Examples of Communication Systems/xDSL Systems - Revision history

Guenter at 09:13, 22 March 2023

2023-03-22T09:13:27Z

Hwang at 19:07, 21 March 2023

2023-03-21T19:07:55Z

Hwang at 19:05, 21 March 2023

2023-03-21T19:05:51Z

Hwang at 18:57, 21 March 2023

2023-03-21T18:57:48Z

Hwang at 18:52, 21 March 2023

2023-03-21T18:52:19Z

Guenter at 16:44, 17 March 2023

2023-03-17T16:44:19Z

Guenter at 16:49, 14 March 2023

2023-03-14T16:49:52Z

Guenter at 16:29, 9 March 2023

2023-03-09T16:29:39Z

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Guenter at 18:02, 8 March 2023

2023-03-08T18:02:29Z

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Noah at 13:57, 7 March 2023

2023-03-07T13:57:25Z

@@ Line 62: / Line 62: @@
 ==ADSL – Asymmetric Digital Subscriber Line ==
 <br>
-[[File:EN_Bei_T_2_2_S4.png|right|frame|ADSL connection from the end customer to the local exchange<br> '''KORREKTUR''']]
+[[File:EN_Bei_T_2_2_S4.png|right|frame|ADSL connection from the end customer to the local exchange]]
 The physical network termination&nbsp; $\rm (NT)$&nbsp; is in the ADSL modem&nbsp; $($"ADSL Transmission Unit Central Office",&nbsp; $\text{ATU-C)}$&nbsp; in the local exchange.&nbsp; Before that,&nbsp; in the&nbsp; "splitter"&nbsp; the low-frequency telephony spectrum is separated from the higher-frequency ADSL spectrum by low-pass and high-pass filtering.
@@ Line 110: / Line 110: @@
 <br>
 In terms of the basic structure of their components,&nbsp; VDSL systems are identical to ADSL systems,&nbsp; with the only exception that the relocation of the splitter and the DSLAM from the local exchange to a cable branch makes the last section between the network operator and the customer,&nbsp; the so-called&nbsp; "last mile".
-[[File:EN_Bei_T_2_2_S5_v8.png|right|frame|Modeling of a VDSL connection from the end customer to the local exchange '''KORREKTUR''']]
+[[File:EN_Bei_T_2_2_S5_v8.png|right|frame|Modeling of a VDSL connection from the end customer to the local exchange]]

@@ Line 132: / Line 132: @@
 Following a few characteristics of the&nbsp; $\rm VDSL(2)$&nbsp; system:
 #VDSL(2) has achieved  since 2006 a maximum transmission rate of&nbsp; $50$&nbsp; to&nbsp; $100$&nbsp; Mbit/s,&nbsp; depending on the standard used.
-#The specified VDSL(2) transmission bandwidth of&nbsp; $30$nbsp; MHz was considered the maximum reasonable bandwidth in 2009.
+#The specified VDSL(2) transmission bandwidth of&nbsp; $30$&nbsp; MHz was considered the maximum reasonable bandwidth in 2009.
 #With complementary measures such as&nbsp; "Dynamic Spectrum Management"&nbsp; and "Advanced Codes"&nbsp; total transmission rates of up to&nbsp; $280$ Mbit/s&nbsp; were expected for short line lengths&nbsp; $($up to&nbsp; $300$&nbsp; meters$)$.}}

@@ Line 110: / Line 110: @@
 <br>
 In terms of the basic structure of their components,&nbsp; VDSL systems are identical to ADSL systems,&nbsp; with the only exception that the relocation of the splitter and the DSLAM from the local exchange to a cable branch makes the last section between the network operator and the customer,&nbsp; the so-called&nbsp; "last mile".
-[[File:EN_Bei_T_2_2_S5_v8.png|right|frame|Modeling of a VDSL connection from the end customer to the local exchange]]
+[[File:EN_Bei_T_2_2_S5_v8.png|right|frame|Modeling of a VDSL connection from the end customer to the local exchange '''KORREKTUR''']]

