A comparison between WCDMAR4 and NGN and the key problems of commercial and operational availability

Starting from the R4 phase, NGN and 3G technology begin to come together: the soft switching mechanism of NGN load and control separation, the unified IP/ATM Packet service bearer are introduced into the 3G core network.

The similarities and differences between WCDMAR4 Network and NGN network can be compared with the overall network architecture, basic transmission network, equipment network element function, Commercial/operational key technology and so on.

Overall network Architecture

In WCDMAR4 and NGN networks, a layered architecture with similar load and control separation is adopted, that is, the original load and control of the switch is separated into a dedicated user interface for media processing and switching functions of the media gateway, as well as the control of the call processing and services to provide a soft switching device, and media gateways, The carrier of media and control flow between SoftSwitch and SoftSwitch and Media gateway is evolved from traditional TDM line switching to broadband packet switching network (IP/ATM) based on packet forwarding. There is no longer a voice media stream between SoftSwitch and a media gateway, but a control message based on h.248. (Computer science)

Basic transport network

WCDMAR4 and NGN have the same requirements for basic transmission network facilities, including routers, switches, and SDH/DWDM transmission devices and transmission links, and all of them adopt wideband IP/ATM load based on packet statistics multiplexing and packet/signal forwarding.

Device Network meta function

WCDMAR4 and NGN business Independent device network elements include: through the h.248 control of Special Media resources (MRS) and in charge of the wide band signaling Interoperability Signaling Gateway (SG).

Mrs is mainly used for soft switching in the general call and intelligent call flow in the packet network in the centralized playback, collection, conference and other media resources support. SG is mainly used for all kinds of application layer signaling (including map, INAP/CAP, etc.) in the Sigtran bearer and based on the tdmmtp1/2 of the exchange between the transfer, they are based on the underlying transport protocol stack is the same, so the interoperability requirements for SG is identical.

In addition, the other network element equipment basically in the function, the business process aspect has the big difference. Mainly reflected in the following aspects:

The difference of network equipment component. WCDMAR4 Network is divided into two parts of access network and core network. The access network is composed of WCDMA base station NodeB and Base station controller RNC. The core network part except the original mobile switch MSC is separated into the control surface SoftSwitch Mscserver and the load face Media Gateway MGW device, the other core network and the Service Application layer network element equipments all inherit the mobile WCDMAR99, including SGSN/GGSN, HLR, Mobile SCP, SMSC and so on.

The NGN network can also be divided into two parts of the access network and the core network: The access network is composed of the Access gateway Ag/iad of the fixed telephone remote/proximal access part separated from the C5 switch, while the core network is composed of the soft exchange of the C5/C4 switch control part and the relay gateway which exchanges with other networks. Other business Application layer network element equipment such as fixed network SCP directly inherit PSTN.

The difference of the soft switch equipment. The difference of softswitch between WCDMAR4 and NGN is mainly embodied in the aspect of business feature set and interactive protocol. WCDMAR4 's Mscserver inherits the business processing and signaling interface functions of all the business control layers of the 3G terminal MSc and Gateway MSc, with Utran Mobile Access network and other pstn/ The PLMN network carries on the control surface flow to realize the 3G user's access and realizes the interworking with other operators or the traditional network, and in the business process calls through the Mobile Extension h.248 protocol to control the mobile access or the relay Media gateway to complete the aggregation, mapping and exchange of the media stream.

NGN SoftSwitch inherits all the service processing and signaling interface function of traditional C4 fixed end board and C5 long-distance board switch, and realizes the interworking of PSTN users and other operators or traditional networks through mgcp/h.248 protocol to control fixed access network or relay gateway to realize aggregation, mapping and exchange of media stream.

WCDMAR4 uses RANAP/BSSAP protocol to connect to mobile users, BICC as SoftSwitch control, and NGN SoftSwitch adopts h.248/mgcp/iua/v5ua access fixed user, h.323/sip/sip-t/ BICC is used as a relay control between SoftSwitch bureaus.

WCDMAR4 SoftSwitch has the features of mobility management and call Management (CM/MM) without the NGN soft switching.

