Two alternative solutions are being used for the ADAMANTIUM Access Network:

• VODAFONE comercial network

The ADAMANTIUM testbed makes use of a live UMTS data service for the Access Network of the user using Vodafone Greece UMTS Access network infrastructure. The IMS ADAMATIUM prototype testbed connects with the UMTS enabled mobile end-users by forwards the traffic to the access network using the IMS Gateway. The IMS Gateway acts also as PCF for the Vodafone network and as a VPN server. The connections with the end users succeed using a VPN link between the end-user mobile and the IMS Gateway. Through this VPN link the end-user can be registered to the ADAMANTIUM IMS platform bypassing VODAFONE Greece firewall and using a real UMTS access network. The client has the capability to use the ADAMANTIUM VoIP and IPTV services.

 In order to configure and set up the clients for the UMTS network access two Vodafone Greece data cards have been installed in a Linux based OS (Ubuntu 9.04) laptop and in a Desktop linux based OS (Ubuntu 9.04) PC. After configuring the UMTS data cards  the clients connect to each other through IMSGW, using VPN connection. The VPN used for better connection management and also for having the clients inside the local ADAMANTIUM network.

 

• R&S test equipment

The UMTS base station emulator CMU200 is the centre part of the network side of the emulation-based testbed. The CMU200 is a test platform that provides all the tests and features required for 3G mobile phones during the development process, during production and in service. It also provides, as part of the test set-ups, a network emulation. This functionality is used for the ADAMANTIUM testbed.

The main purpose of this test set-up is the measurement of a variety of QoS parameters at various layers of the protocol stack, from RF parameters at physical layer to the video quality related parameters at application layer. From the evaluation of these measurements conclusions are drawn and the next most important step is the identification of those QoS parameters that provide an early indication of a decrease of quality in the received signal. For this small set of parameters threshold are defined whose violation trigger warnings or alarms.

The CMU200 receives – via its Ethernet interface – the IP data stream that contains the encapsulated Transport Stream with the IPTV video application. The CMU200 simulates one WCDMA base-station RF interface including the signalling protocol so that the user equipment (I.e. the test terminal in this case) can be tested with regard to various signalling parameters, and can receive the IP data stream. All necessary network and Node B (base station) parameters such as control and data channel configurations can be set.

Next figure shows the CMU200 screen during the tests. The blue curve in the upper window gives the bit rate over time on the down link and the green curve that on the up-link.

The lower part of the screen shows amongst other parameters the number of RLC NACKs (Radio Link Control Negative ACKnowledgements). This number indicates how many down link blocks were repeated since the beginning of the test. It corresponds with the value given on the right for the DL BLER (Down Link BLock Error Rate). In this example, the DL BLER varies over time roughly between 0 % and 20 %, in this case resulting in an average over time of about 2.5 %.