04/19/2023 TRAI 1

Interconnection Issues inNGN

V.K. Agarwal, Dy. AdvisorTelecom Regulatory Authority of India (TRAI)

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04/19/2023 TRAI 2

Present Telecom Scenario

• Present licensing framework is mapping different Telecom services with specific telecommunication licenses

• Low penetration of high speed Internet and Broadband

• Limited availability of Value-added services and content

• Restrictive regulatory framework for launch of new services

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04/19/2023 TRAI 3

Present Telecom Scenario (contd.)

– Separate networks for PSTN, wireless and data

– Huge growth of wireless deployment

– Complex network design to support increasing

bandwidth hungry applications

– Telecom service penetration is high in urban areas.

Digital divide needs to be addressed

– Huge investments are required to set-up access

infrastructure.

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04/19/2023 TRAI 4

Present Telecom Scenario (contd.)

• Migration from PURE voice traffic in early eighties to pure IP traffic in near future

• Growth of voice traffic is stagnating while data traffic shows exponential growth (nearly 100 % annually)

• IP networks are – stable , robust and time

tested– able to support triple play

application– efficient to support

emerging service requirements

– Supports required QoS

Network Traffic Growth Source: Cybermedia Center, Osaka University

IP Networks are future requirement

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04/19/2023 TRAI 5

Drivers for NGN• Increasingly acceptability of IP platform to provide triple

play services• Low cost of IP equipment, reduced power & space

requirement and ease of maintenance• Flexibility to provide different Value Added Services and

content quickly• Increasing convergence of devices pushing for

convergence of Networks• Competition demands integration of the network to

reduce cost as parallel networks means high costs.• Fast growth in telecom sector is reducing average

revenue per user. Therefore need is to boost revenue earnings through launch of new value added services and applications

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04/19/2023 TRAI 6

Enabling Convergence Consumer / Business Services

Reducing Cost

4-Key Business Drivers of NGN

Raising ARPU

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04/19/2023 TRAI 7

Service Convergence Support System Convergence

Device Convergence

4-Convergence

Network Convergence

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04/19/2023 TRAI 8

Openness Quality of Service (QoS)

Scalable

4-Key aspects of NGN Architecture

Reliable

Granular and modular On the fly enhancements Flexibility

Carrier grade High availability Trust

Standard interfaces and protocols Plug-n-play

Consistent performance Preservation of key information parameters

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04/19/2023 TRAI 9

IP Networking, Transportand Aggregation – IP / MPLS

Multi-Access

Service s andApplications

IP Core

4-Segments of NGN Architecture

S-CSCFS-CSCF

I-CSCFI-CSCF

P-CSCFP-CSCF

BGCFBGCF

DBDB

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04/19/2023 TRAI 10

Networks in NGN Scenario

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04/19/2023 TRAI 11

Networks in NGN Scenario (contd.)

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04/19/2023 TRAI 12

Stages of NGN Implementation

NGN is basically Network Convergence which consists of • Core Convergence• Switching convergence• Access Convergence

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04/19/2023 TRAI 13

Present Telecom Networks

End-to-End Mobile Network

GMSC

MSCBSC BTS

MSCBSCBTS

Local Exch.

L2TAX

L1TAX

L2TAX

Local Exch.

End-to-End PSTN Network

ADSL DSLAM

Local Exch.

National ISP

Int’l Internet Bandwidth

Provider

Broadband Network 13

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04/19/2023 TRAI 14

Convergence at Core Network

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04/19/2023 TRAI 15

End-to-End convergence

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04/19/2023 TRAI 16

Stages of NGN ImplementationCore Convergence Switch Level Convergence End-to-End

Convergence Core convergence

is presence of Unified backbone

IP Backbone is being used in converged core network since IP based packet transmission is more efficient

Introduction of Multi Protocol Label Switching (MPLS) is favored as it is now one of the most powerful technology for converged core network.

Migration from TDM based switches to IP based soft switches

Media gateways are used to communicate with legacy central office (CO) TDM switches

Media gateways will not be required in fully converged IP Network.

