[IMS Tech] Relation between IMS, SAE, EPC and LTE

[Anuradha Udunuwara]

What is the connection/relationship between IMS, SAE, EPC and LTE? As I understand LTE is a 4th Generation mobile technology based on all IP and OFDM. What does SAE (System Architecture Evolution) defines? and what does EPC (Evolved Packet Core) defines? How these 2 relate to IMS core? Lot of abbreviations and lot of new terms, but there should be a simple way of understanding this :-)

[Erwan Duval]

Hi Anuradha,

You are right that LTE is a radio technology so equivalent to UTRA networks
The EPC is the name of SAE core network and is equivalent to GPRS networks.

All these architectures belong to 3GPP standards.

In 3GPP R99 :

ME---UTRAN---GPRS

In 3GPP R8 :

UE---LTE---EPC---IMS

LTE for radio access network
EPC to manage mobility, QoS
IMS to control all services (Voice, Presence...)

Another abbreviation : EPS :-)
EPS stands for Evolved Packet Sytem
But for me EPS = LTE + SAE

Regards,

Erwan

On Mon, Mar 2, 2009 at 5:04 AM, Anuradha Udunuwara <udun...@gmail.com> wrote:

What is the connection/relationship between IMS, SAE, EPC and LTE? As I understand LTE is a 4th Generation mobile technology based on all IP and OFDM. What does SAE (System Architecture Evolution) defines? and what does EPC (Evolved Packet Core) defines? How these 2 relate to IMS core? Lot of abbreviations and lot of new terms, but there should be a simple way of understanding this :-)

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IMStech mailing list
IMS...@imsforum.org
http://lists.imsforum.org/mailman/listinfo/imstech

--
Erwan Duval

[priyaranjan sinha]

Hi Anuradha,

 

Unlike Theory of Everything (ToE) commonly argued by Physicists, Networking folks, unfortunately have very little to talk of inter-connected world with every single device, network and service falling in one reference model. Although all of us have been wishing for long.

 

IMS ?

=========

Perhaps for the first time IMS or like minded expert and group of vendors recognized a unified service network. It was mostly being promoted by mobility groups initially. Baselining of SIP (Session Initiation Protocol) for signalling got both the Datacom and Mobility experts finally to agree on something for the first time. Thus IMS has by many means become de-facto standard for deploying "Services Network". It typical has Service Databases, Call Processing Support Data, High Level Service Profile, Content and Application Services deployed by Service Providers. These are independent of transport, access and infrastructure. Although economics is strongly suggesting of  "interconnect IP and backhaul" running these services and carrying traffic nodes to nodes, and network to network.

 

Why EPC or Enhanced Packet Core?

==================

As the traffic from Application Servers or Client reach their network boundaries, they need to inter-operate, transcode, cross past the local policying, trade and quality rules or aggrements - one needs a fusion of handshakes between any two talking entity. In simple words, they must have a common bindings defined by interfaces, parameter, negotiations and above all well understood reference points. And there enters EPC. It is now understood that we all love IP for its agility. Technically Enhanced Packet Core (EPC) provides service APIs in form of reference point to IMS network. IMS networks which consist of service nodes connect to the EPC or core network using its reference points to reach other networks and access networks.

 

SAE (System Architecture Evolution)?

=================

Well SAE is umbrella architecture consisting of EPC (Core Transport and Infratructure connecting Network Functional Nodes and defining Reference Points) and LTE (Access and Air Interface). So SAE has interfaces for Service Network, Broadband Network, Fixed PSTN, Internet or Public Data Network apart from Roaming, Mobility and Radio Access Networks.

 

This far we didn't care much about generations. Now that we have established following:

• IMS is Service Network (e.g., Policy Functions, Call Addmission, Application Logic, Security Policies, interfaces to Content and Service Logic....)
• EPC is Core Network defining the Network Functional Nodes (eg. SGSN, GGSN, 3G-MSC, HSS .... and reference point to speak to access networks and Service Networks) and SAE as umbrella to EPC on the core network side and LTE on the Access and Air Interface

It is OK to add one comment that LTE is one breed of 4G Standards (Or better put beyond 3G) for the Radio Access. Many believe that finally networks will be flatter and least hierarchical and there would exist lesser than two varieties (although, I will wait my life eagerly).

 

Thus LTE connects the wireless high speed data users (they can run VoIP, Video including Downloads) to the Enhanced Packet Core. Enhanced Packet Core itself is IP based network, it provides the interconnection between network nodes running call processing elements, storing customer releated data and performing transcoding, transporting and interoperation between other nodes and networks. While IMS is final exotic brain of providing services of customer's choice controlling the network resources allowing end-users to interact with applications and value-added services.

 

Best Regards,

Priyaranjan Sinha

 

----- Original Message -----
From: "Anuradha Udunuwara"
To: imsg...@imsforum.org, ims...@imsforum.org
Subject: [IMS Tech] Relation between IMS, SAE, EPC and LTE
Date: Mon, 2 Mar 2009 09:34:30 +0530

What is the connection/relationship between IMS, SAE, EPC and LTE? As I understand LTE is a 4th Generation mobile technology based on all IP and OFDM. What does SAE (System Architecture Evolution) defines? and what does EPC (Evolved Packet Core) defines? How these 2 relate to IMS core? Lot of abbreviations and lot of new terms, but there should be a simple way of understanding this :-)

_______________________________________________
IMStech mailing list
IMS...@imsforum.org
http://lists.imsforum.org/mailman/listinfo/imstech

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[Erwan Duval]

Hi Anuradha,

You are right that LTE is a radio technology so equivalent to UTRA networks
The EPC is the name of SAE core network and is equivalent to GPRS networks.

