SECTION 2
GENERAL DESCRIPTIONS
2.1 Multi-band :
For the use in Europe and in other countries worldwide, ETSI has specified GSM standards into two frequency bands. That is the
While the
The Dual band technology enables a network operator with spectrum at both 900MHz and 1800MHz to support the seamless use of dual band handsets across both frequencies. By supporting seamless handovers between 900MHz and 1800MHz, Dual band networks can provide major benefits in terms of capacity enhancement and revenue optimisation through the introduction of new services.
The
It supports the extra functionality required for
The user does not need any special action to use the
E-GSM
With the further development of the GSM standard, an additional range of frequencies has been made available to the “Global system for mobile communications”. For each of the two duplex frequency ranges, one for the forward direction and one for the reverse direction, additional 10 MHz have been added to the bottom end of the bands, extending the frequency range to 50 further channels.
The mobile station transmits in the 880- to 915 MHz range, and the base station transmits in the 925- to 960 MHz range. A duplex spacing of 45 MHz is used, the base station always transmits on the high side of the duplex frequency pair.
The numbering for these additional channels is from 974 to 1023. This is done to avoid assigning one channel number twice within the same standard.
Compared to the primary GSM system, Channel number 0 is used in the extended GSM system, since it does not make sense to reserve it at a guard band within the
DCS 1800
From these figures it follows that the duplex spacing is 95 MHz with 374 channels with bandwidths of 200 kHz each.
The channels are numbered from 512 to 885 in order to distinguish them from the channels in the primary and extended GSM frequency bands.
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