Class-4 Softswitch: Used for Trunk Automatic Exchange (TAX) and Tandem Switching

Class-5 Softswitch : Deployment in access network

A fully IP based network from one end user device to other end user device is end to end convergence.

Only IP based access devices will be permitted in access network.

This is third stage of Network Convergence and will require sufficiently long time due to migration from traditional TDM to total IP user devices.

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04/19/2023 TRAI 17

Supportive & Regulatory Framework

Regulatory framework should facilitate expansion of Infrastructure, especially in rural and remote areas.

Promoting Competition and technology neutrality Focus on ‘Light touch’ regulation with special

emphasis on regulatory forbearance Time bound resolution of regulatory impediments for

rollout and migration to NGN services Govt. support for upgradation of end link will be

desirable

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NGN Interconnection Issues

• Migration from service based interconnection to service neutral interconnection

• Reference interconnect offer (RIO) in NGN environment

• Maintaining Fair cost based interconnection• Ensuring equitable & non-discriminatory

interconnection• Point of interconnect between various

operators• Basis of charging

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Point of Interconnection

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Direct Interconnection among service providers.

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Point of Interconnection

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Interconnect Exchange

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Comparison of two methodology of Interconnection

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IssueConventional Interconnection Scenario

Interconnect Exchange Scenario

Complexity of Network Very High Low

Interconnection and port charges High Low

Capacity Utilization Inefficient EfficientBandwidth Scalability Low HighCAPEX Requirement Initially Low Initially high, as cost of setting up

Interconnect Exchange will be shared among all operators

OPEX Requirement High Low, however the OPEX involved in Exchange will have to be shared

Overall Performance Depends on Individual Operator

May also depend on Interconnect Exchange

Call Handling Inefficient Efficient IUC settlement Difficult EasyImplementation of Number portability and carrier selection

Difficult Easy

Sharing of IN platform Difficult Easy

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Interconnection in Legacy Networks

Charging methodologies• Calling Party Pays (CPP) – widely used

• Receiving Party Pays (RPP),

• Bill and Keep – mostly in Internet scenario

Costing techniques• Distance Based

• Element Based

• Capacity based

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diaCurrent Interconnection Usage Charging(IUC) Scenario in India

• IUC determined based on minutes of usage for various Unbundled Network Elements and the cost of these elements.

• The IUCs for Origination, Transit and Termination are based on the principles of element based charging i.e. one operator charging the other for the resources consumed for carriage of its calls in terms of minutes of use (MOU).

• The total Interconnection Usage Charges for carriage of a call in a multi operator environment are shared for Origination, Transit and Termination on the basis of work done in each segment for the carriage of the call.

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Charging methodologies in NGN

• Calling Party Network Pays,

• Bill and Keep,

• Based on Quality of service,

• Bulk billing.

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Service Level Agreements across multiple networks in NGN Scenario

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Issues and challenges – for IUC Billing and Accounting in NGN

• Inter-operator settlement issues- content and quality based pricing, usage based or bulk billing.

• In an NGN world, the network service provider will not necessarily be the application service provider.

• The network provider will have only limited visibility into third party applications running over its network. The application provider may have extensive visibility into the application that it provides, but only limited visibility into the use of network resources.

• Usage-based billing will be possible only to the extent that the usage can be rigorously and unambiguously measured.

• How will providers and customers ensure that service commitments are met? Whose statistics will govern?

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Issues and challenges – for IUC Billing and Accounting in NGN cont.

• Competitive providers may be reluctant to share statistics about their respective networks with one another, and peering agreements may typically restrict the ability of the providers to disclose information about one another‘s networks to third parties. Can sufficient information be disclosed to customers?

• How will responsibility be allocated if a customer’s traffic fails to achieve its committed service level specification in case of multiple networks? Traffic data can legitimately be interpreted in more than one way. Will it be possible to administer payments and penalties rigorously and fairly?

• How can providers prevent fraud? How can they distinguish between fraud and legitimate use?

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04/19/2023 TRAI 28

Thank Youdacn@trai.gov.in