When channel separation is set to 12.5 kHz, 25 kHz or the like within a restricted frequency range, data transmission speed is normally limited to 4,800 bps, with a highest speed of around 9,600 bps. However, in spite of this relatively low speed, narrowband has important merits. Narrow band allows good receive sensitivity on the receiving end, in other words its range can be extended and it is not readily susceptible to interference. In addition, the 400 MHz band frequency can also make use of the ability of the radio waves to make detours unlike with 2.4 GHz used for Bluetooth, WLAN and the like. Improved performance can be expected due to the fact that the radio waves reach the receiver in spite of obstacles. For example, when using high speed data transmission such as for WLAN (10 Mbps or higher), a wide frequency band of nearly 5 MHz is required. Therefore in applications which use this kind high speed data, the 400 MHz band or 860 MHz band for which only a 2 to 6 MHz useable band is permitted cannot be used. So it will be understood that applications which use this kind high speed data can be achieved with the 2.4 GHz or higher bands for which wide band use is permitted.
* full IP?
* Hight frequency: 1) many cell –
> expensive. 2)
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.. and effects.
> network capacity.
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