While the broadband revolution might be in full swing, the long-promised era of fast and seamless internet connectivity ‘anytime anywhere’ remains tantalisingly out of reach for many European citizens. One approach to this problem is to exploit the growing number of residential wireless hotspots to develop an innovative high-speed open network for broadband communication. Starting in January 2004, the IST-funded OBAN (Open Broadband Access Network) research team has taken major strides towards building a public broadband mobile network based on residential wireless local area networks (WLANs). The basic idea is to use the wireless LANs of existing broadband subscribers – who typically use only a small fraction of the line’s capacity – and make them available for passing or visiting users in urban and suburban areas. In this scenario, the stationary users or hosts continue to use their wireless LAN as before, and passing users can access and maintain communication via these internet access points. Both visitors and hosts share the capacity of such wireless LANs, and access lines according to a general service agreement between all users and the network operator. To encourage uptake among broadband subscribers, it is envisaged that they will receive some form of compensation or incentive for providing access to casual users of their unused WLAN capacity. In this way, it will be possible to offer new and better services to mobile users without having to build a new and costly wireless infrastructure. The viability of the OBAN project rests on the assumption that within a few years, the majority of users will have access to a broadband network at some point.A second assumption is that wireless technology will be the predominant form of technology for in-house communication, both for residential and business users. In urban areas, this large number of 'micro base stations' will provide a continuous radio coverage that will allow users to roam freely while maintaining their communication sessions. Compared to conventional cellular mobile networks, which consist of a limited number of optimally located outdoor base stations and antenna masts, the OBAN network will consist of a much higher number of micro base stations that are located at random. While the idea of open broadband networks is not new, OBAN’s approach is genuinely different to what has been tried before, according to project coordinator Einar Edvardsen of Telenor in Norway. “OBAN will be the first to integrate wireless LAN with fixed networks in a legal, regulatory and commercially correct way. Some current networks which offer public access over private wireless LANs are possibly illegal and commercially non-viable, while other solutions are connected to one operator’s network or only provide roaming features to operators,” he says. Another breakthrough by OBAN will be to deliver faster handover in areas where multiple internet service providers (ISPs) are operating, and where broadband access may be via ADSL connections with an average delay of 10-40 milliseconds. “This means that a user can move from a WLAN cell operated by one ISP to another WLAN cell operated by a different ISP, at the same time as all security and quality-of-service requirements are met,” explains Edvardsen. “The maximum disruption is specified not to exceed 120 milliseconds." Achieving such a fast handover is a unique achievement, he emphasises. "All today’s announcements about mobility and fast handover relate to WLANs that are connected to a common infrastructure, making the handover task relatively easy. In the OBAN approach, we are talking about different networks.” In order to achieve such fast handover, OBAN has developed a unique security solution using a combined SIM and Kerberos authentication method. “This is important in order to guarantee all relevant security requirements quickly enough to comply with the 120 millisecond time limit,” notes Edvardsen. Another innovative feature of the OBAN approach is its unique quality-of-service (QoS) mechanism. “This guarantees that quality requirements for all users in the network are met – not only on the wireless part as 802.11e” he says. While Edvardsen has no doubts about the long-term viability of OBAN’s concept, he acknowledges that putting the idea into practice will not be a straightforward process. “We have had a field trial running for two years now, but with very limited functionality. None of the specific OBAN solutions have been implemented yet and we have not yet utilised the trial for any purpose other than to get the equipment running. We have learnt that it often is a long way from laboratory to the field even when commercial equipment is being used – due to the modifications, adaptations and reconfiguration needed for a new operational environment,” he says. Although the project is slightly behind schedule at the moment, Edvardsen is confident that the team will meet its official completion date at the end of 2006. “The implementation and integration work now have top priority. Full-scale testing in the laboratory and the field will take place in November and December 2006.” Contact: Einar Edvardsen Telenor R&D Snarøyveien 30 N-1331 Fornebu Norway Tel: +47 9152 9029 Fax: +47 6789 1814 Email: firstname.lastname@example.org OBAN project website http://www.ist-oban.org Source: Based on information provided by OBAN.