Peer WLAN Consortium: A P2P Case Study Mobile Multimedia Laboratory Department of Informatics Athens University of Economics & Business Athens MMAPPS Meeting, September 23-25, 2002

24/09/2002MMAPPS: Peer WLAN Consortium2 of 11 Motivation WLANs are becoming ubiquitous: WLAN access points (APs) are easy to setup. WLAN PC users are increasing by the millions. Devices with WLAN interfaces achieve throughput in the Mbps range. Introduction of incentive mechanisms could allow controlled wireless access in a P2P fashion. WLAN access control schemes are being introduced to minimize the effects of uncontrolled wireless connections. Figure: The 802.1X framework.

24/09/2002MMAPPS: Peer WLAN Consortium3 of 11 Definition Peer WLAN Consortium: –A community of peer networks that offers better geographical coverage than any one of its members. –The “peers” are WLAN administrative domains. –A WLAN administrative domain is a collection of APs, connected to an Authentication Server. These elements collectively implement one Authentication Policy for the domain.

24/09/2002MMAPPS: Peer WLAN Consortium4 of 11 Consortium Elements Consortium P2P view Hotspot network view AS: Authentication Server AD: Administrative Domain AP: Access Point U : User AS + Policy AS + Policy AS + Policy AD1 AD2 AD3 AP U U U U U U U U U U U U U U

24/09/2002MMAPPS: Peer WLAN Consortium5 of 11 Description Users within the same consortium can be identified as such by any member domain. Consequently, they may be granted WLAN access. The consortium is not controlled by any central or external entity. The peers are independent and may have different attributes.

24/09/2002MMAPPS: Peer WLAN Consortium6 of 11 Peer Attributes Number of registered users. Hotspot network, and, for each hotspot, its: Geographical location. Bandwidth to the Internet. IP subnet size. Value added services, such as: Digital library access. Location-specific information. MBONE access.

24/09/2002MMAPPS: Peer WLAN Consortium7 of 11 Peer Status A peer’s status at any one time includes: –Users connected to it, along with their: Location. Type (home users vs. visiting users). –Bandwidth utilization. –Services utilization. Global state of the consortium. –Composed of each peer’s current status.

24/09/2002MMAPPS: Peer WLAN Consortium8 of 11 P2P Aspects The consortium is governed by rules on reciprocity that are flexible. Incentives to share a domain’s resources are needed. The basic objective is to provide wireless access. Each peer attempts to maximize the benefit for its registered users: Increase geographical coverage and availability. Enhance performance. Provide value-added services. Ensure QoS levels (prevent abuse from visiting users).

24/09/2002MMAPPS: Peer WLAN Consortium9 of 11 P2P Aspects (cont’d) Reputation system. –Each peer wants to know what the other peers are offering. –Different types of reputation: Service reputation. Network QoS reputation. –Each peer can devise strategies based on this information. Free-riding represents a problem. As, for example, when peers deny access to visitors. Repeated game.

24/09/2002MMAPPS: Peer WLAN Consortium10 of 11 Differences from Existing Schemes Current WISP schemes usually create their hotspot networks on top of a centralized AAA platform. Especially true for GSM/WLAN hybrid wide-area WISPs, which reuse GSM SIM card authentication. Other associations that attempt to set WLAN roaming standards (such as Pass-One) prefer centralized roaming management. They also mandate a large number of procedures. (Tight rules vs. flexible rules.)

24/09/2002MMAPPS: Peer WLAN Consortium11 of 11 Concluding Remarks The consortium scheme is compatible with any 802.1X compliant WLAN infrastructure. One required addition is consortium software running on the Authentication Server. It’s easy for pre-existing WLAN administrative domains to become members. Following certain preconditions. Without having to rethink their whole architecture. No central or external entity controls peer decisions. These decisions are made independently and are influenced by incentive mechanisms.