Base Station Equipment

MCP Channel Unit Subsystem (CUS)

MCP Channel Unit Subsystem (CUS).

Square Peg Communications Inc.’s Multi-Channel Platform (MCP) is a hardware and software platform suitable for use in demanding satcom applications.

The MCP supports the implementation of Channel Unit Subsystems (CUSs) capable of supporting a variety of base station applications via a software-defined radio architecture. It conforms to industry standards for physical, electrical, and protocol interfaces to facilitate integration with other elements of the base station. It allows redundancy to be implemented efficiently where high availability is required.

The MCP also supports the implementation of physical layer testers, which are used to verify the performance of communications equipment intended for use in specific networks. A physical layer tester typically combines the transmit and receive capabilities of base stations and terminals with signal measurement functions and test automation facilities.

The architecture of the MCP is based on the use of a common LAN protocol for communication both within an MCP chassis and with other system elements. This provides a high degree of flexibility in configuring the system. For example, in addition to Channel Units, a CUS implemented with the MCP can include interfaces to terrestrial networks (e.g., T1/E1), as well as host processors to perform station management, network control, and call processing functions. The cards comprising a system can be distributed among multiple synchronized MCP chassis. All elements can be redundant for fault tolerance and high availability.

MCP-based Channel Unit Subsystems provide the modems for the Inmarsat-4 Classic Aero Ground Earth Stations (GESs) and BGAN Micro-Satellite Access Stations (Micro-SASs).

High availability

Hot swappable elements

Scaleable signal processing capability

Ease of maintenance

Scaleable number of channels

Scaleable signal processing capability

Flexible IF interfacing

Flexible baseband interfacing

High density

Excellent RF performance

Channel Unit Subsystem

Enclosure 19” / 7U PICMG® 2.16, rack mount (4U, 12U also available)
Cooling Front to back
Power supplies N+1, AC or DC
Shelf managers
  • Dual redundant per PICMG® 2.9
  • RCMP, CLI, GUI, SNMP interfaces
  • Alarm dry contact relays
Ethernet switches Dual redundant 10/100 or Gigabit
Channel Units 1 to 6 front / rear card pairs

Channel Unit Front Card

Composite channels 4 Tx/Rx (independently tuneable)
Composite channel bandwidth Application-dependent, up to 1.25 MHz
Bearer channels per composite channel Application-dependent; e.g., 4 for BGAN or Classic Aero
DSPs per composite channel 1 x 500 / 600 MHz TigerSHARC or 2 x 500 MHz TigerSHARC
FPGA Xilinx Virtex 4 FX60
DSP / FPGA communications 1 full duplex link port @ 800 Mbps 2 full duplex link ports @ 200 Mbps
DSP expansion 1 expansion connector per DSP cluster for off-board FPGA co-processor
Control processor PPC405
Ethernet interface 10/100/1000BaseT Auto-switching between Switch A, Switch B and front panel

Channel Unit Rear Card

Number of IF feeds 2 Tx + 2 Rx On-card loopback for self-test
Tx/Rx IF frequency range 50 to 90 MHz
Max. total power per Tx feed –17 dBm
Max. per-carrier Tx power Dependent upon number of bearers per composite channel, typically –29 dBm
Tx phase noise density @ 100 Hz:   ≤ –70 dBc/Hz @ 1 kHz:     ≤ –80 dBc/Hz @ 10 kHz:   ≤ –90 dBc/Hz @ 100 kHz: ≤ –100 dBc/Hz
Tx spurious < –86 dBm for carrier at –29 dBm
Tx 3rd order intermodulation < –55 dBc (2 carriers at –20 dBm)
Tx I/Q imbalances Negligible
Typical Rx dynamic range –65 to –25 dBm –10 dBm max total
Reference input 10 MHz
Square Peg Communications Inc.
4017 Carling Avenue, Suite 200 
Ottawa, ON, Canada K2K 2A3
Tel + 1 613 271 0044
Fax+ 1 613 271 3007
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