4/11/40 page 1 Department of Computer Engineering, Kasetsart University Introduction to Computer Communications and Networks CONSYL Digital Carrier Systems

4/11/40 page 2 Department of Computer Engineering, Kasetsart University Introduction to Computer Communications and Networks CONSYL Digital carrier standard T-carrier T-carrier North America, Japan E-carrier E-carrier Europe, Mexico, South America

4/11/40 page 3 Department of Computer Engineering, Kasetsart University Introduction to Computer Communications and Networks CONSYL T1 carrier system PCM MUX DEMUX DS-1 frame

4/11/40 page 4 Department of Computer Engineering, Kasetsart University Introduction to Computer Communications and Networks CONSYL DS-1 frame channel #1 channel #1 channel #2 channel # channel #24 channel #24 framebit 193 bits data rate = (24x8 +1 bit)/125  s = Mbps 8 bit each channel also refers as DS0 each channel also refers as DS0 125  s

4/11/40 page 5 Department of Computer Engineering, Kasetsart University Introduction to Computer Communications and Networks CONSYL T - carrier DSI DSIC DS2 DS3 DS4 DSIC DS2DS2DS2DS2DS2DS2 DS3DS3DS3DS3DS3 DSI Two Mbps DS1 channels are multiplexed into a single Mbps DS1C channel Two DS1C channels are multiplexed into a single Mbps DS2 channel Seven DS2 channels are multiplexed into a single Mbps DS3 channel Six DS3 channels are multiplexed into a single Mbps DS4 channel

4/11/40 page 6 Department of Computer Engineering, Kasetsart University Introduction to Computer Communications and Networks CONSYL E1-frame  s = 32 time slots = Mbps frame synchronization signaling channel 30 voice channel+2 control channel

4/11/40 page 7 Department of Computer Engineering, Kasetsart University Introduction to Computer Communications and Networks CONSYL E - carrier E1E1E1E1 E2E2E2E2 E3E3E3E3 E4E4E4E4 E5 Thirty 64 kbps channels are multiplexed to create one Mbps E1 channel Four E1 channels are multiplexed into a single Mbps E2 channel Four E2 channels are multiplexed into a single Mbps E3 channel Four E3 channels are multiplexed into a single Mbps E4 channel Four E4 channels are multiplexed into a single Mbps E5 channel

4/11/40 page 8 Department of Computer Engineering, Kasetsart University Introduction to Computer Communications and Networks CONSYL Digital carrier comparison J1 E1 T1 J2 E2 T2 J3 E3 T3 J4 E4 T4 J5 E5 x31 x24 x 4 x 7 x 5 x 4 x 6 x 3 x 4 Europ e USA Japan

4/11/40 page 9 Department of Computer Engineering, Kasetsart University Introduction to Computer Communications and Networks CONSYL PDH Digital tramsmission systems (T-carrier, E carrier) combine lower order multiplex stream to get higher bit rate Different streams have small differences in clock signals. Solve by adding justification bit PDH = Plesiochronous Digital Hierachy almost synchronous

4/11/40 page 10 Department of Computer Engineering, Kasetsart University Introduction to Computer Communications and Networks CONSYL PDH Network A B C ADM Customer site Logical network LTE = Line termination equipment ADM = Add-drop multiplexer

4/11/40 page 11 Department of Computer Engineering, Kasetsart University Introduction to Computer Communications and Networks CONSYL PDH deficiencies (I) 140 M LTE M LTE 34 Mbps 8 Mbps 2 Mbps Customer site Lack of flexibility impossible to identify a lower bit rate channel from the higher-order bit stream. demux the high bit rate down to the lower level remux back into higher level for onward transmission Extraction of 2 Mbps channel from 140 Mbps channel

4/11/40 page 12 Department of Computer Engineering, Kasetsart University Introduction to Computer Communications and Networks CONSYL PDH deficiencies (II) Lack of performance No standard for monitoring the performance of traffic channel No management channel

4/11/40 page 13 Department of Computer Engineering, Kasetsart University Introduction to Computer Communications and Networks CONSYL PDH deficiencies (III) Lack of 慚 id-Fibre meet undefined interface specification on the line side of a line transmission LTE G.703 interface non standard line code and optical levels standard Network Node Interface (NNI) functional integration of MUX and LTE PDH SDH

