User Manual

SGD-SB2025NT-TUM, Part 1
Jan 12 Page 10 INTRODUCTION
A radio system will necessitate the use of a number of Solar NIs and one or more Solar TMs,
which together are configured to meet the operational requirement. The Solar NI operates as a
Central NI or a Station NI; they are the same unit. They are fully duplex and include all the
features; it is a matter of system configuration to define which is which and how they are used.
System configuration, base station Rx selection, packet organisation and distribution are the core
functions performed by the Solar TM unit. Solar network changes for operational purposes can
also be made via the Solar TM Unit.
All variants of the SB2025 contain a Station NI, which can be associated with either a separate TM
or, in the case of the SB2025NT, a TM built into the same unit. The interface between the Station
NI and the base station is entirely internal to the SB2025. There is no analogue audio interface to
the unit.
As well as managing the operation of a channel, the TM provides a standard DFSI conforming to
TIA-102.BAHA.
1.2.1 Method of Operation
The Solar Central NI is designed as the analogue interface, port, or gateway, to a packet switching
network; the network is entirely the responsibility of the systems integrator. The Solar TM routes
all Solar traffic and maintains the system configuration information. To fulfil this role the TM is
configured to communicate with all other Solar elements on the network, as defined by the system
design. Provided the network has sufficient data carrying capacity, there is no requirement for the
network traffic to be uniquely Solar.
1.2.2 Basic I/O Facility
With Solar TMs and Solar NIs inter-connected by an IP network, in analogue mode the result will
be that what goes into one NI will come out of another NI. The full audio bandwidth has been
profiled at 300 Hz to >3.4 kHz and has a true transfer profile. This means that control and
selective calling tones will be faithfully reproduced at the output Solar NI. The input signal is
digitized, packetized and delivered to the network – at the destination Solar NI unit(s) the reverse
process takes place ensuring that the output is a true reflection of the original input. In P25 mode,
audio into the Central NI will be Advanced Multi-Band Excitation +2 (AMBE+2) coded and output
from the Station NI(s) and, hence, from the SB2025 Tx(s) as a TIA-102 P25 compliant signal. A
received and voted P25 signal will be AMBE decoded and output from the Central NI as audio.
1.2.3 PMR Wide-Area Cover Facilities
A number of Solar NIs and a minimum of one Solar TM are required to provide infrastructure
facilities for wide area coverage, multi RF Base Stations, PMR system; not including Packet
Switching Network or Control Console – all other requirements for a common PMR system are
included. The Solar NI System would usually be configured to connect an operator/dispatcher
terminal/console through a Central NI or DFSI connection via a Solar TM to a number of Station
NIs each wired directly to a Base Station. Solar will also deliver all the signalling functions
necessary for system operation.
1.3 S OLAR 2 – S TYLE
Solar can be used in PMR systems in several styles but the style can only be activated by the
factory programmed “Facility Key” in the TM. The basic information on the three core styles is as
follows:
(a). Simulcast Style.
Solar has facilities for the synchronization of audio as follows:
•
••
• GO path – Talk Out direction.