An overview of ARIB STD-T108 regulation

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Doc ID 023362 Rev 1

1.2

Low-power radio stations

Low-power radio stations differ from convenience radio stations in output power and usable

frequency band.

Regarding the output power, two different values are permitted as follows.

●

An output power of 1 mW (0 dBm on a 50 ohm load, +3 dBm EIRP considering an

antenna of 3 dBi gain) is permitted in the band greater than or equal to 915.9 MHz to

less than or equal to 916.9 MHz , and greater than or equal to 920.5 MHz and less than

or equal to 929.7 MHz.

●

An output power of 20 mW (+13 dBm on a 50 ohm load, +16 dBm EIRP considering an

antenna of 3 dBi gain) is permitted in the band greater than or equal to 920.5 MHz to

less than or equal to 928.1 MHz.

As for convenience radio stations, an entire radio channel consists of up to 5 consecutive

unit radio channels which are defined such that their center frequency is located from 916.0

MHz to 916.8 MHz and from 920.6 MHz to 928.0 MHz with 200 kHz separation and a

bandwidth of 200 kHz, or which are defined such that their center frequency is located from

928.15 MHz to 929.65 MHz with 100 kHz separation and a bandwidth of 100 kHz. There

aren't specific requirements for the modulation method, while the permissible value for the

occupied bandwidth is (200 x n) kHz or less, where n is the number of unit radio channels

constituting the entire radio channel and is an integer from 1 to 5. In the case that the center

frequency is from 928.15 MHz to 929.65 MHz, it shall be (100 x n) kHz or less.

An adjacent channel leakage power is permitted: five different channel masks are defined,

functions of the usable bandwidth and of the output power. For the five different masks refer

to the figures 3-1 to 3-5 of the ARIB STD-T108 regulation, see References on page 33.

For the transmitter a permissible value for unwanted emission intensity is defined (see

Table 3).

For the receiver a limit for the secondary radiated emissions is defined (see Table 4).

Table 2.

Limit on secondary radiated emissions, etc. at receiver

Frequency band

Limit on secondary radiated

emissions, etc. (antenna input)

Reference bandwidth

f

≤ 710 MHz

-54 dBm

100 kHz

710 MHz < f

≤ 900 MHz

-55 dBm

1 MHz

900 MHz < f

≤ 915 MHz

-55 dBm

100 kHz

915 MHz < f

≤ 930 MHz

-54 dBm

100 kHz

930 MHz < f

≤ 1000 MHz

-55 dBm

100 kHz

1000 MHz < f

-47 dBm

1 MHz