Digital subscriber line access multiplexer (DSLAM)

: http://el.wikipedia.org

Digital Subscriber Line Access Multiplexer (DSLAM) /

DSL (Digital Subscriber Line).

,

, (-Y

Kabelverteiler KV), .

XDSL Connectivity Diagram

DSLAMs ATM

(Asynchronous Transfer Mode) 2005

Ethernet IP-DSLAM.

To DSLAM DSL

ADSL G.shdsl VDSL. DSLAMs

ITU-T G.992.1 ( G.DMT) ADSL 25,875

KHz (6x4,3125) 1104 KHz (256x4,3125) 25,875-138 ( 6-31)KHz

modem DSLAM

138-1104 KHz ( 32-255) DSLAM modem.

splitters

. O Splitter 3

, , modem

. O splitter

ADSL DSLAM

DC

.

splitter .

http://el.wikipedia.org/wiki/Digital_Subscriber_Linehttp://el.wikipedia.org/wiki/2005http://el.wikipedia.org/wiki/Ethernethttp://el.wikipedia.org/wiki/ADSLhttp://el.wikipedia.org/wiki/VDSLhttp://el.wikipedia.org/wiki/%CE%A0%CF%85%CE%BA%CE%BD%CF%89%CF%84%CE%AE%CF%82http://el.wikipedia.org/wiki/%CE%A3%CF%85%CE%BD%CE%B5%CF%87%CE%AD%CF%82_%CF%81%CE%B5%CF%8D%CE%BC%CE%B1http://el.wikipedia.org/wiki/%CE%A4%CE%B7%CE%BB%CE%AD%CF%86%CF%89%CE%BD%CE%BF

ADSL ISDN Annex B

upstream 32-63x4,3125 KHz (138-271,6875 KHz) 64-255

(276-1104 KHz) downstream.

1,1 Mb/s Modem

DSLAM (upstream) 8 Mb/s DSLAM modem (downstream).

downstream

Downstream upstream.

ADSL G.shdsl

2312 Kb/s (2304 ) G.shdsl.bis 5696 Kb/s

,

. G.shdsl

.

ADSL ADSL2 ADSL2+

2208 KHz (512 x 4,3125) downstream

24 Mb/s.

VDSL2

VDSL2 DSL bandplans

,

.

.

30 MHz (3479 tones x 8,625 KHz) 100

Mb/s downstream 100 Mb/s upstream,

17,664 MHz (4096 tones x 4,3125 KHz) 100

Mb/s downstream 50 Mb/s upstream. VDSL2

25,875 8832 KHz ADSL2+ .

ADSL/2/2+ ATM '

Permanent Virtual Circuits (PVC) modems.

ATM cell Ethernet IP ( mode

http://el.wikipedia.org/wiki/Modem

).

Voice over IP

web browsing ftp. VDSL2

' VDSL2

Ethernet IP

VDSL2. PVCs

PVC Voice over IP

data PVC.

DSL

DOCSIS

. DSL

(Kb/s). DSLAM

. DSLAM 1000

ADSL2+ 10 Mb/s

10 Gb/s 1 Gb/s

1 10.

.

DSLAM

DSLAM 1999

. 2003

ATM DSLAMs Siemens Intracom.

Alcatel ZTE IP DSLAMs

2006 Huawei. DSL Vivodi

Cisco DSLAM Ericsson, Forthnet

Alcatel, Tellas Ericsson Alcatel,

Zhone, ON Telecom Marconi/Ericcson, Teledom,

NetOne, Hellas Online iBAS DSLAM Intracom Telecom.

DSL

ADSL

bitstream wholesale ISPs

PVC

VoIP IPTV

( VoIP ). ISPs

(

) ( )

DSLAMs

QoS o wholesale bitestream.

(shared

Local Loop Unbundling Line Sharing),

(full Local Loop Unbundling).

http://el.wikipedia.org/wiki/%CE%91%CE%BC%CE%B5%CF%81%CE%B9%CE%BA%CE%AEhttp://el.wikipedia.org/wiki/%CE%9F%CE%A4%CE%95http://el.wikipedia.org/wiki/1999http://el.wikipedia.org/wiki/%CE%91%CE%B8%CE%AE%CE%BD%CE%B1http://el.wikipedia.org/wiki/%CE%98%CE%B5%CF%83%CF%83%CE%B1%CE%BB%CE%BF%CE%BD%CE%AF%CE%BA%CE%B7http://el.wikipedia.org/wiki/%CE%94%CE%B9%CE%B1%CE%B4%CE%AF%CE%BA%CF%84%CF%85%CE%BF

K DSLAM modems

DSLAMs (

) Huawei, ZTE, - UTStarcom -

Alcatel Lucent, - Nokia Siemens, ZyXEL

Loop Telecom, Teledata Networks ECI Telecom, NEC

Fujitsu, KeyMile, Iskratel, Corecess,

Calix, Allied Telesyn, Adtran, Motorola Tellabs Intracom Telecom.

modems s

hardware

S/W.

DSL chipsets

chipsets Broadcom Ikanos (

2009 Broadband Business Unit Conexant spin-off

Mindspeed GlobespanVirata

Globespan Virata). Analog Devices

chipsets modems. Ikanos DSL Business Division

Centillium Lantiq broadband division Infineon (

Siemens Microelectronics).

SGS-Thomson (ST) division

Alcatel Microelectronics, Freescale (spin-off) Motorola, Texas Instruments

Business Division Infineon.

DSL Amati Communications Corporation " DSL"

Stanford University John Cioffi Aware Executive Chairman .

.

Bandwidth versus distance

Balanced pair cable has higher attenuation at higher frequencies. Therefore, the longer the wire

between DSLAM and subscriber, the slower the maximum possible data rate due to the lower

frequencies being utilized to limit the total attenuation (or due to the higher number of errors at

higher frequencies, effectively lowering the overall frequency/data rate). The following is a

rough guide to the relation between wire distance (based on 0.40 mm copper and ADSL2+

technology) and maximum data rate. Local conditions may vary, especially beyond 2 km, often

necessitating a closer DSLAM to bring acceptable bandwidths:

25 Mbit/s at 1,000 feet (~300 m)

24 Mbit/s at 2,000 feet (~600 m)

23 Mbit/s at 3,000 feet (~900 m)

22 Mbit/s at 4,000 feet (~1.2 km)

21 Mbit/s at 5,000 feet (~1.5 km)

19 Mbit/s at 6,000 feet (~1.8 km)

16 Mbit/s at 7,000 feet (~2.1 km)

8 Mbit/s at 10,000 feet (~3 km)

1.5 Mbit/s at 15,000 feet (4.5 km)

800 kbit/s at 17,000 feet (~5.2 km)

http://el.wikipedia.org/wiki/%CE%A4%CF%83%CE%B9%CF%80%CF%83%CE%B5%CF%84http://el.wikipedia.org/wiki/2009http://en.wikipedia.org/wiki/Attenuationhttp://en.wikipedia.org/wiki/Asymmetric_Digital_Subscriber_Line_2_Plus