4/11/40 page 14 Department of Computer Engineering, Kasetsart University Introduction to Computer Communications and Networks CONSYL SDH & SONET What is SDH/SONET ? What is SDH/SONET ? Standard interface developed for using in the public network multiplexing standard for optical fiber transmission SONET = Synchronous Optical Network refers to the system used within the U.S. and Canada SDH = Synchronous Digital Hierarchy international community term (ITU-T recommendtions)

4/11/40 page 15 Department of Computer Engineering, Kasetsart University Introduction to Computer Communications and Networks CONSYL SDH goals Goals Goals make it possible for different carrier to interwork unify the U.S., European and Japanese digital system Provide a way to multiplex multiple digital signal togethers provide support for operations, administration, and maintenace Characteristics use single master clock to synchronize Bit stream can be a added or extracted directly Basic transmission rate = Mbps

4/11/40 page 16 Department of Computer Engineering, Kasetsart University Introduction to Computer Communications and Networks CONSYL Signaling rates SONETSDH Bit rate (Mbps) STS-1/OC STS-3/OC-3STM STS-9/OC-9STM STS-12/OC-12STM STS-18/OC-18STM STS-24/OC-24STM STS-36/OC-36STM STS-48/OC-48STM STS = Synchronous Transport Signal OC = Optical Carrier STM = Synchronous Transport Module

4/11/40 page 17 Department of Computer Engineering, Kasetsart University Introduction to Computer Communications and Networks CONSYL Synchronous Container 1.5 Mbps 2 Mbps 6 Mbps Each PDH stream is carried in an appropiate container container 1.5 Mbps 2 Mbps 6 Mbps PDH signal 1.5 Mbps 2 Mbps 6 Mbps virtual container Path overhead for monitoring 抯 purpose

4/11/40 page 18 Department of Computer Engineering, Kasetsart University Introduction to Computer Communications and Networks CONSYL Syncronization 抯 techniques phase offset in byte directly access signal signal using pointer data begins anywhere in frame pointer data #1 data #2 POH #1 POH #2 sample frame frame #1 frame #2

4/11/40 page 19 Department of Computer Engineering, Kasetsart University Introduction to Computer Communications and Networks CONSYL SONET System consists of switches, mux and repeaters consists of switches, mux and repeaters section line path mux repeaters repeaters mux mux

4/11/40 page 20 Department of Computer Engineering, Kasetsart University Introduction to Computer Communications and Networks CONSYL SONET Basic Frame structure 1 frame = 810 bytes in 125  s STS-1/OC1 3 bytes 87 bytes SOH LOH Payload 3 bytes 6 bytes 9 bytes TOH Overhead : for system management information SOH = Section Overhead LOH = Line Overhead TOH = Transport Overhead Payload : user data row/column mapping

4/11/40 page 21 Department of Computer Engineering, Kasetsart University Introduction to Computer Communications and Networks CONSYL SDH Basic Frame structure 1 frame = 2430 bytes in 125  s STM-1 9 bytes 261 bytes SOH LOH Payload 3 bytes 6 bytes 9 bytes TOH Overhead : for system management information (OAM) SOH = Section Overhead LOH = Line Overhead TOH = Transport Overhead Payload : user data row/column mapping

4/11/40 page 22 Department of Computer Engineering, Kasetsart University Introduction to Computer Communications and Networks CONSYL STM-1 Frame 9 bytes 261 bytes SOH LOH pointer SOH LOH pointer frame #1 frame #2 Payload #1 Payload #2 POH #1 POH #2

4/11/40 page 23 Department of Computer Engineering, Kasetsart University Introduction to Computer Communications and Networks CONSYL SOH, LOH and POH A1 A2 C1 J1 B1 E1 F1 B3 D1 D2 D3 C2 H1 H2 H3 G1 B2 K1 K2 F2 D4 D5 D6 H4 D7 D8 D9 Z3 D10 D11 D12 Z4 Z1 Z2 E2 Z5 section overhead line overhead path overhead transport overhead STS-1 information payload 3 columns 87 columns 9 rows

