Radyne OM20 Specifications download pdf (Page 183)

MN-OM20– Revision 5 E–1

Appendix E. Drop & Insert (D&I)

E.1 Drop and Insert (D&I)

(For Efficient Drop & Insert refer to Appendix F)

The Radyne OM20 Drop and Insert (D&I) Function provides an interface between a full T1 or

E1 Trunk whose framing is specified in CCITT G.704 and a fractional Nx64 Kbps Satellite

Channel that conforms to the IBS and small IDR Framing Structures. The Drop function allows

the user to select the terrestrial T1 or E1 timeslots that are to be dropped off for transmission

over the link in the specified satellite channels. The Insert function allows the user to select the

T1 or E1 timeslots into which the received satellite channels are to be inserted. The two

functions are completely independent allowing maximum flexibility in choosing configurations.

The Transmit Data Trunk is brought into the modem via the Drop Data In (DDI) SD Port J10.

From there, the TX Baseband Processor extracts the selected timeslots from the G.704 Frame and

prepares them for transmission. The Receive Data Trunk is looped internally to the OM20 by a

connection between the Drop Data Out (DDO) to the Insert Data In (IDI). The data is buffered

inside the modem and the RX Baseband Processor inserts satellite data into the selected timeslots

in the G.704 Frame. The modified terrestrial trunk is then output via the Insert Data Out (IDO)

RD Port J11. The OM20 is not capable of daisy chaining two units together as all loop timing is

done internally to the OM20.

(

DDI

)

DDO

IDI

(

IDO

)

Modem

Terrestrial

Trunk

Figure 3-8. OM20 D&I Configuration

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Radyne OM20 Specifications Page 183