User's Manual

1. Preface
Nowadays, personal mobile communication is developing at a very rapid
rate and persons are having higher expectations and demands on the
mobile communication network. A high-speed and high-capacity
communication network has become the trend of future development. At
present second-generation (2G) mobile communication systems like GSM is
widely used all over the world, but mostly in developing nations, whereas
third-generation (3G) and forth-generation (4G) mobile communication
technology is widely used in Europe, North America and Korea.
For example, Code Division Multiple Access (CDMA) technology is used
which greatly extends the signal width -- the so-called spread spectrum
modulation. As an advanced wireless communication technology, it features
good multi-channel access capability, anti-multipath fading capacity, anti-
narrowband interference capability and security protection capabilities.
The CDMA network has, what is called a “cell breathing effect”. That is, the
coverage will gradually shrink as the cell load increases. The cell breathing
effect makes network planning more complicated. The CDMA technology
itself determines that the load of the network at the early stage of
construction should be higher than that of the GSM network. Therefore,
adding carriers and roaming agreements between them is a major means of
expanding network capacity, and adding BTS’s or Node B base stations is an
auxiliary means of capacity expansion. The aim of the radio network should
to provide continuous coverage, instead of hotspot coverage.
The cost of wireless repeaters are relatively low and the construction is
simple. They have the functions of a mini BTS or Node B. On the network,
repeaters can help a BTS or Node B to achieve the optimal network quality
at a minimum cost.
A cellular tower typically supports a large capacity of users but is affected by
a relatively small coverage footprint. Therefore, the number of users who can
access it is limited and a large amount of channel resources are wasted. The
best way of solving this problem is to use repeaters to extend the BTS
coverage to fully utilize the telecommunication resources. For example, in
cellular network construction in Asia, repeaters are no longer considered as
peripheral devices to cover blind areas in the network but as part of the core
network itself.
The complete coverage is not only a prerequisite for a high quality mobile
cellular network, but also a factor that attracts users. From this point of view,
a network operator should first consider providing a radio network with a
complete coverage. The seamless coverage in urban areas, heavy traffic
areas, office buildings, super markets, and top grade hotels is the first step
to consummate the network.
In such a background, JDTECK has successfully developed advanced
repeaters that are applicable to any mobile network and indoor distributed
antenna system. (DAS) Repeaters are available to support any technology
or frequency used today.
Because a large amount of BTS or Node B devices are deployed in densely
populated urban areas, there is usually no large blind area. Repeaters are
simply used to cover small blind areas and provide signal coverage inside
buildings or sub-ground locations. Typically, radio frequency (RF) repeaters
are used when optical fibers are not available in buildings or when using a
fiber solution is not cost effective.
Since the number of repeaters on a cellular network usually increases with
the number of buildings to be covered in a specific sector, multiple repeaters
may end up feeding from one BTS or Node B. In view of this, only low
powered repeaters (below 1 W) should be deployed in densely populated
areas.
Repeaters adopt an integrated module concept. It is compact in structure
and combines the RF module and the monitoring mode in one unit. Owing to
its high selectivity, stability and reliability, repeaters are widely applied to
indoor signal distribution in small areas such as office buildings, meeting
rooms, hotels, tea shops, night clubs, and cafes where signals are shielded.
They are also used to cover shadow areas outdoors. Such repeaters are
very suitable to signal optimization in densely populated urban areas.
Figure 1 shows the applications of the repeaters.
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