Cable Modems

 

 

Standards

Around 1997 two standards emerged. DAVIC/DVB were first with a European standard, closely followed by MCSN with a US standard (DOCSIS).

 

DVB/DAVIC

 

This standard is based on fixed cell size (ATM) and includes all the standard ways of doing quality of service (QoS) that ATM is known for. In that way, the standard is very well suited to both data i.e. TCP/IP (using AAL5) and telephony as pure ATM.

 

 

DOCSIS

 

Developed by CableLabs and approved by the ITU in March 1998, Data Over Cable Service Interface Specification defines interface standards for cable modems.

 

DOCSIS specifies:

 

*    Downstream traffic transfer rates between 27 and 36 Mbps with 50 MHz to 750+ MHz frequency range.

*    Upstream traffic transfer rates between 320 Kbps and 10 Mbps with 5 to 42 MHz frequency range.

 

 

 


Cable Modems

What is a cable modem?

Modem Architecture

Downstream Characteristics

Upstream Characteristics

Standards