Oliver Thylmann: The D211 and D311 PC Cards also include the option to use SIM based authentication for Wireless LAN gateways that support such authentication. Is Nokia the only company doing this, and are you actively pushing it to become the standard out there?

Paavo Aro: Nokia is actively contributing in e.g. IEEE, IETF, and 3GPP to enable and specify SIM based authentication as standardized method in public and semi-public WLAN hotspots.

Oliver Thylmann: Roaming, which from what it seems would be best accomplished through a SIM card based solution, seems to be important for everyone, and recently several companies founded the WISP Association to establish a standard for global roaming for Wireless LANs. We also talked to one of your senior research engineers recently about Mobile IP and tying all of these various technologies together - roaming on WLAN hotspots worldwide, using GPRS when WLAN is not available, switching to a CSD connection when GPRS takes a hike, and soforth. We think it would be the most amazing thing to be able to roam seamlessly, using Mobile IP to avoid dropping connections, moving from one network to the other. What's Nokia's approach to global roaming? Are you looking at joining WISP? How far will Mobile IP go and how long do you think it will take until the above scenario might work?

Paavo Aro: With "roaming" we mean accessing the network through another operator. "Seamless roaming" takes place with minimal user intervention (typically automatic), but in order to maintain active connections a "handover" mechanism is needed additionally. With "seamless handovers", the temporary break, which occurs with every handover, is short and not perceived as interruption by the user.

For roaming between mobile operators, Nokia strongly promotes reusing existing cellular infrastructure and roaming agreements. Today operators run the global MAP/SS7 signaling network with 25,000 GSM roaming agreements, which will be complemented over the next years with GPRS/3G roaming. Nokia expects cellular roaming to become commonplace for Public WLAN during the next 1-2 years. Other roaming mechanisms are well suited to complement cellular roaming, in particular between service providers within one country ("national roaming"). Nokia has no plans to join WISP since Nokia is not a network operator.

Nokia believes that Mobile IPv6 is the ideal technology for handovers between GSM/GPRS/3G and WLAN networks, since Mobile IPv6 provides mobility independent of radio technology. Nokia expects that Mobile IPv6 will be commercially deployed starting in the beginning of 2004, whereby handovers will be seamless first for data services (eg. file transfer, e-mail, Web browsing), with real-time services following 1-3 years later, as Mobile IPv6 technology improves and integration between cellular and WLAN networks increases.