The document discusses key concepts related to Next Generation Networks (NGN). It describes the NGN reference architecture which includes a transfer network to carry information flows, a network control for establishing links, and service control related to the final service provided to users. It also discusses NGN services, quality of service parameters, mobility, nomadism, presence management, resource control, identification and authentication, metering and monitoring, and security issues in NGN. Finally, it provides examples of NGN soft switch architecture and BSNL's migration strategy to NGN.
2. Changing Telecoms Trends
Fixed line usage is reducing dramatically for “Classical
Services”
Mobile use is increasing steadily even though
penetration is already high.
Broadband Internet deployment shows a rapid growth
trend.
As per statistical result IP traffic increases 10 fold every
year while voice traffic is relatively flat.
7. Services
The NGN architecture supports different services
Such as:-
1. Multimedia services
2. Content delivery services such as video
streaming and broadcasting.
3. NGN provides support for PSTN/ISDN
replacement.
4. In addition, the NGN provides infrastructure for
Value Added Service addition by 3rd party.
8. •The NGN concept takes into consideration new
realities in the telecommunication industry
characterized by factors such as the need to converge
and optimize the operating networks and the
extraordinary expansion of digital traffic.(i.e.
increasing demand for new multimedia services,
increasing demand for mobility, etc.)
• NGN also aims to tackle important concerns
raised from the use of current IP-based services: (i.e.
QoS and security)
Why NGN?
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9. NGN also aims to tackle important concerns raised
from the use of current IP-based services: (i.e. QoS and
security) :-
QoS Parameters
1. Delay (Latency): Time taken to send a packet
from sender to receiver node.Max allowed delay
between sender to receiver is 150 ms.
2. Jitter : Delay variations between packets arrived
at a receiver as compared to the packets spacing
at the sender. Jitter buffer should not exceed 50
ms.
3. Packet Loss.Up to 5% packet loss is affordable.
Why QoS?
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10. Standard QoS for different application.
Traffic Type Bandwidth Maximum
Packet
Loss
Max.
delay
Max. jitter
Video conferencing 100 KBPS 1% 150ms 30ms
VOIP 12to106 KBPS 1% 150ms 30ms
Streaming
Video(MPEG-4)
0.005to10MBPS 2% 5000ms insensitive
Streaming Audio(MP-3) 32 to 320 KBPS 2% 5000ms insensitive
Data Variable sensitive insensitive insensitive
(1) Video-conferencing is sensitive to delay and jitter.
(2) Non real-time streamed multimedia less sensitive to delay, and because it is
making use of error recovery techniques, it is less sensitive to packet loss.
(3) Data applications are not sensitive to delay and jitter, but packet loss may be
critical factor.
11. Speech Quality
• Mean Opinion Score ( MOS )
• An ITU rec P.800
• Grades
5 – Excellent
4 – Good -- ( BSNL Plan > 4.0)
3 – Fair
2 – Poor
1 – Bad
• Round Trip Delay < 300 ms.
12.
13. NGN reference architecture
1. The transfer network carries out the transport in
the form of packets, of information flows
interchanged between peripheral units, user
terminals and service provider servers:
2. The network control includes the functions
necessary to establish the links needed to transfer
information in conformity with request from the
applications, whether these be implemented by
users, operators or service providers.
3. The Service control not an integral part of network
is related to the final service provided for the user.
14. Connection unit
(Access Node,
Access Muxer,
Access Gateway)
and classified in
terms of base
stations and base
station controller
for radio access,
DSLAM for ADSL
access,
distribution centre
for cable network,
etc.
The aggregation functions in linking connection
units to the peripheral units to the peripheral
routing nodes at which level communication
between users are setup. It is independent of
connection technologies Peripheral routing: It
terminates customers virtual access and
handles the elementary information flows they
carry by sorting, classifying and finally routing
them either individually to local customers
(connected upto same routing node) or in
groups to the network core. As well as handling
information flows, routing extracts the control
flows sent by customers and directs them to the
network control.
The core
network, a
very high
speed
meshed
network that
handles the
aggregated
flows that
are
transported
through
various
channels.
15. Network control
• Mediation: Accessing services in a competitive
environment:
• The mediation function represents the interface
between customers and service providers. It
takes the form of a portal which will enable
interchanges with the customer by calling on
different technologies depending upon the
terminal used : HTML pages on PC, WML on a
mobile phone, audio on a fixed telephone, etc.
through this portal customers can navigate
among the components of their service package,
either to use them or manage them.
