The Next Gen Lab
Test network is designed to emulate a next-generation mobile operator network. It follows the layered architecture as proposed by the 3GPP, consisting of connectivity plane, control plane and application plane. In addition to the above, we have a service creation layer.
Connectivity Plane consists of heterogeneous access network technologies such as:
Wireless LAN:
The access point is connected to the backbone switch of the test network and shares the same subnet as the application servers in the core network.
UMTS:
The test network is equipped with an indoor-3G node-B cell (donated by ORANGE) which provides 3G(UMTS) coverage indoors, within the building. On stepping out of the building, the 3G coverage ceases and the mobile devices connect to the public GPRS network. This scenario provides the unique feature of forced handover between 3G –to- GPRS and vice versa.
GPRS:
GPRS coverage is provided by the Orange public GPRS cell around the campus building.
PSTN/ISDN:
Euro ISDN 30 line termination is provided by BT and connects to the media gateway.
Virtual Private Network (VPN):
A VPN connection is established between the test network’s backbone switch and the Orange Labs at Bristol. This routes the sip requests originating from the mobile devices to the application servers in the test network. It has enabled the mobile devices used in the test network to have a global IP address allocated by the orange network. Thus, facilitating SIP interactions between the mobile devices connected to the orange network via 3G/GPRS with the SIP application server in the test network without NAT traversal.
Control Plane, consist of IMS which has the call session control functions, P-CSCF, I-CSCF, S-CSCF, HSS implemented as per the 3GPP IMS release 5 specifications on a single box (donated by the FT R&D). It also has the PDF and PEP implemented on separate linux box, to complete the IMS core.
Media server from Cantata Technologies (now Dialogic) provides the media streaming, mixing and transcoding features, while the media gateway performs the interworking function between the PSTN and the IP core network.
Application Plane, consist of Ubiquity’s (now Avaya) SIP application server connected to the IMS core via the ISC interface.
Service Creation Plane, consists of development environments provided by Ubiquity Software with service object oriented Framework components which hastens the process of service creation.
Mobile devices used for the experimentation are Orange SPV M5000 Pocket PCs running windows mobile 5.0 with WLAN, GPRS and UMTS interfaces and the ability to automatically select the best available network with order of precedence being WLAN, UMTS and GPRS.
SIP User agent used are Kapanga soft IP phone and SJPhone.
