Motorola DHSB5100 installation manual Overview, SURFboard cable modem data path

Section 2

Overview

The SURFboard cable modem delivers digital multimedia content in a two-way transmission system. It provides access to a cable data network, which provides access to the Internet and World Wide Web.

The SURFboard cable modem is authorized by a cable modem terminations system (CMTS) for use on the network and automatically configures itself with parameters received from the CMTS or headend. When the SURFboard cable modem is powered on, it:

!Scans the frequency spectrum to locate the data frequency and automatically locks on to the channel.

!Searches for a message containing the upstream parameters such as frequency, modulation, symbol rate, and forward error correction (FEC) format.

!Transmits a message to the CMTS requesting additional information enabling network connection.

!Establishes Internet Protocol (IP) connectivity using Dynamic Host Configuration Protocol (DHCP)

!Receives a configuration file using the Trivial File Transfer Protocol (TFTP). This file contains additional parameters required by the SURFboard cable modem.

!Registers with the CMTS and is authorized to use the network.

Figure 2-1 illustrates the SURFboard cable modem data path:

Figure 2-1

SURFboard cable modem data path

Network	Customer premises
management
	equipment
services
	HFC plant

		IF Upconverter		RF		SURFboard
Internet	CMTS				Diplex RF	external
					filter	cable
						modem
			RF

Client PC

The SURFboard cable modem supports 64 QAM and 256 QAM signals that are necessary for the DOCSIS/Euro-DOCSIS data network. This network carries IP data in standard MPEG-2 packets. The RF downstream receives data at rates up to 38 Mbps (55 Mbps for Euro-DOCSIS) and the RF upstream transfers data rates of up to 30 Mbps. The actual speeds will vary; speeds of 30 Mbps are only attainable with A-TDMA or S-CDMA technology.

SURFboard Cable Modem Installation Manual