it's simplest pdf describe Mobile network structure to transfer calls between RNC & MGW

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Ahmed Hussien Ali Gomaa Bebars Mobile: 01024614238
Mobile network Structure
Mobile network structure as show in GSM course
We will explain how to transmit call from MS (Mobile station) to another from Transmission view
Transmission
Transmission Method divided three steps
Access layer
Backhaul layer
Core layer
From Site (BTS)HUB (in
most cases HUB locate at
TE (Telecom Egypt
Exchange)
Transport method from Site
to HUB:
1. Fiber
2. Microwave (there
are different
vendors support
Microwave
equipment like as
Ericsson-Huawei-
SIAE-NEC
3. DSL technology
From HUBMTX
MTX refer to place where MSC &
BSC & RNC&GMSC Locate
Transport method from Site to
HUB:
1. Multiplexing technology
(PDH System & SDH
technology)
2. IP Network (MPLS
Network)
Example of Nodes locates at HUB
& MTX:
1. DXX
2. ADM
3. PTN & Tellabs 86xx
From MTXMTX
When MSC or GMSC need connect
Transport method from Site to
HUB:
1. IP Network (MPLS)
Example of Nodes locates at MTX:
1. Routers
2. OSN or any device convert
Packet data to POS (Packet
over SDH) to transfer over
TE network that still use
SDH technology at
transport data

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Ahmed Hussien Ali Gomaa Bebars Mobile: 01024614238
Connection between BSC & MSC & GMSC and other nodes inside MTX connect between them by direct
cable back to back
If two nodes use different protocols we will use transport nodes and also connect by direct cable
TE Cloud
Inside MTX
Inside HUB
SDH Network
Backhaullayer
ACCesslayer

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Ahmed Hussien Ali Gomaa Bebars Mobile: 01024614238
Plesiochronous Digital Hierarchy (PDH): it is old transmission method & use standard frame
E1 European system (32 Ts with rate 2.048 Mb/S)
T1  American System (24 Ts with Rate 1.53 Mb/Sec)
J1 Japan System (24 Ts with Rate 1.53 Mb/Sec)
Note: PDH still transport method used over access layer
When you Multiplex four E1 get E2 & after Multiplex four E2 get E3 & Multiplex E3 get E4 as
maximum rate in this techniques with rate 139 Mb/Sec
SDH (Synchronous Digital Hierarchy): new technology with Basic frame STM1 with Rate 155 Mb/Sec
we can get STM4 (four STM1) & STM16 (Four STM4) & STM64 (four STM16) with rate reach to 10
Gb/Sec
DSL (Digital Subscriber Line) this technology use to Modulate/Demodulate signal over traditional
telephone line
There are different types from DSL (ADSL-HDSL) at Mobile network we use HDSL where download 7
Upload with the same rate
ATM (Synchronous Transfer Mode): new technology use to transfer data & Video & Voice by use
concept cell switching where ATM use cell 53 byte (5 for Header & 48 for data) and use VC (Virtual
Circuit) & VP (Virtual Path) as addressing to route cell inside ATM network
IMA (Inverse Multiplex Technology) this technology use to convert ATM cell into PDH frame to transfer
ATM cell over network use another transport technology
For example:
ATM use BW assign with Mb/Sec, so if you want BW 8 Mb/Sec for ATM cells & we use MW links use
E1 frame to transfer data we will use IMA
MPLS (Multi protocol label Switching): its new technology use to transfer any transport technology
(E1 or FR or ATM) over packet switch network, MPLS actual transport method use now to transport data
at Backhaul network
E1:1
E1:2
E1:3
E1:4
ATM use BW 8 Mb/Sec
IMA

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Ahmed Hussien Ali Gomaa Bebars Mobile: 01024614238
Access layer:
Most common technology used in this layer at Egypt MW links
Any MW links divided into two common parts:
1. ODU (Outdoor Units)
a. RAU (Radio Access Unit)
b. Horn antenna
c. Reflector
d. IF cable (Intermediate frequency cable) use to connect ODU & IDU (this cable Coaxial
cable)
2. IDU (indoor type): there are different types according to Vendor type
a. Ericsson: Mini link E – Traffic Node (TN) – Compact Node (CN) – High cap (HC)
b. Huawei: RTN (Radio Traffic Node)
c. SIAE : Access link compact (ALC PDH- ALC+2-ALC+2e)
d. NEC: Paso link – I Paso Link
Sites connect tin chain connection till reach to HUB MW then connect with Backhaul node with direct
cable
DSL: use DSLAM at HUB & Modem and we use Modem at site I will explain used of them in other part
Backhaul layer:
Use to multiplex all data come from different sites to transport them to MTX and there are different types
from Nodes use in this layer each of them according to transport technology used
1. DXX (Digital Drop Multiplexer): common vendor used in Egypt network Ericsson & use
Tellabs 81xx family. DXX use PDH transport technology and Maximum data transport E4
2. ADM (Add drop Multiplexer): also common vendor node used Ericsson & use Tellabs 64xx
family Nodes
3. Tellabs 86xx family new node from Ericsson use MPLS transport technology to transport data at
Backhaul layer (engineer at Egypt field called it BEP Node, where BEP is Backhaul evaluation
Project)
4. PTN (Packet Transport Node) 6900 series from Huawei use MPLS technology to transport
data
PTN & Tellabs 86xx connect with RNC (Ericsson) by direct ATM Ports
BSC (Ericsson) Connect with ADM then ADM Connect with PTN or Tellabs 86xx
BSCH & RNCH (Huawei) connect direct with PTN node