Metropolitan Public WiFi Access Based on Broadband Sharing (Invited Paper) Pablo Vidales, Alexander Manecke Deutsche Telekom Laboratories Berlin, Germany Email: name.surname@telekom.de Marcin Solarski IBM Software Laboratories Krakow, Poland Email: marcin.solarski@pl.ibm.com Abstract—As mobile applications become more pervasive and the demand for affordable mobile broadband Internet access grows, bandwidth sharing solutions via IEEE 802.11-based tech- nology populate the telecommunications market. Many of the existing solutions are based on the willingness of Internet user communities to share their broadband connection at home. How- ever, some other access sharing models have introduce incentives for those users that share their Internet connection. Another aspect that differentiates current solutions is the approach to deploy such a service. In general, these solutions can be grouped in three categories: the ones that follow a guerrilla approach, those that partner with ISPs, and the sharing solutions that originate inside the telcos. These options are compared in this paper from the business and technology angles, discussing the pros and cons of each of them. In addition, a broadband sharing enabling solution, called Extended HotSpots is described. This solution was evaluated during a field trial in the city of Berlin and the results collected are included in this paper. Index Terms—Metropolitan networks, brodband sharing, IEEE 802.11, WiFi. I. INTRODUCTION While broadband Internet has become a commodity in the home and office environments [1], broadband access for mobile applications is still an expensive service, not widely used. Large outdoor deployments of WiFi wireless access have only very recently become part of the list of hot topics of Governments and telecoms. Several metropolises, mainly in the USA, like San Francisco or Chicago, and in less number in Europe, started to deploy citywide access networks based on WiFi technology, often partially supported by industry part- ners, aiming to drive on-line transactions of local SMEs and charge premium fees to enterprise customers, or subsidize the service by advertising and marketing revenues. Nevertheless, the investment risk in building such a planned infrastructure is high, due to uncertainties in service revenues and the multi- million capital needed to achieve the critical mass of WiFi hotspots and footprint. However, there are alternatives to achieve large deployments of wireless access. On approach is to build such wide area wireless networks reusing the existing wired broadband access infrastructure already serving masses of consumers, and enable their Customer Premise Equipment (CPE), i.e. broadband routers, to become public hotspots. The best-known market example of this type of solutions is the company FON that started to build a sharing community in 2006 [2]. Initially, this company offered a subsidized WiFi access point to anybody with a broadband Internet access who registered to become a member of their community. In addition, FON worked on strategic partnerships with Internet Service Providers to accel- erate the community growth by leveraging on the established ISP customer base as a distribution channels. Partnerships with telecoms operators, like BT, Cegatelle, Swidish are examples of this strategy. The current status quo of the market is rounded up with numerous local initiatives of building WiFi communities. They follow a grass-root user movement, promoting a fair sharing principle that translates into free roaming for community members and optionally some usage fees for non-members [3], [4], [5], [6]. In this new type of public access networks, based on sharing the current broadband infrastructure with third parties, a solution that facilitates secure, control and reliable access sharing reusing the WiFi access points (mas- sively deployed at the consumer premises) is needed. So far, broadband access network resources have only being used for the home needs, however, following the peer-to-peer spirit, individual users could share their subscribed broadband access over their private wireless routers, and under the supervision of a central authority; for trust and security purposes. Such an infrastructure poses a number of challenges, from which the most important are listed next: • Security threats arise when opening a broadband access platform used before only by ISP private customers, i.e. the need for user authentication and access control to shared resources, separation of the owner’s and guest users’ traffic for traceability, and virtualization of the security mechanisms to allow multiple methods to act on the same CPE [7]. • Weaker management and control over the network elements. As the access network elements, WiFi access points, are installed at customer premises, the infrastruc- ture is exposed to physical access by non-authorized par- ties. Not only may the devices be unexpectedly switched 2009 Mexican International Conference on Computer Science 978-0-7695-3882-2/09 $26.00 © 2009 IEEE DOI 10.1109/ENC.2009.22 146