The iDEN RF signal consisted of 4 subcarriers, whose center
frequencies are separated by 4.5 kHz from each other. Apictorial representation of the modulation
riding on each subcarrier is shown in Fig. 1.35.
Each subcarrier has 16 kbps, and the resulting signal produced an aggregate data rate of 64 kbps.
1.2.7 Bluetooth (BT) Personal Area Network
Bluetooth is a low-power, short-range radio technology that was originally intended to be used in device
connection applications such as mobile phone headsets, computer peripherals, and cable replacement.
The short-range aspect of this system makes this a Personal Area Network (PAN) [32, 33].
Bluetooth operates in the 2.4-GHz industrial, scientific, and medical (ISM) band. The channel
spacing is 1 MHz, with each channel having a data rate of at least 1 Mbps. The system uses a TDMA
with TDD communication.
Packets of voice and data are transmitted between Bluetooth devices. After each transmission, the
device hops to another frequency channel; this is called FHSS. This hopping pattern is across 79 channels.
Since the frequency band will have varying degrees of interference, certain channels can be
excluded from the hopping sequence to provide further robustness to interference.
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