Abstract—With the development of wireless network and rapidly increasing requirements for mobile computing, peer-to-peer technology on Mobile IP (Mobile P2P) becomes a new focus. Mobile P2P is a more and more interested topic for live streaming in next generation. However, the direct porting of existing P2P application on Mobile IP is difficult to overcome time-critical limitation. Handover under Mobile IP usually leads to overlay failure and session interruption, which lead to long handover delay and intolerable service disruption time. The wireless network has more uncertain dynamics than the wired network, and the dynamics degrade the stable data rate for P2P live streaming. In order to improve the streaming continuity, we propose a cross-layer design to achieve the seamless handover and adjust the playback quality. This article discusses the architecture of present Mobile IP network, and we overcome the challenges to apply P2P service on Mobile IP. The proposed scheme maintains P2P session during IP handover and successfully reroutes packets to the new visited subnet. The motivation is the successful integration of Mobile IP and P2P live streaming, and the goal is the improvement of playback continuity. The simulation results explain that our proposed scheme indeed meliorates the performance of mobile P2P live streaming. Index Terms—Mobile IP, MIPv6, mobile P2P, P2P live streaming. I. INTRODUCTION As technology for high quality multimedia application prevails, everyone has been able to enjoy audiovisual communication and high definition video content through wireless network. The peer-to-peer (P2P) solution can satisfy the various kinds of multimedia service through Internet via the self-organized overlay. P2P applications can provide voice and video services, such as Skype [1] and Joost [2]. With the high scalability and the low commercial cost [3], P2P network becomes a popular solution recently. With fast developments of wireless technology and available bandwidth, P2P service can be applied in nomadic computation to build the collaborative network [4]. In such all-IP network, people can use real-time P2P applications on the mobile devices. Compared to the common server-client solution on wireless network, P2P solution improves resource utilization and traffic distribution, assigns resources based on their locality and delay, and balances the load among the group of peers [4]. The next generation network is expected to be dominated by mobile devices [5]. For mobility, Mobile IP is a popular solution to the ubiquitous computing. In fact, IP should serve the dual purposes: a routing direction and an endpoint identifier. However, the dual purposes lead to a dilemma of IP addressing in supporting mobility. 1 Mobile IP [6] uses home address and care-of-address (CoA) to solve the mobility problem. 2 When a mobile node (MN) moves from a foreign domain to another foreign domain, the CoA handover is operated to ensure the session guaranty. MN must send information about its new location and new CoA to its home agent (HA) during IP handover. However, the long handover delay is unsuitable for the integration of P2P live streaming and mobile computing. The long handover delay results from the two-level shortcomings. (1) The IP handover and the CoA update must interrupt the streaming. (2) The change of CoA may lead to the erroneous peer departure. Via Open Systems Interconnection (OSI) network stack, we can discover several challenges of P2P network on Mobile IP due to CoA handover. • In application layer's opinion, the CoA handover breaks the session. In general, P2P software uses (IP, port) as the identification (ID), hence when a mobile node changes its CoA, P2P network opines that someone peer leaves and then another peer joins. • In transport layer's opinion, TCP and UDP may fail in IP handover. For TCP, IP handover causes the TCP timeout to break the TCP session, and P2P session is interrupted. For UDP, although packets can be routed to the new IP address via CoA's prefix, the corresponding request messages must be resubmitted. • If application layer is independent from network layer in the mobile node, P2P software must wait for a timeout to know the UDP disconnection. These disadvantages result in a long service disruption time. In addition, Mobile IP [7] should adopt the co-located CoA scheme to avoid the triangular routing problem. The route optimization solution considers the time-critical issue in P2P real-time service. Hence, the binding update helps to keep the traffic session. Server-client programs, such as FTP and HTTP, can work well over Mobile IP due to the uninterrupted program. However, P2P live streaming programs cannot tolerate long triangular routing delay and long handover delay due to time sensitivity and data continuity. We propose Cross-Layer Mobile P2P (XLMP2P) scheme and develop a simulation environment under Mobile IP. We modify the binding update and P2P delivery to achieve the seamless handover. Using a cross-layer method, P2P information is attached on a binding update to keep the real-time P2P service during handover. The cross-layer 1 If IP address is changed for mobility, it cannot be an endpoint identifier; if IP address is not changed for mobility, it cannot be a routing direction. 2 The home address is a stationary IP address, and the CoA is a variable IP address. Mobile IP allows MN to be identified by MN’s static home address, regardless of any location in the Internet. A Cross-Layer Design for P2P Live Streaming with Graceful Handover in Mobile IP Network Jun-Li Kuo a , Chen-Hua Shih b , and Yaw-Chung Chen c a Information and Communications Research Laboratories, Industrial Technology Research Institute, Taiwan b Chung Shan Institute of Science and Technology, Taiwan c Computer Science, National Chiao Tung University, Taiwan 2013 13th International Conference on ITS Telecommunications (ITST) 978-1-4799-0846-2/13/$31.00 ©2013 IEEE 456