CPSC 3600 - DAY 13
MARCH 6, 2017

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ACCESS AND INTERCONNECTION TECHNOLOGIES
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	Internet Access Technology - data communications system that connects
	an internet subscriber to an internet service provider

	Narrowband - technologies that deliver data up to 128Kbps
		ex. T1, Dialup, ISDN

	Broadband - high data rates 1Mbps+
		ex. DSL, Cable Modem, Wireless access, T1 or higher speed

	Local loop - physical connection between a telephone company and 
	subscriber's location

	The local loop consists of twisted pair and often has higher bandwidth
	than the rest of the phone ssytem

	DSL - one of the main technologies used to supply high speed data com

	ADSL - most widely used variant and the type most residential customers
		use.

	ADSL uses Discrete Multi Tone modulation (DMT), which combines freq.
	multiplexing and inversing multiplexing

	DMT is implemented by dividing bandwidth into 286 subchannels
		255 for Downstream
		31 for Upstream

	Maximum theoretical speeds for ADSL
		Range from 8.448 Mb/s downstream and 640Kb/s upstream
		Mandatory control channel which requires 64Kb/s on upstream
		channel

	Installation requires splitter
		Uses freqency division multiplexing, divides bandwidth
		according to high and low frequencies
		passive divide
		splitter installed where the local loop enters a structure

	Cable Modem
		limitations of telephone local loop
		high bandwidth
		higher tolerance to electrical interference
		FDM signal splitting in pace for the many channels delivered
		silmultaneously

	Theoretical Data Rates for Cable Modems
		52 Mb/s downstream
		512 Kb/s upstream

	Hybrid Fiber Coax
		Combination of coaxial cables and optical fibers
		Fiber to neighborhood, cable to houses
	
	Fiber to the curb
		Similar to HFC, runs as close to subscriber
	
	Fiber to the building
		Optical fiber to the building, used in office buildings

	Fiber to the home
		Optical fiber to home/ residential subscribers

	Fiber to the Premises
		Refers to FTTB and FTTH

	Head-end modem
		refers to the modem used at the central office
	
	Tail-End Modem
		refers to modem used at the subscriber's location

	DOCSIS
		specifies both the format of data that can be sent as well as
		the messages that are used to request service (pay-per-view)

	Wireless Access Technologies
		Rural areas are the most difficult
		WIMAX
		3G services
		Satellite

	Access technologies handle the last mile problem
	Core - connection between providers

	+---------------+----------------+-----------------+------------------+
	| Name		| Bit Rate	 | Voice Circuit   | Location	      |
	+---------------+----------------+-----------------+------------------+
	| T1		| 1.544 Mbps	 | 24		   | North America    |
	+---------------+----------------+-----------------+------------------+
	| T2		| 6.312 Mbps     | 96              | North America    |
	+---------------+----------------+-----------------+------------------+
	| T3		| 44.736 Mbps    | 672		   | North America    |
	+---------------+----------------+-----------------+------------------+
	| E1		| 2.048 Mbps     | 30		   | Europe	      |
	+---------------+----------------+-----------------+------------------+
	| E2		| 8.448 Mbps     | 120		   | Europe	      |
	+---------------+----------------+-----------------+------------------+
	| E3		| 34.368 Mbps    | 480		   | Europe	      |
	+---------------+----------------+-----------------+------------------+