CSI CSI-DSP85-L7AB, Installation Manual

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Cellular Specialties, Inc. (CSI) developed the DSP85 digital repeater for use within enclosed structures where signal from local dispatch
sites is insufficient to operate on scene communication equipment. Adequate signal must be available outside the structure as a prerequi-
site to achieving in-building coverage. The Digital Repeater is connected to an external antenna, usually on the roof, and to one or more
internal antennas placed strategically throughout the area where wireless service is desired.
The external antenna typically is directional, such as a “yagi”. Internal antennas are typically omnidirectional, although various other types
may be used depending on the coverage application. The
CSI DSP Repeater amplifies both the “uplink” (Transceiver to tower) &
“downlink”(tower to Transceiver) signals thus facilitating communications to and from the intended wireless infrastructure.
With a maximum total of +85 dB nominal gain on both the up and down links, gain can be adjusted over a range from +53.5dB to +85dB in
0.5dB steps. Control of the repeater is achieved utilizing a computer connected to comm. port 1 or 2 or via a Crossover Ethernet cable
connected to the Ethernet port. There are also LED indicators near the display to indicate ALARM status, AGC status, UL PWR, DL PWR,
OSC, SHUT DWN and a D/L SIGNAL STRENGTH bargraph.
A specific filtering process modifies each amplification chain. This process digitally converts the assigned spectrum and then applies
digital signal processing (DSP) techniques. DSP is used to create passbands that selects the RF energy passing through either the uplink
or downlink paths. After the digital processing is complete, the information is converted back to an analog signal that is applied to the
remaining stages of amplification. The resulting signals emitted by the repeater are specific to the network service providers’ require-
ments. If these requirements change, only the DSP configuration parameters need change in order to adapt. Configuration parameters are
created at the factory and supplied as files that may be downloaded to the repeater. The filter set configurations stored in memory
determine the unit’s adaptability to various field applications. The following pages describe the public safety band plan as well as the
convention CSI uses to identify and store the files that make up the filter set. All DSP85 repeaters are shipped with an active filter set that
is programmed according to the ordering parties’ specifications. In most cases, the installer will not have to program a filter.
AGC = Automatic Gain Control ERP = Effective Radiated Power
APC = Automatic Power Control FPGA = Field Programmable Gate Array
AUI = Attachment Unit Interface LED = Light Emitting Diode
CPU = Central Processing Unit OIP3 = Third-Order Intercept Point
CSI = Cellular Specialties, Inc. RF = Radio Frequency
DAS = Distributed Antenna System SBC = Single board Computer
DHCP = Dynamic Host Configuration SNMP = Simple Network Management Protocol
Protocol TMI = Text Menu Interface
DSP = Digital Signal Processing USB = Universal Serial Bus
EEPROM = Electrically Erasable UHCI = Universal Host Controller Interface
Programmable read-
only Memory
Antennas used for the purpose of radiating signals indoors are limited to a maximum gain of 3 dBi. The outdoor antenna used for the
purpose of communicating to the wireless infrastructure is limited to 14dBi gain, or any combination of gain and loss that equates to
14dB at input. Each antenna must be positioned to observe minimum separation requirements from all users and bystanders. The
following guidelines should be used when considering separation distances.
INDOOR antennas must be placed such that, under normal conditions, personnel cannot come within 20 cm (~8.0 in.) from any inside
antenna. Adhering to this minimum separation will ensure that the employee or bystander cannot exceed RF exposures beyond the
maximum permissible limit as defined by section 1.1310 i.e. limits for General Population/Uncontrolled Exposure.
OUTDOOR antenna must be positioned such that, under normal conditions, personnel cannot approach closer than 120 cm. (~4 ft.). A
directional antenna having a maximum gain of 14 dBi is used, precautions should be taken to prevent personnel from routinely passing
through the main radiation beam at a distance closer than specified.
Product Introduction
Terms used in this manual
Important Safety Information