16. MOBILITY
• Under the concept of mobility, the most
obvious aspect is radio access networks
allowing users to communicate from
wherever they happen to be through a
terminal they carry with them, and to move
about during the communication. Mobility
being a term reserved for the ability to
move around during a single session.
17. NOMADISM
• Nomadism means a user being able to get through to his
communication and information retrieval services from
different physical accesses, whether they be different
terminals with different identifications and capabilities or
different network access interfaces and local loop operators.
• Yet nomadism, unlike mobility, is not really concerned with
the continuity of an access or communication session.
• In the standardization of UMTS, there is a definition of the
concept of ‘VHE’, or Virtual Home Environment, that has the
objective of giving the user a consistent impression of the
execution, the presentation and the management of his
services, no matter where he may be located, no matter
what type of access and terminal he is using and no matter
which network is being visited.
18. Managing presence: in the
network, in the services, or both
• In traditional telephone networks, the status of the user
was simply ‘free’ or ‘busy’ and was supplied only after a
call was made.
• Presence management, however, consists in
permanently posting the status that the user of the
network wishes to make known to others:
• ‘I can be contacted by members of my sports club’, etc.
The concept the potential to transform the way people
communicate, and theoretically could be applied to all
forms of communications.
• It could also be shared by many services and thus
become, at least in part, one of the generic control
functions associated with the network.
19. Controlling resources
• Controlling performed at two levels, that of the global
network and that of the equipment, and corresponds to
several entities: physical link, virtual circuit, address,
transmission rate, memory capacity, etc.)
• Although it is an important characteristic of NGN, this
‘de-correlation’ is nevertheless difficult to apply, and this
is one of the reasons for the continuing variations in
vocabulary used to describe this function: ‘ Gatekeeper’,
‘Call Server’, ‘ Policy Server’, or ‘Session Server’ are all
used for sets of functions that are not always identical.
• Even though the above definition is evocative of
information transfer in particular, the control of resources
also concerns other types of equipment that may be
used in applications ( voice servers, cache servers,
transcoders, etc.)
20. CONTROLLING SERVICES
Each service is controlled in a specific way. Algorithms and
data are combined to enable the implementation of end
services between two customers or between a customer and
a server.
For example , for a VoD service, the user I given a choice of
commands for selecting, then navigating within a movie
supplied by a provider , using such command as fast forward,
rewind, pause etc. which are commonly used on a VCR or
DVD player.
Service control is not part of the network, but uses it so that
the media component of the service transferred between the
terminals and the servers with the expected quality of service
and with a minimum of constraints regarding location of
customers and providers.
21. IDENTIFICATION AND
AUTHENTICATION
• The identification function consists in establishing the link between a
terminal that accesses a network, the user of such a terminal and a
customer who has a contract with a network or service operator.
This customer may be represented by an anonymous account. Such
is the case, for example, with anonymous pre-paid communications,
where the contract is implicit.
• This identification may be authenticated in order to reduce the risk of
forgery and to ensure the identification of a terminal matches its
associated physical address and its user. In conventional telephony,
for call set-up purposes, identification is deduced from the address
of the subscriber’s copper line and no authentication is performed.
• On GSM and UMTS mobiles, identification is carried out through the
SIM card and authenticated through the PIN code.
• For Internet applications, including access, the still prevalent, simple
pair of operations ‘ login/password’ gives an authenticated
identification.
22. METERING AND MONITORING
In the simplest cases, the local exchange of a PSTN measures the
duration of the communications, and billing then depends on this
duration and on the number dialed. The circuit-mode structure of the
network automatically ensures that the service contract is respected and
no other verification is necessary. The situation became more
complicated once rerouting mechanisms were introduced and the
metering was effectively distributed.
Providing means to control and count the resources used in an access
or service session is the business of service and network control, and
the existence of this metering and monitoring has strong consequences
for the service and network architecture.
The distribution of control and the possibility of establishing different
qualities of service at the same interfaces seriously complicate the
implementation of this monitoring and metering as well as the possibility
of forwarding the related data without any distortion up to contractual
points of reference.
In the conventional circuit or packet networks, local contractual metering
was considered sufficient, as long as what passed for a contract could
be deduced from what actually happened on that access.
23. Signaling was used to trace the metering information
back to the origin of the call, but disruptions can
upset this process, and can lead to the need to
abandon the service.
In routed packet (IP) networks, it is also at access that either
the time or the quantity of packets transmitted can be
measured , but it is very difficult to check that an end-to-end
quality of service contract has been strictly respected, and it
comes back to ensuring beforehand, through the resource
control, that the architecture will guarantee that the contract is
respected In fact, it is easier today to establish contracts
making available large capacities of resources between
network or service operators than to verify the dynamic and
distant consumption of such resources by individual users.