All these architectures belong to 3GPP standards.

In 3GPP R99 :

ME---UTRAN---GPRS

In 3GPP R8 :

UE---LTE---EPC---IMS

LTE for radio access network
EPC to manage mobility, QoS
IMS to control all services (Voice, Presence...)

Another abbreviation : EPS :-)
EPS stands for Evolved Packet Sytem
But for me EPS = LTE + SAE

Regards,

Erwan

On Mon, Mar 2, 2009 at 5:04 AM, Anuradha Udunuwara <udun...@gmail.com> wrote:

What is the connection/relationship between IMS, SAE, EPC and LTE? As I understand LTE is a 4th Generation mobile technology based on all IP and OFDM. What does SAE (System Architecture Evolution) defines? and what does EPC (Evolved Packet Core) defines? How these 2 relate to IMS core? Lot of abbreviations and lot of new terms, but there should be a simple way of understanding this :-)

_______________________________________________
IMStech mailing list
IMS...@imsforum.org
http://lists.imsforum.org/mailman/listinfo/imstech

--
Erwan Duval

[priyaranjan sinha]

Hi Anuradha,

 

Unlike Theory of Everything (ToE) commonly argued by Physicists, Networking folks, unfortunately have very little to talk of inter-connected world with every single device, network and service falling in one reference model. Although all of us have been wishing for long.

 

IMS ?

=========

Perhaps for the first time IMS or like minded expert and group of vendors recognized a unified service network. It was mostly being promoted by mobility groups initially. Baselining of SIP (Session Initiation Protocol) for signalling got both the Datacom and Mobility experts finally to agree on something for the first time. Thus IMS has by many means become de-facto standard for deploying "Services Network". It typical has Service Databases, Call Processing Support Data, High Level Service Profile, Content and Application Services deployed by Service Providers. These are independent of transport, access and infrastructure. Although economics is strongly suggesting of  "interconnect IP and backhaul" running these services and carrying traffic nodes to nodes, and network to network.

 

Why EPC or Enhanced Packet Core?

==================

As the traffic from Application Servers or Client reach their network boundaries, they need to inter-operate, transcode, cross past the local policying, trade and quality rules or aggrements - one needs a fusion of handshakes between any two talking entity. In simple words, they must have a common bindings defined by interfaces, parameter, negotiations and above all well understood reference points. And there enters EPC. It is now understood that we all love IP for its agility. Technically Enhanced Packet Core (EPC) provides service APIs in form of reference point to IMS network. IMS networks which consist of service nodes connect to the EPC or core network using its reference points to reach other networks and access networks.

 

SAE (System Architecture Evolution)?

=================

Well SAE is umbrella architecture consisting of EPC (Core Transport and Infratructure connecting Network Functional Nodes and defining Reference Points) and LTE (Access and Air Interface). So SAE has interfaces for Service Network, Broadband Network, Fixed PSTN, Internet or Public Data Network apart from Roaming, Mobility and Radio Access Networks.

 

This far we didn't care much about generations. Now that we have established following:

• IMS is Service Network (e.g., Policy Functions, Call Addmission, Application Logic, Security Policies, interfaces to Content and Service Logic....)
• EPC is Core Network defining the Network Functional Nodes (eg. SGSN, GGSN, 3G-MSC, HSS .... and reference point to speak to access networks and Service Networks) and SAE as umbrella to EPC on the core network side and LTE on the Access and Air Interface

It is OK to add one comment that LTE is one breed of 4G Standards (Or better put beyond 3G) for the Radio Access. Many believe that finally networks will be flatter and least hierarchical and there would exist lesser than two varieties (although, I will wait my life eagerly).

 

Thus LTE connects the wireless high speed data users (they can run VoIP, Video including Downloads) to the Enhanced Packet Core. Enhanced Packet Core itself is IP based network, it provides the interconnection between network nodes running call processing elements, storing customer releated data and performing transcoding, transporting and interoperation between other nodes and networks. While IMS is final exotic brain of providing services of customer's choice controlling the network resources allowing end-users to interact with applications and value-added services.

 

Best Regards,

Priyaranjan Sinha

 

----- Original Message -----
From: "Anuradha Udunuwara"
To: imsg...@imsforum.org, ims...@imsforum.org
Subject: [IMS Tech] Relation between IMS, SAE, EPC and LTE
Date: Mon, 2 Mar 2009 09:34:30 +0530

What is the connection/relationship between IMS, SAE, EPC and LTE? As I understand LTE is a 4th Generation mobile technology based on all IP and OFDM. What does SAE (System Architecture Evolution) defines? and what does EPC (Evolved Packet Core) defines? How these 2 relate to IMS core? Lot of abbreviations and lot of new terms, but there should be a simple way of understanding this :-)

_______________________________________________
IMStech mailing list
IMS...@imsforum.org
http://lists.imsforum.org/mailman/listinfo/imstech

--

[Austin Pereira]

http://3gamericas.org/documents/3GPP_Rel-8_Beyond_02_12_09.pdf

Good read to get a high level overview of many of terms below.

--- On Sun, 3/1/09, Anuradha Udunuwara <udun...@gmail.com> wrote: