PowerPoint Presentation
Introduction Overview of NGN Based on Softswitch Network Architectures of Softswitch- Involved Wireless Networks A Typical Call Scenario in Softswitch- Involved Wireless Networks
Introduction
NGN is proposed as an integrated architecture involving various legacy networks UMTS has defined a migration to a packet- switched core network Utilizing softswitch to migrate from GSM to both UMTS and NGN
2G 3G GSM UMTS+NGN
Overview of NGN Based on Softswitch
NGN 3 characters an open network architecture
decomposed flexible
a service-oriented network call control function service control function
/ new & inter-network service
Overview of NGN Based on Softswitch
NGN 3 functional layers Transport layer
Transport of all kinds of traffics across the NGN Signaling Any kinds of media
Call control & Signaling layer Softswitch Call Control based on signaling message received from Transport layer Handle establishment and teardown of media connections by controlling components in the Transport layer
Overview of NGN Based on Softswitch
Service & Application layer Provides the control, logic and execution for the services or applications
Softswitch is the core element of the NGN in the Call Control & Signaling Layer
NGN 3 functional layers
Softswitch 3 Functions Call control function with various signaling protocol
ISUP, H.323, SIP, Megaco/H.248 Provides the call control portion of the legacy switch in circuit- switched network
Control media gateway Transform of the media between packet-switch network and circuit-switched network Provides the call switching portion of the legacy switch in circuit-switched network
Overview of NGN Based on Softswitch
Provide necessary control abilities to the service plane elements
Implement various services and applications Service plane elements include Application Sever and Media Server
GSM Introduction
Base Transceiver Station(BTS) Base Station Controller(BSC)
BSCBTSs BSCradio channel setupfrequency hopping handovers BSCMSMSC
GSM Introduction
Network Subsystem
Visitor Location Register(VLR) Home Location Register(HLR) Authentication Center(AUC) Operations and Maintenance Center(OMC)
GSM Introduction
Base Station SubsystemA Interface Mobile Switching CenterNetwork and Switch Subsystem
GSM Introduction
Softswitch-involved GSM network
NSS divides into IP NSS, Circuit NSS Softswitch, MG and SG in IP NSS can serve as a MSC replacement for GSM networks Circuit NSS includes all the remaining circuit-based elements
MSC, HLR and AC Softswitch & GMSC coexist
Softswitch-involved GSM network
Softswitch control the MG and SG by Megaco protocol Must provide extra functionalities for Wireless Network
Mobility Management(MM) Radio Resource(RR)
Softswitch-involved UMTS R99 network
Differences between GSM and UMTS R99 MS UE(User Equipment) BSS RNS(Radio Network Subsystems)
BTS Node B BSC RNC(Radio Network Controller)
Above changes are all in BSS Control the RNC with lu-cs interface Control the BSC with A interface
Since the NSS keeps the same, things are mostly unchanged to softswitch
lu-cs interface needs to be concerned
Softswitch-involved UMTS R99 network
Softswitch-involved UMTS R4 Network
Differences between UMTS R99 and R4 MSC MG + MSC server(IP)
Softswitch = MSC server
A Typical Call Scenario in Softswitch- Involved Wireless Networks (0/5)
Terminations Logical entities on an MG that act as sources or sinks of media streams.
Contexts An association between a number of terminations for the purposes of sharing media between those terminations.
A Typical Call Scenario in Softswitch- Involved Wireless Networks (1/5)
BSS Softswitch MG PSTN
4.Add Reply, (C1),(T1)
Softswitch receives Setup Message from MS Softswitch requests the MG based on call-routing to
establish a new context and termination
MS
A Typical Call Scenario in Softswitch- Involved Wireless Networks (2/5)
BSS Softswitch MG PSTN
Softswitch requests the BSS to set up a traffic channel over the radio interface with MS.
5.Allocate Channel
8.Allocate Complete
6.Assignment Cmd
7.Assignment Comp
A Typical Call Scenario in Softswitch- Involved Wireless Networks (3/5)
BSS Softswitch MG PSTN
Requests the MG to add a new termination to C1. A path is created from one side of MG to the other.
9.Add Request, (C1), ($)
BSS Softswitch MG PSTN
Modify the context established on the MG. Ring-back tone Full two-way media path
15.Modify Request,(C1),(T1)
A Typical Call Scenario in Softswitch- Involved Wireless Networks (4/5)
14. ANM
20.Connect Ack
19. Connect
Softswitch sends a Connect message to the MS MS responds with a Connect acknowledge
MS
A Typical Call Scenario in Softswitch- Involved Wireless Networks (5/5)
Conclusion
The 3G wireless networks and the NGN have similar objectives and architectures. So Applying softswitch into the wireless networks not only helps the revolution from 2G to 3G, but also provides a smooth migration towards the NGN. As the wireless network keeps evolving, the softswitch may be further decomposed into more dedicated functional entities, as suggested in UMTS Release 5.
References
Qiang Wei, Sen Su, Junliang Chen, “Study on Application of Softswitch in Wireless Networks”, Communication Technology Proceedings, 2003. ICCT 2003. International Conference on Vol.1, 9-11 April 2003 Page:127-130 vol.1 “Softswitch in Mobile Networks”, Ericsson White Paper, April 2005. 3GPP, GSM Specifications: http://www.3gpp.com 3GPP, UMTS Specifications: http://www.3gpp.com
Outline
Introduction
NGN 3 functional layers
GSM Introduction
GSM Introduction
GSM Introduction
GSM Introduction
Softswitch-involved GSM network
Softswitch-involved GSM network
Softswitch-involved GSM network
A Typical Call Scenario in Softswitch-Involved Wireless Networks (0/5)
A Typical Call Scenario in Softswitch-Involved Wireless Networks (1/5)
A Typical Call Scenario in Softswitch-Involved Wireless Networks (2/5)
A Typical Call Scenario in Softswitch-Involved Wireless Networks (3/5)
A Typical Call Scenario in Softswitch-Involved Wireless Networks (4/5)
A Typical Call Scenario in Softswitch-Involved Wireless Networks (5/5)
Conclusion
References