1 Branch line on the basis of pdh dts
1.1 Characteristic of the pdh dts transmission line
Characteristic of the PDH DTS transmission line. МКТ-7х4 cable is the symmetrical one, two cables and 7 quads and 4 wires. The capacity of transmission line on the base of a МКТ-7х4 cable is equal to PCM- 120:
NDTS
symmmetrical cable=
NDTS
=
=14
The total quantity of E1 streams in the transmission line is:
Table 1.1 – Basic parameters of PCM- 120
№ |
Parameter |
Value |
1 |
Bitrate of input digital streams, kbps |
2048 |
2 |
Bitrate of a group digital stream, kbps |
8448 |
3 |
Cable type |
МКС 4х4 |
4 |
Maximal length of communication link, km |
600 |
5 |
Quantity of digital streams |
4 |
6 |
Quantity of voice-band channels |
120 |
7 |
Frame frequency, kHz |
8 |
8 |
Re-sync time of frame alignment signal, ms |
0,75 |
9 |
Maximal frequency of justification, Hz |
102 |
10 |
Line path coder type |
HDB-3 or AMI |
11 |
Length of: regeneration section, km section of remote supply, km |
5+/-0,5 200 |
NE1 line = NDTS ∙4 =14 ∙ 4 = 56 (E1)
Let us calculate quantity of the remained E1 streams to the SDH ring:
Nring-1 = NE1 line – ( NSNN-8-DNN-9 + NSNN-8-DNN-10) = 56 – (1+27) = 28
ADE – analog-digital equipment; SO MUX – secondary order multiplexer; LPTE – linear path terminal equipment; LP PCM – linear path with pulse code modulation usage.
Figure 1.1 – The terminal station (TS) structure chart
System
PCM-120 is designed for channels at the local and vnutrizonovyh
networks when using balanced cables SKAP and the ISS. It provides 120
voice frequency channels with a transmission rate of the digital
multicast stream 8448 kbit/s. in addition, it is possible to arrange
four digital channels for digital data transmission with a total
bandwidth of 32 kbit/s the possibility of analog-digital conversion
of the secondary standard groups (...312 552 kHz).
The
required communication range of 600 km, determined by the maximum
possible length of intrazonal network, provide serviced (PPR) and
neabsco - giveme (IUU) regeneration points. The nominal length of the
recovery area is 5km, the Distance between the PPR is determined by
the capabilities of DP maintenance-free regeneration points, equal to
200km. On intra-area networks line path is constructed using two
cables for local networks—one. In a linear path uses the type code
of the COI-3.
In
Fig. 10.10 shows the structural scheme of the organization in
connection with the use of SP IQ M-120. The composition of the
terminal apparatus, the PCM 120 includes equipment secondary
temporary grouppopupmenu (VVG), analog-to-digital conversion of the
signal of the secondary group (atso CRCW), the terminal equipment of
a linear path (OLT) and a set of instrumentation. Line path in
addition to OLT serviceable and maintenance-free regeneration points
and cable.
In
the transmitting part of the equipment VVG formed a group flow with a
transmission rate of 8448 kbit/s by bitwise combining the four
digital streams with a speed of 2048 kbps.
PDBS – primary digital bit stream; SDBS – secondary digital bit stream; GR– group;STG – secondary time grouping; SS – service signals; RJC – rate justificationcommand; CS – control signal; DI – discrete information; NRJ – negative ratejustification; PRJ – positive rate justification; Тfr – frame period.
TS - 1
1
2
.
.
.
480
TS - 2
1
2
.
.
.
480
F
igure
1.2 – DTS frame forming
MKC-7x4
Figure 1.3 – Transmission line on the base of a МКС 7х4
Figure 1.4 – Distribution of E1 streams between network nodes
Figure
1.5 – Situational diagram of transmission line
LP PCM-120
LP PCM-120
LP PCM-120
LP PCM-120
PCM-120
Figure 1.5 – Organizational scheme of SNN8 – DNN10 transmission line