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COM594: Mobile Technology Lecture Week 1 Introduction to Mobility 2 What is mobility? Moving, in motion Migrating, changing location Immobile Mobile Changing roles 1.3 Highway Scenario GSM, 3G, WLAN, Bluetooth, ... PDA, laptop, cellular phones, GPS, sensors Mobility Market Growth in Mobile versus Fixed Broadband Subscribers The Internet is not Mobile..! • Unfortunately the Internet does not support ‘native-mobility’ • The TCP/IP stack was not designed with mobility in mind. • Much has been achieved, but the approach has been by the development of ‘Tunneling Protocols’ • Tunneling means essentially using existing IP packets as ‘wrappers’, and running everything over the existing structure. The Internet is not Mobile..! • However, we shall see that seamless, real-time mobility requires that ‘sessions stay alive’ when devices move between different types of access networks and across networks belonging to different operators. • What is required is the capability to implement what has become known as ‘Session-mobility’. • This is a very tough challenge; • However, if it can be achieved, the potential benefits for communications is enormous. The Internet is not Mobile..! • To understand the problem we need a detailed understanding of the way that the Internet works. • We need to appreciate the limitations of current Mobility ‘solutions’; • Then we can begin to consider new approaches to building a truly ‘Mobile Internet’ The Future of Mobile Markets Device Divergence Network Convergence with cellular transition to “all-IP”? IP Everywhere Fixed and Cellular (Mobile) Networks: IP is the ‘fundamental Building Block’ Wireless Residential Gateway (Access Point) WiFi Enabled Tablet Convergence between fixed and cellular networks DSLAM Broadband Network Gateway IP/Ethernet Transport Network Home ENB Internet DSLAM (Digital Subscriber Line Access Multiplexer) ENB (Enhanced Node B) Cellular Smartphone Macro ENB Packet Data Network/ Serving Gateway Correspondent Node Towards an ‘Always-On’ scenario: Current cellular network standards allow mobile data-enabled devices to Be attached to a cellular network without allocating them an IP address. Legacy cellular networks are typically configured to automatically deallocate a device’s IP address after a period of inactivity. The new generation of cellular standards are designed only to support always-on behaviour, and so, for example, when a device attaches to an all-IP LTE network, it must, by default, receive an IP address and be automatically enabled to send and receive IP packets.