This situation may be improved by distributed
metering and post hoc verification or payment, but
the major difficulty, between integrating control and
metering, remains the generalization of pre-payment
possibilities to all types of services.
24. Security issues
Denial of services: It should possible to
prove that the user has used the
service.
Invasion of Privacy: The user data sent
over the network should be fully
protected. Suitable encryption codes
are used.
Theft of service: Without charge
service use should not be possible.
27. Trunk Media Gateway
PLMN
PSTN
MPLS
TMGW
IP MPLS
MG connects different types of networks, one
of its main functions is to convert between
the different transmission and coding
techniques.
28. Application Servers (AS) Can be broken
apart and distributed in the network
CORBA is Common Object
request Broker
Architecture.
It defines APIs,
communication protocol, and
object/service information
models to enable
heterogeneous applications
written in various languages
running on various platforms
to interoperate.
LDAP-Lightweight
Directory Access Protocol
31. Class 4 Switch
• Commonly known a “Long Distance”
switch or TAX
• Primarily interconnects with E1 lines and
larger
• Owned and operated by LD carriers
• Interconnected to other class 4 switches
and Class 5 switches.
• Provide the backbone of the PSTN
32. Control switch perform call control, routing
Signaling, protocol
Mediation and CDR
Generation.
I-Gate Media gateway
provide switching
platform through
which traffic between
TDM port is switched
and carried.
MGCP/H.248
protocol control the
soft switch for the
call establishment
& release process
35. Class 5 Switch
• Commonly known as a “Local” switch
• Provides local phone service to a
metropolitan area.
• Examples are a 5ESS or OCB-283
• Handles a large number of individual
phone lines.
• Provides enhanced features such as call
waiting, 3 way calling and caller ID.
36. Migration Strategy of BSNL :
• Introduce IP in Transit network at Level-1 TAX
locations (IP TAX Project) - Class 4 NGN.
• Extend IP network to Level-2 TAXs and large
scale implementation in Access Network. –
Class 5 NGN
• Develop MPLS core at Circle and LDCA Level.
• Offer Voice and Multimedia services to
Broadband Subscribers using DSL, Optical
Ethernet technologies.
37. Existing PSTN network in an Area
PSTN)
Remote Access
Unit
MGC
feature
MSU-1
....
MSU-2 MSU-3 MSU-4 MSU-5 MSU-6 MSU-7 MSU-8 MSU-9 MSU-n
Local Access
Unit
38. MGC
feature
.... ....
IP network
TGW
TGW
Soft SwitchSoft Switch
Introduction of two Soft-Switches & NGN class 5
LAGW
IP-LGW PCB plugged into
existing CSN = LAGW to
implement class 5
applications.
In LAGW Ethernet replaces
E1 interface
Access
Unit
Line Access
Gateway Unit
TDM Network
n- MSU are replaced by multiple Soft
Switches while keeping all existing
Subscribers Units.
39. From CSN Access Node to CSN Line Access Gateway (1/2)
TDM Network
Subscriber
line MDF
CS
N
DDF
Alcatel switches (OCB283)E1
1)
Subscriber
line MDF
CS
N
DDF
OCB283 replaced by NGN Soft-
Switches for class 5 application
IP network
2)
TGWE1 TGW
Disconnection of
E1 linksSubscriber
line MDF
CS
N IP network
3)
TGW TGW
40. Subscriber
line MDF CSN-IP
IP network
4)
Connection of the CSN-IP to the
MPLS network for class 5
application
From CSN Access Node to CSN Line Access GateWay (2/2)
Plug-In two PCB to convert it in IP
Line Access GateWay
41. Network Elements of BSNL-NGN
• Soft Switch
– Hardware
– Software
• Signaling Gateway
– Hardware
– Software
• Trunk Media Gateway (TMG)
– Hardware
– Software
• NMS
• LAN Switch (16 Ports)
• Announcement Server
• Billing Interface
• Administrative Interface
• Alarms Interface
• NTP (Network Time Protocol) Server
45. Advantages in NGN
• Bandwidth saving:-Up to 1:4
• Reduced Energy Consumption:- Up to 1:3
saving.
• Reduced operational costs;- Up to 90%
Saving.
• Reduced accommodation Costs:- Up to 1:5.
• Network Consolidation 7 trunk optimization.
• Capability to provide all services including
Network Wide services.
