Multipoint Communications in a Beyond-3G Internetwork

We consider the problem of supporting IPbased quasi-reliable mobile multipoint communications in a Beyond-3G internetwork which combines the current Internet (including all connected home users and wired or wireless LANs) with the soon-to-be-deployed 3G networks and the future digital broadcast networks. We summarize existing IETF protocols such as IP multicast, Mobile IP, and Cellular IP, which we believe help in solving the problem. We refer to filtering techniques useful for delivering media to mobile users. We discuss the Mobile IP and IP multicast constraints as well as their interoperability problems, and we present existing alternatives. We also offer our own perspective by outlining requirements for future mobile multicast protocols; by describing fundamentals of the mobile multicast problem; by mentioning our own approach to the problem, which involves IETF protocols and current trends; and by presenting the Beyond-3G internetwork we envisage

Designing a Peer-to-Peer Wireless Network Confederation

We present the Peer-to-Peer Wireless Network Confederation (P2PWNC), a P2P system designed to enable the sharing of WLAN bandwidth among residential hotspots. The benefits of joining the Confederation outweigh the costs, and its token-based incentive mechanism prevents free-riding

Peer-to-Peer Wireless Network Confederation

The Institute of Electrical and Electronics Engineers (IEEE) ratified the initial version of the standard for Wireless Local Area Networks known as IEEE 802.11 in 1997 (IEEE Standards, 2004). Belonging to the same family of standards as the Ethernet, it was labeled “Wireless Ethernet” and considered an appropriate networking technology for offices because it did not rely on cables. Although burdened by a lack of strong security (Fluhrer, 2001) and lower throughput compared to its wired equivalent, IEEE 802.11 was a success. The cost of manufacturing 802.11 chipsets fell quickly, and 802.11 found its way from desktop PCs to laptops and next generation cellular phones. Wi-Fi, a consumer-friendly moniker for 802.11, was adopted and the Wireless Ethernet Compatibility Alliance (WECA), a nonprofit international association, was formed in 1999 to certify the interoperability of Wi-Fi products. WECA changed its name to the Wi-Fi Alliance in 2002 (Wi-Fi Alliance, 2004). The two main components of Wi-Fi networks are the wireless clients and the Wi-Fi access points, which are the wireless equivalent of Ethernet hubs. Clients equipped with Wi-Fi can communicate wirelessly with nearby access points that link them to each other, to the local wired network and to the Internet. Clients can also communicate with each other without access points (assuming their radios are within range) in a so called “ad hoc” mode (IEEE Std. 802.11, 1999). Newer IEEE specifications include 802.11g, which enables clients and access points to connect to each other at speeds of up to 54 Mbps; and 802.11i, which employs advanced authentication and encryption algorithms to protect against unauthorized users that attempt to gain access to private networks (IEEE Standards, 2004). Standard 802.11i also protects the confidentiality and integrity of wireless sessions, which are usually susceptible to eavesdropping and hijacking attacks. The term “Wi-Fi hotspot” is now being used to describe any area where Wi-Fi connectivity is available via nearby access point. Public hotspots can be found in airport lounges and shopping malls, in coffee shops and restaurants, and in hotels and exhibition centers. Wi-Fi users, which include business travelers as well as casual users, can use their portable devices in these hotspots to access e-mail, their corporate intranets and the Internet. Users can browse the Web, use instant messaging and location-based services, place cheaper voice-over-IP calls and conduct videoconferences. Nevertheless, such practice is still not commonplace (Stone, 2003). </jats:p

A Peer-to-Peer Approach to Wireless LAN Roaming

We make the case for a Global Confederation of Peer-to-Peer (P2P) Wireless Local Area Networks. A P2P Wireless Network Confederation (P2PWNC) is a community of administrative domains that offer wireless Internet access to each other&apos;s registered users. The ubiquitous Internet access that the roaming users of these domains could enjoy compensates for their home domain&apos;s cost of providing access to visitors. Existing roaming schemes utilize central authorities or bilateral contracts to control access to resources. In contrast, a P2PWNC forms a pure P2P community in which participating domains are autonomous entities. Domains make independent decisions concerning the amount of bandwidth they contribute. As a result, similarly to existing P2P systems, a P2PWNC will suffer from &quot;free-riding&quot; if no incentive mechanisms exist to ensure that domains offer the amount of resources that is economically justified. Flexible rules on reciprocity can be set to delimit domain actions and encourage domains to provide in order to consume. In this paper, we present several aspects of the P2PWNC requirements and design. We outline several P2PWNC implementation issues relating to user privacy and the confederation&apos;s real-world deployment. We also describe the P2PWNC prototype that we developed