The difference of mobile, fixed access and relay. The Mobile Access Media gateway and the Utran Access network carry on the complex control plane interaction (Q.AAL2/IUUP), convert the Utran traffic to the IP/ATM core Network Service stream, and transfer the non-access layer signaling from utran (such as Layer 3 call control) To Mscserver or forward control commands from Mscserver to Utran, fixed access media gateways directly or through an access to traditional pots or ISDN users, convert analog or digital line signals to IP/ATM core network traffic, convert user call process events to h.248/ MGCP or IUA message escalation or reverse conversion.

Both the mobile Relay media gateway and the fixed relay media gateway bear the load type between the VOIP/VOATM and the traditional circuit switched networks, the voice codec mode conversion and the echo suppression, but the encoding and decoding algorithm used in the mobile and fixed network (mobile adopts AMR/EFR and fixed network adopts g.723/g.729) And the demand of ECHO suppression function parameters are different, and the mobile relay media Gateway also involves the processing of complex user face and Trfo function.

The media control protocols between SoftSwitch and media gateways also differ greatly in WCDMAR4 and NGN, The Mobile Media Control Protocol (H.248) has been extensively expanded on the basis of the fixed network protocol, including the ITU-T CBC Resource control Model q.1950 extension and the 3GPP ts29.232umts domain-specific extension.

Comparison of key issues between WCDMAR4 and NGN for commercial and operational

The similarities and differences of WCDMAR4 and NGN network in commercial and operational can be compared mainly from the aspects of QoS and network security of the host network.

Hosting Network QoS problem. Generally speaking, the QoS problem of WCDMAR4 is more easy to solve than NGN, because WCDMAR4 is confronted with the same load core layer QoS problem as the NGN, while the access layer does not have the Access Layer QoS problem, the difficult point of the NGN network to solve the QoS problem lies in the hosting network access layer.

Hosting network access Layer QoS. Regardless of the 3G voice or data application, it is essential to carry the IP bearer network through the Utran access network, because the RNC, NodeB, MGW and SGSN access network related entities are based on the ATM high speed forwarding and differentiated QoS class processing ability, The perfect QoS protocol guarantee mechanism based on each transaction makes the WCDMAR4 Utran access network provide a good QoS guarantee without introducing additional mechanism when the resource allocation is sufficient. The hierarchy of fixed voice or data users accessing IP core network in NGN network is more complicated, the optional access mode is more, and it is more difficult to implement the QoS guarantee than WCDMAR4 access network. Different modes of access correspond to different QoS policies.

Hosting Network core backbone layer QoS. NGN and WCDMAR4 have similar requirements to the QoS capabilities of IP Core backbone network, including IP routers and L2 switching devices, and the experience of integrated QoS solutions can be borrowed from each other, in the case of WCDMAR4 and NGN core load network sharing, Its QoS engineering can also be unified planning.

The problem of network security. The softswitch of NGN must adopt nonstandard authentication mechanism to confirm the identity validity of Access Gateway (AG/IAD), its authentication to NGN user is implied in the process of Ag/iad equipment authentication, and WCDMAR4 is cooperated by HLR, Mscserver, Utran and terminal UE, It provides a complete and powerful standard bidirectional authentication encryption mechanism to ensure the identity reliability, data integrity and business privacy of the access user. Mscserver authentication to the access MGW, it can be supported by establishing authentication and h.248 protocol encryption ability through WCDMAR4 of SCTP connection between core devices.

In the open public IP hosting network, both WCDMAR4 and NGN can consider providing the network layer authentication and information integrity protection through the tunnel IPSec mode between the core device End-to-end IPSec or the external router, while the introduction of Layer 2 and layer 3VPN (VLAN and IPVPN) can be considered. The logic isolation of WCDMAR4 and NGN real-time service and other non-real-time business is realized to eliminate network security hidden trouble more thoroughly.

Comparison of NGN and WCDMAR4 in the network format

Load-carrying Network group network. The WCDMAR4 and NGN are basically the same in the host network.

Signaling network networking. In the premise of using IP as signaling control surface, there are some differences between WCDMAR4 and NGN signaling network. In the fixed NGN network, SIP or H.323 is generally used as the inter-agency signaling, while the signaling between the corresponding and far soft switching is generally selected for planar addressing, the WCDMAR4 signaling network considers two completely different situations, such as call independent mobile signaling Network (MAP/CAP) and call Signaling Network (BICC).