NGN is a layered architecture consisting of
1.Transport,
2.Access,
3.Control and
4.Application layer.
It is important to note that all the layers are independent from each
other. Change in one layer should not affect other layers.
Access Layer:
Access Layers is responsible for direct subscriber attachment function. NGN can support all kind of existing access as well as upcoming access. NGN is capable of processing traffic originated from PSTN, GSM, CDMA, xDSL, WiMAX or any other access system. Depending upon the type of access, protocol conversion and/or media conversion may be required at the NGN Gateways.
Access Layer consists of Gateways. Example of getaways is Media Gateway,Access gateway. Signalling gateway etc.
Media gateway terminates media,coming from PSTN/PLMN in E1 / STM. Here, it is responsible for packetisation of media under the instruction of control layer. After packetisation of information it throws packets to the transport Network. Access gateway is nearer to subscriber. Subscriber can directly be terminated in Access Gateway. All the required configuration of such subscribers should be done at control layer. Access Gateway and Media Gateways are responsible for carriage of Media whereas Signalling gateway is carrying signalling generated by PSTN and informs Control Layer about the signalling in required format.
Transport Layer
Transport Layer of NGN is based on IP (Internet Protocol). It can utilize the advantage of MPLS (Multi Protocol Label Switching). Transport Layer forms the core of the Network. It basically consists of Routers, which are responsible for carrying traffic originated by access layer. As the same core network is going to
be used for all kinds of subscribers enjoying different kind of real time and non real time services, it should be able to make use of band width policies and Qos policies. Operator has to think of managed Network for its subscribers. It is basically an assembly of routers connected with optical network. Traffic coming from gateways is properly routed by those routers.
Control Layer
It is responsible of call setup, routing and charging policies and other controls in NGN environment. It consists of call servers where all information of the network resides. These call servers are responsible for setting up, modifying, charging and tear down of the calls. NGN may work on soft switch principle. It consists of
MGC (Media Gateway Controller) as an overall controller and MGs(Media Gateway) for termination of traffic. MGC is basically a server and it is having all the necessary information of network MGC instructs MGs for establishing the call. Under the control of MGC, MG performs different call related tasks such as
connection, modification and termination of media streams, packetisation of media etc.
Application Layer
It is responsible for OSS/BSS. Enhanced services to the subscribers will be provided with the help of application servers. It may include prepaid servers, announcement servers, Service servers etc. Hence NGN is making service separation from Network. Any service can be introduced with the help of server at
any time without any modifications in the control, transport or access.
1.Transport,
2.Access,
3.Control and
4.Application layer.
It is important to note that all the layers are independent from each
other. Change in one layer should not affect other layers.
Access Layer:
Access Layers is responsible for direct subscriber attachment function. NGN can support all kind of existing access as well as upcoming access. NGN is capable of processing traffic originated from PSTN, GSM, CDMA, xDSL, WiMAX or any other access system. Depending upon the type of access, protocol conversion and/or media conversion may be required at the NGN Gateways.
Access Layer consists of Gateways. Example of getaways is Media Gateway,Access gateway. Signalling gateway etc.
Media gateway terminates media,coming from PSTN/PLMN in E1 / STM. Here, it is responsible for packetisation of media under the instruction of control layer. After packetisation of information it throws packets to the transport Network. Access gateway is nearer to subscriber. Subscriber can directly be terminated in Access Gateway. All the required configuration of such subscribers should be done at control layer. Access Gateway and Media Gateways are responsible for carriage of Media whereas Signalling gateway is carrying signalling generated by PSTN and informs Control Layer about the signalling in required format.
Transport Layer
Transport Layer of NGN is based on IP (Internet Protocol). It can utilize the advantage of MPLS (Multi Protocol Label Switching). Transport Layer forms the core of the Network. It basically consists of Routers, which are responsible for carrying traffic originated by access layer. As the same core network is going to
be used for all kinds of subscribers enjoying different kind of real time and non real time services, it should be able to make use of band width policies and Qos policies. Operator has to think of managed Network for its subscribers. It is basically an assembly of routers connected with optical network. Traffic coming from gateways is properly routed by those routers.
Control Layer
It is responsible of call setup, routing and charging policies and other controls in NGN environment. It consists of call servers where all information of the network resides. These call servers are responsible for setting up, modifying, charging and tear down of the calls. NGN may work on soft switch principle. It consists of
MGC (Media Gateway Controller) as an overall controller and MGs(Media Gateway) for termination of traffic. MGC is basically a server and it is having all the necessary information of network MGC instructs MGs for establishing the call. Under the control of MGC, MG performs different call related tasks such as
connection, modification and termination of media streams, packetisation of media etc.
Application Layer
It is responsible for OSS/BSS. Enhanced services to the subscribers will be provided with the help of application servers. It may include prepaid servers, announcement servers, Service servers etc. Hence NGN is making service separation from Network. Any service can be introduced with the help of server at
any time without any modifications in the control, transport or access.
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