@@ Line 62: / Line 62: @@
 ==ADSL – Asymmetric Digital Subscriber Line ==
 <br>
-[[File:EN_Bei_T_2_2_S4.png|right|frame|ADSL connection from the end customer to the local exchange<br>]]
+[[File:EN_Bei_T_2_2_S4.png|right|frame|ADSL connection from the end customer to the local exchange<br> '''KORREKTUR''']]
 The physical network termination&nbsp; $\rm (NT)$&nbsp; is in the ADSL modem&nbsp; $($"ADSL Transmission Unit Central Office",&nbsp; $\text{ATU-C)}$&nbsp; in the local exchange.&nbsp; Before that,&nbsp; in the&nbsp; "splitter"&nbsp; the low-frequency telephony spectrum is separated from the higher-frequency ADSL spectrum by low-pass and high-pass filtering.

@@ Line 44: / Line 44: @@
 #The systems for&nbsp;  $\rm ADSL$&nbsp; and&nbsp;  $\rm ADSL$&nbsp; shown below represent the most common implementation.&nbsp; Data transport at the protocol level is based on the&nbsp; $\rm ATM$&nbsp; technology&nbsp; $($"Asynchronous Transfer Mode"$)$.
 #Despite a large data overhead,&nbsp; ATM still offers advantages over&nbsp; "Ethernet"&nbsp; in terms of guaranteed quality of service&nbsp; $\rm (QoS)$,&nbsp; i.e. effective bit rate,&nbsp; low delay and jitter.
-#Ethernet,&nbsp; on the other hand,&nbsp; enables very high data transmission rates,&nbsp; especially through the&nbsp; &raquo;'''10 Gbit/s Ethernet'''&laquo;&nbsp; and&raquo;'''100 Gbit/s Ethernet'''&laquo;&nbsp; $($"Metro Ethernet"$)$&nbsp; variants.&nbsp; ATM,&nbsp; on the other hand,&nbsp; is more suitable for lower data rates.
+#Ethernet,&nbsp; on the other hand,&nbsp; enables very high data transmission rates,&nbsp; especially through the&nbsp; &raquo;'''10 Gbit/s Ethernet'''&laquo;&nbsp; and &raquo;'''100 Gbit/s Ethernet'''&laquo;&nbsp; $($"Metro Ethernet"$)$&nbsp; variants.&nbsp; ATM,&nbsp; on the other hand,&nbsp; is more suitable for lower data rates.
 #In 2009 there were numerous discussions about whether ATM should be replaced by&nbsp; "10 Gbit/s Ethernet"&nbsp; in the course of&nbsp; "Next Generation Network".&nbsp; However,&nbsp; upgrading the backbone from ATM to Ethernet represents a not inconsiderable investment.

@@ Line 26: / Line 26: @@
 In an example,&nbsp;  the configuration most frequently encountered in Germany is shown according to the graphic.&nbsp; Note:
-[[File:P_ID1919__Bei_T_2_2_S1b_v2.png|right|frame|Reference model according to&nbsp; "$\text{1TR112 U-R2-V7.0 DTAG}$"]]
+[[File:EN_Bei_T_2_2_S1b_v8.png|right|frame|Reference model according to&nbsp; "$\text{1TR112 U-R2-V7.0 DTAG}$"]]
 *In all xDSL variants deployed today,&nbsp; the data service converted in the modems is combined with the telephone service.&nbsp; This allows transmission over the existing telephone network.
@@ Line 110: / Line 110: @@
 <br>
 In terms of the basic structure of their components,&nbsp; VDSL systems are identical to ADSL systems,&nbsp; with the only exception that the relocation of the splitter and the DSLAM from the local exchange to a cable branch makes the last section between the network operator and the customer,&nbsp; the so-called&nbsp; "last mile".
-[[File:P_ID1920__Bei_T_2_2_S5_v1.png|right|frame|Modeling of a VDSL connection from the end customer to the local exchange]]
+[[File:EN_Bei_T_2_2_S5_v8.png|right|frame|Modeling of a VDSL connection from the end customer to the local exchange]]
 This measure was necessary because VDSL can only exploit its advantage&nbsp; &ndash; the greater transmission speed &ndash;&nbsp; over very short distances due to the attenuation of the higher frequencies,&nbsp; which increases sharply with line length.
-DSLAM and BBRAS are still connected via&nbsp; [https://en.wikipedia.org/wiki/STM-1 $\text{STM-1}$&nbsp; interfaces.&nbsp; Therefore,&nbsp; the route between the local exchange and the cable branch must now also be laid with optical fiber.
+DSLAM and BBRAS are still connected via&nbsp; [https://en.wikipedia.org/wiki/STM-1 $\text{STM-1}$]&nbsp; interfaces.&nbsp; Therefore,&nbsp; the route between the local exchange and the cable branch must now also be laid with optical fiber.
 A distinction is made between two alternative VDSL variants:
@@ Line 139: / Line 139: @@
 <br>
 Some xDSL modems offer an&nbsp; Ethernet interface for connecting the data terminals and a transparent connection to the remote terminal,&nbsp; based on the&nbsp; "Internet Protocol"&nbsp; $\rm (IP)$.&nbsp; The following should be noted:
-[[File:EN_Bei_T_2_2_S6.png|right|frame|Modeling of an xDSL connection through the use of an xDSL router]]
+[[File:EN_Bei_T_2_2_S6b_v8.png|right|frame|Modeling of an xDSL connection through the use of an xDSL router]]

@@ Line 8: / Line 8: @@
 ==Reference models==
 <br>
-[[File:EN_Bei_T_2_2_S1.png|right|frame|xDSL reference model of the ITU]]
+[[File:EN_Bei_T_2_2_S1_v3.png|right|frame|xDSL reference model of the ITU]]
 Based on the following general ITU reference model,&nbsp; it can be quickly seen that xDSL is physically a pure access transmission technology that is only used in the local loop network area between the fiber termination point and the network termination at the end customer.
@@ Line 62: / Line 62: @@
 ==ADSL – Asymmetric Digital Subscriber Line ==
 <br>
 The physical network termination&nbsp; $\rm (NT)$&nbsp; is in the ADSL modem&nbsp; $($"ADSL Transmission Unit Central Office",&nbsp; $\text{ATU-C)}$&nbsp; in the local exchange.&nbsp; Before that,&nbsp; in the&nbsp; "splitter"&nbsp; the low-frequency telephony spectrum is separated from the higher-frequency ADSL spectrum by low-pass and high-pass filtering.
 The graphic shows an ADSL connection from the end customer to the local exchange,&nbsp; which is described very briefly below.&nbsp; The reverse data connection paths are in each case mirror-inverted.
 *The splitter forwards the telephone signals to the ISDN/POTS exchange and the ADSL signals to the&nbsp; "digital subscriber line access multiplexer"&nbsp; $\rm (DSLAM)$,&nbsp; in which the&nbsp; "$\text{ATU-C}$"&nbsp; is implemented as a plug-in card.
@@ Line 138: / Line 139: @@
 <br>
 Some xDSL modems offer an&nbsp; Ethernet interface for connecting the data terminals and a transparent connection to the remote terminal,&nbsp; based on the&nbsp; "Internet Protocol"&nbsp; $\rm (IP)$.&nbsp; The following should be noted:
-[[File:P_ID1922__Bei_T_2_2_S6b_v3.png|right|frame|Modeling of an xDSL connection through the use of an xDSL router]]
+[[File:EN_Bei_T_2_2_S6.png|right|frame|Modeling of an xDSL connection through the use of an xDSL router]]
@@ Line 157: / Line 158: @@
 Finally,&nbsp; necessary components for a DSL connection are listed.&nbsp; The graph shows examples of these,&nbsp; mostly from&nbsp; "Deutsche Telekom".
 $\rm NTBA$:&nbsp; The commonly used term is&nbsp; "Network Termination for ISDN Basic Rate Access".&nbsp;  Tasks of the NTBA are:

@@ Line 127: / Line 127: @@
 [[File:P_ID1922__Bei_T_2_2_S6b_v3.png|left|frame|Modeling of an xDSL connection through the use of an xDSL router]]
 <br><br>
-In the second graphic, a $\rm xDSL router$&nbsp; is used as the xTU-R interface.
+In the second graphic, an $\rm xDSL\:router$&nbsp; is used as the xTU-R interface.
 *This enables the connection of multiple terminals in a network with shared xDSL line.
 *Here, instead of the modem, a router initializes the&nbsp; ''Point-to-Point-Protocol-over-Ethernet'' connection.