User's Manual

2. FUNCTIONAL DESCRIPTION
2.1. PURPOSE
Cellular telephone systems transmit signals in two directions between base
transceiver station (BTS) and mobile stations (MS) within the signal coverage area.
If weak signal transmissions occur within the coverage area because of indoor
applications, topological conditions or distance from the transmitter, extension of the
transmission range can be achieved by means of an optical distribution system.
Such a system contains an optical Master Unit and several Remote Units. The
number of the Remote Units depends on the hardware and software configuration.
The Remote Units are connected to the Master Unit with optical links. The optical
loss must be less than 10 dB inclusive optical couplers or splitters.
The Master Unit is the connection to the base transceiver stations. The configuration
of a Master Unit depends on the number of the Remote Units and the frequency
range.
WDM (Wave Division Multiplex) filters are integrated in the optical modules. For the
UL, a wavelength within 1540 nm – 1562 nm is used. For the DL, a wavelength of
1310 ±20 nm is used. The maximum output power for the UL and DL is 5.7 mW.
2.2. THE ION-M7P (INTELLIGENT OPTICAL NETWORK; MMR)
The fibre-optic distribution system is designed for LTE 700 MHz services. Each fibre
is able to operate services of up to four providers. One Master Unit can operate up to
124 Remote Units.
An auto-levelling function for compensating different fibre losses and a
comprehensive supervision concept are implemented. Auto-levelling in the DL works
with optical power measurement, in the UL a 10.7 MHz signal is used for measuring
the optical loss.
The Remote Unit ION-M7P is connected to a central Master Unit via optical fibre
lines. Specific customer designs for lamp pole or wall mounting are available. Thus,
the system provides many advantages in view of easy site acquisition.