems
may jump immediately to the next frequency in the hopping sequence (see clause 4.3.1.6.1.2 point 2) provided the limit
for maximum dwell is respected.