Telecom Dictionary

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RAO
Revenue Accounting Office

RBHC 
Regional Bell Holding Company

RBOC
Regional Bell Operating company

RBS 
robbed bit signaling

Regional Bell Holding Company (RBHC)
RBHC is one of 7 regional companies created by the AT&T divestiture to assume ownership of 
the Bell operating companies. They are Ameritech, Bell Atlantic, Bell South, NYNEX, Pacific 
Telesis, Southwestern Bell and US West.

Repeater
In digital transmission, a repeater is equipment that receives a pulse train, amplifies it, retimes it, 
and then reconstructs the signal for retransmission. In IEEE 802 local area network (LAN) 
standards, a repeater is essentially two transceivers joined back to back and attached to two 
adjacent LAN segments. See transceiver.

RFC 
request for comment

RFE
Request for Engineering

RFI 
radio frequency interference

RFP 
request for proposal

RF 
radio frequency

Routers
In IEEE 802 local area network (LAN) standards, routers are devices that connect autonomous 
networks of like architecture at the network layer (layer 3). Unlike a bridge which operates 
transparently to communicating end-terminals at the logical link layer (layer 2), a router reacts 
only to packets addressed to it by either a terminal or another router. Routers perform packet (as 
opposed to frame) routing and forwarding functions; they can select one of many potential paths 
based on transit delay, network congestion or other criteria. How routers perform their functions 
is largely determined by the protocols implemented in the networks they interconnect.

RSU 
remote switching unit