4/11/40 page 24 Department of Computer Engineering, Kasetsart University Introduction to Computer Communications and Networks CONSYL SDH mux scheme AUG AU-4 VC-4 TUG-3 TU-3 VC-3 C-4 VC-3 AU-3 TUG-2 TU-2 VC-2 C-2 TU-12 VC-12 C-12 TU-11 VC-11 C-11 C-3 x1 x3 x7 x1 x3 x4 140 Mbps 45 Mbps 34 Mbps 6 Mbps 2 Mbps 1.5 Mbps STM-1 SONET-specific Europe-specific Universal PDH Tributaries

4/11/40 page 25 Department of Computer Engineering, Kasetsart University Introduction to Computer Communications and Networks CONSYL Administrative Unit Tributary Unit Group SDH Elements Containers Virtual Containers Tributary Unit Administrative Unit Administrative Unit Group path overhead pointer Tributary Unit Group Tributary Unit section overhead STM-1

4/11/40 page 26 Department of Computer Engineering, Kasetsart University Introduction to Computer Communications and Networks CONSYL Containers mapping fixed stuff alignment signaling fixed stuff containers #bytes capacity C C C C C sample C2 mapping C-12 E1

4/11/40 page 27 Department of Computer Engineering, Kasetsart University Introduction to Computer Communications and Networks CONSYL Containers, VC & TU C-11 C-12 C-2 VC-11 VC-12 VC-2 TU-11 TU-12 TU-2 plus POH plus pointer 9 bytes 3 bytes 4 bytes 12 bytes

4/11/40 page 28 Department of Computer Engineering, Kasetsart University Introduction to Computer Communications and Networks CONSYL TU-X format bytes 36 bytes 108 bytes TU-11 TU-12 TU-2 3 columns 9 rows 4 columns 9 rows 12 columns 9 rows 125  s 1728 kbps 2304 kbps 6912 kbps

4/11/40 page 29 Department of Computer Engineering, Kasetsart University Introduction to Computer Communications and Networks CONSYL TUG-2 to VC POH VC-3 TUG-2 4xTU-11 3xTU-12 1xTU-2 7xTUG2 9 bytes 12 bytes total 85 columns TUG-2 may be 4xTU-11 3xTU-12 1xTU-2

4/11/40 page 30 Department of Computer Engineering, Kasetsart University Introduction to Computer Communications and Networks CONSYL AU-3 to AUG J1 B3 C2 G1 F2 H4 Z3 Z4 Z5 J1 B3 C2 G1 F2 H4 Z3 Z4 Z5 J1 B3 C2 G1 F2 H4 Z3 Z4 Z J1 B3 C2 G1 F2 H4 Z3 Z4 Z5 J1 B3 C2 G1 F2 H4 Z3 Z4 Z5 J1 B3 C2 G1 F2 H4 Z3 Z4 Z H1 H2 H3 A B C A B C A B C A B C A B C VC-3 plus 2 column fixed stuff AU-3 3xAU-3 to AUG

4/11/40 page 31 Department of Computer Engineering, Kasetsart University Introduction to Computer Communications and Networks CONSYL TUG-3 to VC-4 C-3 VC-3 TU-3 TUG-3 TU-3 PTR justification bytes total 260 columns POHPOH 3xTUG-3 VC-4 fixed stuff

4/11/40 page 32 Department of Computer Engineering, Kasetsart University Introduction to Computer Communications and Networks CONSYL High order mux Nx9 Nx261 MUX STM-1 #1 STM-1 #2 STM-1 #N byte interleave stream

4/11/40 page 33 Department of Computer Engineering, Kasetsart University Introduction to Computer Communications and Networks CONSYL 1xOC3 and 3xoC1 OC3 = 3xOC1 OC3 = 3xOC1 a Mbps carriers consisting of 3 separated OC3 carriers OC3c = 1X155.52Mbps carriers OC3c = 1X155.52Mbps carriers a data stream from single source of Mbps Higher-order frames also exist (e.g. OC12c). The amount of actual user data in an OC3c stream is slighly higher thanin an OC-3 stream!